通信类外文文献翻译

合集下载

通信类中英文翻译、外文文献翻译

美国科罗拉多州大学关于在噪声环境下对大量连续语音识别系统的改进---------噪声环境下说话声音的识别工作简介在本文中，我们报道美国科罗拉多州大学关于噪声环境下海军研究语音词汇系统方面的最新改进成果。

特别地,我们介绍在有限语音数据的前提下，为了了解不确定观察者和变化的环境的任务(或调查方法)，我们必须在提高听觉和语言模式方面努力下工夫。

在大量连续词汇语音识别系统中,我们将展开MAPLR自适应方法研究。

它包括单个或多重最大可能线形回归。

当前噪声环境下语音识别系统使用了大量声音词汇识别的声音识别引擎。

这种引擎在美国科罗拉多州大学目前得到了飞速的发展，本系统在噪声环境下说话声音系统(SPINE-2)评价数据中单词错识率表现为30.5%，比起2001年的SPINE-2来,在相关词汇错识率减少16%。

1.介绍为获得噪声环境下的有活力的连续声音系统的声音，我们试图在艺术的领域做出计算和提出改善，这个工作有几方面的难点：依赖训练的有限数据工作；在训练和测试中各种各样的军事噪声存在；在每次识别适用性阶段中，不可想象的听觉溪流和有限数量的声音。

在2000年11月的SPIN-1和2001年11月SPIN-2中，海军研究词汇通过DARPT在工作上给了很大的帮助。

在2001年参加评估的种类有：SPIIBM,华盛顿大学，美国科罗拉多州大学，AT&T,奥瑞哥研究所，和梅隆卡内基大学。

它们中的许多先前已经报道了SPINE-1和SPLNE-2工作的结果。

在这方面的工作中不乏表现最好的系统.我们在特性和主模式中使用了自适应系统，同时也使用了被用于训练各种参数类型的多重声音平行理论(例如MFCC、PCP等)。

其中每种识别系统的输出通常通过一个假定的熔合的方法来结合。

这种方法能提供一个单独的结果，这个结果的错误率将比任何一个单独的识别系统的结果要低。

美国科罗拉多州大学参加了SPIN-2和SPIN-1的两次评估工作。

我们2001年11月的SPIN-2是美国科罗拉多州大学识别系统基础上第一次被命名为SONIC(大量连续语音识别系统)的。

通信类英文文献

the Evolution of Modern MobileCommunication TechnologyRadha PoovendranIn now highly the informationization society, the information and the correspondence have become the modern society “the life”. The information exchange mainly relies on the computer correspondence, but corresponds takes the transmission method, with the sensing technology, the computer technology fuses mutually, has become in the 21st century the international society and the world economic development powerful engine. In order to of adapt the time request, the new generation of mobile communication technology seasonable and lives, the new generation of mobile communication technology is the people said that third generation's core characteristic is the wide band addressing turns on non-gap roaming between the rigid network and numerous different communications system's, gains the multimedia communication services.Along with the time progress, the technical innovation, people's life request's enhancement, the mobile communication technology renewal speed is quite astonishing, almost every other ten year mobile communication technology has a transformation update, from the 1980s “the mobile phone” to present's 3G handset, during has had two mobile communication technology transformation, transits from 1G AMPS to 2GGSM, from GSM to IMT-2000 (i.e. 3G technology). Knows modern on me the mobile communication technology to have the following several aspect important technology:1. wideband modulation and multiple access techniqueThe wireless high speed data transmission cannot only depend on the frequency spectrum constantly the expansion, should be higher than the present number magnitude at least in the frequency spectrum efficiency, may use three technologies in the physical level, namely OFDM, UWB and free time modulation code. OFDM with other encoding method's union, nimbly OFDM and TDMA, FDMA, CDMA, SDMA combines the multiple access technique.In the 1960s the OFDM multi-channel data transmission has succeeded uses in Kineplex and the Kathryn high frequency military channels. OFDM has used in 1.6 Mbit/s high bit rate digital subscriber line (HDSL), 6 Mbit/s asymmetrical digital subscriber line (ADSL), 100 Mbit/s really high speed figure subscriber's line (VDSL), digital audio frequency broadcast and digital video broadcast and so on. OFDM applies on 5 GHz provides 54 Mbit/s wireless local network IEEE 802.11 a and IEEE 802.11g, high performance this region network Hiper LAN/2 and ETSI-BRAN, but also takes metropolitan area network IEEE 802.16 and the integrated service digit broadcast (ISDB-T) the standard. Compares with the single load frequency modulation system servicepattern, the OFDM modulation service pattern needs to solve the relatively big peak even power ratio (PAPR, Peak to Average Power Ratio) and to the frequency shifting and the phase noise sensitive question.High speed mobile communication's another request is under the wide noise bandwidth, must demodulate the signal-to-noise ratio to reduce as far as possible, thus increases the cover area. May adopt the anti-fading the full start power control and the pilot frequency auxiliary fast track demodulation technology, like the frequency range anti-fading's Rake receive and the track technology, the OFDMA technology which declines from the time domain and the frequency range resistance time and the frequency selectivity, the link auto-adapted technology, the union coding technique.2. frequency spectrum use factor lift techniqueThe fundamental research pointed out: In the independent Rayleigh scattering channel, the data rate and the antenna several tenth linear relationships, the capacity may reach Shannon 90%. Is launching and the receiving end may obtain the capacity and the frequency spectrum efficiency gain by the multi-antenna development channel space. The MIMO technology mainly includes the spatial multiplying and the space diversity technology, concurrent or the salvo same information enhances the transmission reliability on the independent channel.Receives and dispatches the bilateral space diversity is thehigh-capacity wireless communication system uses one of technical. Bell Lab free time's opposite angle BLAST (D-BLAST) capacity increase to receive and dispatch the bilateral smallest antenna number in administrative levels the function. The cross time domain which and the air zone expansion signal constitutes using MIMO may also resist the multi-diameter disturbance. V-BLAST system when indoor 24~34 dB, the frequency spectrum use factor is 20~40 bit/s/Hz. But launches and the receiving end uses 16 antennas, when 30 dB, the frequency spectrum use factor increases to 60~70 bit/s/Hz.The smart antenna automatic tracking needs the signal and the auto-adapted free time processing algorithm, produces the dimensional orientation wave beam using the antenna array, causes the main wave beam alignment subscriber signal direction of arrival through the digital signal processing technology, the side lobe or zero falls the alignment unwanted signal direction of arrival. The auto-adapted array antennas (AAA, Adaptive Array Antennas) disturbs the counter-balance balancer (ICE, Interference Canceling Equalizer) to be possible to reduce disturbs and cuts the emissive power.3. software radio technologyThe software radio technology is in the hardware platform through the software edition by a terminal implementation different system in many kinds of communication services. It uses the digital signalprocessing language description telecommunication part, downloads the digital signal processing hardware by the software routine (DSPH, Digital Signal Pocessing Hardware). By has the general opening wireless structure (OW A, Open Wireless Architecture), compatible many kinds of patterns between many kinds of technical standards seamless cut.UWB is also called the pulse to be radio, the modulation uses the pulse width in the nanosecond level fast rise and the drop pulse, the pulse cover frequency spectrum from the cocurrent to the lucky hertz, does not need in the radio frequency which the convention narrow band frequency modulation needs to transform, after pulse formation, may deliver directly to the antenna launch.4. software radio technologyThe software radio technology is in the hardware platform through the software edition by a terminal implementation different system in many kinds of communication services. It uses the digital signal processing language description telecommunication part, downloads the digital signal processing hardware by the software routine (DSPH, Digital Signal Pocessing Hardware). By has the general opening wireless structure (OW A, Open Wireless Architecture), compatible many kinds of patterns between many kinds of technical standards seamless cut.5. network security and QoSQoS divides into wireless and the wired side two parts, wirelessside's QoS involves the radio resource management and the dispatch, the admission control and the mobility management and so on, the mobility management mainly includes the terminal mobility, individual mobility and service mobility. Wired side's QoS involves based on the IP diffSer discrimination service and the RSVP end-to-end resources reservation mechanism. Mechanism maps the wireless side IP diffSer IP the QoS. Network security including network turning on security, core network security, application security, safety mechanism visibility and configurable.In the above modern mobile communication key technologies's foundation, has had the land honeycomb mobile communication, the satellite communication as well as the wireless Internet communication, these mailing address caused the correspondence appearance to have the huge change, used the digital technique the modern wireless communication already to permeate the national economy each domain and people's daily life, for this reason, we needed to care that its trend of development, hoped it developed toward more and more convenient people's life's direction, will let now us have a look at the modern mobile communication the future trend of development.modern mobile communication technological development seven new tendencies :First, mobility management already from terminal management toindividual management and intelligent management development Second, network already from synchronized digital circuit to asynchronous digital grouping and asynchronous transfer mode (ATM) development;the three, software's developments actuated from the algorithm to the procedure-oriented and face the goal tendency development;the four, information processing have developed from the voice to the data and the image;five, wireless frequency spectrum processing already from narrow band simulation to the narrow band CDMA development;the six, computers have developed from central processing to the distributional server and intellectualized processing;the seven, semiconductor devices have developed from each chip 16,000,000,000,000 /150MHz speed VLSI to 0.5 /350MHz speed VLSI and 2,000,000,000,000,000 /550MHz speed VLSI.Under this tendency's guidance, the mobile service rapid development, it satisfied the people in any time, any place to carry on the correspondence with any individual the desire. The mobile communication realizes in the future the ideal person-to-person communication service way that must be taken. In the information support technology, the market competition and under the demand combined action, the mobile communication technology's development isprogresses by leaps and bounds, presents the following several general trends: 1) network service digitization, grouping; 2) networking wide band; 3) networking intellectualization; 4) higher frequency band; 5) more effective use frequency; 6) each kind of network tends the fusion. The understanding, grasps these tendencies has the vital practical significance to the mobile communication operator and the equipment manufacturer.。

数据通信毕业论文外文文献英文翻译

郑州轻工业学院本科毕业设计（论文）——英文翻译题目差错控制编码解决加性噪声的仿真学生姓名专业班级通信工程05-2 学号 12院（系）计算机与通信工程学院指导教师完成时间 2009年4月26日英文原文:Data communicationsGildas Avoine and Philippe OechslinEPFL, Lausanne, Switzerlandfgildas.avoine, philippe.oechsling@ep.chAbstractData communications are communications and computer technology resulting from the combination of a new means of communication. To transfer information between the two places must have transmission channel, according to the different transmission media, there is wired data communications and wireless data communications division. But they are through the transmission channel data link terminals and computers, different locations of implementation of the data terminal software and hardware and the sharing of information resources.1 The development of data communicationsThe first phase: the main language, through the human, horsepower, war and other means of transmission of original information.Phase II: Letter Post. (An increase means the dissemination of information)The third stage: printing. (Expand the scope of information dissemination)Phase IV: telegraph, telephone, radio. (Electric to enter the time)Fifth stage: the information age, with the exception of language information, there are data, images, text and so on.1.1 The history of modern data communicationsCommunication as a Telecommunications are from the 19th century, the beginning Year 30. Faraday discovered electromagnetic induction in 1831. Morse invented telegraph in 1837. Maxwell's electromagnetic theory in 1833. Bell invented the telephone in 1876. Marconi invented radio in 1895. Telecom has opened up in the new era. Tube invented in 1906 in order to simulate the development of communications.Sampling theorem of Nyquist criteria In 1928. Shannong theorem in 1948. The invention of the 20th century, thesemiconductor 50, thereby the development of digital communications. During the 20th century, the invention of integrated circuits 60. Made during the 20th century, 40 the concept of geostationary satellites, but can not be achieved. During the 20th century, space technology 50. Implementation in 1963 first synchronized satellite communications. The invention of the 20th century, 60 laser, intended to be used for communications, was not successful. 70 The invention of the 20th century, optical fiber, optical fiber communications can be developed.1.2 Key figuresBell (1847-1922), English, job in London in 1868. In 1871 to work in Boston. In 1873, he was appointed professor at Boston University. In 1875, invented many Telegram Rd. In 1876, invented the telephone. Lot of patents have been life. Yes, a deaf wife.Marconi (1874-1937), Italian people, in 1894, the pilot at his father's estate. 1896, to London. In 1897, the company set up the radio reported. In 1899, the first time the British and French wireless communications. 1916, implementation of short-wave radio communications. 1929, set up a global wireless communications network. Kim won the Nobel Prize. Took part in the Fascist Party.1.3 Classification of Communication SystemsAccording to type of information: Telephone communication system, Cable television system ,Data communication systems.Modulation by sub: Baseband transmission,Modulation transfer.Characteristics of transmission signals in accordance with sub: Analog Communication System ,Digital communication system.Transmission means of communication system: Cable Communications,Twisted pair, coaxial cable and so on.And long-distance telephone communication. Modulation: SSB / FDM. Based on the PCM time division multiple coaxial digital base-band transmission technology. Will gradually replace the coaxial fiber.Microwave relay communications:Comparison of coaxial and easy to set up, low investment, short-cycle. Analog phone microwave communications mainly SSB / FM /FDM modulation, communication capacity of 6,000 road / Channel. Digital microwave using BPSK, QPSK and QAM modulation techniques. The use of 64QAM, 256QAM such as multi-level modulation technique enhance the capacity of microwave communications can be transmitted at 40M Channel 1920 ~ 7680 Telephone Rd PCM figure.Optical Fiber Communication: Optical fiber communication is the use of lasers in optical fiber transmission characteristics of long-distance with a large communication capacity, communication, long distance and strong anti-interference characteristics. Currently used for local, long distance, trunk transmission, and progressive development of fiber-optic communications network users. At present, based on the long-wave lasers and single-mode optical fiber, each fiber road approach more than 10,000 calls, optical fiber communication itself is very strong force. Over the past decades, optical fiber communication technology develops very quickly, and there is a variety of applications, access devices, photoelectric conversion equipment, transmission equipment, switching equipment, network equipment and so on. Fiber-optic communications equipment has photoelectric conversion module and digital signal processing unit is composed of two parts.Satellite communications: Distance communications, transmission capacity, coverage, and not subject to geographical constraints and high reliability. At present, the use of sophisticated techniques Analog modulation, frequency division multiplexing and frequency division multiple access. Digital satellite communication using digital modulation, time division multiple road in time division multiple access.Mobile Communications: GSM, CDMA. Number of key technologies for mobile communications: modulation techniques, error correction coding and digital voice encoding. Data Communication Systems.1.4 Five basic types of data communication system:（1）Off-line data transmission is simply the use of a telephone or similar link to transmit data without involving a computer system.The equipment used at both ends of such a link is not part of a computer, or at least does not immediately make the data available for computer process, that is, the data when sent and / or received are 'off-line'.This type of data communication is relatively cheap and simple.（2）Remote batch is the term used for the way in which data communication technology is used geographically to separate the input and / or output of data from the computer on which they are processed in batch mode.（3）On-line data collection is the method of using communications technology to provide input data to a computer as such input arises-the data are then stored in the computer (say on a magnetic disk) and processed either at predetermined intervals or as required.（4）Enquiry-response systems provide, as the term suggests, the facility for a user to extract information from a computer.The enquiry facility is passive, that is, does not modify the information stored.The interrogation may be simple, for example, 'RETRIEVE THE RECORD FOR EMPLOYEE NUMBER 1234 'or complex.Such systems may use terminals producing hard copy and / or visual displays.（5）Real-time systems are those in which information is made available to and processed by a computer system in a dynamic manner so that either the computer may cause action to be taken to influence events as they occur (for example as in a process control application) or human operators may be influenced by the accurate and up-to-date information stored in the computer, for example as in reservation systems.2 Signal spectrum with bandwidthElectromagnetic data signals are encoded, the signal to be included in the data transmission. Signal in time for the general argument to show the message (or data) as a parameter (amplitude, frequency or phase) as the dependent variable. Signal of their value since the time variables are or not continuous, can be divided into continuous signals and discrete signals; according to whether the values of the dependent variable continuous, can be divided into analog signals and digital Signal.Signals with time-domain and frequency domain performance of the two most basic forms and features. Time-domain signal over time to reflect changing circumstances. Frequency domain characteristics of signals not only contain the same information domain, and the spectrum of signal analysis, can also be a clear understanding of the distribution ofthe signal spectrum and share the bandwidth. In order to receive the signal transmission and receiving equipment on the request channel, Only know the time-domain characteristics of the signal is not enough, it is also necessary to know the distribution of the signal spectrum. Time-domain characteristics of signals to show the letter .It’s changes over time. Because most of the signal energy is concentrated in a relatively narrow band, so most of our energy focused on the signal that Paragraph referred to as the effective band Bandwidth, or bandwidth. Have any signal bandwidth. In general, the greater the bandwidth of the signal using this signal to send data Rate on the higher bandwidth requirements of transmission medium greater. We will introduce the following simple common signal and bandwidth of the spectrum.More or less the voice signal spectrum at 20 Hz ~ 2000 kHz range (below 20 Hz infrasound signals for higher than 2000 KHz. For the ultrasonic signal), but with a much narrower bandwidth of the voice can produce an acceptable return, and the standard voice-frequency signal gnal 0 ~ 4 MHz, so the bandwidth of 4 MHz.As a special example of the monostable pulse infinite bandwidth. As for the binary signal, the bandwidth depends on the generalThe exact shape of the signal waveform, as well as the order of 0,1. The greater the bandwidth of the signal, it more faithfully express the number of sequences.3 The cut-off frequency channel with bandwidthAccording to Fourier series we know that if a signal for all frequency components can be completely the same through the transmission channel to the receiving end, then at the receiving frequency components of these formed by stacking up the signal and send the signal side are exactly the same, That is fully recovered from the receiving end of the send-side signals. But on the real world, there is no channel to no wear and tear through all the Frequency components. If all the Fourier components are equivalent attenuation, then the signal reception while Receive termination at an amplitude up Attenuation, but the distortion did not happen. However, all the transmission channel and equipment for different frequency components of the degree of attenuation is differentSome frequency components almost no attenuation, and attenuation of some frequency components by anumber, that is to say, channel also has a certain amount of vibrationIncrease the frequency characteristics, resulting in output signal distortion. Usually are frequency of 0 Hz to fc-wide channel at Chuan harmonic lost during the attenuation does not occur (or are a very small attenuation constant), whereas in the fc frequency harmonics at all above the transmission cross Decay process a lot, we put the signal in the transmission channel of the amplitude attenuation of a component to the original 0.707(that is, the output signal Reduce by half the power) when the frequency of the corresponding channel known as the cut-off frequency (cut - off frequency).Cut-off frequency transmission medium reflects the inherent physical properties. Other cases, it is because people interested in Line filter is installed to limit the bandwidth used by each user. In some cases, because of the add channel Two-pass filter, which corresponds to two-channel cut-off frequency f1 and f2, they were called up under the cut-off frequency and the cut-off frequency.This difference between the two cut-off frequency f2-f1 is called the channel bandwidth. If the input signal bandwidth is less than the bandwidth of channel, then the entire input signal Frequency components can be adopted by the Department of channels, which the letter Road to be the output of the output waveform will be true yet. However, if the input signal bandwidth greater than the channel bandwidth, the signal of a Frequency components can not be more on the channel, so that the signal output will be sent with the sending end of the signal is somewhat different, that is produced Distortion. In order to ensure the accuracy of data transmission, we must limit the signal bandwidth.4 Data transfer rateChannel maximum data transfer rate Unit time to be able to transfer binary data transfer rate as the median. Improve data transfer rate means that the space occupied by each Reduce the time that the sequence of binary digital pulse will reduce the cycle time, of course, will also reduce the pulse width.The previous section we already know, even if the binary digital pulse signal through a limited bandwidth channel will also be the ideal generated wave Shape distortion, and when must the input signal bandwidth, the smaller channel bandwidth, output waveformdistortion will be greater. Another angle Degree that when a certain channel bandwidth, the greater the bandwidth of the input signal, the output signal the greater the distortion, so when the data transmissionRate to a certain degree (signal bandwidth increases to a certain extent), in the on-channel output signal from the receiver could not have been Distortion of the output signal sent to recover a number of sequences. That is to say, even for an ideal channel, the limited bandwidth limit System of channel data transfer rate.At early 1924, H. Nyquist (Nyquist) to recognize the basic limitations of this existence, and deduced that the noise-free Limited bandwidth channel maximum data transfer rate formula. In 1948, C. Shannon (Shannon) put into the work of Nyquist 1 Step-by-step expansion of the channel by the random noise interference. Here we do not add on to prove to those now seen as the result of a classic.Nyquist proved that any continuous signal f (t) through a noise-free bandwidth for channel B, its output signal as a Time bandwidth of B continuous signal g (t). If you want to output digital signal, it must be the rate of g (t) for interval Sample. 2B samples per second times faster than are meaningless, because the signal bandwidth B is higher than the high-frequency component other than a letter has been Road decay away. If g (t) by V of discrete levels, namely, the likely outcome of each sample for the V level of a discrete one, The biggest channel data rate Rm ax as follows:Rmax = 2Blog 2 V (bit / s)For example, a 3000 Hz noise bandwidth of the channel should not transmit rate of more than 6,000 bits / second binary digital signal.In front of us considered only the ideal noise-free channel. There is noise in the channel, the situation will rapidly deteriorate. Channel Thermal noise with signal power and noise power ratio to measure the signal power and noise power as the signal-to-noise ratio (S ignal - to -- Noise Ratio). If we express the signal power S, and N express the noise power, while signal to noise ratio should be expressed as S / N. However, people Usually do not use the absolute value of signal to noise ratio, but the use of 10 lo g1 0S / N to indicate the units are decibels (d B). For the S / N equal 10 Channel, said its signal to noise ratio for the 1 0 d B; the same token, if the channel S / N equal to one hundred, then the signal to noiseratio for the 2 0 d B; And so on. S hannon noise channel has about the maximum data rate of the conclusions are: The bandwidth for the BH z, signal to noise ratio for the S / N Channel, the maximum data rate Rm ax as follows:Rmax = Blog 2 (1 + S / N) (bits / second)For example, for a bandwidth of 3 kHz, signal to noise ratio of 30 dB for the channel, regardless of their use to quantify the number of levels, nor Fast sampling rate control, the data transfer rate can not be greater than 30,000 bits / second. S h a n n o n the conclusions are derived based on information theory Out for a very wide scope, in order to go beyond this conclusion, like you want to invent perpetual motion machine, as it is almost impossible.It is worth noting that, S hannon conclusions give only a theoretical limit, and in fact, we should be pretty near the limit Difficult.SUMMARYMessage signals are (or data) of a magnetic encoder, the signal contains the message to be transmitted. Signal according to the dependent variable Whether or not a row of values, can be classified into analog signals and digital signals, the corresponding communication can be divided into analog communication and digital communication.Fourier has proven: any signal (either analog or digital signal) are different types of harmonic frequencies Composed of any signal has a corresponding bandwidth. And any transmission channel signal attenuation signals will, therefore, Channel transmission of any signal at all, there is a data transfer rate limitations, and this is Chengkui N yquist (Nyquist) theorem and S hannon (Shannon) theorem tells us to conclusions.Transmission medium of computer networks and communication are the most basic part of it at the cost of the entire computer network in a very Large proportion. In order to improve the utilization of transmission medium, we can use multiplexing. Frequency division multiplexing technology has many Road multiplexing, wave division multiplexing and TDM three that they use on different occasions.Data exchange technologies such as circuit switching, packet switching and packetswitching three have their respective advantages and disadvantages. M odem are at Analog phone line for the computer's binary data transmission equipment. Modem AM modulation methods have, FM, phase modulation and quadrature amplitude modulation, and M odem also supports data compression and error control. The concept of data communications Data communication is based on "data" for business communications systems, data are pre-agreed with a good meaning of numbers, letters or symbols and their combinations.参考文献[1]C.Y.Huang and A.Polydoros,“Two small SNR classification rules for CPM,”inProc.IEEE Milcom,vol.3,San Diego,CA,USA,Oct.1992,pp.1236–1240.[2]“Envelope-based classification schemes for continuous-phase binary Frequency-shift-keyed modulations,”in Pr oc.IEEE Milcom,vol.3,Fort Monmouth,NJ,USA,Oct.1994,pp. 796–800.[3]A.E.El-Mahdy and N.M.Namazi,“Classification of multiple M-ary frequency-shift keying over a rayleigh fading channel,”IEEE m.,vol.50,no.6,pp.967–974,June 2002.[4]Consulative Committee for Space Data Systems(CCSDS),Radio Frequency and Modulation SDS,2001,no.401.[5]E.E.Azzouz and A.K.Nandi,“Procedure for automatic recognition of analogue and digital modulations,”IEE mun,vol.143,no.5,pp.259–266,Oct.1996.[6]A.Puengn im,T.Robert,N.Thomas,and J.Vidal,“Hidden Markov models for digital modulation classification in unknown ISI channels,”in Eusipco2007,Poznan,Poland, September 2007,pp.1882–1885.[7]E.Vassalo and M.Visintin,“Carrier phase synchronization for GMSK signals,”I nt.J.Satell. Commun.,vol.20,no.6,pp.391–415,Nov.2002.[8]J.G.Proakis,Digital Communications.Mc Graw Hill,2001.[9]L.Rabiner,“A tutorial on hidden Markov models and selected applications in speechrecognition,”Proc.IEEE,vol.77,no.2,pp.257–286,1989.英文译文：数据通信Gildas Avoine and Philippe OechslinEPFL, Lausanne, Switzerlandfgildas.avoine, philippe.oechsling@ep.ch摘要数据通信是通信技术和计算机技术相结合而产生的一种新的通信方式。

通信工程外文资料翻译2篇

南京理工大学毕业设计(论文)外文资料翻译学院（系）：电子工程与光电技术学院专业：通信工程姓名：学号：外文出处：1. IEEE TRANSACTIONS ONANTENNAS AND PROPAGATION,VOL. 53,NO.9, SEPTEMBER 20052. IEEE TRANSACTIONS ONMICROWA VE THEORY ANDTECHNIQUES, VOL. 53,NO.6,JUNE 2005附件：1.外文资料翻译译文一；2.外文资料翻译译文二；3.外文原文一；4.外文原文二；注：请将该封面与附件装订成册。

附件1：外文资料翻译译文一在单封装超宽波段无线通信中使用LTCC技术的平面天线作者：Chen Ying and Y.P.Zhang摘要：此通讯提出了一个使用低温度共烧陶瓷技术的平面天线用于超宽频带（UWB）无线通信的单封装解决方案。

该天线具有一个通过微带线反馈的椭圆形的辐射体。

该辐射体和微带线拥有与其它UWBR电路相同的接地板。

实验结果表明原型天线已达到110.9％的带宽，从1.34到5.43 dBi的增益，宽模式和频率从3到10.6GHz 的相对恒定的群延迟。

更多地还发现，标准化天线辐射功率谱密度基本符合FCCS 对于室内UWB系统的发射限制。

关键词：低温共烧陶瓷（LTCC），平面天线，超宽频带（UWB）。

一、引言现在，发展用于窄范围高速度的无线通信网络的超宽频带（UWB）无线电是一个研究热点。

超宽带无线电利用一个7.5 GHz的超宽带宽来交换信息。

使用这样大的带宽，在使U超宽带无线电发挥它最大的作用上存在一些问题.其中的一个主要问题是用于移植系统的超宽带天线的设计。

好的超宽带天线应具有较低的回波损耗，全向辐射模式，从3.1至10.6 GHz的超宽带宽下的高效率，同时也应当满足FCCS规定的发射限制。

现在已经有一些超宽带天线，如钻石偶极子和互补缝隙天线。

它们已被证明适用于超宽带无线电[1] - [4]。

[最新]通信专业的外文及外文翻译

Research,,,,,on,,,,,Carrier,,,,,T racking,,,,,in,,,,,Hybrid,,, ,,DS/FH,,,,,Spread,,,,,Spectrum,,,,,TT&C,,,,,SystemAbstractBecause,,,,,of,,,,,the,,,,,effect,,,,,of,,,,,carrier,,,,,frequency,,,,,hopping,,,,,,the,,,,,inp ut,,,,,IF,,,,,signal,,,,,of,,,,,carrier,,,,,tracking,,,,,loop,,,,,in,,,,,DS/FHSS,,,,,(Direct,,,,,Sequ ence/Frequency,,,,,Hopping,,,,,Spread,,,,,Spectrum),,,,,TT&C,,,,,(Telemetry,,,,,,Trackin g,,,,,&,,,,,Command),,,,,System,,,,,is,,,,,characterized,,,,,by,,,,,the,,,,,Doppler,,,,,frequen cy,,,,,agile.,,,,,The,,,,,tracking,,,,,loop,,,,,will,,,,,shift,,,,,to,,,,,the,,,,,frequency,,,,,step,,,,, response,,,,,state,,,,,ceaselessly,,,,,and,,,,,the,,,,,measurement,,,,,resolution,,,,,severely,,, ,,decline,,,,,,even,,,,,the,,,,,loop,,,,,is,,,,,likely,,,,,to,,,,,be,,,,,unlocked.,,,,,This,,,,,paper,,,, ,presents,,,,,a,,,,,carrier,,,,,tracking,,,,,loop,,,,,aided,,,,,by,,,,,frequency,,,,,hopping,,,,,pat tern.,,,,,In,,,,,order,,,,,to,,,,,keep,,,,,the,,,,,stability,,,,,of,,,,,the,,,,,tracking,,,,,loop,,,,,,the,, ,,,Doppler,,,,,frequency,,,,,agility,,,,,in,,,,,the,,,,,next,,,,,frequency,,,,,hopping,,,,,dwell,,,, ,is,,,,,estimated,,,,,and,,,,,timely,,,,,compensated,,,,,to,,,,,the,,,,,frequency,,,,,adjustment, ,,,,of,,,,,carrier,,,,,NCO,,,,,according,,,,,to,,,,,the,,,,,preset,,,,,frequency,,,,,hopping,,,,,pat tern,,,,,and,,,,,current,,,,,spacecraft,,,,,velocity.,,,,,Simulation,,,,,results,,,,,show,,,,,that,,, ,,this,,,,,method,,,,,effectively,,,,,eliminates,,,,,the,,,,,instability,,,,,due,,,,,to,,,,,carrier,,,,, frequency,,,,,hopping,,,,,,and,,,,,the,,,,,resolution,,,,,of,,,,,loop,,,,,meets,,,,,the,,,,,require ment,,,,,of,,,,,TT&C,,,,,system.,,,,,Keywords：carrier,,,,,tracking；DS/FHSS；frequency,,,,,agility；aided；TT&CI．INTRODUCTIONThe,,,,,main,,,,,function,,,,,of,,,,,TT&C,,,,,(Telemetry,,,,,,Tracking,,,,,and,,,,,Com mand),,,,,system,,,,,is,,,,,ranging,,,,,and,,,,,velocity,,,,,measurement.,,,,,Presently,,,,,,the, ,,,,most,,,,,common,,,,,used,,,,,TT&C,,,,,systems,,,,,are,,,,,unit,,,,,carrier,,,,,system,,,,,an d,,,,,unit,,,,,spread,,,,,spectrum,,,,,system.,,,,,For,,,,,the,,,,,unit,,,,,carrier,,,,,TT&C,,,,,sys tem,,,,,,ranging,,,,,is,,,,,realized,,,,,by,,,,,measuring,,,,,the,,,,,phase,,,,,difference,,,,,betw een,,,,,transmitted,,,,,and,,,,,received,,,,,tones,,,,,,and,,,,,for,,,,,the,,,,,unit,,,,,spread,,,,,sp ectrum,,,,,TT&C,,,,,system,,,,,,according,,,,,to,,,,,the,,,,,autocorrelation,,,,,properties,,,,, of,,,,,PN,,,,,code,,,,,,ranging,,,,,is,,,,,realized,,,,,by,,,,,measuring,,,,,the,,,,,phase,,,,,delay, ,,,,between,,,,,the,,,,,received,,,,,and,,,,,local,,,,,pseudonoise,,,,,(PN),,,,,code.,,,,,V elocity ,,,,,measurement,,,,,in,,,,,both,,,,,of,,,,,TT&C,,,,,systems,,,,,depends,,,,,on,,,,,extracting,, ,,,the,,,,,frequency,,,,,difference,,,,,resulting,,,,,from,,,,,the,,,,,Doppler,,,,,phenomena,,,,, between,,,,,the,,,,,transmitted,,,,,and,,,,,received,,,,,carrier.,,,,,While,,,,,all,,,,,the,,,,,proc esses,,,,,mentioned,,,,,above,,,,,are,,,,,finished,,,,,on,,,,,the,,,,,ground,,,,,of,,,,,high,,,,,res olution,,,,,carrier,,,,,tracking,,,,,,and,,,,,the,,,,,phase,,,,,lock,,,,,loop,,,,,is,,,,,the,,,,,comm on,,,,,used,,,,,method,,,,,to,,,,,implement,,,,,it,,,,,in,,,,,TT&C,,,,,system.,,,,,As,,,,,the,,,,,s pace,,,,,electromagnetism,,,,,environment,,,,,become,,,,,more,,,,,and,,,,,more,,,,,complic ated,,,,,,the,,,,,capability,,,,,of,,,,,anti-jamming,,,,,is,,,,,required,,,,,by,,,,,the,,,,,future,,,,, TT&C,,,,,system,,,,,[1].,,,,,So,,,,,we,,,,,consider,,,,,using,,,,,the,,,,,hybrid,,,,,DS/FHSS,,,, ,(Direct,,,,,Sequence/Frequency,,,,,Hopping,,,,,Spread,,,,,Spectrum),,,,,technology,,,,,to ,,,,,build,,,,,a,,,,,more,,,,,robust,,,,,TT&C,,,,,system.,,,,,,,,,,For,,,,,many,,,,,ordinary,,,,,hybrid,,,,,DS/FHSS,,,,,communication,,,,,systems,,,,,,th e,,,,,most,,,,,important,,,,,function,,,,,is,,,,,demodulating,,,,,data,,,,,but,,,,,not,,,,,measuri ng,,,,,,so,,,,,it,,,,,is,,,,,not,,,,,necessary,,,,,to,,,,,measure,,,,,the,,,,,carrier,,,,,frequency,,,,,p recisely.,,,,,However,,,,,,in,,,,,hybrid,,,,,DS/FHSS,,,,,TT&C,,,,,system,,,,,,measuring,,,,, and,,,,,tracking,,,,,the,,,,,carrier,,,,,precisely,,,,,is,,,,,the,,,,,foundation,,,,,of,,,,,system,,,,, ,so,,,,,some,,,,,special,,,,,problem,,,,,needs,,,,,to,,,,,be,,,,,solved.,,,,,In,,,,,the,,,,,hybrid,,,, ,DS/FHSS,,,,,TT&C,,,,,system,,,,,,even,,,,,the,,,,,received,,,,,signal,,,,,has,,,,,been,,,,,de hopped,,,,,by,,,,,the,,,,,pattern,,,,,synchronization,,,,,module,,,,,,due,,,,,to,,,,,the,,,,,Dopp ler,,,,,Effect,,,,,and,,,,,carrier,,,,,frequency,,,,,hopping,,,,,,the,,,,,input,,,,,frequency,,,,,of, ,,,,tracking,,,,,loop,,,,,contains,,,,,frequency,,,,,agility,,,,,severely.,,,,,As,,,,,a,,,,,result,,,,,, the,,,,,loop,,,,,is,,,,,likely,,,,,to,,,,,shift,,,,,to,,,,,the,,,,,frequency,,,,,step,,,,,responses,,,,,state,,,,,again,,,,,and,,,,,again,,,,,,and,,,,,it,,,,,seems,,,,,to,,,,,be,,,,,impossible,,,,,for,,,,,freq uency,,,,,measurement,,,,,and,,,,,carrier,,,,,tracking.,,,,,,,,,,The,,,,,paper,,,,,is,,,,,organize d,,,,,as,,,,,follows.,,,,,In,,,,,section,,,,,I,,,,,,the,,,,,frequency,,,,,hopping,,,,,pattern,,,,,sync hronization,,,,,module,,,,,in,,,,,the,,,,,DS/FHSS,,,,,TT&C,,,,,system,,,,,is,,,,,introduced., ,,,,In,,,,,section,,,,,II,,,,,,we,,,,,analyze,,,,,how,,,,,the,,,,,carrier,,,,,frequency,,,,,hopping,,, ,,influences,,,,,the,,,,,performance,,,,,of,,,,,the,,,,,carrier,,,,,tracking,,,,,loop.,,,,,In,,,,,sect ion,,,,,III,,,,,,a,,,,,carrier,,,,,tracking,,,,,loop,,,,,aided,,,,,by,,,,,frequency,,,,,hopping,,,,,pat tern,,,,,and,,,,,current,,,,,spacecraft,,,,,velocity,,,,,is,,,,,proposed.,,,,,In,,,,,section,,,,,IV,,,, ,,a,,,,,simulation,,,,,mode,,,,,on,,,,,the,,,,,ground,,,,,of,,,,,actual,,,,,requirement,,,,,of,,,,,T T&C,,,,,system,,,,,is,,,,,built,,,,,and,,,,,the,,,,,results,,,,,of,,,,,simulation,,,,,show,,,,,that,,, ,,this,,,,,method,,,,,is,,,,,very,,,,,simple,,,,,and,,,,,effective,,,,,for,,,,,DS/FHSS,,,,,TT&C,, ,,,system.,,,,,Finally,,,,,,some,,,,,conclusions,,,,,are,,,,,drawn,,,,,in,,,,,section,,,,,V.II．INPUT,,,,,SIGNAL,,,,,OF,,,,,CARRIER,,,,,TRACKING,,,,,LOOPAs,,,,,the,,,,,traditional,,,,,TT&C,,,,,and,,,,,communication,,,,,system,,,,,,the,,,,,inp ut,,,,,signal,,,,,of,,,,,carrier,,,,,tracking,,,,,loop,,,,,must,,,,,be,,,,,a,,,,,monotonous,,,,,inter mediate,,,,,frequency,,,,,signal,,,,,,so,,,,,the,,,,,received,,,,,RF,,,,,signal,,,,,should,,,,,be,,,, ,dehopped,,,,,by,,,,,the,,,,,frequency,,,,,hopping,,,,,patternsynchronization,,,,,module.,,,, ,In,,,,,FH,,,,,communication,,,,,system,,,,,,the,,,,,signal,,,,,during,,,,,a,,,,,hop,,,,,dwell,,,,, time,,,,,is,,,,,a,,,,,narrowband,,,,,signal,,,,,and,,,,,the,,,,,general,,,,,power,,,,,detector,,,,,is ,,,,,commonly,,,,,used,,,,,to,,,,,detect,,,,,the,,,,,frequency,,,,,hopping,,,,,signal,,,,,[2].,,,,,B ut,,,,,in,,,,,the,,,,,hybrid,,,,,DS/FHSS,,,,,TT&C,,,,,system,,,,,,the,,,,,signal,,,,,is,,,,,subme rged,,,,,in,,,,,the,,,,,noise,,,,,,it,,,,,is,,,,,impossible,,,,,to,,,,,acquire,,,,,signal,,,,,directly,,,,, by,,,,,power,,,,,detector,,,,,such,,,,,as,,,,,FH,,,,,communication,,,,,system.,,,,,However,,,, ,,the,,,,,signal,,,,,during,,,,,a,,,,,hop,,,,,dwell,,,,,time,,,,,in,,,,,the,,,,,system,,,,,just,,,,,is,,,,, a,,,,,direct,,,,,sequence,,,,,spread,,,,,spectrum,,,,,signal,,,,,,so,,,,,we,,,,,can,,,,,acquire,,,,,i t,,,,,based,,,,,on,,,,,the,,,,,acquisition,,,,,of,,,,,direct,,,,,sequence,,,,,spread,,,,,spectrum,,,, ,signal.,,,,,The,,,,,acquisition,,,,,methods,,,,,,such,,,,,as,,,,,serial-search,,,,,acquisition,,,,, ,parallel,,,,,acquisition,,,,,and,,,,,rapid,,,,,acquisition,,,,,based,,,,,on,,,,,FFT,,,,,have,,,,,be en,,,,,discussed,,,,,in,,,,,a,,,,,lot,,,,,of,,,,,papers,,,,,[3-5],,,,,,so,,,,,we,,,,,won’t,,,,,discuss,,, ,,the,,,,,problem,,,,,detailedly,,,,,in,,,,,this,,,,,paper.,,,,,In,,,,,our,,,,,system,,,,,,since,,,,,one,,,,,hop,,,,,dwell,,,,,time,,,,,is,,,,,very,,,,,short,,,,,,the,,,,,rapid,,,,,acquisition,,,,,based,,,,, on,,,,,FFT,,,,,which,,,,,can,,,,,extract,,,,,the,,,,,phase,,,,,delay,,,,,and,,,,,carrier,,,,,frequen cy,,,,,at,,,,,one,,,,,time,,,,,will,,,,,be,,,,,the,,,,,best,,,,,way,,,,,for,,,,,acquisition.,,,,,The,,,,,s cheme,,,,,of,,,,,the,,,,,frequency,,,,,hopping,,,,,patters,,,,,acquisition,,,,,,i.e.,,,,,,coarse,,,,, synchronization,,,,,,could,,,,,be,,,,,shown,,,,,as,,,,,Fig,,,,,1.Figure,,,,,1.,,,,,Scheme,,,,,of,,,,,frequency,,,,,hopping,,,,,pattern,,,,,synchronizationThe,,,,,synchronization,,,,,of,,,,,frequency,,,,,hopping,,,,,pattern,,,,,is,,,,,realized,,,,, by,,,,,the,,,,,local,,,,,frequency,,,,,synthesizer,,,,,rapid,,,,,searching,,,,,and,,,,,the,,,,,two,,, ,,dimension,,,,,rapid,,,,,acquisition,,,,,of,,,,,Direct,,,,,Sequence,,,,,PN,,,,,code,,,,,phase,,, ,,and,,,,,carrier,,,,,frequency.,,,,,At,,,,,the,,,,,beginning,,,,,,the,,,,,link,,,,,switch,,,,,is,,,,,o n,,,,,the,,,,,location,,,,,1,,,,,,and,,,,,the,,,,,output,,,,,signal,,,,,of,,,,,local,,,,,frequency,,,,,s ynthesizer,,,,,with,,,,,higher,,,,,hop,,,,,speed,,,,,than,,,,,the,,,,,received,,,,,one,,,,,is,,,,,mi xed,,,,,with,,,,,the,,,,,received,,,,,signal.,,,,,Then,,,,,,via,,,,,the,,,,,band,,,,,pass,,,,,filter,,,,, ,the,,,,,output,,,,,signal,,,,,of,,,,,mixer,,,,,is,,,,,fed,,,,,into,,,,,the,,,,,acquisition,,,,,module, ,,,,of,,,,,PN,,,,,code,,,,,and,,,,,carrier.,,,,,If,,,,,the,,,,,output,,,,,of,,,,,correlator,,,,,in,,,,,acq uisition,,,,,module,,,,,is,,,,,less,,,,,than,,,,,the,,,,,preset,,,,,threshold,,,,,,the,,,,,direct,,,,,se quence,,,,,spread,,,,,spectrum,,,,,signal,,,,,is,,,,,not,,,,,acquired,,,,,during,,,,,this,,,,,hop,,, ,,dwell,,,,,time,,,,,and,,,,,the,,,,,local,,,,,frequency,,,,,synthesizer,,,,,steps,,,,,the,,,,,next,,, ,,frequency.,,,,,By,,,,,contrast,,,,,,if,,,,,detection,,,,,variable,,,,,of,,,,,acquisition,,,,,modul e,,,,,is,,,,,more,,,,,than,,,,,the,,,,,preset,,,,,threshold,,,,,,it,,,,,means,,,,,that,,,,,the,,,,,freque ncy,,,,,hopping,,,,,signal,,,,,is,,,,,acquired,,,,,and,,,,,the,,,,,mixer,,,,,outputs,,,,,a,,,,,stable, ,,,,district,,,,,spread,,,,,spectrum,,,,,signal.,,,,,After,,,,,that,,,,,,the,,,,,switch,,,,,is,,,,,on,,,,, the,,,,,location,,,,,2,,,,,and,,,,,the,,,,,local,,,,,frequency,,,,,synthesizer,,,,,will,,,,,timely,,,,, change,,,,,the,,,,,output,,,,,frequency,,,,,according,,,,,to,,,,,the,,,,,frequency,,,,,hopping,,, ,,pattern.,,,,,After,,,,,the,,,,,coarse,,,,,synchronization,,,,,mentioned,,,,,above,,,,,,the,,,,,D S/FHSS,,,,,signal,,,,,have,,,,,being,,,,,dehopped,,,,,is,,,,,fed,,,,,to,,,,,PN,,,,,code,,,,,tracking,,,,,loop,,,,,and,,,,,a,,,,,fine,,,,,alignment,,,,,between,,,,,the,,,,,received,,,,,PN,,,,,code,,,,,and,,,,,local,,,,,PN,,,,,code,,,,,is,,,,,achieved,,,,,by ,,,,,a,,,,,code,,,,,tracking,,,,,loop,,,,,na mely ,,,,,the,,,,,delay-locked,,,,,loop.,,,,,Then,,,,,,the,,,,,output,,,,,of,,,,,code,,,,,tracking,,,,,loop,,,,,,i.e.,,,,,,a,,,,,duplicate,,,,,of,,,,,received,,,,,PN,,,,,code,,,,,,is,,,,,mixed,,,,,to,,,,,th e,,,,,IF,,,,,direct,,,,,sequence,,,,,spread,,,,,spectrum,,,,,signal,,,,,dehopped,,,,,by ,,,,,coarse ,,,,,synchronization,,,,,,and,,,,,a,,,,,monotonous,,,,,intermediate,,,,,frequency ,,,,,narrowb and,,,,,,,,,,signal,,,,,which,,,,,will,,,,,be,,,,,fed,,,,,to,,,,,carrier,,,,,tracking,,,,,loop,,,,,is,,,,,o btained.III.,,,,,CHARACTERISTIC,,,,,OF,,,,,DS/FHSS,,,,,CARRIER,,,,,TRA CKING,,,,,LOOPCompared,,,,,with,,,,,the,,,,,carrier,,,,,tracking,,,,,loop,,,,,in,,,,,ordinarycommunica tion,,,,,system,,,,,,because,,,,,of,,,,,the,,,,,high,,,,,dynamic,,,,,of,,,,,the,,,,,spacecraft,,,,,,e specially,,,,,during,,,,,the,,,,,landing,,,,,,accelerating,,,,,and,,,,,decelerating,,,,,,the,,,,,car rier,,,,,tracking,,,,,loop,,,,,of,,,,,hybrid,,,,,DS/FHSS,,,,,TT&C,,,,,system,,,,,will,,,,,be,,,,,i nfluenced,,,,,more,,,,,severely ,,,,,by,,,,,the,,,,,Doppler,,,,,Effect,,,,,(up,,,,,to,,,,,100KHz).,,,,,Addition,,,,,to,,,,,that,,,,,,a,,,,,Doppler,,,,,frequency ,,,,,agility ,,,,,resulted,,,,,from,,,,,th e,,,,,carrier,,,,,frequency ,,,,,hopping,,,,,won’t,,,,,be,,,,,eliminated,,,,,by ,,,,,dehopping,,,,,t he,,,,,frequency ,,,,,hopping,,,,,carrier,,,,,,and,,,,,which,,,,,becomes,,,,,the,,,,,main,,,,,fact or,,,,,influencing,,,,,the,,,,,performance,,,,,of,,,,,carrier,,,,,tracking,,,,,loop,,,,,in,,,,,DS/F HSS,,,,,TT&C,,,,,system.,,,,,The,,,,,frequency ,,,,,of,,,,,downlink,,,,,signal,,,,,of,,,,,DS/F HSS,,,,,TT&C,,,,,system,,,,,may ,,,,,be,,,,,described,,,,,as:)()(1)()()()(000i v i f c i f i f i f i f d +=+= where,,,,,i,,,,,is,,,,,the,,,,,sequence,,,,,number,,,,,of,,,,,carrier,,,,,frequency ,,,,,,)(0i f is,,,,,the,,,,,,,,,,ith,,,,,carrier,,,,,frequency ,,,,,,,,,,,)(i f d is,,,,,the,,,,,Doppler,,,,,frequency ,,,,,offset,,,,,during,,,,,the,,,,,,,,,,ith,,,,,hop,,,,,dwell,,,,,time,,,,,and,,,,,,,,,,)(i v ,,,,,is,,,,,the,,,,,current,,,,,speed,,,,,of,,,,,spacecraft.,,,,,We,,,,,can,,,,,assume,,,,,that,,,,,the,,,,,synchroniz ation,,,,,of,,,,,frequency ,,,,,hopping,,,,,pattern,,,,,has,,,,,been,,,,,completed,,,,,,and,,,,,the,,,,,output,,,,,frequency ,,,,,of,,,,,local,,,,,frequency ,,,,,synthesizer,,,,,is)()()(i f i f i f o lo ∆-=,,,,,,,,,,,where,,,,,)(i f ∆is,,,,,the,,,,,frequency ,,,,,difference,,,,,between,,,,,the,,,,,received,,,,,and,,,,,local,,,,,frequency ,,,,,,i.e.,,,,,,the,,,,,intermediate,,,,,freque ncy ,,,,,of,,,,,input,,,,,signal,,,,,of,,,,,carrier,,,,,tracking,,,,,loop.,,,,,Passing,,,,,a,,,,,IF,,,,,ba nd,,,,,pass,,,,,filter,,,,,,a,,,,,IF,,,,,signal,,,,,,the,,,,,frequency ,,,,,of,,,,,which,,,,,is,,,,,)(i f ∆,,,,,,is,,,,,obtained.,,,,,According,,,,,to,,,,,the,,,,,relation,,,,,among,,,,,the,,,,,velocity ,,,,,,carrier,,,,,frequen cy ,,,,,and,,,,,Doppler,,,,,frequency ,,,,,offset,,,,,,the,,,,,input,,,,,frequency ,,,,,of,,,,,carrier,,,,,tracking,,,,,loop,,,,,is,,,,,derived,,,,,easily,,,,,as,,,,,follow:,,,,,)()(1)()()()(0i v i f c i f i f i f i f d in +=+=∆∆ Then,,,,,,between,,,,,the,,,,,interval,,,,,of,,,,,the,,,,,,,,,,ith,,,,,frequency ,,,,,and,,,,,the,,,,,(i+i)th,,,,,frequency ,,,,,,the,,,,,Doppler,,,,,frequency ,,,,,agility ,,,,,)(i f d ∆,,,,,is,,,,,genera ted,,,,,,and,,,,,can,,,,,be,,,,,expressed,,,,,as:,,,,,)]()()1()1([1)(00i v i f i v i f c i f d -++=∆ Generally,,,,,speaking,,,,,,we,,,,,assume,,,,,that,,,,,the,,,,,velocity ,,,,,of,,,,,spacecraft ,,,,,during,,,,,two,,,,,adjacent,,,,,frequency ,,,,,won’t,,,,,change,,,,,,i.e.)()1(i v i v =+,,,,,,s o )()(1)(0i f i v ci f d ∆∆=,,,,,,which,,,,,shows,,,,,,,,,,that,,,,,the,,,,,frequency,,,,,agility,,,,,is,,,,,a,,,,,function,,,,,of,,,,,the,,,,,frequency ,,,,,difference,,,,,of,,,,,two,,,,,adjacent,,,,,hop,,,,,a nd,,,,,the,,,,,current,,,,,speed,,,,,of,,,,,spacecraft.,,,,,,,,,,Then,,,,,,the,,,,,input,,,,,signal,,,,,of,,,,,the,,,,,carrier,,,,,tracking,,,,,loop,,,,,can,,,,,be ,,,,,expressed,,,,,as:,,,,,,,,,, )(])()()(1222sin[)(2)(0t n nT t p n f n v c t f t f t R P t s n ab +++-++∙=∑∞∞→∆∆τσπππ where,,,,,P,,,,,is,,,,,the,,,,,carrier,,,,,power,,,,,after,,,,,the,,,,,synchronization,,,,,of,,,,,freq uency ,,,,,hopping,,,,,pattern,,,,,,)(t R ,,,,,is,,,,,the,,,,,modulated,,,,,data,,,,,,∆f ,,,,,is,,,,,the,,,,,intermediate,,,,,frequency ,,,,,,d f and,,,,,τ,,,,,are,,,,,the,,,,,rudimental,,,,,frequency ,,,,,o ffset,,,,,and,,,,,rudimental,,,,,phase,,,,,offset,,,,,brought,,,,,from,,,,,acquisition,,,,,module ,,,,,respective.,,,,,;1)(,10=≤≤t p t otherwise,,,,,0)(=t p ,,,,,,T,,,,,is,,,,,one,,,,,hop,,,,,dw ell,,,,,time,,,,,,σ,,,,,,,,,,is,,,,,the,,,,,timing,,,,,error,,,,,of,,,,,the,,,,,synchronization,,,,,of,,,,,f requency ,,,,,hopping,,,,,patterns,,,,,,n(t),,,,,is,,,,,the,,,,,additive,,,,,white,,,,,Gaussian,,,,,noise,,,,,with,,,,,two-side,,,,,power,,,,,spectral,,,,,density ,,,,,2N W/Hz,,,,,and,,,,,c,,,,,is,,,,,t he,,,,,velocity ,,,,,of,,,,,light.,,,,,The,,,,,tracking,,,,,resolution,,,,,is,,,,,the,,,,,basic,,,,,description,,,,,of,,,,,the,,,,,loop,,,,,performance,,,,,,and,,,,,we,,,,,can,,,,,obtain,,,,,it,,,,,by ,,,,,the,,,,,error,,,,,transfer,,,,,fun ction,,,,,as,,,,,follow:,,,,,where,,,,,,F(s),,,,,is,,,,,the,,,,,transfer,,,,,function,,,,,of,,,,,loop,,,,,filter,,,,,,K,,,,,is,,,,,the,,,,,gain,,,,,of,,,,,open,,,,,loop.,,,,,Then,,,,,we,,,,,can,,,,,apply,,,,,the,,,,,limit,,,,,theorem,,,,,,which,,,,,is,,,,,expressed,,,,,as,,,,,)()()(0100lim s H s s s Θ=∞→θ,to,,,,,derive,,,,,the,,,,,steady-state,,,,,tracking,,,,,error.,,,,,Unfortunately ,,,,,,the,,,,,derivation,,,,,of,,,,,Laplacian,,,,,transfer,,,,,of,,,,,,,,,,is,,,,,seen,,,,,to,,,,,be,,,,,impossible,,,,,,so,,,,,we,,,,,can’t,,,,,calcula te,,,,,the,,,,,measuring,,,,,error,,,,,precisely ,,,,,and,,,,,only,,,,,analyze,,,,,it,,,,,by ,,,,,simula tion.,,,,,For,,,,,the,,,,,2edorder,,,,,loop,,,,,,the,,,,,acquisition,,,,,time,,,,,can,,,,,be,,,,,expre ssed,,,,,as:3202nT ξωωρ∆= where,,,,,,0ω,,,,,is,,,,,the,,,,,initial,,,,,frequency ,,,,,offset,,,,,,n ω,,,,,and,,,,,ξ,,,,,are,,,,,the,,,,,natural,,,,,frequency ,,,,,and,,,,,damping,,,,,factor,,,,,of,,,,,the,,,,,tracking,,,,,loop.,,,,,In,,,,,the,,,,,hybrid,,,,,DS/FHSS,,,,,TT&C,,,,,system,,,,,,0ω,,,,,just,,,,,is,,,,,the,,,,,freque ncy ,,,,,agility ,,,,,which,,,,,is,,,,,a,,,,,function,,,,,of,,,,,time,,,,,according,,,,,to,,,,,the,,,,,fre quency ,,,,,hopping,,,,,pattern.,,,,,Thereby ,,,,,,three,,,,,cases,,,,,are,,,,,discussed.,,,,,Case,,,,,1:,,,,,Tp<Tc,,,,,,,,,,,i.e.,,,,,,hop,,,,,dwell,,,,,time,,,,,is,,,,,more,,,,,than,,,,,the,,,,,loop,,,,,acquisition,,,,,time.The,,,,,carrier,,,,,tracking,,,,,loop,,,,,is,,,,,able,,,,,to,,,,,acqu ire,,,,,and,,,,,track,,,,,the,,,,,DS/FHSS,,,,,TT&C,,,,,signal,,,,,,but,,,,,shift,,,,,the,,,,,unlock ,,,,,state,,,,,immediately ,,,,,when,,,,,the,,,,,next,,,,,frequency ,,,,,signal,,,,,is,,,,,fed,,,,,to,,,,,the,,,,,loop.,,,,,The,,,,,loop,,,,,steps,,,,,to,,,,,lock,,,,,,unlock,,,,,,re-lock,,,,,,re-unlock,,,,,s tate,,,,,repeatedly,,,,,for,,,,,all,,,,,time,,,,,,and,,,,,the,,,,,Doppler,,,,,offset,,,,,can’t,,,,,be,,,,,extracted,,,,,accurately .Case,,,,,2:,,,,,Tp>Tc,,,,,,i.e.,,,,,,hop,,,,,dwell,,,,,time,,,,,is,,,,,less,,,,,than,,,,,the,,,,,lo op,,,,,acquisition,,,,,time.,,,,,During,,,,,the,,,,,acquisition,,,,,state,,,,,of,,,,,loop,,,,,,the,,,,,f requency ,,,,,of,,,,,input,,,,,signal,,,,,is,,,,,likely ,,,,,to,,,,,step,,,,,up,,,,,suddenly ,,,,,,and,,,,,t hen,,,,,the,,,,,loop,,,,,steps,,,,,to,,,,,the,,,,,acquisition,,,,,state,,,,,once,,,,,again.,,,,,For,,,,,t he,,,,,case,,,,,,the,,,,,tracking,,,,,loop,,,,,will,,,,,step,,,,,to,,,,,acquisition,,,,,state,,,,,again,,,,,and,,,,,again,,,,,for,,,,,all,,,,,time.,,,,,,,,,,Case,,,,,3:,,,,,For,,,,,the,,,,,non-ideal,,,,,2ed,,,,,or,,,,,high-degree,,,,,order,,,,,loop,,,,,,the,,,,,acquisition,,,,,band,,,,,p ω∆,,,,,is,,,,,limited,,,,,,and,,,,,the,,,,,hopping,,,,,frequenc y ,,,,,agility,,,,,)(i f d ∆,,,,,also,,,,,influences,,,,,the,,,,,performance,,,,,of,,,,,loop.,,,,,When )(i f d ∆<p ω∆,,,,,,,,,,,the,,,,,conclusion,,,,,is,,,,,same,,,,,as,,,,,the,,,,,analysis,,,,,,,,,,mentio ned,,,,,above,,,,,,and,,,,,when )(i f d ∆>p ω∆,,,,,,,,,,,the,,,,,tracking,,,,,loop,,,,,won’t,,,,,loc ked,,,,,the,,,,,signal,,,,,forever.The,,,,,simulation,,,,,result,,,,,of,,,,,2ed,,,,,order,,,,,tracking,,,,,loop,,,,,used,,,,,com monly,,,,,in,,,,,TT&C,,,,,field,,,,,is,,,,,shown,,,,,in,,,,,Fig,,,,,2.,,,,,The,,,,,Doppler,,,,,agilit y ,,,,,is,,,,,plotted,,,,,by ,,,,,broken,,,,,line,,,,,and,,,,,the,,,,,time,,,,,response,,,,,is,,,,,denoted ,,,,,by ,,,,,real,,,,,line.,,,,,Fig.,,,,,2(a),,,,,shows,,,,,the,,,,,tracking,,,,,performance,,,,,witho ut,,,,,Doppler,,,,,offset,,,,,agility;,,,,,the,,,,,time,,,,,response,,,,,as,,,,,Tp<Tc,,,,,is,,,,,descr ibed,,,,,in,,,,,Fig.,,,,,2(b),,,,,,the,,,,,loop,,,,,state,,,,,is,,,,,alternating,,,,,between,,,,,locked,,,,,and,,,,,,,,,,unlocked.,,,,,In,,,,,Fig.,,,,,2(c),,,,,,the,,,,,loop,,,,,is,,,,,acquiring,,,,,signal,,,,,f orever.,,,,,Because,,,,,the,,,,,frequency ,,,,,is,,,,,changed,,,,,before,,,,,stepping,,,,,to,,,,,the ,,,,,locked,,,,,state,,,,,,the,,,,,loop,,,,,won’t,,,,,acquire,,,,,any ,,,,,signal,,,,,at,,,,,all,,,,,time.,,,,,In,,,,,Fig,,,,,2(d),,,,,,when )(i f d ∆>p ω∆,,,,,,the,,,,,tracking,,,,,capability ,,,,,of,,,,,the,,,,,loop,,,,,is,,,,,invalid,,,,,entirely .Figure,,,,,2.,,,,,Time,,,,,response,,,,,of,,,,,tracking,,,,,loop,,,,,with,,,,,Doppler,,,,,offset,,,,,agility:,,,,,,,,,,,,,,,(a) No,,,,,hopping,,,,,,(b),,,,,Tp<Tc,,,,,,,,,,,,,,,,(c),,,,,Tp>T c,,,,,,(d),,,,,)(i f d ∆>pω∆IV.,,,,,THE,,,,,SCHEME,,,,,OF,,,,,CARRIER,,,,,TRACKING,,,,,LOO P,,,,,AIDED,,,,,BY,,,,,HOPPING,,,,,PA TTERNThe,,,,,structure,,,,,of,,,,,the,,,,,carrier,,,,,track,,,,,loop,,,,,aided,,,,,by,,,,,the,,,,,hoppi ng,,,,,frequency,,,,,pattern,,,,,is,,,,,shown,,,,,in,,,,,Fig,,,,,3.,,,,,Generally,,,,,speaking,,,,,, we,,,,,can,,,,,assume,,,,,that,,,,,the,,,,,velocity,,,,,during,,,,,the,,,,,interval,,,,,time,,,,,betw een,,,,,two,,,,,adjacent,,,,,frequency,,,,,will,,,,,keep,,,,,a,,,,,fixed,,,,,value,,,,,,then,,,,,the,,,,,doppler,,,,,frequency,,,,,offset,,,,,,,,,,in,,,,,the,,,,,next,,,,,frequency,,,,,interval,,,,,c an,,,,,be,,,,,calculated,,,,,by,,,,,the,,,,,current,,,,,velocity,,,,,of,,,,,spacecraft,,,,,combined,,,,,with,,,,,carrier,,,,,frequency.,,,,,The,,,,,is,,,,,added,,,,,timely,,,,,to,,,,,the,,,,,adjust ment,,,,,value,,,,,of,,,,,the,,,,,carrier,,,,,NCO,,,,,when,,,,,the,,,,,new,,,,,frequency,,,,,signa l,,,,,is,,,,,fed,,,,,to,,,,,the,,,,,loop.,,,,,So,,,,,the,,,,,output,,,,,frequency,,,,,of,,,,,NCO,,,,,also ,,,,,changes,,,,,synchronal,,,,,as,,,,,the,,,,,frequency,,,,,changing,,,,,of,,,,,input,,,,,signal,,, ,,,and,,,,,the,,,,,loop,,,,,keeps,,,,,stable.,,,,,Deserve,,,,,to,,,,,mentioned,,,,,,before,,,,,the,,,, ,loop,,,,,stepped,,,,,to,,,,,steady,,,,,state,,,,,,the,,,,,spacecraft,,,,,velocity,,,,,used,,,,,by,,,,,t he,,,,,scheme,,,,,is,,,,,given,,,,,from,,,,,the,,,,,acquisition,,,,,module.,,,,,After,,,,,having,,, ,,being,,,,,locked,,,,,state,,,,,,then,,,,,the,,,,,velocity,,,,,should,,,,,be,,,,,extracted,,,,,from,, ,,,the,,,,,loop,,,,,itself,,,,,directly.,,,,,By,,,,,this,,,,,way,,,,,,the,,,,,loop,,,,,is,,,,,able,,,,,to,,,,, keep,,,,,stable,,,,,even,,,,,on,,,,,the,,,,,high,,,,,dynamic,,,,,condition.,,,,,Figure,,,,,3.,,,,,Carrier,,,,,tracking,,,,,loop,,,,,aided,,,,,by,,,,,frequency,,,,,hopping,,,,,patternBesides,,,,,the,,,,,thermal,,,,,noise,,,,,jitter,,,,,,the,,,,,main,,,,,error,,,,,of,,,,,carrier,,,, ,tracking,,,,,loop,,,,,aided,,,,,by,,,,,the,,,,,frequency,,,,,hopping,,,,,pattern,,,,,is,,,,,the,,,,,f requency,,,,,jitter,,,,,of,,,,,the,,,,,frequency,,,,,synthesizer,,,,,and,,,,,timing,,,,,error,,,,,due ,,,,,to,,,,,frequency,,,,,pattern,,,,,synchronization.,,,,,The,,,,,former,,,,,one,,,,,depends,,,,, on,,,,,the,,,,,resolution,,,,,of,,,,,frequency,,,,,synthesizer,,,,,as,,,,,other,,,,,communication,,,,,and,,,,,we,,,,,only,,,,,discuss,,,,,the,,,,,latter,,,,,one.,,,,,Briefly,,,,,,when,,,,,the,,,,,local, ,,,,frequency,,,,,changing,,,,,of,,,,,the,,,,,local,,,,,frequency,,,,,synthesizer,,,,,is,,,,,advanc ed,,,,,or,,,,,retarded,,,,,to,,,,,the,,,,,one,,,,,of,,,,,receive,,,,,signal,,,,,,the,,,,,aiding,,,,,modu le,,,,,will,,,,,provide,,,,,a,,,,,frequency,,,,,offset,,,,,to,,,,,the,,,,,carrier,,,,,NCO,,,,,at,,,,,the, ,,,,wrong,,,,,time,,,,,and,,,,,the,,,,,loop,,,,,will,,,,,step,,,,,to,,,,,the,,,,,unlocked,,,,,state,,,,, at,,,,,once,,,,,,i.e.,,,,,,response,,,,,of,,,,,frequency,,,,,step.,,,,,Fortunately,,,,,,when,,,,,the,, ,,,frequency,,,,,of,,,,,input,,,,,signal,,,,,changes,,,,,actually,,,,,,the,,,,,loop,,,,,will,,,,,retur n,,,,,to,,,,,the,,,,,steady,,,,,state,,,,,rapidly.,,,,,But,,,,,as,,,,,the,,,,,increase,,,,,of,,,,,synchro nization,,,,,error,,,,,,it,,,,,also,,,,,be,,,,,likely,,,,,to,,,,,become,,,,,too,,,,,severe,,,,,to,,,,,me et,,,,,the,,,,,resolution,,,,,requirement,,,,,of,,,,,the,,,,,TT&C,,,,,system.V.,,,,,SIMULA TIOMThe,,,,,model,,,,,of,,,,,carrier,,,,,tracking,,,,,loop,,,,,of,,,,,hybrid,,,,,DS/FHSS,,,,,sys tem,,,,,is,,,,,shown,,,,,in,,,,,Fig,,,,,3,,,,,,which,,,,,is,,,,,built,,,,,in,,,,,the,,,,,simulink,,,,,of,, ,,,Matlab.,,,,,The,,,,,tracking,,,,,loop,,,,,is,,,,,the,,,,,standard,,,,,costas,,,,,loop,,,,,commo nly,,,,,used,,,,,in,,,,,the,,,,,TT&C,,,,,field,,,,,,which,,,,,is,,,,,able,,,,,to,,,,,eliminate,,,,,the,, ,,,inference,,,,,resulted,,,,,form,,,,,the,,,,,polarity,,,,,change,,,,,of,,,,,the,,,,,modulated,,,,, data,,,,,[9].,,,,,To,,,,,adapt,,,,,the,,,,,Doppler,,,,,frequency,,,,,change,,,,,due,,,,,to,,,,,the,,,, ,spacecraft,,,,,movement,,,,,,the,,,,,loop,,,,,is,,,,,designed,,,,,as,,,,,a,,,,,2ed,,,,,order,,,,,loo p,,,,,,and,,,,,the,,,,,loop,,,,,filter,,,,,is,,,,,a,,,,,1st,,,,,order,,,,,filter.,,,,,The,,,,,simulation,,,,, parameter,,,,,is,,,,,set,,,,,according,,,,,to,,,,,the,,,,,actual,,,,,TT&C,,,,,task,,,,,as,,,,,follow s:,,,,,Carrier,,,,,frequency:,,,,,2.2GHz~2.3GHz,,,,,Amount,,,,,of,,,,,frequencies:,,,,,128,,,,,Frequency,,,,,hopping,,,,,pattern:,,,,,based,,,,,on,,,,,m-sequence,,,,,Rudimental,,,,,frequency,,,,,offset,,,,,after,,,,,acquisition:,,,,,300Hz,,,,,Intermediate,,,,,frequency,,,,,of,,,,,the,,,,,carrier,,,,,tracking,,,,,loop:,,,,,4.8MHz,,,,,Sampling,,,,,frequency:,,,,,16.3Mbps,,,,,Noise,,,,,Bandwidth,,,,,of,,,,,the,,,,,loop:,,,,,10Hz,,,,,A.,,,,,The,,,,,time,,,,,response,,,,,on,,,,,uniform,,,,,motion,,,,,and,,,,,,,,,,uniformly,,,, ,accelerated,,,,,motionWe,,,,,assume,,,,,the,,,,,spacecraft,,,,,speed,,,,,is,,,,,7.9km/s,,,,,,by,,,,,the,,,,,relation ,,,,,among,,,,,the,,,,,Doppler,,,,,frequency,,,,,,carrier,,,,,frequency,,,,,and,,,,,velocity,,,,,,t he,,,,,frequency,,,,,offset,,,,,of,,,,,the,,,,,input,,,,,IF,,,,,signal,,,,,of,,,,,loop,,,,,is,,,,,obtaine d,,,,,as,,,,,Fig,,,,,4(a).,,,,,The,,,,,max,,,,,frequency,,,,,agility,,,,,is,,,,,up,,,,,to,,,,,2.3KHz.,,, ,,The,,,,,time,,,,,response,,,,,without,,,,,aid,,,,,is,,,,,shown,,,,,in,,,,,the,,,,,Fig,,,,,4(b),,,,,an d,,,,,the,,,,,one,,,,,with,,,,,aid,,,,,by,,,,,hopping,,,,,pattern,,,,,is,,,,,shown,,,,,in,,,,,Fig4(c)., ,,,,The,,,,,results,,,,,show,,,,,that,,,,,the,,,,,loop,,,,,without,,,,,aid,,,,,is,,,,,unlocked,,,,,com pletely,,,,,,while,,,,,the,,,,,one,,,,,with,,,,,aid,,,,,can,,,,,track,,,,,the,,,,,carrier,,,,,accurately .,,,,,When,,,,,the,,,,,spacecraft,,,,,is,,,,,on,,,,,the,,,,,uniformly,,,,,accelerated,,,,,motion,,,,, (the,,,,,initial,,,,,speed,,,,,is,,,,,7.9km/s,,,,,,and,,,,,speed,,,,,accelerator,,,,,is,,,,,30g),,,,,,th e,,,,,time,,,,,response,,,,,is,,,,,shown,,,,,in,,,,,Fig,,,,,5.,,,,,The,,,,,same,,,,,conclusion,,,,,is, ,,,,obtained,,,,,as,,,,,pre-paragraph.,,,,,Figure,,,,,4.,,,,,,,,,,The,,,,,time,,,,,response,,,,,on,,,,,uniform,,,,,,,,,,,,,,,motion:,,,,,(a)doppler,,,,,frequency,(b)without,,,,,aid,,,,,,(c),,,,,with,,,,,aid.Figure,,,,,5.,,,,,Time,,,,,response,,,,,on,,,,,uniformly,,,,,accelerated,,,,,motion:(a)doppler,,,,,frequency,(b)without,,,,,aid,,,,,(c),,,,,with,,,,,aidB.,,,,,Tracking,,,,,resolution,,,,,on,,,,,different,,,,,hopping,,,,,speedIn,,,,,this,,,,,simulation,,,,,,the,,,,,resolution,,,,,of,,,,,carrier,,,,,tracking,,,,,loop,,,,,is, ,,,,obtained,,,,,by,,,,,calculating,,,,,variance.,,,,,The,,,,,relation,,,,,between,,,,,tracking,,,, ,resolution,,,,,and,,,,,hopping,,,,,speed,,,,,is,,,,,shown,,,,,in,,,,,Fig,,,,,6,,,,,on,,,,,different,, ,,,input,,,,,SNR,,,,,and,,,,,the,,,,,minimum,,,,,value,,,,,insuring,,,,,the,,,,,demodulating,,,, ,correctly,,,,,in,,,,,TT&C,,,,,system,,,,,is,,,,,13,,,,,dB.,,,,,The,,,,,result,,,,,of,,,,,simulation ,,,,,testified,,,,,that,,,,,the,,,,,resolution,,,,,is,,,,,not,,,,,sensitive,,,,,to,,,,,the,,,,,hopping,,,,, speed,,,,,and,,,,,the,,,,,scheme,,,,,is,,,,,very,,,,,robust,,,,,for,,,,,different,,,,,hopping,,,,,spe ed.Figure,,,,,6.,,,,,Stead-state,,,,,tracking,,,,,resolution,,,,,vs,,,,,hopping,,,,,speedC.,,,,,Tracking,,,,,resolution,,,,,on,,,,,different,,,,,timing,,,,,error,,,,,of,,,,,frequency, ,,,,,,,,,pattern,,,,,,,,,,synchronization,,,,,,,,,,For,,,,,carrier,,,,,tracking,,,,,loop,,,,,aided,,,,,by,,,,,the,,,,,frequency,,,,,hopping,,,,,p attern,,,,,,according,,,,,to,,,,,the,,,,,above,,,,,discussion,,,,,the,,,,,main,,,,,factor,,,,,impact ing,,,,,the,,,,,stability,,,,,of,,,,,loop,,,,,is,,,,,the,,,,,timing,,,,,error,,,,,caused,,,,,by,,,,,the,,,,, patterns,,,,,synchronization.,,,,,Fig,,,,,7,,,,,shows,,,,,the,,,,,stead-state,,,,,tracking,,,,,acc uracies,,,,,on,,,,,different,,,,,timing,,,,,error,,,,,of,,,,,synchronization,,,,,pattern,,,,,on,,,,,d ifferent,,,,,input,,,,,SNR.,,,,,The,,,,,measuring,,,,,error,,,,,is,,,,,increase,,,,,as,,,,,increasin g,,,,,of,,,,,timing,,,,,error,,,,,and,,,,,the,,,,,measurement,,,,,error,,,,,resulted,,,,,from,,,,,the ,,,,,SNR,,,,,even,,,,,can,,,,,be,,,,,ignored,,,,,when,,,,,the,,,,,time,,,,,error,,,,,is,,,,,up,,,,,to,,, ,,some,,,,,specified,,,,,value.,,,,,Consequently,,,,,,we,,,,,can,,,,,infer,,,,,that,,,,,the,,,,,trac k,,,,,accuracy,,,,,won’t,,,,,meet,,,,,the,,,,,requirement,,,,,of,,,,,TT&C,,,,,system,,,,,finally ,,,,,,and,,,,,the,,,,,problem,,,,,needs,,,,,to,,,,,be,,,,,researched,,,,,in,,,,,the,,,,,future.Figure,,,,,7.,,,,,Stead-state,,,,,tracking,,,,,resolution,,,,,vs,,,,,timing,,,,,error,,,,,of,,,,,,,,,,pattern,,,,,synchronization。

通信类英文文献及翻译

附录一、英文原文：Detecting Anomaly Trafﬁc using Flow Data in the realVoIP networkI. INTRODUCTIONRecently, many SIP[3]/RTP[4]-based VoIP applications and services have appeared and their penetration ratio is gradually increasing due to the free or cheap call charge and the easy subscription method. Thus, some of the subscribers to the PSTN service tend to change their home telephone services to VoIP products. For example, companies in Korea such as LG Dacom, Samsung Net- works, and KT have begun to deploy SIP/RTP-based VoIP services. It is reported that more than ﬁve million users have subscribed the commercial VoIP services and 50% of all the users are joined in 2009 in Korea [1]. According to IDC, it is expected that the number of VoIP users in US will increase to 27 millions in 2009 [2]. Hence, as the VoIP service becomes popular, it is not surprising that a lot of VoIP anomaly trafﬁc has been already known [5]. So, Most commercial service such as VoIP services should provide essential security functions regarding privacy, authentication, integrity and non-repudiation for preventing malicious trafﬁc. Particu- larly, most of current SIP/RTP-based VoIP services supply the minimal security function related with authentication. Though secure transport-layer protocols such as Transport Layer Security (TLS) [6] or Secure RTP (SRTP) [7] have been standardized, they have not been fully implemented anddeployed in current VoIP applications because of the overheads of implementation and performance. Thus, un-encrypted VoIP packets could be easily sniffed and forged, especially in wireless LANs. In spite of authentication,the authentication keys such as MD5 in the SIP header could be maliciously exploited, because SIP is a text-based protocol and unencrypted SIP packets are easily decoded. Therefore, VoIP services are very vulnerable to attacks exploiting SIP and RTP. We aim at proposing a VoIP anomaly trafﬁc detection method using the ﬂow-based trafﬁc measurement archi-tecture. We consider three representative VoIP anomalies called CANCEL, BYE Denial of Service (DoS) and RTP ﬂooding attacks in this paper, because we found that malicious users in wireless LAN could easily perform these attacks in the real VoIP network. For monitoring VoIP packets, we employ the IETF IP Flow Information eXport (IPFIX) [9] standard that is based on NetFlow v9. This trafﬁc measurement method provides a ﬂexible and extensible template structure for various protocols, which is useful for observing SIP/RTP ﬂows [10]. In order to capture and export VoIP packets into IPFIX ﬂows, we deﬁne two additional IPFIX templates for SIP and RTP ﬂows. Furthermore, we add four IPFIX ﬁelds to observe packets which are necessary to detect VoIP source spooﬁng attacks in WLANs.II. RELATED WORK[8] proposed a ﬂooding detection method by the Hellinger Distance (HD) concept. In [8], they have pre- sented INVITE, SYN and RTP ﬂooding detection meth-ods. The HD is the difference value between a training data set and a testing data set. The training data set collected trafﬁc over n sampling period of duration Δ testing data set collected trafﬁc next the training data set in the same period. If the HD is close to ‘1’, this testing data set is regarded as anomaly trafﬁc. For using this method, they assumed that initial training data set didnot have any anomaly trafﬁc. Since this method was based on packet counts, it might not easily extended to detect other anomaly trafﬁc except ﬂooding. On the other hand, [11] has proposed a VoIP anomaly trafﬁc detection method using Extended Finite State Machine (EFSM). [11] has suggested INVITE ﬂooding, BYE DoS anomaly trafﬁc and media spamming detection methods. However, the state machine required more memory because it had to maintain each ﬂow. [13] has presented NetFlow-based VoIP anomaly detection methods for INVITE, REGIS-TER, RTP ﬂooding, and REGISTER/INVITE scan. How-ever, the VoIP DoS attacks considered in this paper were not considered. In [14], an IDS approach to detect SIP anomalies was developed, but only simulation results are presented. For monitoring VoIP trafﬁc, SIPFIX [10] has been proposed as an IPFIX extension. The key ideas of the SIPFIX are application-layer inspection and SDP analysis for carrying media session information. Yet, this paper presents only the possibility of applying SIPFIX to DoS anomaly trafﬁc detection and prevention. We described the preliminary idea of detecting VoIP anomaly trafﬁc in [15]. This paper elaborates BYE DoS anomaly trafﬁc and RTP ﬂooding anomaly trafﬁc detec-tion method based on IPFIX. Based on [15], we have considered SIP and RTP anomaly trafﬁc generated in wireless LAN. In this case, it is possible to generate the similiar anomaly trafﬁc with normal VoIP trafﬁc, because attackers can easily extract normal user information from unencrypted VoIP packets. In this paper, we have extended the idea with additional SIP detection methods using information of wireless LAN packets. Furthermore, we have shown the real experiment results at the commercial VoIP network.III. THE VOIP ANOMALY TRAFFIC DETECTION METHOD A. CANCEL DoS Anomaly Trafﬁc DetectionAs the SIP INVITE message is not usually encrypted, attackers could extract ﬁelds necessary to reproduce the forged SIP CANCEL message by snifﬁng SIP INVITE packets, especially in wireless LANs. Thus, we cannot tell the difference between the normal SIP CANCEL message and the replicated one, because the faked CANCEL packet includes the normal ﬁelds inferred from the SIP INVITE message. The attacker will perform the SIP CANCEL DoS attack at the same wireless LAN, because the purpose of the SIP CANCEL attack is to prevent the normal call estab-lishment when a victim is waiting for calls. Therefore, as soon as the attacker catches a call invitation message for a victim, it will send a SIP CANCEL message, which makes the call establishment failed. We have generated faked SIP CANCEL message using sniffed a SIP INVITE in SIP header of this CANCEL message is the same as normal SIP CANCEL message, because the attacker can obtain the SIP header ﬁeld from unencrypted normal SIP message in wireless LAN environment. Therefore it is impossible to detect the CANCEL DoS anomaly trafﬁc using SIP headers, we use the different values of the wireless LAN frame. That is, the sequence number in the frame will tell the difference between a victim host and an attacker. We look into source MAC address and sequence number in the MAC frame including a SIP CANCEL message as shown in Algorithm 1. We compare the source MAC address of SIP CANCEL packets with that of the previously saved SIP INVITE ﬂow. If the source MAC address of a SIP CANCEL ﬂow is changed, it will be highly probable that the CANCEL packet is generated by a unknown user. However, the source MAC address could be spoofed. Regarding source spooﬁng detection, we employ the method in [12] that uses sequence numbers of frames. We calculate the gap between n-th and (n-1)-th frames. As the sequence number ﬁeld in a MAC header uses 12 bits, it varies from 0 to 4095. When we ﬁnd that the sequence number gap between a single SIP ﬂow is greater than the threshold value of N that willbe set from the experiments, we determine that the SIP host address as been spoofed for the anomaly trafﬁc.B. BYE DoS Anomaly Trafﬁc DetectionIn commercial VoIP applications, SIP BYE messages use the same authentication ﬁeld is included in the SIP IN-VITE message for security and accounting purposes. How-ever, attackers can reproduce BYE DoS packets through snifﬁng normal SIP INVITE packets in wireless faked SIP BYE message is same with the normal SIP BYE. Therefore, it is difﬁcult to detect the BYE DoS anomaly trafﬁc using only SIP header snifﬁng SIP INVITE message, the attacker at the same or different subnets could terminate the normal in- progress call, because it could succeed in generating a BYE message to the SIP proxy server. In the SIP BYE attack, it is difﬁcult to distinguish from the normal call termination procedure. That is, we apply the timestamp of RTP trafﬁc for detecting the SIP BYE attack. Generally, after normal call termination, the bi-directional RTP ﬂow is terminated in a bref space of time. However, if the call termination procedure is anomaly, we can observe that a directional RTP media ﬂow is still ongoing, whereas an attacked directional RTP ﬂow is broken. Therefore, in order to detect the SIP BYE attack, we decide that we watch a directional RTP ﬂow for a long time threshold of N sec after SIP BYE message. The threshold of N is also set from the 2 explains the procedure to detect BYE DoS anomal trafﬁc using captured timestamp of the RTP packet. We maintain SIP session information between clients with INVITE and OK messages including the same Call-ID and 4-tuple (source/destination IP Address and port number) of the BYE packet. We set a time threshold value by adding Nsec to the timestamp value of the BYE message. The reason why we use the captured timestamp is that a few RTP packets are observed under second. If RTP trafﬁc is observed after the time threshold, this willbe considered as a BYE DoS attack, because the VoIP session will be terminated with normal BYE messages. C. RTP Anomaly Trafﬁc Detection Algorithm 3 describes an RTP ﬂooding detection method that uses SSRC and sequence numbers of the RTP header. During a single RTP session, typically, the same SSRC value is maintained. If SSRC is changed, it is highly probable that anomaly has occurred. In addition, if there is a big sequence number gap between RTP packets, we determine that anomaly RTP trafﬁc has happened. As inspecting every sequence number for a packet is difﬁcult, we calculate the sequence number gap using the ﬁrst, last, maximum and minimum sequence numbers. In the RTP header, the sequence number ﬁeld uses 16 bits from 0 to 65535. When we observe a wide sequence number gap in our algorithm, we consider it as an RTP ﬂooding attack.IV. PERFORMANCE EVALUATIONA. Experiment EnvironmentIn order to detect VoIP anomaly trafﬁc, we established an experimental environment as ﬁgure 1. In this envi-ronment, we employed two VoIP phones with wireless LANs, one attacker, a wireless access router and an IPFIX ﬂow collector. For the realistic performance evaluation, we directly used one of the working VoIP networks deployed in Korea where an 11-digit telephone number (070-XXXX-XXXX) has been assigned to a SIP wireless SIP phones supporting , we could make calls to/from the PSTN or cellular phones. In the wireless access router, we used two wireless LAN cards- one is to support the AP service, and the other is to monitor packets. Moreover, in order to observe VoIP packets in the wireless access router, we modiﬁed nProbe [16], that is an open IPFIX ﬂow generator, to create and export IPFIX ﬂows related with SIP, RTP, and information. As the IPFIX collector, we have modiﬁed libipﬁx so that it could provide the IPFIX ﬂow decoding function for SIP, RTP, and templates. We used MySQL for the ﬂow DB.B. Experimental ResultsIn order to evaluate our proposed algorithms, we gen-erated 1,946 VoIP calls with two commercial SIP phones and a VoIP anomaly trafﬁc generator. Table I showsour experimental results with precision, recall, and F-score that is the harmonic mean of precision and recall. In CANCEL DoS anomaly trafﬁc detection, our algorithm represented a few false negative cases, which was related with the gap threshold of the sequence number in MAC header. The average of the F-score value for detecting the SIP CANCEL anomaly is %.For BYE anomaly tests, we generated 755 BYE mes-sages including 118 BYE DoS anomalies in the exper-iment. The proposed BYE DoS anomaly trafﬁc detec-tion algorithm found 112 anomalies with the F-score of %. If an RTP ﬂow is terminated before the threshold, we regard the anomaly ﬂow as a normal one. In this algorithm, we extract RTP session information from INVITE and OK or session description messages using the same Call-ID of BYE message. It is possible not to capture those packet, resulting in a few false-negative cases. The RTP ﬂooding anomaly trafﬁc detection experiment for 810 RTP sessions resulted in the F score of 98%.The reason of false-positive cases was related with the sequence number in RTP header. If the sequence number of anomaly trafﬁc is overlapped with the range of the normal trafﬁc, our algorithm will consider it as normal trafﬁc.V. CONCLUSIONSWe have proposed a ﬂow-based anomaly trafﬁc detec-tion method against SIP and RTP-based anomaly trafﬁc in this paper. We presented VoIP anomaly trafﬁc detection methods with ﬂow data on the wireless access router. We used the IETF IPFIX standard to monitor SIP/RTP ﬂows passing through wireless access routers, because its template architecture is easily extensible to several protocols. For this purpose, we deﬁned two new IPFIX templates for SIP and RTP trafﬁc and four new IPFIX ﬁelds for trafﬁc. Using these IPFIX ﬂow templates,we proposed CANCEL/BYE DoS and RTP ﬂooding trafﬁc detection algorithms. From experimental results on the working VoIP network in Korea, we showed that our method is able to detect three representative VoIP attacks on SIP phones. In CANCEL/BYE DoS anomaly trafﬁcdetection method, we employed threshold values about time and sequence number gap for classﬁcation of normal and abnormal VoIP packets. This paper has not been mentioned the test result about suitable threshold values. For the future work, we will show the experimental result about evaluation of the threshold values for our detection method.二、英文翻译：交通流数据检测异常在真实的世界中使用的VoIP网络一 .介绍最近,许多SIP[3],[4]基于服务器的VoIP应用和服务出现了,并逐渐增加他们的穿透比及由于自由和廉价的通话费且极易订阅的方法。

通信技术类英文文献

通信技术类英文文献IntroductionIn today’s digital age, communication technology plays a crucial role in connecting people, businesses, and devices. From traditional landline telephones to modern smartphones and internet-based communication platforms, the field of communication technology has witnessed significant advancements. This article aims to explore various aspects of communication technology, including its history, types, applications, and future trends.History of Communication Technology1.Early forms of communication technology–Smoke signals–Carrier pigeons–Semaphore telegraphs2.Invention of the telegraph–Samuel Morse and Morse code–Telegraph lines and the expansion of communication networks 3.Telephone revolution–Alexander Graham Bell and the invention of the telephone–Introduction of telephone exchanges and switchboards4.Birth of wireless communication–Guglielmo Marconi and radio transmission–Wireless telegraphy and its impact on long-distancecommunicationTypes of Communication Technology1.Wired communication technology–Traditional landline telephones–Ethernet cables for internet connectivity–Fiber optic cables for high-speed data transmission2.Wireless communication technology–Radio communication–Cellular networks (2G, 3G, 4G, and 5G)–Satellite communication3.Internet-based communication technology–Email and instant messaging–Voice over Internet Protocol (VoIP)–Video conferencing and online collaboration toolsApplications of Communication Technology1.Personal communication–Mobile phones and smartphones–Social media platforms–Messaging apps2.Business communication–Teleconferencing and virtual meetings–Cloud-based collaboration tools–Customer relationship management (CRM) systems3.Healthcare communication–Telemedicine and remote patient monitoring–Electronic health records (EHR)–Communication systems in hospitals and healthcare facilities munication in education–Online learning platforms–Virtual classrooms and webinars–Educational apps and softwareFuture Trends in Communication Technology1.Internet of Things (IoT)–Interconnected devices and sensors–Smart homes and cities2.5G and beyond–Faster data speeds and lower latency–Enhanced connectivity for autonomous vehicles and IoT devices3.Artificial Intelligence (AI) in communication–Chatbots and virtual assistants–Natural language processing for improved communication4.Blockchain technology in communication–Secure and transparent data exchange–Decentralized communication networksConclusionCommunication technology has evolved significantly over the years, revolutionizing the way we connect and interact. From the early forms of communication to the advent of wireless and internet-based technologies, communication has become faster, more efficient, and accessible to a wider audience. As we look towards the future, emerging trends such as IoT, 5G, AI, and blockchain promise to further transform the field of communication technology, opening up new possibilities and opportunities for individuals, businesses, and society as a whole.。

通信工程外文文献

外文资料和中文翻译外文资料：Review of UMTS1.1 UMTS Network ArchitectureThe European/Japanese 3G standard is referred to as UMTS. UMTS is one of a number of standards ratified by the ITU-T under the umbrella of IMT-2000. It is currently the dominant standard, with the US CDMA2000 standard gaining ground, particularly with operators that have deployed cdmaOne as their 2G technology. At time of writing,Japan is the most advanced in terms of 3G network deployment. The three incumbent operators there have implemented three different technologies: J-Phone is using UMTS,KDDI has a CDMA2000 network, and the largest operator NTT DoCoMo is using a system branded as FOMA (Freedom of Multimedia Access). FOMA is based on the original UMTS proposal, prior to its harmonization and standardization.The UMTS standard is specified as a migration from the second generation GSM standard to UMTS via the General Packet Radio System (GPRS) and Enhanced Data for Global Evolution (EDGE), as shown in Figure. This is a sound rationale since as of April 2003, there were over 847 Million GSM subscribers worldwide1, accounting for68% of the global cellular subscriber figures. The emphasis is on keeping as much ofthe GSM network as possible to operate with the new system.We are now well on the road towards Third Generation (3G), where the network will support all traffic types: voice, video and data, and we should see an eventual explosion in the services available on the mobile device. The driving technology for this is the IP protocol. Many cellular operators are now at a position referred to as 2.5G, with the deployment of GPRS, which introduces an IP backbone into the mobile core network.The diagram below, Figure 2, shows an overview of the key components in a GPRS network, and how it fits into the existing GSM infrastructure.The interface between the SGSN and GGSN is known as the Gn interface and uses the GPRS tunneling protocol (GTP, discussed later). The primary reason for the introduction of this infrastructure is to offer connections to external packet networks, such as the Internet or a corporate Intranet.This brings the IP protocol into the network as a transport between the SGSN and GGSN. This allows data services such as email or web browsing on the mobile device,with users being charged based on volume of data rather than time connected.The dominant standard for delivery of 3G networks and services is the Universal Mobile Telecommunications System, or UMTS. The first deployment of UMTS is the Release ’99 architecture, shown below in Figure 3.In this network, the major change is in the radio access network (RAN) with the introduction of CDMA technology for the air interface, and ATM as a transport in the transmission part. These changes have been introduced principally to support the transport of voice, video and data services on the same network. The core network remains relatively unchanged, with primarily software upgrades. However, the IP protocol pushes further into the network with the RNC now communicating with the 3G SGSN using IP.The next evolution step is the Release 4 architecture, Figure 4. Here, the GSM core is replaced with an IP network infrastructure based around Voice over IP technology.The MSC evolves into two separate components: a Media Gateway (MGW) and an MSC Server (MSS). This essentially breaks apart the roles of connection and connection control. An MSS can handle multiple MGWs, making the network more scaleable.Since there are now a number of IP clouds in the 3G network, it makes sense to merge these together into one IP or IP/ATM backbone (it is likely both options will be available to operators.) This extends IP right across the whole network, all the way to the BTS.This is referred to as the All-IP network, or the Release 5 architecture, as shown in Figure 5. The HLR/VLR/EIR are generalised and referred to as the HLR Subsystem(HSS).Now the last remnants of traditional telecommunications switching are removed, leaving a network operating completely on the IP protocol, and generalised for the transport of many service types. Real-time services are supported through the introduction of a new network domain, the IP Multimedia Subsystem (IMS).Currently the 3GPP are working on Release 6, which purports to cover all aspects not addressed in frozen releases. Some call UMTS Release 6 4G and it includes such issues as interworking of hot spot radio access technologies such as wireless LAN.1.2 UMTS FDD and TDDLike any CDMA system, UMTS needs a wide frequency band in which to operate to effectively spread signals. The defining characteristic of the system is the chip rate, where a chip is the width of one symbol of the CDMA code. UMTS uses a chip rate of 3.84Mchips/s and this converts to a required spectrum carrier of 5MHz wide. Since this is wider than the 1.25MHz needed for the existing cdmaOne system, the UMTS air interface is termed ‘wideband’ CDMA.There are actually two radio technologies under the UMTS umbrella: UMTS FDD and TDD. FDD stands for Frequency Division Duplex, and like GSM, separates traffic in the uplink and downlink by placing them at different frequency channels. Therefore an operator must have a pair of frequencies allocated to allow them to run a network, hence the term ‘paired spectrum’. TDD or Time Division Duplex requires only one frequency channel, and uplink and downlink traffic are separated by sending them at different times. The ITU-T spectrum usage, as shown in Figure 6, for FDD is 1920- 980MHz for uplink traffic, and 2110-2170MHz for downlink. The minimum allocation an operator needs is two paired 5MHz channels, one for uplink and one for downlink, at a separation of 190MHz. However, to provide comprehensive coverage and services, it is recommended that an operator be given three channels. Considering the spectrum allocation, there are 12 paired channels available, and many countries have now completed the licencing process for this spectrum, allocating between two and four channels per licence. This has tended to work out a costly process for operators, since the regulatory authorities in some countries, notably in Europe, have auctioned these licences to the highest bidder. This has resulted in spectrum fees as high as tens of billions of dollars in some countries.The Time Division Duplex (TDD) system, which needs only one 5MHz band in which to operate, often referred to as unpaired spectrum. The differences between UMTS FDD and TDD are only evident at the lower layers, particularly on the radio interface. At higher layers, the bulk of the operation of the two systems is the same. As the name suggests, the TDD system separates uplink and downlink traffic by placing them in different time slots. As will be seen later, UMTS uses a 10ms frame structure which is divided into 15 equal timeslots. TDD can allocate these to be either uplink or downlink,with one or more breakpoints between the two in a frame defined. In this way, it is well suited to packet traffic, since this allows great flexibility in dynamically dimensioning for asymmetry in traffic flow.The TDD system should not really be considered as an independent network, but rather as a supplementfor an FDD system to provide hotspot coverage at higher data rates. It is rather unsuitable for large scale deployment due to interference between sites, since a BTS may be trying to detect a weak signal from a UE, which is blocked out by a relatively strong signal at the same frequency from a nearby BTS. TDD is ideal for indoor coverage over small areas.Since FDD is the main access technology being developed currently, the explanations presented here will focus purely on this system.1.3 UMTS Bearer ModelThe procedures of a mobile device connecting to a UMTS network can be split into two areas: the access stratum (AS) and the non-access stratum (NAS). The access stratum involves all the layers and subsystems that offer general services to the non-access stratum. In UMTS, the access stratum consists of all of the elements in the radio access network, including the underlying ATM transport network, and the various mechanisms such as those to provide reliable information exchange. All of the non-access stratum functions are those between the mobile device and the core network, for example, mobility management. Figure 7 shows the architecture model. The AS interacts with the NAS through the use of service access points (SAPs).UMTS radio access network (UTRAN) provides this separation of NAS and AS functions, and allows for AS functions to be fully controlled and implemented within the UTRAN. The two major UTRAN interfaces are the Uu, which is the interface between the mobile device, or User Equipment (UE) and the UTRAN, and the Iu, which is the interface between the UTRAN and the core network. Both of these interfaces can be divided into control and user planes each with appropriate protocol functions.A Bearer Service is a link between two points, which is defined by a certain set of characteristics. In the case of UMTS, the bearer service is delivered using radio access bearers.A Radio access bearer (RAB) is defined as the service that the access stratum (i.e.UTRAN) provides to the non-access stratum for transfer of user data between the User Equipment and Core Network. A RAB can consist of a number of subflows, which are data streams to the core network within the RAB that have different QoS characteristics,such as different reliabilities. A common example of this is different classes of bits with different bit error rates can be realised as different RAB subflows. RAB subflows are established and released at the time the RAB is established and released, and are delivered together over the same transport bearer.A Radio Link is defined as a logical association between a single User Equipment (UE) and a single UTRAN access point, such as an RNC. It is physically comprised of one or more radio bearers and should not be confused with radio access bearer.Looking within the UTRAN, the general architecture model is as shown in Figure 8 below. Now shown are the Node B or Base Station (BTS) and Radio Network Controller (RNC) components, and their respective internal interfaces. The UTRAN is subdivided into blocks referred to as Radio Network Subsystems (RNS), where each RNS consists of one controlling RNC (CRNC) and all the BTSs under its control. Unique to UMTS is the interface between RNSs, the Iur interface, which plays a key role in handover procedures. The interface between the BTS and RNC is the Iub interface.All the ‘I’ interfaces: Iu, Iur and Iub, currently3 use ATM as a transport layer. In the context of ATM, the BTS is seen as a host accessing an ATM network, within which the RNC is an ATM switch. Therefore, the Iub is a UNI interface, whereas the Iu and Iur interfaces are considered to be NNI, as illustrated in Figure 9.This distinction is because the BTS to RNC link is a point-to-point connection in that a BTS or RNC will only communicate with the RNC or BTS directly connected to it, and will not require communication beyond that element to another network element.For each user connection to the core network, there is only one RNC, which maintains the link between the UE and core network domain, as highlighted in Figure 10. This RNC is referred to as the serving RNC or SRNC. That SRNC plus the BTSs under its control is then referred to as the SRNS. This is a logical definition with reference to that UE only. In an RNS, the RNC that controls a BTS is known as the controlling RNC or CRNC. This is with reference to the BTS, cells under its control and all the common and shared channels within.As the UE moves, it may perform a soft or hard handover to another cell. In the case of a soft handover, the SRNC will activate the new connection to the new BTS. Should the new BTS be under the control of another RNC, the SRNC will also alert this new RNC to activate a connection along the Iur interface. The UE now has two links, one directly to the SRNC, and the second, through the new RNC along the Iur interface. In this case, this new RNC is logically referred to as a drift RNC or DRNC, see Figure 10. It is not involved in any processing of the call and merely relays it to the SRNC for connection to the core. In summary, SRNC and DRNC are usually associated with the UE and the CRNC is associated with the BTS. Since these are logical functions it is normal practice that a single RNC is capable of dealing with all these functions.A situation may arise where a UE is connected to a BTS for which the SRNC is not the CRNC for that BTS. In that situation, the network may invoke the Serving RNC Relocation procedure to move the core network connection. This process is described inSection 3.中文翻译：通用移动通信系统的回顾1.1 UMTS网络架构欧洲/日本的3G标准，被称为UMTS。

1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。

使用LabVIEW中的TCP/IP和UDP协议前言互联网络协议(IP)，用户数据报协议(UDP)和传输控制协议(TCP)是网络通信的基本的工具。

TCP与IP的名称来自于一组最著名的因特网协议中的两个--传输控制协议和互联网络协议。

你能使用TCP/IP来进行单一网络或者互连网络间的通信。

单独的网络会被大的地理距离分隔。

TCP/IP把数据从一个子网网络或者因特网连接的计算机发送到另一个上。

因为TCP/IP 在大多数计算机上是可用的，它能在多样化的系统中间传送信息。

LabVIEW和TCP/IP你能在所有平台上的LabVIEW中使用TCP/IP。

LabVIEW包含了TCP和UDP程序还有能让你建立客户端或者服务器程序的功能。

IPIP执行低层次的计算机间的数据传送。

在组成部分里的IP数据包称为数据报。

一个数据报包含表明来源和目的地地址的数据和报头字。

IP为通过网络或者因特网把数据发送到指定的目的地的数据报确定正确的路径。

IP协议并不能保证发送。

事实上，如果数据报在传输中被复制，IP可能多次传送一个单独的数据报。

所以，程序很少用IP而是用TCP或者UDP代替。

UDPUDP在计算机进程中提供简单而低层次的通信。

进程通过把数据报发送到一个目的地计算机或者端口进行通信。

一个端口是你发送数据的位置。

IP处理计算机对计算机的发送。

在数据报到达目的地计算机后，UDP把数据报移动到其目的端口。

如果目的端口不是开放的，UDP 将删除数据报。

UDP将发生IP的同样的发送问题。

应用程序的UDP的可靠性不强。

例如，一项应用程序能经常把大量信息的数据传送到目的地而丢失少量的数据是肯定的。

在LabVIEW中使用UDP协议因为UDP不是一个TCP似的一个以连接为基础的协议，在你发送或者收到数据之前，你不需要和目的地建立一种连接。

相反，当你每发送一个数据报时，由你指定数据目的地。

操作系统不会报告传输差错使用UDP打开功能在一个端口上打开一个UDP插口。

同时打开的UDP端口的数量仍依赖于操作系统。

UDP的打开的功能返回到网络连接时唯一识别UDP套接字。

使用这种连接在子VI程序中就是靠这个套接字。

用UDP编写功能发送数据到目的地，然后使用UDP阅读功能阅读那个数据。

每写一个操作要求一个目的地地址和端口。

每阅读一个操作包含来源地址和端口。

UDP保存你所发送的每一个命令所指定的数据报字节。

在理论上，你能发送任何大小的数据报。

然而，你最好不使用UDP来发送大的数据报，因为它不像TCP一样可靠。

当你在一个端口上结束所有通信时，使用UDP结束功能去释放系统资源。

UDP多路广播你能使用UDP的功能来与一个单独的客户端通信或者通过广播对于所有局域网上的计算机通信。

如果你想要传送成倍增加具体的计算机信息，你必须通过客户端列表构建UDP功能反复执行。

因为LabVIEW能把数据的作为一个单独的拷贝发送到每个客户端并且保存对收到数据感兴趣的客户端列表，所以运用这种技术建立完全相同的网络交换。

使用多路广播可以在网络上的进行单个的发送端和多倍的客户端之间的通信而不需要保存客户列表或者要求发送端把数据多重拷贝后发送给每个客户端。

为了通过多路广播收到数据广播，所有客户端必须加入一个多路广播组。

而发送端不需要加入该组。

发送端只需规定一个多路广播的IP地址来定义这个多路广播组。

多路广播的IP地址范围在224.0.0.0到239.255.255.255中。

当一个客户端想要加入一个多路广播组时，它只需预定这个组的多路广播的IP地址。

在客户端预定到一个多路广播组之后，客户端收到从多路广播的IP 地址发送的数据。

对于LabVIEW中的多路广播，使用UDP多路广播的打开程序有能力读、写或者读和写UDP 数据。

规定TTL为写数据，多路广播地址为读数据，多路广播端口号为读写数据。

默认TTL 是1，这意味着LabVIEW仅仅把数据报发送到本地的网络上。

当一个发送方收到一个多路广播数据报时，它消耗数据报的生存时间。

如果TTL大于1，发送方把数据报转发到其它数据报。

下面的表格说明了当你规定一个TTL的值时，一个多路广播数据报的运行。

0 主机上还存留数据报1 数据报发送到每个在同一本地网络上已预定那个IP地址的客户端。

中枢/转发器和桥路/开关转发数据报。

发送方不转发数据报如果TTL为1。

如果你规定一个值大于1，数据报通过TTL-1层被发送，并且发送方转发它。

参阅在LabVIEW\例子\comm\UDP.llb中的UDP多路广播接受方程序和UDP多路广播发送方程序VI中使用UDP多路广播的例程。

TCPTCP保证在网络中的可靠的通信，按顺序发送而没有差错，损失或者重发。

TCP直到收到一个确认才转发。

系统要求在使用TCP/IP之前，确认你有必需的要求，这变化依赖于你使用的平台。

(Windows和UNIX系统)TCP/IP。

你不需要使用第三种产品连接使用TCP/IP。

如果你的网络适当地被构成，LabVIEW没有要求附加的设置。

(Mac OS系统) LabVIEW网络要求打开传送，包括Mac OS 7.5和更新的版本。

在LabVIEW中使用TCPTCP是一个以连接为基础的协议，这意味着站点必须在传送数据之前建立一种连接。

TCP许可多重、同时的连接。

你可以通过等待一种输入的连接或者通过积极地寻求一种与指定的地址连接建立连接。

在建立TCP连接时，你必须指定一个地址和该地址的端口。

端口范围在0到65,535点之间。

UNIX系统为特殊的应用程序保留端口数少于1,024。

在一个给定的地址中不同的端口能识别不同的服务。

使用TCP的打开连接功能来与一个指定地址进行积极的连接。

如果连接成功，功能返回网络连接的返回数唯一识别那个连接。

使用这种连接refnum来访问子VI程序。

你能使用如下技术来等输入连接：用TCP听程序创建立一个听者并且在一个指定的端口等待一种可接受的TCP连接。

如果连接成功，VI程序返回连接数，地址和远程TCP客户端口。

TCP创建听者功创建一个听者然后用TCP的听者功能上等待的一个听者接受新的连接。

在听者功能上的TCP等待返回你所发送的功能和返回数的同样的听者ID。

当你结束等候新的连接时，用TCP关闭连接功能区关闭一个听者。

你不能对一个听者进行读写。

用第二种技术的优势是你能使用TCP关闭连接功能来取消听操作，这在你想要为了一种连接听而没有超时，但是你想要取消当另一个条件变真时的听时是很有用的。

你能在任何时间关闭听程序。

当你建立一种连接时，用TCP读功能和TCP写功能能在远程应用中队数据进行读写。

用TCP关闭连接功能区关闭远程连接。

如果没被读的仍保留着而关闭连接，你可能失去数据。

当关闭连接时，在你的计算机上使用较高层次协议。

在连接被关闭后，你不能再读写它。

TCP和UDP之间的区别在你想要可靠的数据传输时，TCP是最好的协议。

UDP是高性能的无需连接的协议，但是它不保证可靠性。

建立TCP客户端注意：请参考最近的版本LabVIEW帮助功能对这些指令和功能的细节描述。

完成如下步骤使用TCP功能建立一个TCP顾客。

1.用TCP的打开连接功能来打开一个服务器的连接。

你必须规定服务器的因特网地址和服务器的端口。

地址在网络上识别计算机。

远程端口在服务器使用听的计算机上识别一个通信通道。

当你建立一个TCP服务器时，你要规定你想要服务器为通信使用的端口。

2.用TCP的写功能把信息发送到服务器上。

3.用TCP的读功能来读发自服务器的信息。

你必须规定你想读的字节数。

4.用TCP的关闭功能来关闭与服务器的连接。

请参阅labview\examples\comm\TCP.llb中对单一数据客户端的TCP例程。

超时和差错当你设计一种网络应用时，应细心考虑失败是如何发生的。

例如，如果服务器被毁，确定如何使每个客户VI程序掌控它。

一种解决方式是确保每个客户VI程序有超时功能。

如果发生没能在一定量的时间之后生产结果，客户端继续执行。

在继续时，客户端能试图重建连接或者报告出错。

如果必要的话，客户端VI程序能关闭应用程序。

建立TCP服务器注意：请参考最近的版本LabVIEW帮助功能对这些指令和功能的细节描述。

完全如下步骤用TCP功能来建立一个TCP服务器。

1.使用TCP听程序等待连接。

你必须规定端口。

这个端口必须是客户端试图访问的同一个端口。

2.如果连接被建立，用TCP读功能从接受到信息的端口读信息。

3.用TCP写功能返回结果。

数据必须是一种客户端能接受的形式。

4.用TCP关连接功能来关闭连接。

请参阅labview\examples\comm\TCP.llb中对单一数据客户端的TCP例程。

TCP和UDP例子请参阅labview\examples\comm\TCP.llb和labview\examples\comm\UDP.llb中用TCP和UDP的VI程序和功能。

Application Note 160 Using LabVIEW™ with TCP/IP and UDP IntroductionInternet Protocol (IP), User Datagram Protocol (UDP), and Transmission Control Protocol (TCP) are basic tools for network communication. The name TCP/IP comes from two of the best-known protocols of the Internet protocol suite, the Transmission Control Protocol and the Internet Protocol.You can use TCP/IP to communicate over single networks or interconnected networks. The individual networks can be separated by large geographical distances. TCP/IP routes data from one network or Internet-connected computer to another. Because TCP/IP is available on most computers, it can transfer information among diverse systems.LabVIEW and TCP/IPYou can use the TCP/IP protocols with LabVIEW on all platforms. LabVIEW includes TCP and UDP VIs and functions you can use to create client or server VIs.IPIP performs the low-level service of moving data between computers. IP packages data into components called datagrams.A datagram contains the data and a header that indicates the source and destination addresses. IP determines the correct path for the datagram to take across the network or Internet and sends the data to the specified destination.IP cannot guarantee delivery. In fact, IP might deliver a single datagram more than once if the datagram is duplicated in transmission. Programs rarely use IP but use TCP or UDP instead.UDPUDP provides simple, low-level communication among processes on computers. Processes communicate by sending datagrams to a destination computer or port. A port is the location where you send data. IP handles thecomputer-to-computer delivery. After the datagram reaches the destination computer, UDP moves the datagram to its destination port. If the destination port is not open, UDP discards the datagram. UDP shares the same delivery problems of IP.Use UDP in applications in which reliability is not critical. For example, an application might transmit informative data to a destination frequently enough that a few lost segments of data are not problematic.LabVIEW™, National Instruments™, and ™ are trademarks of National Instruments Corporation. Product and company names mentioned herein are trademarks or trade names of their respective companies. For patents covering National Instruments products, refer to the appropriate location: Help»Patents in your software, thepatents.txt file on your CD, or /patents.342028C-01 © 2000–2004 National Instruments Corporation. All rights reserved. March 2004Using UDP in LabVIEWBecause UDP is not a connection-based protocol such as TCP, you do not need to establish a connection with a destination before you send or receive data. Instead, you specify the destination for the data when you send each datagram. Operating systems do not report transmission errors.Use the UDP Open function to open a UDP socket on a port. The number of simultaneously open UDP ports dependson the operating system. The UDP Open function returns a network connection refnum that uniquely identifies theUDP socket. Use this connection refnum to refer to this socket in subsequent VI calls.Use the UDP Write function to send data to a destination, and use the UDP Read function to read that data. Each write operation requires a destination address and port. Each read operation contains the source address and port. UDP preserves the datagram bytes that you specified for each command you send.In theory, you can send datagrams of any size. However, you typically would not use UDP to send large datagrams because it is not as reliable as TCP.When you finish all communications on a port, use the UDP Close function to free system resources.UDP MulticastYou can use the UDP functions to communicate to a single client (single-cast) or to all computers on the subnet througha broadcast. If you want to communicate to multiple specific computers, you must configure the UDP functions to iterate through a list of clients. Using this technique creates duplicate network traffic because LabVIEW sends a separate copy of the data to each client and maintains a list of clients interested in receiving the data.Use multicasting to communicate between a single sender and multiple clients on a network without requiring the sender to maintain a list of clients or send multiple copies of the data to each client. To receive data broadcast by a multicast sender, all clients must join a multicast group. The sender does not have to join a group to send data. The sender specifies a multicast IP address, which defines a multicast group. Multicast IP addresses are in the 224.0.0.0to 239.255.255.255 range. When a client wants to join a multicast group, it subscribes to the multicast IP addressof the group. After subscribing to a multicast group, the client receives data sent to the multicast IP address.To multicast in LabVIEW, use the UDP Multicast Open VI to open connections capable of reading, writing, or reading and writing UDP data. Specify the time-to-live (TTL) for writing data, the multicast address for reading data, and the multicast port number for reading and writing data. The default TTL is 1, which means LabVIEW sends the datagram only to the local subnet. When a router receives a multicast datagram, it decrements the datagram TTL. If the TTL is greater than 1, the router forwards the datagram to other routers. The following table lists what action occurs to a multicast datagram when you specify a value for the time-to-live parameter.Datagram remains on the host computer.1 Datagram sent to every client on the same local subnet that subscribes to that IP address. Hubs/repeatersand bridges/switches forward the datagram. Routers do not forward the datagram if the TTL is 1.Application Note 160 2 If you specify a value greater than 1, the datagram is sent and routers forward it through TTL-1 layers.Refer to the UDP Multicast Receiver VI and the UDP Multicast Sender VI in the labview\examples\comm\UDP.llb for examples of using UDP multicasting.TCPTCP ensures reliable transmission across networks, delivering data in sequence without errors, loss, or duplication.TCP retransmits the datagram until it receives an acknowledgment.System RequirementsBefore using TCP/IP, confirm that you have the necessary requirements, which vary depending on the platform you use.(Windows and UNIX) TCP/IP is built in. You do not need to use a third-party product to communicate using TCP/IP.If your network is configured properly, LabVIEW requires no additional setup.(Mac OS) LabVIEW networking requires Open Transport, included in Mac OS 7.5 and later.Using TCP in LabVIEWTCP is a connection-based protocol, which means that sites must establish a connection before transferring data. TCP permits multiple, simultaneous connections.You initiate a connection by waiting for an incoming connection or by actively seeking a connection with a specified address. In establishing TCP connections, you have to specify the address and a port at that address. A number between 0 and 65,535 represents a port. UNIX reserves port numbers less than 1,024 for privileged applications. Different ports at a given address identify different services at that address.Use the TCP Open Connection function to actively establish a connection with a specific address and port. If the connection is successful, the function returns a network connection refnum that uniquely identifies that connection.Use this connection refnum to refer to the connection in subsequent VI calls.You can use the following techniques to wait for an incoming connection:Use the TCP Listen VI to create a listener and wait for an accepted TCP connection at a specified port. If theconnection is successful, the VI returns a connection refnum, the address, and the port of the remote TCP client.Use the TCP Create Listener function to create a listener and use the TCP Wait on Listener function to listen for and accept new connections. The TCP Wait on Listener function returns the same listener ID you wired to the function and the connection refnum for a connection. When you finish waiting for new connections, use the TCP Close Connection function to close a listener. You cannot read from or write to a listener.The advantage of using the second technique is that you can use the TCP Close Connection function to cancel a listen operation, which is useful when you want to listen for a connection without using a timeout, but you want to cancel the listen when another condition becomes true. You can close the listen VI at any time.When you establish a connection, use the TCP Read function and the TCP Write function to read and write data to the remote application.Use the TCP Close Connection function to close the connection to the remote application. If unread data remains and the connection closes, you might lose data. Use a higher level protocol for your computer to determine when to close the connection. After a connection is closed, you cannot read from it or write to it again.© National Instruments Corporation 3 Application Note 160Deciding between TCP and UDPTCP is the best protocol to use if you want reliable data transmission. UDP is a connectionless protocol with higher performance, but it does not ensure reliable data transmission.Creating a TCP ClientNote Refer to the LabVIEW Help for the most recent version of these instructions and details for each of thefunctions.Complete the following steps to create a TCP client using the TCP functions.1. Use the TCP Open Connection function to open a connection to a server. Y ou must specify the Internet address ofthe server and the port for the server.The address identifies a computer on the network. The remote port identifies a communication channel on the computer that the server uses to listen for communication requests. When you create a TCP server, you specify the port that you want the server to use for communication.2. Use the TCP Write function to send a message to a server.3. Use the TCP Read function to read a message from the server. Y ou must specify the number of bytes you want toread.4. Use the TCP Close Connection function to close the connection to the server.Refer to the Simple Data Client VI in the labview\examples\comm\TCP.llb for an example of a TCP client. Timeouts and ErrorsWhen you design a network application, consider carefully what should happen if something fails. For example, if the server crashes, determine how each client VI handles it.One solution is to make sure that each client VI has a timeout. If something fails to produce results after a certain amount of time, the client continues execution. In continuing, the client can try to reestablish the connection or report the error. If necessary, the client VI can shut down the application.Creating a TCP ServerNote Refer to the LabVIEW Help for the most recent version of these instructions and details for each of thefunctions.Complete the following steps to create a TCP server using the TCP functions.1. Use the TCP Listen VI to wait for a connection. You must specify the port. This port must be the same port that theclient attempts to access.2. If a connection is established, use the TCP Read function to read from that port to retrieve a message.3.Use the TCP Write function to return results. The data must be in a form that the client can accept. 4. Use theTCP Close Connection function to close the connection.Refer to the Simple Data Server VI in the labview\examples\comm\TCP.llb for an example of a TCP server. TCP and UDP ExamplesRefer to the labview\examples\comm\TCP.llb and the labview\examples\comm\UDP.llb for examples of using the TCP and UDP VIs and functions.。

通信类外文文献翻译

通信类中英文翻译、外文文献翻译

通信类英文文献

数据通信 毕业论文外文文献英文翻译

通信工程外文资料翻译2篇

[最新]通信专业的外文及外文翻译

通信类英文文献及翻译

通信技术类英文文献

通信工程外文文献

数据通信毕业论文外文文献英文翻译