CDMA Technology Overview

CDMA Technology Overview目录CDMA TECHNOLOGY (2)2G - CDMAONE (2)3G - CDMA2000 (4)3G - CDMA2000 1X (6)3G - CDMA2000 1XEV-DO TECHNOLOGIES (8)CDMA2000 1XEV-DO RELEASE 0 (8)CDMA2000 1XEV-DO REVISION A (REV A) (9)CDMA2000 1XEV-DO REVISION B (11)3G - ULTRA MOBILE BROADBAND (11)CDMA TechnologyThe world is demanding more from wireless communication technologies than ever before as more people around the world are subscribing to wireless. Add in exciting Third-Generation (3G) wireless data services and applications - such as wireless email, web, digital picture taking/sending, assisted-GPS position location applications, video and audio streaming and TV broadcasting - and wireless networks are doing much more than just a few years ago.This is where CDMA technology fits in. CDMA consistently provides better capacity for voice and data communications than other commercial mobile technologies, allowing more subscribers to connect at any given time, and it is the common platform on which 3G technologies are built.CDMA is a "spread spectrum" technology, allowing many users to occupy the same time and frequency allocations in a given band/space. As its name implies, CDMA (Code Division Multiple Access) assigns unique codes to each communication to differentiate it from others in the same spectrum. In a world of finite spectrum resources, CDMA enables many more people to share the airwaves at the same time than do alternative technologies.The CDMA air interface is used in both 2G and 3G networks. 2G CDMA standards are branded cdmaOne and include IS-95A and IS-95B. CDMA is the foundation for 3G services: the two dominant IMT-2000 standards, CDMA2000 and WCDMA, are based on CDMA.cdmaOne: The Family of IS-95 CDMA TechnologiescdmaOne describes a complete wireless system based on the TIA/EIA IS-95 CDMA standard, including IS-95A and IS-95B revisions. It represents the end-to-end wireless system and all the necessary specifications that govern its operation. cdmaOne provides a family of related services including cellular, PCS and fixed wireless (wireless local loop).CDMA2000: Leading the 3G revolutionCDMA2000 represents a family of ITU-approved, IMT-2000 (3G) standards and includes CDMA2000 1X and CDMA2000 1xEV technologies. They deliver increased network capacity to meet growing demand for wireless services and high-speed data services. CDMA2000 1X was the world's first 3G technology commercially deployed (October 2000).CDMA DeploymentsCDMA is the fastest growing wireless technology and it will continue to grow at a faster pace than any other technology. It is the platform on which 2G and 3G advanced services are built.2G - cdmaOnecdmaOne: The Family of IS-95 CDMA TechnologiescdmaOne describes a complete wireless system based on the TIA/EIA IS-95 CDMA standard, including IS-95A and IS-95B revisions. It represents the end-to-end wireless system and all the necessary specifications that govern its operation. cdmaOne provides a family of related services including cellular, PCS and fixed wireless (wireless local loop).IS-95A: The first CDMA cellular standardTIA/EIA IS-95 (Telecommunications Industry Association / Electronic Industries Association Interim Standard - 95) was first published in July 1993. The IS-95A revision was published in May 1995 and is the basis for many of the commercial 2G CDMA systems aroundthe world. IS-95A describes the structure of the wideband 1.25 MHz CDMA channels, power control, call processing, hand-offs, and registration techniques for system operation. In addition to voice services, many IS-95A operators provide circuit-switched data connections at 14.4 kbps. IS-95A was first deployed in September 1995 by Hutchison (HK).IS-95B: 2.5GThe IS-95B revision, also termed TIA/EIA-95, combines IS-95A, ANSI-J-STD-008 and TSB-74 into a single document. The ANSI-J-STD-008 specification, published in 1995, defines a compatibility standard for 1.8 to 2.0 GHz CDMA PCS systems. TSB-74 describes interaction between IS-95A and CDMA PCS systems that conform to ANSI-J-STD-008. Many operators that have commercialized IS-95B systems offer 64 kbps packet-switched data, in addition to voice services. Due to the data speeds IS-95B is capable of reaching, it is categorized as a 2.5G technology. cdmaOne IS-95B was first deployed in September 1999 in Korea and has since been adopted by operators in Japan and Peru.cdmaOne Network diagram2G - cdmaOne AdvantagesWhen implemented in a cellular network, cdmaOne technology offers numerous benefits to the cellular operators and their subscribers:1.Capacity increases of 8 to 10 times that of an AMPS analog system and 4 to 5 times thatof a GSM system2.Improved call quality, with better and more consistent sound as compared to AMPSsystems3.Simplified system planning through the use of the same frequency in every sector ofevery cell4.Enhanced privacy5.Improved coverage characteristics, allowing for the possibility of fewer cell sites6.Increased talk time for portables7.Bandwidth on demand3G - CDMA2000Third Generation (3G) is the term used to describe the latest generation of mobile services which provide advanced voice communications and high-speed data connectivity, including access to the Internet, mobile data applications and multimedia content. The International Telecommunication Union (ITU), working with industry standards bodies from around the world, has defined the technical requirements and standards as well as the use of spectrum for 3G systems under the IMT-2000 (International Mobile Telecommunications-2000) program.The ITU requires that IMT-2000 (3G) networks, among other capabilities, deliver improved system capacity and spectrum efficiency over 2G systems and that they support data services at minimum transmission rates of 144 kbps in mobile (outdoor) and 2 Mbps in fixed (indoor) environments.Based on these requirements, in 1999 the ITU approved five radio interface modes for IMT-2000 standards (Recommendation 1457). Three of the five approved standards (CDMA2000®, TD-SCDMA, WCDMA) are based on CDMA. CDMA2000 is also known by its ITU name, IMT-2000 CDMA Multi-Carrier (MC).The world's first 3G commercial system was launched by SK Telecom (South Korea) in October 2000 using CDMA2000 1X. By the end of 2006 there will be more than 430 million 3G users across all six continents, In Korea, Japan and North America there are already more 3G users than 2G subscribers, and globally the number of 3G subscribers is expected to surpass 2G in 2011, ten years since 3G’s inception and 5 years less than it took 2G to surpass 1G.CDMA2000 TechnologiesCDMA2000 represents a family of standards and includes:CDMA2000 builds on the inherent advantages of CDMA technologies and introduces other enhancements, such as Orthogonal Frequency Division Multiplexing (OFDM and OFDMA), advanced control and signaling mechanisms, improved interference management techniques, end-to-end Quality of Service (QoS), and new antenna techniques such as Multiple Inputs Multiple Outputs (MIMO) and Space Division Multiple Access (SDMA) to increase data throughput rates and quality of service, while significantly improving network capacity and reducing delivery cost.Key features of CDMA2000 are:∙Leading performance: CDMA2000 performance in terms of data-speeds, voice capacity and latencies continue to outperform in commercial deployments other comparable technologies∙Efficient use of spectrum: CDMA2000 technologies offer the highest voice capacity and data throughput using the least amount of spectrum, lowering the cost of delivery for operators and delivering superior customer experience for the end users ∙Support for advanced mobile services: CDMA2000 1xEV-DO enables the delivery of a broad range of advanced services, such as high-performance VoIP, push-to-talk, video telephony, multimedia messaging, multicasting and multi-playing online gaming with richly rendered 3D graphics∙All-IP – CDMA2000 technologies are compatible with IP and ready to support network convergence. Today, CDMA2000 operators that have deployed IP-based services enjoy more flexibility and higher bandwidth efficiencies, which translate into greater control and significant cost savings∙Devices selection: CDMA2000 offers the broadest selection of devices and has a significant cost advantage compared to other 3G technologies to meet the diverse market needs around the world∙Seamless evolution path : CDMA2000 has a solid and long-term evolution path which is built on the principle of backward and forward compatibility, in-band migration, and support of hybrid network configurations∙Flexibility:CDMA2000 systems have been designed for urban as well as remote rural areas for fixed wireless, wireless local loop (WLL), limited mobility and full mobilility applications in multiple spectrum bands, including 450 MHz, 800 MHz, 1700 MHz, 1900Mhz and 2100 MHzCDMA2000 Advantages∙Superior Voice Clarity∙High-Speed Broadband Data Connectivity∙Low End-to-End Latency∙Increased Voice and Data Throughput Capacity∙Time-to-Market Performance Advantage∙Long-Term, Robust and Evolutionary Migration Path with Forward and Backward Compatibility∙Differentiated Value-Added Services such as VoIP, PTT, Multicasting, Position Location, etc.∙Flexible Network Architecture with connectivity to ANSI-41, GSM-MAP and IP-based Networks and flexible Backhaul Connectivity (see the text at the end – we can do that later)∙Application, User and Flow-based Quality of Service (QoS)∙Flexible Spectrum Allocations with Excellent Propagation Characteristics∙Robust Link Budget for Extended Coverage and Increased Data Throughputs at the Cell Edge∙Multi-mode, Multi-band, Global Roaming∙Improved Security and Privacy∙Lower Total Cost of Ownership (TCO)3G - CDMA2000 1XCDMA2000 1X (IS-2000) was recognized by the International Telecommunications Union (ITU) as an IMT-2000 standard in November 1999. It was the first IMT-2000 technology deployed worldwide, in October 2000.1X is the most spectrally efficient wide area network technology for circuit-switched voice communications and it supports packet data speeds of up to 307 kbps in a single 1.25 MHz channel.Key features of CDMA2000 1X include:∙Voice Capacity: Supports 33-35 up to 40 simultaneous voice calls per single 1.25 MHz FDD channel. A new codec, 4GV, for CDMA2000 1X will increase voice capacity by 40%.∙High-Speed Data: Release 0 supports bi-directional peak data rates of up to 153 kbps and an average of 60-100 kbps in commercial networks in a 1.25 MHz channel. Release 1 can deliver peak data rates of up to 307 kbps.∙Applications:Supports circuit-switched voice, short messaging service (SMS), multimedia messaging service (MMS), games, GPS-based location services, music and video downloadsCDMA2000 1X handsets are backwards compatible with cdmaOne systems.CDMA2000 network diagramThe following fundamental CDMA air interface techniques are incorporated into CDMA2000 1X and backward compatible with cdmaOne:∙Direct Sequence Spread Spectrum Multiple Access–to improve spectral efficiency (system capacity)∙Orthogonal Code Channelization–for user separation on the downlink (mitigates interference)∙Random Access–to efficiently share radio access resources among all users∙Fast Uplink Power Control–to resolve the near-far field effect (reduce interference) ∙Rake Receivers–to resolve and benefit from multipath interference and support soft handoffs∙Soft Handoff– to handoff users between base stations∙Softer Handoff – to handoff users between base station sectors∙Soft Handoff (SHO) Active Set –to provide seamless service with increased spectral efficiency∙Single Frequency Re-use– to increase overall network capacity∙Downlink Slotted Paging – to extend the battery life of mobile devices∙Blind Rate Detection – to enable variable rate decoding without additional overhead ∙Downlink Reference Channel – to share a common pilot to increase capacity∙Downlink Channel Structure–to simplify system implementation and efficiency by separating channels with Walsh codes∙Scrambling– to provide communications privacy∙Speech Regulated Vocoders– to reduce interference and increase system capacityIn addition to the above techniques shared with cdmaOne, CDMA2000 1X incorporates the following new evolutionary air interface techniques that are crucial to enhancing the performance of the standard:∙Variable Length Orthogonal Codes – to support variable data rates∙Uplink Complex Spreading –to increase data rates and network capacity∙Fast Downlink Power Control – to reduce transmit power usage and increase capacity ∙Data Rate Configurable Channels–to support applications that use a variety of data rates∙Dual-Event Downlink Paging– to further extend the battery life of mobile devices∙Uplink Channel Structure– to multiplex control and data channels∙Reserve Mode Random Access– to access the network more efficiently∙Parallel Turbo Codes–to improve capacity through more efficient forward error correction∙Coherent Uplink Detection – to improve data rates and coverage∙Continuous Uplink Operation–to increase transmission range and capacity, while reducing interference to hearing aids and other devices3G - CDMA2000 1xEV-DO TechnologiesCDMA2000 1xEV-DO (Evolution-Data Optimized) introduces new high-speed packet-switched transmission techniques that are specifically designed and optimized for a data-centric broadband network that can deliver peak data rates beyond 2 Mbps in a mobile environment. CDMA2000 1xEV-DO was approved as an IMT-2000 standard (cdma2000 High Rate packet Data Air∙Broadband data: Provides a peak data rate of 2.4 Mbps in the forward link and 153 kbps in the reverse link in a single 1.25 MHz FDD carrier. In commercial networks, Rel 0 delivers average throughput of 300-700 kbps in the forward link and 70-90 kbps in the reverse link∙Offers an "always on" user experience∙Leverages the existing suite of Internet Protocols (IP), and hence supports IP-based network connectivity and software applications∙Applications: Supports broadband data applications, such as broadband Internet or VPN access, MP3 music downloads, 3D gaming, TV broadcasts, video and audio downloads.In many countries, it has been deployed as a DSL substitute.In most all cases, CDMA2000 1xEV-DO devices include a CDMA2000 1X modem to be compatible with CDMA2000 1X and cdmaOne systems.CDMA2000 1xEV-DO Release 0 network diagramIn addition to the air interface techniques described in the previous section on CDMA2000 1X, the following new high-speed packet data transmission enhancements are incorporated into CDMA2000 1xEV-DO Rel 0:∙High-Speed Packet-Switched Downlink Channelization Structure–bundling downlink resources into a packet data channel to enable high-speed data rate transmissions by combining all of the available Walsh codes and power ∙Fast and Adaptive Modulation and Coding Schemes–to optimize the delivery of packets based on changes in the radio environment∙Fast and Adaptive Packet Data Scheduling– to rapidly adapt to changes in the radio link∙Fast Hybrid ARQ – to acknowledge correct receipt of data and retransmit erroneous data ∙Incremental Redundancy Feedback in the Downlink –to increase the effective data rate in the uplink by terminating the transmission of a packet early if it is decoded earlier than expected∙Fast Downlink Rate Control– to rapidly adjust to changes in the radio environment ∙Uplink Rate Control– to efficiently control the transmission of mobile devices∙Downlink Multiple User Separation–to efficiently assign the downlink channel to users∙Downlink Transmission Signaling– to indicate the downlink modulation and coding ∙Closed Loop Downlink Power Control– to reduce power used by the base station∙Uplink Rate Detection– to enable correct decoding of uplink data traffic∙Short Transmission Time Intervals (TTI)– to accelerate the transmission of packetsCDMA2000 1xEV-DO Revision A (Rev A)Rev A is an evolution of CDMA2000 1xEV-DO Rel 0 that increases peak rates on reverse and forward links to support a wide-variety of symmetric, delay-sensitive, real-time, and concurrent voice and broadband data applications. It also incorporates OFDM technology to enable multicasting (one-to-many) multimedia content delivery.Rev. A’s more symmetric uplink speeds enable users to send large files, email with attachments, high resolution photographs and personal videos from their mobile devices. With its low network latency, service tiering with Quality of Service (QoS) and IP-based broadband architecture, Rev Ais able to support time-sensitive applications, such as Voice over IP (VoIP), Push-to-Talk (PTT) and video telephony. Rev A was launched in October 2006, and it is the only All-IP, advanced broadband technology commercially deployed today.Key features of Rev A include:∙Improved broadband speeds : Provides a peak data rate of 3.1 Mbps in the forward link and 1.8 Mbps in the reverse link in a 1.25 MHz FDD carrier. In commercial networks, Rev A achieves average throughput of 450-800 kbps in the forward link and 300-400 kbps in the reverse link∙Higher spectral efficiency : Supports1.2 times Rel 0 forward link sector capacity and3.4 times reverse link sector capacity. Increased rate quantization on both forward and reverse link enables more efficient use air link resources, better network utilization and lower cost of delivery∙Increased Capacity –On both the forward and reverse link, Rev A allows operators to support more users and it improves the cost of delivering voice, data and multimedia services.∙Symmetry –By increasing uplink speeds, Rev A is the first commercially available wireless technology to deliver a true synchronic broadband experience. Symmetry is important for applications where users send packets of data as often as they receive them, such as receiving and sending email with attachments.∙Low latency : The average latency of Rev A is below 50 milliseconds, making it ideal for delay-sensitive applications.∙Advanced Quality of Service (QoS) mechanisms that support the prioritization and delivery of individual packets based on the type of application or user profile. These mechanisms ensure a consistent, high-quality user experience.∙All-IP: Internet Protocol (IP) is the foundation for CDMA2000 radio access networks.Like 1xEV-DO Rel 0, All-IP Rev A networks provide operators service flexibility and higher bandwidth efficiencies, which translate into greater control and significant cost savings.∙Advanced services: Enables the enhanced performance of real-time broadband, symmetric data link, and delay sensitive services such as VoIP, push-to-talk (PTT), push-to-media (PTM), video conferencing, multicasting, and rich 3D gaming with multiple players.∙Backward compatibility:Rev A networks support existing Rel 0 applications and devices. This backward compatibility preserves an operator’s previous network investments. Rev A it is backwards compatible with 1X and cdmaOne systems through multi-mode devices .In addition to the air interface techniques used in CDMA2000 1X and 1xEV-DO Rel 0, the following new high-speed packet-switched uplink techniques are incorporated into CDMA2000 1xEV-DO Rev A:∙Fast Uplink Rate Control– to efficiently control the transmission of mobile devices∙Fast Hybrid ARQ in Uplink–to acknowledge correct receipt of data and retransmit erroneous data∙Incremental Redundancy Feedback in Uplink– to increase the effective data rate in the downlink by terminating the transmission of a packet early if it is decoded earlier than expected∙Uplink Channelization– to enable better control of the uplink data flows∙Short Transmission Time Interval (TTI)– to accelerate the transmission of packetsCDMA2000 1xEV-DO Revision BThe Revision B (Rev B) is an evolutionary step of Rev A that consists of aggregating multiple EV-DO Rev A channels to provide higher performance for multimedia delivery, bi-directional data transmissions and VoIP-based concurrent services. The Rev B standard was published by the Third Generation Partnership Project 2 (3GPP2) under document number 3GPP2 C.S0024-B and by the Telecommunications Industry Association (TIA) and Electronics Industry Association as TIA/EIA/IS-856-B. Rev B will be commercially available in 2008.Rev B builds on the efficiencies of Rev A by introducing the concept of dynamically scalable bandwidth. Through aggregation of multiple 1.25 MHz Rev A channels, Rev B enables data traffic to flow over more than one carrier and hence improve user data rates, latencies on both forward and reverse link. Peak data rates are proportional to the number of carriers aggregated. When 15 channels are combined within a 20 MHz bandwidth, Rev B delivers peak rates of 46.5 Mbps in forward link and 27 Mbps in the reverse link. With the 64-QAM scheme, the peak data rate in the forward link increase in a single 1.25 MHz carrier to 4.9 Mbps, an aggregated 5 MHz will deliver up to 14.7 Mbps and within 20 MHz of bandwidth up to 73.5 Mbps. By increasing the bandwidth, an operator can support more users per sector or lower their cost per megabyte to encourage longer usage. To achieve this performance, the 1.25 MHz carriers do not have to be adjacent to one another, thus giving operators the flexibility to combine blocks of spectrum from different bands. This is unique benefit of Rev B that is not available to WCDMA/HSDPA.In addition to supporting mobile broadband data and OFDM-based multicasting, the lower latency characteristics of Rev B improve the performance of delay-sensitive applications such as VoIP, push-to-talk, video telephony, concurrent voice and multimedia and multiplayer online gaming. Rev. B also allows operators to consider the deployment of “hot zones” where the demand for data is high.3G - Ultra Mobile BroadbandUltra Mobile Broadband (UMB) is a breakthrough technology which will support the ITU’s vision for next generation services. It combines the best aspects of CDMA, TDM, LS-OFDM, OFDM, and OFDMA into a single air interface using advanced and highly optimized control and signaling mechanisms. It also incorporates advanced antenna techniques such as MIMO and SDMA. The combination of these techniques enables UMB to achieve higher peak data rates, very low latency and very high spectral efficiency. The technology has a flexible and dynamic mode of operation to combine and allocate spectrum as needed for the variety of user applications and activities.The UMB standard is currently being developed by the 3GPP2 with the publication scheduled for April 2007 and commercial availability in early 2009.Key Features of UMB include:∙Multiple radio and advanced antenna techniques∙Sophisticated control and signaling mechanisms (minimized) combine the best aspects of CDMA, TDM, OFDM, and OFDMA into a single air interface ∙Multiple Input Multiple Output (MIMO) and Space Division Multiple Access (SDMA)∙Improved interference management techniques∙Ultra-high mobile broadband peak data rates∙Up to 280Mbps peak data rate on forward link∙Up to 68Mbps peak data rate on reverse link∙Ultra-low network latency∙An average of 16.8 msec (32-byte, RTT) end-to-end network latency ∙Enhanced VoIP capacity and user experience∙Up to 500 simultaneous VoIP users (10 MHz FDD allocations) ∙Scalable IP-based flat or hierarchical architecture∙Greater service deployment flexibility, improved performance, and lower cost of ownership∙Flexible spectrum allocations∙Scalable, non-contiguous and dynamic channel (bandwidth) allocations∙Support for bandwidth allocations of 1.25 MHz, 5 MHz, 10 MHz and 20 MHz ∙Less power consumption∙Improved battery life。