Mobile Evolution to 3G         Third Generation Mobile System (3G):                                   Cdma2000       1) IN...
Mobile Evolution to 3G                                              UMTSComputer data                     Telecommunicatio...
Mobile Evolution to 3G    1.2) Technical requirement and radio environment                                                ...
Mobile Evolution to 3G1.3) Comparison between 2G &2.5G and 3G     Aspects                         2G                  2.5G...
Mobile Evolution to 3GCommonality for          They are primary The same as 2G         A key objectivedifferent           ...
Mobile Evolution to 3G        Type of                   Use only circuit          Use packet and            Use packet and...
Mobile Evolution to 3GProgressing from the previous two generations, the technologies for the (3G)mobile system have been ...
Mobile Evolution to 3G1.5.1) Paradigm Shifts in Third-Generation SystemsWireless data transmission via mobile system offer...
Mobile Evolution to 3G1.6) W-CDMA and cdma2000        The CDMA- based 3G standards selected from numerous proposals to    ...
Mobile Evolution to 3G                                           Table 9.3      The impact of system normalized spectrum e...
Mobile Evolution to 3GOHG’s efforts have result in:    • A direct spread mode with 3.84Mcps for new frequency bands,      ...
Mobile Evolution to 3G       • Direct sequencing (DS) frequency division duplex (FDD) mode 1       • Multi-carrier (MC) FD...
Mobile Evolution to 3G1) The local bearer service provides a connection between terminalequipment (TE) and mobile equipmen...
Mobile Evolution to 3G        2) Reverse LinkIn CDMA 2000 we have seven different radio configurations, to accommodatediff...
Mobile Evolution to 3G                                     1500, 2700, 4800, 9600, 19200, 38400, 76800, and      5        ...
Mobile Evolution to 3G        The cdma2000 system provides a continuous waveform for all data rates.        This includes ...
Mobile Evolution to 3GHadamard sequences make useful sets for wireless-CDMA. Walsh functions aregenerated by mapping codew...
Mobile Evolution to 3Gappropriate spreading code according to the transmission rate. However, a code inthe code tree can b...
Mobile Evolution to 3GThus, the amplitude of the resulting signal I + jQ is the product of amplitude ofboth the signals an...
Mobile Evolution to 3GUPLINK SPREADING WITH MORE DETAILS                                     ٢٠
Mobile Evolution to 3G2) MULTICARRIER SPREADING ONLY AT BASE STATIONVariable data rate capacity, essential for next genera...
Mobile Evolution to 3Gdownlink), while complex scrambling helps in equalizing power in the I & Qbranches        2.1.3) Rat...
Mobile Evolution to 3G         interleaved and may have different transmit power levels and frame error         rate set p...
Mobile Evolution to 3G         The cdma2000 reverse link includes a separate low rate, low power,         continuous, orth...
Mobile Evolution to 3Gchip rate systems are denoted as 3X, 6X, 9X, and 12X and they arerespectively operated at 3.6864, 7....
Mobile Evolution to 3G      The Reverse Dedicated Channel may be used for the transmission of user      traffic, control, ...
Mobile Evolution to 3G3X, and 6X). R-SCH1 is mapped to the I Channel and R-SCH2 is mappedto the Q channel.Additional Suppl...
Mobile Evolution to 3G                                            Reverse Dedicated Channel                           Wals...
Mobile Evolution to 3G2.3.2) Reverse Pilot Channel (R-PICH)        The Pilot Channel for the Reverse Dedicated Channels co...
Mobile Evolution to 3G       Figure 6, Figure 7, and Figure 8 describe the modulation for the Reverse       Fundamental Ch...
Mobile Evolution to 3G    In the second mode, the high data rate modes can have convolutional    coding with K = 9, or tur...
Mobile Evolution to 3G Channel   Bits                        Add               Add 8              Add                     ...
Mobile Evolution to 3G                      Reverse Fundamental Channel and Reverse Supplemental Channel Structure for Rad...
Mobile Evolution to 3G      There can be one or more access channels per frequency assignment.      Different access chann...
Mobile Evolution to 3GEach Access Channel frame contains 96 bits (20 ms frame at 4800 bps).Each Access Channel frame shall...
Mobile Evolution to 3GThe Access Channel preamble shall consist of frames of 96 zeros that aretransmitted at the 4800 bps ...
Mobile Evolution to 3GThe Enhanced Access Channel uses a random-access protocol. EnhancedAccess Channels are uniquely iden...
Mobile Evolution to 3G        An Enhanced Access Channel frame of 20, 10, or 5 ms duration shall        begin only when Sy...
Mobile Evolution to 3GEnhanced Access Channel Frame Structure for the Enhanced AccessHeader                               ...
Mobile Evolution to 3G                           Enhanced Access Channel Frame Structure                                  ...
Mobile Evolution to 3GI and Q Mapping for Enhanced Access Channel, Reverse Common Control Channel, and Reverse Traffic Cha...
Mobile Evolution to 3G         Channel Structure for the Data on the Enhanced Access Channel and the                    Re...
Mobile Evolution to 3GPilot Channel associated with the Reverse Access Channels consists of anall ‘0’ channel.The Access p...
Mobile Evolution to 3G2.5) Slotting and Channel Arrangement      Access probe transmissions are slotted. The slot is long ...
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
Third Generation Mobile System (3G): Cdma2000
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Third Generation Mobile System (3G): Cdma2000

  1. 1. Mobile Evolution to 3G Third Generation Mobile System (3G): Cdma2000 1) INTRODUCRTION:1.1) Market requirements and services for 3G mobile radio system 2G are very successful world wide in providing services to users. But the customer base increasing much faster than initially expected. UMTS expecting around 400 million mobile subscribers world wide in year 2000, and about 1800 million subscribers in the year 2010, However 2G are limited in maximum data rates, also high percentage of mobile multimedia users will increase after year 2000. UMTS also expected in 2010 that 60% of the traffic in Europe would be created by mobile multimedia. A similar growth of mobile data traffic is expects in worldwide. Market requirements need more advanced services than current voice and low data rate services. Market requirements are classified in three different sections: ١
  2. 2. Mobile Evolution to 3G UMTSComputer data Telecommunication audio- video content• Computer data • Mobility • Video on• E-mail • Video demand• Real time image conferencing • Interactive transfer • GSM, ISDN video services• Multimedia service • Electronic document transfer • Video newspaper• Mobile telephony • Telescoping computing • Wide band data • Value-added services internet services Fig 1 Future service will range from low up to high user data rate (maximum 2Mbps for IMT-2000/UMTS systems). The transmission of, for example, a large presentation of a size of 16Mbps would need 8 second with a 2Mbps service compared to current data transmission in GSM with 9.6Kbps, where 28 minutes would be necessary ٢
  3. 3. Mobile Evolution to 3G 1.2) Technical requirement and radio environment Mbps 10 M Wireless terminal 1.0 0.1 3G uniting FDD- and TDD-services 2G FDD: e.g. GSM, IS-136, IS-95 CDMA, 2G TDD: PDC E.g. DECT, PHS 0.01 Office or room Building stationary Pedestrian vehicular Indoor Outdoor Fig 2These market requirements and services need results in international technicalrequirement for ongoing definition of third generation mobile radio systems. High data rates requirements are up to at least 144Kbps in vehicular up to at least 384Kbps in outdoor to indoor, and up to 2Mbps indoor and picocell environment. Circuit-switched and packet-switched services for symmetric and asymmetric need to be supported. Third generation systems will operates in all radio environments. In addition, the ability for global roaming has to be supported in the system design. ٣
  4. 4. Mobile Evolution to 3G1.3) Comparison between 2G &2.5G and 3G Aspects 2G 2.5G 3G Frequency band They operates at The same as 2G Use of common multiple global frequency frequency bands, band from 800 MHz ,900 1885 to 2025 MHz (cellular MHz and band) and in from 2110 to 1.5GHz, 1.8GHz 2200 MHz (PCS band) Roaming Generally limited The same as 2G Improved in to specific region global roaming due to the use of due to the use of SIM, and UIM common global modules frequency. facilitating border roaming capability Data services Good for voice , Good for voice. Perfect for voice, but limited in But improved in support many data application data services by data services less than 32kbps using GPRS that than 2G and can operates at 2.5G, from 172kbps, EDGE 144kbps in that can operates mobility till a1t 384kbps 2Mcps indoor Digital modulation Use Gaussian GPRS is the Use quadrate phase minimum shift same like GSM, shift keying keying (GMSK) EDGE use 8 for GSM , and phase shift (QPSK) 64 array keying (8PSK) orthogonal modulation for IS-95 ٤
  5. 5. Mobile Evolution to 3GCommonality for They are primary The same as 2G A key objectivedifferent optimized for is maximizingoperating specific the commonalityenvironment operating optimization of environment radio (e.g. vehicular & interference for pedestrian and multiple may assign for operating fixed wireless environment, access (FWA) (e.g. vehicular, pedestrian, office, FWA and satellite operation)Quality of Limited quality of Improved QOS Better QOS haveservices services due to compared to 2G 4 classes and presence of(QOS) but still didn’t differ for the blocking, limited capacity meet the market type of data requirement application used. Conversational class used for (e.g. voice call) and streaming class used for (e.g. video on demand) these two classes are used for delay sensitive application. Interactive class used for (e.g. e- mail and telnet) and background class used for (e.g. downloading) the last two types of QOS used for delay insensitive application. ٥
  6. 6. Mobile Evolution to 3G Type of Use only circuit Use packet and Use packet and switching switching circuit switching circuit switching Table 11.4) 2G to 3G Evolution GSM Associations ETSI associatio T1 UWCC TIA CDG 2G GSM TDMA IS-95 IS-136 2.5G GPRS/EDGE 1XRTT HDR 3G W-CDMA UWC-136 Cdma2000 3G harmonization 3GPP UWCC 3GPP2 Group Fig 3As we saw from this flow chart that there is three systems for the secondgeneration. GSM from Europe and IS-136 from America that is working overlaidon the old analog system AMPS, and the third one is IS-95 that is completelydigital. And the two main proposals those will path for the 3G Is w-CDMA from Europe, and cdma2000 from America, which is multi- carrier from IS-95? That will be explained later.1.5) Standardizing comminute for 3G mobileInternational Mobile Telecommunications 2000 (IMT-2000), a representativename for third generation (3G) mobile communication system, aims to providean effective solution for the next-generation mobile services. ٦
  7. 7. Mobile Evolution to 3GProgressing from the previous two generations, the technologies for the (3G)mobile system have been significantly improved in terms of system capacity,voice quality, and ease of use.3G systems are expected to offer better system capacity and higher data ratetransmission speed to support wireless Internet access and wire-less multimediaservices (including audio, video and images). To bridge 2G technologies to 3Gtechnologies. EDGE and GPRS were introduced; they are typically referred to as2.5G technologies.The initiation of 3G comes from manufactures, not operators. Work on 3Gstarted around 1992, when international telecommunication union (ITU) formedtask group (TG) 8/1 working on FPLMTS, which was later renamed IMT-2000 in1996 or 1997. Work in TG 8/1 was accelerated in 1994, which involvedgovernment agents, manufactures, and operators around the world. In 1996 NTTand Ericsson initiated 3 g developments. In 1997, the U. S. Telecommunicationindustry association (TIA) chose the CDMA technology for the 3G. Europeantelecommunication standards institute (ETSI) also selected the CDMA technologyfor the 3G. In the same year, Wideband CDMA (W-CDMA), cdma2000, and 3Gtime division duplexing (TDD) were developed by the universal mobiletelecommunication system (UMTS), TIA 45.5, and china /Europe, respectively.The 3G technology supports 144kbps bandwidth, with high-speed movement (e.g.in vehicles), 384kbps bandwidth with pedestrian (e.g. on campus), and 2Mbps forstationary (e.g. in buildings). The services will include high- quality voice,Internet / Intranet accesses, and multimedia. ٧
  8. 8. Mobile Evolution to 3G1.5.1) Paradigm Shifts in Third-Generation SystemsWireless data transmission via mobile system offers tremendous opportunities fortechnologists and entrepreneurs ensure to provide their services at the right placeand the right time. The concepts of the third-generation systems introduce two paradigm shifts: 1) The shift from voice centric traffic to data centric traffic demands a packet-based infrastructure of the irrational circuit- based infrastructure. 2) Data applications continue to evolve: As a result, advanced application protocols and human interfaces become very crucial in practical applications 3G wireless communications requires a very broadband spectrum and fast data to support high-quality Internet access and multimedia services. Bandwidth, however is always limited the next table lists the existing spectrum used by the 2G systems and new sum Allocated for 3G. According to the table, only 25 percent (155 MHz out of 628 MHz) of the spectrum is newly created for the terrestrial 3G usage. Terrestrial spectrum allocation for 2G and 3G SPECTRUM BANDWIDTH SYSTEMS 50 MHz Amps, IS-95, IS- 800 MHz 136 900 MHz 50 MHz GSM 900 1500 MHz 48 MHz Japan PDC 1700 MHz 60 MHz Korean PCS 1800 MHz 150 MHz GSM 1800 1900 MHz 120 MHz PCS 2100 MHz 155 MHz 3G Table 2 ٨
  9. 9. Mobile Evolution to 3G1.6) W-CDMA and cdma2000 The CDMA- based 3G standards selected from numerous proposals to ITU have become the major stream for IMT-2000. In practical, W- CDMA and cdma2000 are two major proposals for the third- generation systems. Even though both systems are CDMA-based, many distinguishing features can be identified, as listed in the next table for one, W-CDMA uses dedicated time division multiplexing (TDM) pilot signal, where by the channel estimation information is collected from another signal stream. This approach reduces the overall pilot power. In contrast, cdma2000 uses common code division multiplexing (CDM) pilot, where by channel estimation information can be collected by signal stream. W-CDMA does not need base station timing synchronization, whereas base station timing synchronization in cdma2000 can provide decreased latency and reduced chance of dropping calls during soft handoff. Comparison between W-CDMA and cdma2000 TECHNOLOGY W-CDMA CDMA2000 Chip rate 4.096 then become 3.6864Mcps 3.84Mcps Forward link pilot Dedicated pilot with Common pilot with structure TDM CDM Base station timing Asynchronous Synchronous using synchronization GPS receivers Forward link modes A multi-carrier mode capable of overlay onto IS-95 carriers Spectrum efficiency 17.8/22.4 for self 36.7/29 for self for forward link evolution evolution /reverse link measured 18.4/22 for chines 26.4/27.2 for chines by Erlang/MHz/cell evolution evolution ٩
  10. 10. Mobile Evolution to 3G Table 9.3 The impact of system normalized spectrum efficiency in Erlang/MHz/cell for voice services in a vehicular environment was shown in the previous table shown * Higher Erlang/MHz/Omni cell equates to greater efficiency9.1.7) Harmonization Since both W-CDMA and cdma2000 have been simultaneously adapted for the 3G standard, harmonization of these two systems becomes necessary to make IMT-2000 deployment successful. Two crucial events have significantly enhanced harmonization of W-CDMA and cdma2000. The first is Ericsson’s acquisition of Qualcomm’s infrastructure division, which resolved contention of intellectual property rights (IPR) between the two companies. The second event is the adoption of operator’s harmonization group (OHG) recommendations by all major players. OHG has drawn its harmonization framework heavily from W-CDMA and cdma2000. The goals are: • To provide the foundation for accelerated growth in the 3G millennium • To create a single integrated 3G CDMA specification and process from the separate W-CDMA and cdma2000 proposals being developed by the third generation partnership project (3GPP) and (3GPP2). ١٠
  11. 11. Mobile Evolution to 3GOHG’s efforts have result in: • A direct spread mode with 3.84Mcps for new frequency bands, and multi-carrier mode with 3.6864Mcps for operation overlaid to IS-95 signals. • A CDM pilot added to the direct spread mode • A harmonized solution for SCDMA (a TDD mode Third Generation system proposed by china) The manufacturing community has agreed to cross-license intellectual property on fair, reasonable and nondiscriminatory terms for 3G development. However, due to political reasons, the two chip rates and the two synchronous and asynchronous systems are likely to coexist. Furthermore, the equipment Supplies have their own concerns on current markets and wireless technologies. Thus it is likely that the 3G harmonization cannot be achieved at the physical layer. Instead more efforts will be spent on interoperability oh higher layer protocols for W-CDMA and cdma2000, which results in higher costs with degraded performance. The activities of the 3G development so far have focused on physical and MAC layers. Three radio modules (modes) were selected for 3G CDMA radio access: MODE FDD(DS) FDD(MC) TDD Chip rate 3.84MCps 3.6864MCps 3.84MCps Common pilot CDM CDM To be determined Dedicated pilot TDM CDM To be determined Base station Asynchronous/ Synchronous as To be determined synchronization synchronous cdma2000 Table 4 ١١
  12. 12. Mobile Evolution to 3G • Direct sequencing (DS) frequency division duplex (FDD) mode 1 • Multi-carrier (MC) FDD mode 2 • Time division duplex (TDD) mode The direct sequence mode will be based on the W-CDMA proposal, and the MC mode will be based on the cdma2000 proposal. The TDD mode is an unpaired band solution to better facilitate indoors cordless communications; it has been studied in china. This mode provides asymmetric data services and is a potential low-cost solution.1.8) Quality of services in 3G From the viewpoint of end users, QOS should be provided on the end- to-end basis. QOS attributes should be general but simple, and their number should be small. From the point of view of the network, QOS will be defined with a set of parameters blocking probability, voice quality, data application, and time of service...Etc. The 3G QOS control mechanism should: 1) Efficiently utilize resources based on the ability to dynamically change QOS parameters during a communication session 2) Interwork with current QOS schemes 3) Present end-to-end QOS to the users with appropriate mapping. The end-to-end service on the application level uses the bearer services of the underlying networks, partitioned into three segments. ١٢
  13. 13. Mobile Evolution to 3G1) The local bearer service provides a connection between terminalequipment (TE) and mobile equipment (ME). A TE can be a PC or PADconnected to the 3G network through a MT.2) The 3G-bearer service provides 3G QOS.3) An external bearer service provides the connection to the other partyin the call. This bearer may utilize several network services (e.g. another3G bearer service) connecting to the other party of the communicationsessionThe QOS classes defined for mobile networks are very different fromfixed networks due to the restrictions and limitations of the air interface.Based on delay sensitivity,Four QOS classes have been defined for 3G traffic: conversational,streaming, interactive, and background.Conversational class is defined for the most delay-sensitive applications(traditional voice calls), and the transfer delay is strictly limited.Steaming class is defined for one-way real time video/audio (e.g. video-on-demand).Both conversational and streaming classes will need better channelcoding and retransmission to reduce the error rate in order to meet therequired QOS.Interactive and background classes and defined for delay-insensitiveservices. The interactive class is used for application such as Telnet,interactive e-mail, and web browsing.The background class is defined for activities such as ftp or backgrounddownloading of e-mails.Among traffic classes just listed, the conversational class is most delay-sensitive, and the background class is the most delay-insensitive ١٣
  14. 14. Mobile Evolution to 3G 2) Reverse LinkIn CDMA 2000 we have seven different radio configurations, to accommodatedifferent requirements of users; here we summarize these radio configurations Radio Configuration Characteristics for the Reverse CDMA Channel Radio Associated Data Rates, Forward Error Correction, Config Spreading and General Characteristics Rate 1200, 2400, 4800, and 9600 bps data rates with R = 1/3, 1 1 64-ary orthogonal modulation 1800, 3600, 7200, and 14400 bps data rates with 2 1 R = 1/2, 64-ary orthogonal modulation 1500, 2700, 4800, 9600, 19200, 38400, 76800, and 3 1 153600 bps with R = 1/4, 307200 bps data rate with R = 1/2, BPSK modulation with a pilot 1800, 3600, 7200, 14400, 28800, 57600, 115200, and 4 1 230400 with R = 1/4, BPSK modulation with a pilot ١٤
  15. 15. Mobile Evolution to 3G 1500, 2700, 4800, 9600, 19200, 38400, 76800, and 5 3 153600 bps with R = 1/4, 307200 and 614400 bps data rate with R = 1/3, BPSK modulation with a pilot 1800, 3600, 7200, 14400, 28800, 57600, 115200, 6 3 230400, and 460800 bps with R = 1/4, 1036800 bps data rate with R = ½, BPSK modulation with a pilot For Radio Configurations 3 through 6, the Reverse Dedicated Control Channel and Reverse Fundamental Channel also allow a 9600 bps, 5 ms format. Table 5 Reverse CDMA Channels Received at the Base Station REVERSE CDMA CHANNEL (1.25 MHz or 5 MHz channel received by base station) Reverse Reverse Reverse Enhanced Access Traffic Common Dedicated Access Channel Channel Control Channel Channel (RC 1 or 2) Channel (RC 3 to 6) Reverse Reverse Reverse Reverse Fundamental Pilot Channel Pilot Channel Pilot Channel Channel 0 to 7 Reverse 0 or 1 Reverse Enhanced Access Reverse Common Supplemental Dedicated Control Channel Control Channel Code Channels Channel 0 or 1 Reverse Fundamental Channel 0 to 2 Reverse Supplemental Channels Power Control Subchannel Fig 52.1) Reverse Link Physical Layer Characteristics 2.1.1) Continuous Waveform ١٥
  16. 16. Mobile Evolution to 3G The cdma2000 system provides a continuous waveform for all data rates. This includes a continuous pilot and continuous data-channel waveforms. This continuous waveform minimizes biomedical interference to devices such as hearing aids and pacemakers. It also permits a range increase at lower transmission rates. The continuous waveform also enables the interleaving to be performed over the entire frame, rather than just thePortions that are not gated off. This enables the interleaving to achieve the fullbenefit of the frame time diversity. The base station uses the pilot for multipathsearches, tracking, coherent demodulation, and to measure the quality of the linkfor power-control purposes. The cdma2000 system uses separate orthogonal channels for the pilot and each of the data channels. Hence, the relative levels of the Pilot and the physical data channels can easily be adjusted without changing the frame structure or power levels of some symbols of a frame. Also, this flexibility is provided with no performance degradation relative to an approach where the pilot is only sent in short bursts. 2.1.2) Orthogonal Channels Provided Using Different Length Walsh Sequences (OVSF)The cdma2000 system uses orthogonal channels for the Pilot and the otherphysical data channels. Using different length Walsh sequences, with the higherrate channels using shorter Walsh sequences provides these orthogonal channels.Short Walsh sequences allow high encoder output rates to be accommodated. Thecdma2000 system takes advantage of this by using a low code rate. Thechannelization codes are orthogonal variable spreading factor (OVSF) codes thatpreserve the orthogonality between a users different physical channels and supportmultiple data rates. To generate an orthogonal set of functions, the Walsh and ١٦
  17. 17. Mobile Evolution to 3GHadamard sequences make useful sets for wireless-CDMA. Walsh functions aregenerated by mapping codeword rows of special square matrices called HadamardMatrices. The Hadamard matrix of desired length can be generated by thefollowing recursive procedure:The OVSF codes can be generated using code tree below:The generated codes of the same layer form a set of Walsh functions and they areorthogonal. Also, any two codes of different layers are orthogonal except for thecase that one of the two codes is a mother code of the other. We can choose an ١٧
  18. 18. Mobile Evolution to 3Gappropriate spreading code according to the transmission rate. However, a code inthe code tree can be used by a mobile station iff no other code on the path from thespecific code to the root of the tree or in the subtree below the specific code isused by the same mobile station. Thus, the information signal Xk (t) is firstlycoded by the channelization code Cok and subsequently scrambled by ascrambling code Cs. All the channels of one cell use the same scrambling codewhereas; the different cells use different, distinct scrambling codes. Use of twocodes in two steps is referred to as Multiple spreading. Similarly, for the uplink,each mobile requires a channelization code for transmission to the base station in aserving cell. Further, a distinct scrambling code is assigned to each mobile. Thus,all the mobiles in a cell have a common set of Channelization codes and aseparate, distinguished scrambling code.Both in the uplink and downlink, the scrambling operation is complex .Thiscomplex scrambling is used to equalize the power levels in the I and Q channelsbecause unequal power levels result in a strange constellation. Mathematically,complex scrambling performs the multiplication of two complex signals: thecomplex signal Ic+jQc which is already spread using channelization code and thecomplex scrambling signal Is+jQs. ١٨
  19. 19. Mobile Evolution to 3GThus, the amplitude of the resulting signal I + jQ is the product of amplitude ofboth the signals and phase is the sum of their phase. So, when the two channels (Iand Q) have unequal amplitudes, the amplitude of the resulting constellation isalso constant.The family of scrambling codes : Maximal length PN sequences (m-sequence): The long PN codes used in wireless CDMA are of period N= 2^42-1with feedback characteristic polynomial to be X41+X3+1 .These long codes aretruncated to form a cycle of 2^15 bits for its implementation as a scrambling code.The truncated sequences are selected through computer simulation. Extensivesearch is required for the sequences with minimum cross-correlation values.1) DIRECT SEQUENCE SPREADING CAN BE DONE AT BOTH BASESTATION AND MOBILE STATION ١٩
  20. 20. Mobile Evolution to 3GUPLINK SPREADING WITH MORE DETAILS ٢٠
  21. 21. Mobile Evolution to 3G2) MULTICARRIER SPREADING ONLY AT BASE STATIONVariable data rate capacity, essential for next generation mobile communicationsystems, is achieved by using orthogonal channelization codes. Two-step multiplespreading provides flexibility and distinguishability amongst all users (uplink & ٢١
  22. 22. Mobile Evolution to 3Gdownlink), while complex scrambling helps in equalizing power in the I & Qbranches 2.1.3) Rate Matching The cdma2000 system uses several approaches to match the data rates to the Walsh spreader input rates. These include adjusting the code rate, using puncturing, symbol repetition, and sequence repetition. The general design approach is to first try to use a low rate code, but to not reduce the rate below R = 1/4 since the gains of smaller rates would be small and the decoder implementation complexity would increase. 2.1.4) Low Spectral SidelobesThe cdma2000 system achieves low spectral sidelobes with non-ideal mobilepower amplifiers by splitting the physical channels between the in-phase (I) andquadrature (Q) data channels and by using a complex-multiply-type PN spreadingapproach. 2.1.5) Independent Data Channels The cdma2000 system provides two types of physical data channels (Fundamental and Supplemental) on the reverse link that can each be adapted to a particular type of service. The use of Fundamental and Supplemental Channels enables the system to be optimized for multiple simultaneous services. These channels are separately coded and ٢٢
  23. 23. Mobile Evolution to 3G interleaved and may have different transmit power levels and frame error rate set points. Each channel carries different types of services depending on the service scenarios. 2.1.6) Power-Control 2.1.6.1) Reverse Power Control DONE FOR MS.There are three components of reverse power control: open loop, closed loop, andouter loop. Open loop power control sets the transmit power based upon the powerthat is received at the mobile station. Open loop power control compensates for thepath loss from the mobile station to the base station and handles very slow fading.Closed loop power control consists of an 800 bps feedback loop from the basestation to the mobile station to set the transmit power of the mobile station. Closedloop power control compensates for medium to fast fading and for inaccuracies inopen loop power control. Outer loop power control is implementation specific but typically adjusts the closed loop power control threshold in the base station in order to maintain a desired frame error rate. 2.1.6.2) Forward Power Control DONE FOR BS. The power of the forward link channels for a specific user is adjusted at a rate of 800 bits per second. The forward power control information is time-multiplexed with the reverse link pilot. 2.1.7) Separate Dedicated Control Channel ٢٣
  24. 24. Mobile Evolution to 3G The cdma2000 reverse link includes a separate low rate, low power, continuous, orthogonal, Dedicated Control Channel. This allows for a flexible Dedicated Control Channel structure that does not impact the other pilot and physical channel frame structures. 2.1.8) Frame LengthThe cdma2000 system supports 5 and 20 ms frames for control information on theFundamental and Dedicated Control Channels, and uses 20 ms frames for othertypes of data (including voice). Interleaving and sequence repetitions are over theentire frame interval. This provides improved time diversity over systems that useshorter frames.The 20 ms frames are used for voice. A shorter frame would reduce onecomponent of the total voice delay, but degrade the demodulation performancedue to the shorter interleaving span. 2.1.9) Direct-Spread Chip RateThe cdma2000 system uses a chip rate that is a multiple of the TIA/EIA-95-B chiprate of 1.2288 Mcps, and nominal channel spacing that are a multiple of 1.25MHz. This channel spacing provides a flexible and convenient spacing for carrierfrequency allocations of 5, 10, 15, and 20 MHz.2.2) Reverse Link Modulation and Coding The cdma2000 reverse link uses direct-sequence spreading with the TIA/EIA-95-B chip rate of 1.2288 Mcps (denoted as a 1X chip rate) or chip rates that are 3, 6, 9, or 12 times the TIA/EIA-95-B chip rate. Higher ٢٤
  25. 25. Mobile Evolution to 3Gchip rate systems are denoted as 3X, 6X, 9X, and 12X and they arerespectively operated at 3.6864, 7.3728, 11.0592, and 14.7456 Mcps.The 1X system can be used anywhere that a TIA/EIA-95-B reverse link isused. An IA/EIA-95-B reverse link carrier frequency can also be sharedwith mobiles transmitting the TIA/EIA-95-B waveform and thosetransmitting the 1X cdma2000 waveform. The higher chip rate reverselinks can be used in applications where larger bandwidth allocations areavailable. Mobiles that support a higher chip rate would typically alsosupport the 1X chip rate. This will allow these mobiles to access basestations that only support the 1X chip rate and allow operators with largerbandwidth allocations the flexibility of using a mixture of 1X and higherchip rate systems.Within an operator’s allocated band, the 1X cdma2000 reverse linkswould typically occupy the same bandwidth as TIA/EIA-95-B reverselink systems (i.e., 1.25 MHz) and higher chip rate cdma2000 links wouldtypically occupy a bandwidth that is 1.25 MHzTimes the higher chip rate factor. A guard band of 1.25 MHz/2 = 625 kHzwould typically be used on both sides of the operator’s allocated band.The Reverse CDMA Channel is composed of Reverse Common Channelsand Reverse Dedicated Channels.The mobile station to initiate communications with the base station and torespond to Forward Link Paging Channel messages uses the ReverseCommon Channel. The Reverse Common Channel uses a random-accessprotocol. Reverse Common Channels are uniquely identified by their longcode. ٢٥
  26. 26. Mobile Evolution to 3G The Reverse Dedicated Channel may be used for the transmission of user traffic, control, and signaling information to the base station.2.3) Reverse Dedicated Channel 2.3.1) Walsh and PN Spreading Reverse Dedicated Channels consist of up to several physical channels: a Reverse Pilot Channel, which is always used, and a Reverse Fundamental Channel (R-FCH), one or more Reverse Supplemental Channels (R-SCH), and a Reverse Dedicated Control Channel (R-DCCH). The R-FCH, R-SCH, R-DCCH may or may not be used depending on the service scenario. Each physical channel is spread with a Walsh code sequence to provide orthogonal channelization among these physical channels. The spread Pilot and R- DCCH are mapped to the in-phase (I) data channel. The spread R-FCH and R-SCH are mapped to the quadrature (Q) data channel. Then, the I and Q data channels are Spread using a complex-multiply PN spreading approach. Figure 9.6 shows this Reverse Dedicated Channel structure. The Supplemental Channel (R-SCH) is spread using a two bit Walsh function. Optionally two Supplemental Channels (denoted as R-SCH1 and R-SCH2 on Figure 9.6) can be accommodated to support bearer service profiles where more than one R-SCH is needed. In that case both Supplemental Channels are spread using a four bit Walsh functions (reducing the maximum supported data rate of each Supplemental for 1X, ٢٦
  27. 27. Mobile Evolution to 3G3X, and 6X). R-SCH1 is mapped to the I Channel and R-SCH2 is mappedto the Q channel.Additional Supplemental Channels can be accommodated by increasingthe Walsh length for Supplemental Channel to 8 bits and mappingadditional R-SCHs to the I and Q channel.The quadrature direct-sequence spreading uses the TIA/EIA-95-BI-channel and Q-channel PN sequences. These sequences have a period of2^15 chips. So for the 1X chip rate they repeat 75 times in 2 seconds(i.e., once every 26.66 ms).The TIA/EIA-95-B long code, with a period of 2^42 – 1 chips, is used forall of the chip rates. ٢٧
  28. 28. Mobile Evolution to 3G Reverse Dedicated Channel Walsh Cover (+ + – – ) or (+ + – – – – + +) Complex Multiplier Reverse Relative Supplemental C Gain Channel 2 + + Reverse + Baseband Pilot A Σ Σ Filter Channel + – Reverse Relative Dedicated B cos(2π fct) Gain Control Channel Walsh Cover Σ Gain s(t) (+ + + + + + + + – – – – – – – – ) Reverse Relative Fundamental C Gain Channel + + Baseband Walsh Cover Σ Σ Filter Reverse (+ + + + – – – – + + + + – – – – ) + + Supplemental Channel 1, Reverse Relative C sin(2π fct) Common Control GainChannel, or Enhanced Access Channel Walsh Cover Walsh Cover (+ – ) or (+ + – – ) (+ – ) Notes : for Reverse Supplemental Channel 1. Binary signals are represented with ± 1 values (+ + + + – – – – ) with the mapping +1 for ‘0’ and –1 for ‘1’. for Reverse Common Control Channel Unused channels and gated-off symbols are Decimator and Enhanced Access Channel represented with zero values. by Factor 2. When the Reverse Common Control Channel or of 2 Enhanced Access Channel is used, the only additional channel is the Reverse Pilot Channel. 3. All of the pre-baseband-filter operations occur I-Channel Q-Channel at the chip rate. PN Sequence PN Sequence 1-Chip Delay Long Long Code Code Mask Generator Fig 6Figure 6 shows the physical channels separated by orthogonal Walshfunctions and the I and Q channel in phase quadrature. The I data channeland the Q data channel are labeled as DI and DQ, respectively.The Reverse Pilot Channel is used for initial acquisition, time tracking,Rake-receiver coherent reference recovery, and power-controlmeasurements. The levels of the Fundamental, Supplemental, andDedicated Control Channels are adjusted relative to the Reverse PilotChannel by using the gains GF, GS, and GC. These are slow adjustmentsto adapt to different coding and interleaving and to adapt to differentpropagation conditions. ٢٨
  29. 29. Mobile Evolution to 3G2.3.2) Reverse Pilot Channel (R-PICH) The Pilot Channel for the Reverse Dedicated Channels consists of a fixed reference value and multiplexed forward Power-Control (PC) information as illustrated in Figure 34. This time multiplexed forward Power Control information is referred to as the power control sub-channel. This sub- channel provides information on the quality of the forward link at the rate of 1 bit per 1.25 ms Power-Control Group (PCG) and is used by the forward link channels to adjust their power. The power-control symbol repetition means that the 1-bit value is constant for that repeated-symbol duration. The power-control bit uses the last portion of each power- control group. The +1 pilot symbols and the multiplexed power-control symbols are all sent with the same power level. The binary power-control symbols are represented with ±1 values in Figure 7. Gating Rate 1.25 ms 1 Pilot PC 1/2 1/4 5 ms 20 ms Fig 79.2.3.3) Reverse Fundamental Channel (R-FCH) ٢٩
  30. 30. Mobile Evolution to 3G Figure 6, Figure 7, and Figure 8 describe the modulation for the Reverse Fundamental Channel (R-FCH). This channel supports 5 and 20 ms frames. The 20 ms frame structures provide rates derived from the TIA/EIA-95-B Rate Set 1 or Rate Set 2 rate sets. The 5 ms frames provide 24 information bits per frame with a 16-bit CRC. Within each 20 ms frame interval, either one 20 ms R-FCH structure, up to four 5 ms R-FCH structure(s), or nothing can be transmitted.2.3.4) Reverse Supplemental Channel (R-SCH) The Supplemental Channel (R-SCH) can be operated in two distinct modes as shown on Figure 6. The first mode is used for data rates not exceeding 14.4 kbps. In the second mode, the base station explicitly knows the rate information. In the first mode, the variable rates provided are those derived from the TIA/EIA-95-B Rate Set 1 (RS1) and Rate Set 2 (RS2). The structures for the variable-rate modes are identical to the 20 ms Reverse Fundamental Channel (R-FCH) structures followed by a 2-symbol repetition factor. This repetition factor compensates for the shorter Walsh sequence of the R-SCH compared to that of the R-FCH. When two Supplemental Channels are used (R-SCH1 and R-SCH2) each Supplemental Channel is spread using a four bit Walsh sequence. Since the R-FCH is also spread by a four bit Walsh sequence, the 2 symbol repetition factor is removed in the case when two Supplemental Channels are being used. ٣٠
  31. 31. Mobile Evolution to 3G In the second mode, the high data rate modes can have convolutional coding with K = 9, or turbo coding with two K = 4 component encoders. Figure11, Figure 12, Figure 13, Figure 14, and Figure 15 give the R-SCH structures for the high data rate modes with K = 9 convolutional coding and 1X, 3X, 6X, 9X, and 12X chip rates. With turbo coding, the structures are changed as follows:• The K = 9 encoder is replaced by a turbo encoder with the same basic (before puncturing) rate.• The 8-bit encoder tail is replaced by a 6-bit encoder tail.• Two reserved bits are added after the 6-bit encoder tail to keep the number of information bits constant regardless of the encoding method. Reverse Fundamental Channel and Reverse Supplemental Channel Structure for Radio Configuration 3 Channel Bits Add Add 8 Convolutional Frame Reserved/ Symbol Symbol Block or Turbo C Quality Encoder Repetition Puncture Interleaver Encoder Indicator Tail Bits Bits/Frame Bits Rate (kbps) R Factor Deletion Symbols Rate (ksps) 24 (5 ms) 16 9.6 1/4 2× None 384 76.8 16 6 1.5 1/4 16× 1 of 5 1,536 76.8 40 6 2.7 1/4 8× 1 of 9 1,536 76.8 80 8 4.8 1/4 4× None 1,536 76.8 172 12 9.6 1/4 2× None 1,536N 76.8 360 16 19.2 1/4 1× None 1,536N 76.8 744 16 38.4 1/4 1× None 3,072N 153.6 1,512 16 76.8 1/4 1× None 6,144N 307.2 3,048 16 153.6 1/4 1× None 12,288N 614.4 6,120 16 307.2 1/2 1× None 12,288N 614.4 Notes: 1. The 5 ms frame is only used for the Reverse Fundamental Channels, and only rates of 9.6 kbps or less are used for Reverse Fundamental Channels. 2. Turbo coding may be used for the Reverse Supplemental Channels with rates of 19.2 kbps or more; otherwise, K = 9 convolutional coding is used. 3. With convolutional coding, the Reserved/Encoder Tail bits provide an encoder tail. With turbo coding, the first two of these bits are reserved bits that are encoded and the last six bits are replaced by an internally generated tail. 4. N is the number of consecutive 20 ms frames over which the interleaving is done (N = 1, 2, or 4). Table 6 Reverse Fundamental Channel and Reverse Supplemental Channel Structure for Radio Configuration 4 ٣١
  32. 32. Mobile Evolution to 3G Channel Bits Add Add 8 Add Convolutional Frame Reserved/ Symbol Symbol Block Reserved or Turbo C Quality Encoder Repetition Puncture Interleaver Bits Encoder Indicator Tail Bits Bits/Frame Bits Bits Rate (kbps) R Factor Deletion Symbols Rate (ksps) 24 (5 ms) 0 16 9.6 1/4 2× None 384 76.8 21 1 6 1.8 1/4 16× 8 of 24 1,536 76.8 55 1 8 3.6 1/4 8× 8 of 24 1,536 76.8 125 1 10 7.2 1/4 4× 8 of 24 1,536 76.8 267 1 12 14.4 1/4 2× 8 of 24 1,536N 76.8 552 0 16 28.8 1/4 1× 4 of 12 1,536N 76.8 1,128 0 16 57.6 1/4 1× 4 of 12 3,072N 153.6 2,280 0 16 115.2 1/4 1× 4 of 12 6,144N 307.2 4,584 0 16 230.4 1/4 1× 4 of 12 12,288N 614.4 Notes: 1. The 5 ms frame is only used for the Reverse Fundamental Channels, and only rates of 14.4 kbps or less are used for Reverse Fundamental Channels. 2. Turbo coding may be used for the Reverse Supplemental Channels with rates of 28.8 kbps or more; otherwise, K = 9 convolutional coding is used. 3. With convolutional coding, the Reserved/Encoder Tail bits provide an encoder tail. With turbo coding, the first two of these bits are reserved bits that are encoded and the last six bits are replaced by an internally generated tail. 4. N is the number of consecutive 20 ms frames over which the interleaving is done (N = 1, 2, or 4). Table 7Reverse Fundamental Channel and Reverse Supplemental Channel Structure for Radio Configuration 5 Channel Bits Add Add 8 Convolutional Frame Reserved/ Symbol Symbol Block or Turbo C Quality Encoder Repetition Puncture Interleaver Encoder Indicator Tail Bits Bits/Frame Bits Rate (kbps) R Factor Deletion Symbols Rate (ksps) 24 (5 ms) 16 9.6 1/4 2× None 384 76.8 16 6 1.5 1/4 16× 1 of 5 1,536 76.8 40 6 2.7 1/4 8× 1 of 9 1,536 76.8 80 8 4.8 1/4 4× None 1,536 76.8 172 12 9.6 1/4 2× None 1,536N 76.8 360 16 19.2 1/4 1× None 1,536N 76.8 744 16 38.4 1/4 1× None 3,072N 153.6 1,512 16 76.8 1/4 1× None 6,144N 307.2 3,048 16 153.6 1/4 1× None 12,288N 614.4 6,120 16 307.2 1/3 1× None 18,432N 921.6 12,264 16 614.4 1/3 1× None 36,864N 1,843.2 Notes: 1. The 5 ms frame is only used for the Reverse Fundamental Channels, and only rates of 9.6 kbps or less are used for Reverse Fundamental Channels. 2. Turbo coding may be used for the Reverse Supplemental Channels with rates of 19.2 kbps or more; otherwise, K = 9 convolutional coding is used. 3. With convolutional coding, the Reserved/Encoder Tail bits provide an encoder tail. With turbo coding, the first two of these bits are reserved bits that are encoded and the last six bits are replaced by an internally generated tail. 4. N is the number of consecutive 20 ms frames over which the interleaving is done (N = 1, 2, or 4). Table8 ٣٢
  33. 33. Mobile Evolution to 3G Reverse Fundamental Channel and Reverse Supplemental Channel Structure for Radio Configuration 6 Channel Bits Add Add 8 Add Convolutional Frame Reserved/ Symbol Symbol Block Reserved or Turbo C Quality Encoder Repetition Puncture Interleaver Bits Encoder Indicator Tail Bits Bits/Frame Bits Bits Rate (kbps) R Factor Deletion Symbols Rate (ksps) 24 (5 ms) 0 16 9.6 1/4 2× None 384 76.8 21 1 6 1.8 1/4 16× 8 of 24 1,536 76.8 55 1 8 3.6 1/4 8× 8 of 24 1,536 76.8 125 1 10 7.2 1/4 4× 8 of 24 1,536 76.8 267 1 12 14.4 1/4 2× 8 of 24 1,536N 76.8 552 0 16 28.8 1/4 1× None 2,304N 115.2 1,128 0 16 57.6 1/4 1× None 4,608N 230.4 2,280 0 16 115.2 1/4 1× None 9,216N 460.8 4,584 0 16 230.4 1/4 1× None 18,432N 921.6 9,192 0 16 460.8 1/4 1× None 36,864N 1,843.2 20,712 0 16 1,036.8 1/2 1× 2 of 18 36,864N 1,843.2 Notes: 1. The 5 ms frame is only used for the Reverse Fundamental Channels, and only rates of 14.4 kbps or less are used for Reverse Fundamental Channels. 2. Turbo coding may be used for the Reverse Supplemental Channels with rates of 28.8 kbps or more; otherwise, K = 9 convolutional coding is used. 3. With convolutional coding, the Reserved/Encoder Tail bits provide an encoder tail. With turbo coding, the first two of these bits are reserved bits that are encoded and the last six bits are replaced by an internally generated tail. 4. N is the number of consecutive 20 ms frames over which the interleaving is done (N = 1, 2, or 4). Table 92.3.5) Reverse Common Channel The Reverse Access Channel (R-ACH) and the Reverse Common Control Channel (R-CCCH) are common channels used for communication of messages from the mobile station to the base station. The R-CCCH differs from the R-ACH in that the R-CCCH offers extended capabilities beyond the Reverse Access Channel (R-ACH). The R-ACH and R-CCCH are multiple access channels as mobile stations transmit without explicit authorization by the base station. The Reverse Access Channel and Reverse Common Control Channel use a slotted Aloha type of mechanisms with higher capture probabilities due to the CDMA properties of the channel (simultaneous transmission of multiple users). ٣٣
  34. 34. Mobile Evolution to 3G There can be one or more access channels per frequency assignment. Different access channels are distinguished by different long codes. The Reverse Common Control Channel (R-CCCH) uses a physical structure similar to the Reverse Access Channel (R-ACH). The main difference between the R-CCCH and the R-ACH is in the addition of frame sizes of 5 and 10 ms as well as data rates of 19.2 and 38.4 kbps. The R-CCCH may use the same long codes as the R-ACH or they may use different long codes. .2.4) Access Channel The Access Channel is used by the mobile station to initiate communication with the base station and to respond to Paging Channel messages. An Access Channel transmission is a coded, interleaved, and modulated spread-spectrum signal. The Access Channel uses a random- access protocol. Access Channels are uniquely identified by their long codes. The mobile station shall transmit information on the Access Channel at a fixed data rate of 4800 bps. An Access Channel frame shall be 20 ms in duration. An Access Channel frame shall begin only when System Time is an integral multiple of 20 ms. The Reverse CDMA Channel may contain up to 32 Access Channels numbered 0 through 31 per supported Paging Channel. At least one Access Channel exists on the Reverse CDMA Channel for each Paging Channel on the corresponding Forward CDMA Channel. Each Access Channel is associated with a single Paging Channel. ٣٤
  35. 35. Mobile Evolution to 3GEach Access Channel frame contains 96 bits (20 ms frame at 4800 bps).Each Access Channel frame shall consist of 88 information bits and eightEncoder Tail Bits (see Figure 8). The channel structure for spreadingrate1 is shown in figure. Access Channel Frame Structure 96 bits (20ms) 4800 bps 88 8 Frame Information Bits T Notation T - Encoder Tail Bits Channel Structure for the Header on the Enhanced Access Channel for spreading Rate 1 fig. 8 Access Repeated Channel Code Code Bits Add 8 Convolutional Symbol Symbol Symbol Encoder Encoder 4.8 kbps Repetition 28.8 ksps 88 Bits/Frame Tail Bits R = 1/3, K = 9 (4.4 kbps) Block Repeated Modulation Symbol Code Symbol 64-ary (Walsh Chip) Interleaver Orthogonal (576 28.8 ksps 4.8 ksps Modulator Symbols) (307.2 kcps) Long Long Code Code Mask 1.2288 Mcps Generator I-Channel PN Sequence cos(2π fct) Signal Point I Mapping Channel Baseband 0 → +1 Gain Filter 1 → –1 s(t) Σ Signal Point Q 1/2 PN Mapping Channel Baseband Chip 0 → +1 Gain Filter Delay 1 → –1 Q-Channel sin(2π fct) PN Sequence Fig 9 ٣٥
  36. 36. Mobile Evolution to 3GThe Access Channel preamble shall consist of frames of 96 zeros that aretransmitted at the 4800 bps rate. The Access Channel preamble istransmitted to aid the base station in acquiring an Access Channeltransmission.2.4.1) Enhanced Access ChannelThe Enhanced Access Channel is used by the mobile station to initiatecommunication with the base station or to respond to a mobile stationdirected message. The Enhanced Access Channel can be used in one ofthree possible modes: Basic Access Mode, Power Controlled AccessMode, and Reservation Access Mode.When operating in the Basic Access Mode, the mobile station shall nottransmit the Enhanced Access header on the Enhanced Access Channel.In Basic Access Mode, the access probe shall consist of an EnhancedAccess Channel preamble, followed by Enhanced Access data.When operating in the Power Controlled Access Mode, the EnhancedAccess Channel probe shall consist of an Enhanced Access Channelpreamble, followed by an Enhanced Access header and Enhanced Accessdata.When operating in the Reservation Access Mode, the Enhanced AccessChannel probe shall consist of an Enhanced Access Channel preamble,followed by an Enhanced Access header. Enhanced Access data is sent onthe Reverse Common Control Channel upon receiving permission fromthe base station. ٣٦
  37. 37. Mobile Evolution to 3GThe Enhanced Access Channel uses a random-access protocol. EnhancedAccess Channels are uniquely identified by their long codes. TheEnhanced Access Channel probe structure is shown in Figure 9.10 Enhanced Access Channel Probe StructureTx Power Enhanced Access Not transmitted in Not transmitted in Channel Preamble Basic Access Mode Reservation Access Mode Preamble Reverse Pilot Channel Enhanced Enhanced Enhanced Access Access Header Access Data Header Enhanced Access Data Preamble Transmission (See Figure 2.1.3.4.2.3-1) Reverse Pilot Channel Transmission 1.25 ms 5 ms (1 to RACH_MAX_CAP_SZ) x 5 ms Fig 10The mobile station shall transmit the Enhanced Access header on theEnhanced Access Channel at a fixed data rate of 9600 bps. The mobilestation shall transmit the Enhanced Access data on the Enhanced AccessChannel at a fixed data rate of 9600, 19200, or 38400 bps.The frame duration for the Enhanced Access header on the EnhancedAccess Channel shall be 5 ms in duration. The frame duration for theEnhanced Access data on the Enhanced Access Channel shall be 20, 10,or 5 ms in duration. ٣٧
  38. 38. Mobile Evolution to 3G An Enhanced Access Channel frame of 20, 10, or 5 ms duration shall begin only when System Time is an integral multiple of 20, 10, or 5 ms respectively. The Reverse CDMA Channel may contain up to 32 Enhanced Access Channels per Forward Common Control Channel supported, numbered 0 through 31. There is a Forward Common Assignment Channel associated with every Enhanced Access Channel operating in the Power Controlled Access Mode or the Reservation Access Mode. Table 10 summarizes the Enhanced Access Channel bit allocations. Enhanced Access Channel Frame Structure Summary Number of Bits per Frame Frame Frame Frame Transmissio Total Informatio Encoder QualityLength (ms) Type n Rate (bps) Bits n Bits Tail Bits Indicator 5 Header 9600 48 32 8 8 20 Data 9600 192 172 12 8 20 Data 19200 384 360 16 8 20 Data 38400 768 744 16 8 10 Data 19200 192 172 12 8 10 Data 38400 384 360 16 8 5 Data 38400 192 172 12 8 Table10 Enhanced Access Channel header frames shall consist of 48 bits. These 48 bits shall be composed of 32 information bits followed by eight frame quality indicator (CRC) bits and eight Encoder Tail Bits, as shown in ٣٨
  39. 39. Mobile Evolution to 3GEnhanced Access Channel Frame Structure for the Enhanced AccessHeader 48 bits (5ms) 9600 bps 32 8 8 Frame Information Bits F T Notation F - Frame Quality Indicator (CRC) T - Encoder Tail Bits Fig 11 Channel Structure for the Header on the Enhanced Access Channel for Spreading Rate 1 Modulation Enhanced Add 8-Bit Block Symbols Add 8 Convolutional Symbol Access Frame Interleaver Encoder Encoder Repetition C Channel Quality (768 Tail Bits R = 1/4, K = 9 (4× Factor) Bits Indicator Symbols) 32 Bits per 9.6 kbps 153.6 ksps 5 ms Frame Fig.12 Channel for the Header on the Enhanced Access Channel for Spreading Rate 3 Enhanced Add 8-Bit Block Add 8 Convolutional Symbol Access Frame Interleaver Encoder Encoder Repetition C Channel Quality (768 Tail Bits R = 1/4, K = 9 (4× Factor) Bits Indicator Symbols) 32 Bits per 9.6 kbps 153.6 ksps 5 ms Frame Fig 13 ٣٩
  40. 40. Mobile Evolution to 3G Enhanced Access Channel Frame Structure 192 bits (20ms) 9600 bps 172 12 8 Frame Information Bits F T 384 bits (20ms) 19200 bps 360 16 8 Frame Information Bits F T 768 bits (20ms) 38400 bps 744 16 8 Frame Information Bits F T 192 bits (10ms) 19200 bps 172 12 8 Frame Information Bits F T 384 bits (10ms) 38400 bps 360 16 8 Frame Information Bits F T 192 bits (5ms) 38400 bps 172 12 8 Frame Information Bits F T Notation F - Frame Quality Indicator (CRC) T - Encoder Tail Bits Fig 14 ٤٠
  41. 41. Mobile Evolution to 3GI and Q Mapping for Enhanced Access Channel, Reverse Common Control Channel, and Reverse Traffic Channel with Radio Configurations 3 and 4 Walsh Cover (+ + – – ) or (+ + – – – – + +) Complex Multiplier Reverse Relative Supplemental C Gain Channel 2 + + Reverse + Baseband Pilot A Σ Σ Filter Channel + – Reverse Relative Dedicated B cos(2π fct) Gain Control Channel Walsh Cover Σ Gain s(t) (+ + + + + + + + – – – – – – – – ) Reverse Relative Fundamental C Gain Channel + + Baseband Walsh Cover Σ Σ Filter Reverse (+ + + + – – – – + + + + – – – – ) + + Supplemental Channel 1, Reverse Relative C sin(2π fct) Common Control Gain Channel, or Enhanced Access Channel Walsh Cover Walsh Cover (+ – ) or (+ + – – ) (+ – ) Notes : for Reverse Supplemental Channel 1. Binary signals are represented with ± 1 values (+ + + + – – – – ) with the mapping +1 for ‘0’ and –1 for ‘1’. for Reverse Common Control Channel Unused channels and gated-off symbols are Decimator and Enhanced Access Channel represented with zero values. by Factor 2. When the Reverse Common Control Channel or of 2 Enhanced Access Channel is used, the only additional channel is the Reverse Pilot Channel. 3. All of the pre-baseband-filter operations occur I-Channel Q-Channel at the chip rate. PN Sequence PN Sequence 1-Chip Delay Long Long Code Code Mask Generator Fig15 Channel Structure for the Data on the Enhanced Access Channel and the Reverse Common Control Channel for Spreading Rate 1 Modulation Reverse Symbols Add Common Add 8 Convolutional Frame Symbol Block Control Encoder Encoder C Quality Repetition Interleaver Channel Tail Bits R = 1/4, K = 9 Indicator Bits Bits/Frame Bits Rate (kbps) Factor Symbols Rate (ksps) 172 (5 ms) 12 38.4 1× 768 153.6 360 (10 ms) 16 38.4 1× 1,536 153.6 172 (10 ms) 12 19.2 2× 1,536 153.6 744 (20 ms) 16 38.4 1× 3,072 153.6 360 (20 ms) 16 19.2 2× 3,072 153.6 172 (20 ms) 12 9.6 4× 3,072 153.6 Fig 16 ٤١
  42. 42. Mobile Evolution to 3G Channel Structure for the Data on the Enhanced Access Channel and the Reverse Common Control Channel for Spreading Rate 3 Reverse Add Common Add 8 Convolutional Frame Symbol Block Control Encoder Encoder C Quality Repetition Interleaver Channel Tail Bits R = 1/4, K = 9 Indicator Bits Bits/Frame Bits Rate (kbps) Factor Symbols Rate (ksps) 172 (5 ms) 12 38.4 1× 768 153.6 360 (10 ms) 16 38.4 1× 1,536 153.6 172 (10 ms) 12 19.2 2× 1,536 153.6 744 (20 ms) 16 38.4 1× 3,072 153.6 360 (20 ms) 16 19.2 2× 3,072 153.6 172 (20 ms) 12 9.6 4× 3,072 153.6 Fig 17The last eight bits of each Enhanced Access Channel frame are called theEncoder Tail Bits. These eight bits shall be set to ‘0’.Each transmission on the R-ACH or R-CCCH (denoted as an accessprobe) consists of an Access Preamble and an Access Channel MessageCapsule. The Access Preamble is a transmission of only the non-databearing Reverse Pilot Channel (R-PICH) at an increased power level; theAccess Channel Message Capsule transmission consists of the databearing R-ACH or R-CCCH and the associated, non-data bearing ReversePilot Channel.2.4.2) Reverse Pilot Channel and the Access PreambleThe Reverse Pilot Channel associated with the Reverse Access Channelor Reverse Common Control Channel has a similar structure to theReverse Pilot Channel used when the mobile station is communicatingwith the base station in a dedicated mode. The key difference is that theReverse Pilot Channel associated with the Reverse Access Channels doesnot have a Power Control sub-channel and therefore no Power Controlbits are time-multiplexed with the Reverse Pilot Channel. The Reverse ٤٢
  43. 43. Mobile Evolution to 3GPilot Channel associated with the Reverse Access Channels consists of anall ‘0’ channel.The Access preamble consists of transmissions only on the Reverse PilotChannel. The preamble length is an integer number of 1.25 ms intervals.A zero length preamble (no preamble) is permitted. The number of 1.25ms intervals to be used is indicated by the base station. The preamblelength depends upon the rate at which the base station can search the PNspace, the cell radius, and the multipath characteristics of the cell.The base station search rate is dependent upon the hardware configurationof the cell. When more possible PN hypotheses can be searched inparallel, then the base station can acquire the mobile station faster.Similarly, when the cell radius is larger, the number of PN hypothesesincreases. In addition, different multipath conditions may makecombining losses higher or have more fading, resulting in moreaccumulations being required for a given probability of detection.The preamble for the R-ACH and R-CCCH is transmitted at a specifiedpower setting stronger than the Reverse Pilot Channel depending upondata rate and mobile station power limitations. If the mobile station mustreduce its R-ACH or R-CCCH transmission rate due to insufficient outputpower, then the mobile station transmits the preamble(as well as the access probe itself) at the maximum available power. ٤٣
  44. 44. Mobile Evolution to 3G2.5) Slotting and Channel Arrangement Access probe transmissions are slotted. The slot is long enough to accommodate the preamble and the longest message. The base station indicates the slot length. The transmission must begin at the beginning of the slot; the transmission is not required to last any longer than the number of frames required to transmit the message. To reduce delay, the slotting for different access channels can be offset. The acquisition process is substantially simpler due to the system slotted design. The base station attempts to acquire mobile station at the beginning of slots, during the time in which the mobile station would send the acquisition preamble. 2.5.1) Reverse Common Control Channel The Reverse Common Control Channel is used for the transmission of user and signaling information to the base station when Reverse Traffic Channels are not in use. A Reverse Common Control Channel transmission is a coded, interleaved, and modulated spread-spectrum signal. The mobile station transmits during intervals specified by the base station. Reverse Common Control Channels are uniquely identified by their long codes. The Reverse Common Control Channel preamble and data transmission structure is shown in Figure 18. ٤٤

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