Presentation on theme: "As Part of Pedagogy Activity in EC Department, 2011, 2012"— Presentation transcript:
1As Part of Pedagogy Activity in EC Department, 2011, 2012 Simulation and Analysis of 3G Air interface Wideband Coded Division Multiple Access working in Downlink FDD4th August, 2012Presented By: Prof. Amit DegadaElectronics and Communication Department, Institute of Technology, Nirma University, Ahmedabad
2ज्ञानं ज्ञेयं परिज्ञाता त्रिविधा कर्म च यत्तु दना । करणं कर्म कर्तेति त्रिविधः कर्मसंग्रहः ॥१८- १८॥ MeaningKnowledge, the Object of knowledge, and the knower are the three factors that motivate the action; the senses, the work, and the doerare the three constituents of action The Bhagavad Gita(18.18)
3Presentation Outline The Objective Standardization Body Motivation to workWCDMA ParametersCDMA Transmitter and Receiver: A General ApproachAir Interface ArchitectureWCDMA ChannelsWCDMA Transmitter
4The Objective of the Lecture How the Technology has evolved.Various Air Interfaces of 3GPhysical Layer of WCDMA Working In Downlink FDD
103GPP- A Global Initiative 3GPP - Third Generation Partnership ProjectARIB - Association of Radio Industries and BusinessesCWTS - China Wireless Telecommunication Standard groupETSI - European Telecommunications Standards InstituteT1 - Standards Committee T1 TelecommunicationsTTA - Telecommunications Technology AssociationTTC - Telecommunication Technology CommitteeIETF - Internet Engineering Task ForceITU-R - International Telecommunication Union -RadiocommunicationITU-T - International Telecommunication Union - Telecommunication StandardizationSource: univ.zte.com/cn
12UMTS General Architecture Figure : General ArchitectureUser Equipment:Mobile Equipment : Radio Transmission & contains applications.Mobile Termination, Terminal EquipmentUSIM : Data and Procedures which unambiguously and securely identify itself in Smart Card.
133GPP Rel.6 ObjectivesMigration from GSM based Network to 3G standard WCDMAScope and definition in progressIP Multimedia Services, phase 2IMS messaging and group managementWireless LAN interworkingSpeech enabled services Distributed speech recognition (DSR)Number portabilityOther enhancements
143GPP2 Defines 3rd Generation Partnership Project “Two” Separate organization, as 3GPP closely tied to GSM and UMTSGoal of ultimate merger (3GPP + 3GPP2) remains
15Various Air interfaces of 3G WCDMACDMA20003GTD-SCDMACDMA 2000standardsUWCCDMA is the main technology of 3G
16Presentation Outline The Objective Standardization Body Motivation to workWCDMA ParametersCDMA Transmitter and Receiver: A General ApproachAir Interface ArchitectureWCDMA ChannelsWCDMA Transmitter
21Simplex Vs. Duplex Fig. Duplex Scenario While in Duplex we have access to both transmitter and receiver Simultaneously.Mobile can Send and receive data Simultaneously
22Circuit Switching Vs. packet Switching Traditional Connection for Voice Communication requires that a Physical path Connecting the users at the end of the line and that path stays open until the Conversation ends. This is Called Circuit Switching.Most Modern Technology Defers from this Traditional Model because they uses packet data.Chopped into piecesGiven a destination addressMixed with other data from other SourceTransmitted over channel with other dataReconstructed at other endPacket Data was originally developed for Internet.
23WCDMA Works in Two mode FDD and TDD systems frequency allocation Source: Information and Communication university.frequencyTimeFDDGuard frequencyMSBSFDD and TDD systems frequency allocationTDDGuard time
24FDD - WCDMA Improved performance over 2G systems: Improved Capacity and coverageCoherent uplink using a user-dedicated pilotFast power control in the downlinkSeamless inter-frequency handoverHigh degree of service flexibility:Multi-rate service : with maximums of Kb/s for full coverage and 2 Mb/s for limited coveragePacket access modeHigh degree of operator flexibility:Support of asynchronous inter-base-station Support of different deployment scenarios, including hierarchical cell structure (HCS) and hot-spot scenariosSupport of new technologies like multi-user detection (MUD) and adaptive antenna arrays (SDMA)
25Symmetric vs. Asymmetric Transmission Same Data rate for Uplink and downlinkDifferent Data Rate
26Presentation Outline The Objective Standardization Body Motivation to workWCDMA ParametersCDMA Transmitter and Receiver: A General ApproachAir Interface ArchitectureWCDMA ChannelsWCDMA Transmitter
27WCDMA Parameters Source:  Channel bandwidth 5 MHz Duplex mode FDD and TDDDownlink RF channel structureDirect spreadChip rate3.84 MbpsFrame length10 msData modulationQPSK (downlink), 8 PSKBPSK (uplink)Channel codingConvolutional and turbo codesCoherent detectionUser dedicated time multiplexed pilot (downlink and uplink), common pilot in the downlink.MultirateVariable spreading and multicodeSpreading factors4–256 (Downlink), 4–512 (Uplink)Spreading (downlink)OVSF sequences for channel separationGold sequences for cellSpreading (uplink)OVSF sequences, Gold sequence 241-1HandoverSoft handoverInterfrequency handoverSource: 
28Presentation Outline The Objective Standardization Body Motivation to workWCDMA ParametersCDMA Transmitter and Receiver: A General ApproachAir Interface ArchitectureWCDMA ChannelsWCDMA Transmitter
29CDMA Transmitter And Receiver Selection of Code is Utmost ImportantFig. Block diagram of the mobile transmitterFig. Block diagram of the base station receiver
30Spreading in WCDMAPseudo Random (PN) sequence: A bit stream of ‘1’s and ‘0’s occurring randomly, or almost randomly, with some unique properties.Linear shift registeranan-1an-2an-rc1c2c3cr
31Spreading and Scrambling in WCDMA Spreading: To multiply the input information bits by a PN code and get processing gain, thechip level signal’s bandwidth is much wider than that of input information bits.It maintains the orthogonality among different physical channels of each user.Scrambling: To separate the signals from the different users. It doesn’t change the signalbandwidth. Each cell has a unique scrambling code in the system.Fig. Relation between spreading and scrambling Fig. Spreading for all downlink physical channels except SCH Selecting codeshigh autocorrelation low cross correlationSuppressinginterferenceWCDMA
32Spreading in WCDMA OVSF Code and Gold Code OVSF Code: Purpose: SpreadingGeneration Methedology: Code-TreeC2,1=1 1Fig. Auto-correlation and cross correlation betweenthe OVSF codes of length 128C1,1= 1C2,2=1 -1C4,3=C4,4=Gold Code:Purpose: ScramblingGeneration: modulo-2 sum of 2 m-sequencesFig. Auto and cross correlation of Gold Code
33OVSF Code Fig OVSF code Matrix of 8 ×8 length. Fig OVSF code plot for code number 6 from 128 ×128 OVSF code Matrix
35Gold CodeA set of Gold codes can be generated with the following steps.Pick two maximum length sequences of the same length such that their absolute cross-correlation is less than or equal towhere is the size of the LFSR used to generate the maximum length sequence (Gold '67).
36Presentation Outline The Objective Standardization Body Motivation to workWCDMA ParametersCDMA Transmitter and Receiver: A General ApproachAir Interface ArchitectureWCDMA ChannelsWCDMA Transmitter
38Presentation Outline The Objective Standardization Body Motivation to workWCDMA ParametersCDMA Transmitter and Receiver: A General ApproachAir Interface ArchitectureWCDMA ChannelsWCDMA Transmitter
39Logical Channel Control Channel (CCH) Broadcast Control Channel (BCCH) Paging Control Channel (PCCH)Dedicated Control Channel (DCCH)Common Control Channel (CCCH)Shared Channel Control Channel (SHCCH)ODMA Dedicated Control Channel (ODCCH)ODMA Common Control Channel (OCCCH)Control Channel (CCH)Traffic Channel (TCH)Dedicated Traffic Channel (DTCH)ODMA Dedicated Traffic Channel (ODTCH)Common Traffic Channel (CTCH)
41Physical Channel Downlink Channels Uplink Channels Dedicated physical ChannelCommon physical ChannelDownlink ChannelsDownlink Dedicated Physical Channel (DPCH)Physical Downlink Shared Channel (DSCH)Primary and Secondary Common Pilot Channels (CPICH)Primary and Secondary Common Control Physical Channels (CCPCH)Synchronization Channel (SCH)
42Mapping of Transport channel into Physical Channel Source: The Transport Channels are Channel Coded and matched to the datarate offered by physical Channels.
43Downlink Physical Channels The length of a radio frame is 10 ms and one frame consists of 15 time slots.The number of bits per time slot depends on the physical channel.There is one downlink dedicated physical channel, one shared and five common control channelsDedicated Downlink physical channel (DPCH)Physical downlink shared channel (DSCH)Primary and secondary common pilot channels (CPICH)Primary and secondary common control physical channels (CCPCH)Synchronization channel (SCH)
45Channel Symbol rate (ksps) DPDCH and DPCCH FieldSlotFormat #Channel Bit rate(kbps)Channel Symbol rate (ksps)SFBits/slotDPDCH Bits/slotDPCCH Bits/slotTransmittedSlot perRadio frame NTrNData1NData2NTPCNPilotNTFC1157.5512102481000816Source: 
46Downlink Dedicated Physical channel (DPCH) Fig. Data After SpreadingFig Data after Scrambling
47Simulation of Downlink Channels Methodology.Generation of DataMapped to I and Q branchAdjust into Frame by Adding TPC, TFCI bits……Spreading & ScramblingDivide to Real and Imag branchModulation
48DPCHAccording to 3GPP standards, one slot (10ms/15 = .666 ms) layout is asfollows:|--Data1--|--TPC--|--TFCI--|--Data2--|--pilot--|| | | | | |Total bits = 1280, SF=4 ==>num_chips=1280*4=5120chips/slotChannel rate is 1280(bit/slot)*15(slot) =1920 kbps.To form a slot and then a frame we need to break our data stream intoaccording to Data1 and Data2(format#0).
49Common Downlink Physical channel Common Pilot Channel (CPICH)P-CPICHS-CPICHFig Common Pilot Channel (CPICH) 
50Common Control Physical Channel Primary-CCPCHSecondary-CCPCHFig Primary-CCPCH Fig Secondary-CCPCH 
51Synchronisation Channel (SCH) The Synchronisation Channel (SCH) is a downlink signal used for cell search.Consists of Two ChannelFig. Structure of Synchronisation Channel (SCH) 
52Synchronisation Code Generation PSCDefine:a = <x1, x2, x3, …, x16>a= <1, 1, 1, 1, 1, 1, -1, -1, 1, -1, 1, -1, 1, -1, -1, 1 >Now PSC is Defined asCpsc = (1 + j) × <a, a, a, -a, -a, a, -a, -a, a, a, a, -a, a, -a, a, a>
67ReferenceJ. Schiller, “Mobile Communication”, second edition Pearson Education Private LTD.Rudolf Tanner and Jason woodword, “WCDMA Requirements and practical design”, John Wiley and Sons LTD.Holama H. and Toskala A. “WCDMA for UMTS”, John Wiley and Sons LTD.T Rappaport, “Wireless Communications, Principles and Practices”, Second Edition, Prentice Hall, 2002.Viterbi Andrew J “CDMA: Principles of spread spectrum communication”, second edition prentice hall LTD.Proakis J. G. “Digital Communication”, third edition prentice hall LTD.M. R. Karim and Sarraf M., “W-CDMA and CDMA 2000 for 3G Mobile Networks”, McGrawHill, 2002.Stallings, W “Wireless Communications and Networks” Prentice Hall LTD.Widrow, B., & Stearns, S.D “Adaptive Signal Processing” Prentice Hall: New JerseyHaykin, S “Adaptive Filter Theory” Prentice Hall: Eaglewood Cliffs
68ReferenceE. Berruto, M. Gudmundson, R. Menolascino, W. Mohr, and M. Pizarroso, “Research activities on UMTS radio interface, network architectures, and planning,” IEEE Commun. Mag., vol. 36, pp. 82–95, FebD. Grillo, Ed., “Special section on third-generation mobile systems in Europe”,” IEEE Personal Commun. Mag., vol. 5, pp. 5–38, AprBahl P. and Girod B., Eds., “Special section on wireless video,” IEEE Commun. Mag., vol. 36, pp , June 1998.W. Mohr and S. Onoe, “The 3GPP proposal for IMT-2000,” IEEE Commun. Mag., pp , DecHomer, J., Bitmead, R.R., & Mareels, I “Quantifying the effects of dimension on the convergence rate of LMS adaptive FIR estimator,” IEEE Transactions on Signal Processing, 46 (10):Homer, J “A review of the developments in adaptive echo cancellation for telecommunications,” Journal of Electrical and Electronics Engineering, Australia, 18(2):Homer J., Mareels I., Bitmead R.R., Wahlberg B., & Gustafsson F. “LMS estimation via structural detection” IEEE Transactions on Signal Processing, 46(10): , 1998A.J. Viterbi, “The Evolution of Digital Wireless Technology from Space Exploration to Personal Communication Ser vices,” IEEE Trans. Veh. Technol., Vol. 43, No. 3, pp. 638—644, August 1994.D.L. Schilling, “Wireless Communication Going into the 21st Century,” IEEE Trans. Veh. Technol., Vol. 43, No. 3, pp , August 1994.B. Girod and N. F¨aber, “Feedback-based error control for mobile video transmission,” IEEE Proceedings, vol. 87, pp , Oct
69ReferenceD.L. Schilling, “Wireless Communication Going into the 21st Century,” IEEE Trans. Veh. Technol., Vol. 43, No. 3, pp , August 1994.W. Mohr and S. Onoe, “The 3GPP proposal for IMT-2000,” IEEE Commun. Mag., pp , DecZhang X., Gang. H., “Strategies of improving QoS for Video Transmission over 3G Wireless Network”, Hohai university.Cherriman P., Hanzo L., “ Robust H.263 Video Transmission over Mobile Channels In interference Limited Environment”, 1st IEEE wireless video communication workshop.Gharvi H., “Video Transmission for Third Generation Mobile Communication Systems”, Milcom, 2001.
70Reference [3GPP Technical specification] 3GPP TSG Technical Specification TS “Physical channels and mapping of transport channels”.3GPP TSG Technical Specification TS “Spreading and modulation”3GPP TSG Technical Specification TS “Multiplexing and channel coding (FDD)”3GPP TSG Technical Specification TS “Physical layer procedures (FDD)”
71Reference [Websites]  CDMA Development Group RAKE Receiver: Another Advantage of CDMA over Other Systems. [Accessed Oct ].CDMA seminars onWCDMA chapter-6: