Simulation of Third Generation CDMA Systems - Virginia Tech

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the desired MS specific scrambling code. The following figure illustrates the descramblingprocessC S*ReconstructedFrameDescrambledFrame3 Figure 3.11: DescramblingC S is the scrambling code of the desired Mobile Station in the uplink. It represents thescrambling code of the desired base station in the downlink simulator. The asterisk (*)indicates complex conjugation. Figure 3.12 shows the despreading operation,C IRe{}∫dtDescrambledFrameC QIm{}∫dt4 Figure 3.12: Despreadingwhere C I and C Q represent the appropriate spreading codes in figure 3.12.The despread decision statistic from each branch is combined and a hard decision ismade on the bit. Maximal Ratio Combining (MRC) is employed. We assume that we haveperfect amplitude estimate of the channel while estimating the weights for MRC.42
3.2.7 BER CounterThe bit error rate counter compares the decision of the hard-limiter for the I channelor the data channel to the transmitted data at the I channel and counts the number of error.BER is evaluated by averaging the number of error over several transmitted frames. At least400 frames are used to compute the BER at low SNR. To compute the BER at higher SNR,as many as 4000 frames were used.3.2.8 Analytical Treatment of the Uplink SimulatorLet us assume for the time being that no MAI is present in the system. The followingfigure shows the transmitter and the signals at different points.C I (t)d I (t)C SC (t)d s(t)s(t)d Q (t)jC Q (t)Figure 3.13: TransmitterThe data at the I channel is represented by the signal d I (t), while the data at the Q channel isrepresented by d Q (t).The spread data is denoted as,d () t = d () t c () t + jd () t c () t(3.22)s I I Q Qc I and c Q are I and Q channel spreading codes respectively.43
Page 1 and 2: Simulation of Third Generation CDMA
Page 3 and 4: AcknowledgmentsI would like to expr
Page 5 and 6: 2.9.2. Transmit Diversity Schemes2.
Page 7 and 8: List of Tables1.1 3G Data Rate Requ
Page 9 and 10: 3.9 Implementation of Pulse shaping
Page 11 and 12: Chapter 1IntroductionThe goal for t
Page 13 and 14: 1.3 Third Generation Cellular Syste
Page 15 and 16: 1.4. WCDMA: Air Interface for 3GOne
Page 17 and 18: 1.4.2 WCDMA Key Technical Character
Page 19 and 20: Chapter 2WCDMA Physical LayerThis c
Page 21 and 22: Channelization Code(C D )cos(ω c t
Page 23 and 24: DataPilotTFCI FBI TPCT slot =2560 c
Page 25 and 26: 2.4 Uplink Spreading CodesThe sprea
Page 27 and 28: Figure 2.6: Auto-correlation for Tw
Page 29 and 30: The following block diagram shows t
Page 31 and 32: 0.180.160.140.12Probabilty Density0
Page 33 and 34: ar( 0) = 2vr( 0) + 1 (2.12)mod 4ar(
Page 35 and 36: 2.8 Channel CodingThe main purpose
Page 37 and 38: 2.9.2 Transmit Diversity SchemesTra
Page 39 and 40: These differences will become evide
Page 41 and 42: Dtoffset = 2 (3.15)cHere c is the v
Page 43 and 44: Each ray is split into two rays, on
Page 45 and 46: The pass-band of the pulse shaping
Page 47 and 48: The Rayleigh waveform is generated
Page 49 and 50: This expression can be used directl
Page 51: e -jϕ1FrameAlignmentResamplingDesc
Page 55 and 56: (t)R i ’(t)R i (t)e -jϕ i C SC *
Page 57 and 58: IT+ τT + τi i i I iτ iτ iiiz =
Page 59 and 60: 3.3.2 MAI for DownlinkThe MAI in th
Page 61 and 62: menu is provided which gives the op
Page 63 and 64: up_sim.mpar_up.mat ovsf_gen.m scram
Page 65 and 66: 3.6 Code OptimizationThe simulator
Page 67 and 68: Chapter 4Simulation ResultsThis cha
Page 69 and 70: 10 0 E b/N 010 -1BER10 -210 -30 int
Page 71 and 72: 10 0 Number of Interfererssf=32sf=1
Page 73 and 74: 10 0 E b/N 00 interferer2 interfere
Page 75 and 76: 10 -1 Number of InterferersBER10 -2
Page 77 and 78: constraint length. So for a constra
Page 79 and 80: Table 4.1: Performance Improvement
Page 81 and 82: channel model based on measurement
Page 83 and 84: [7] Kevin Laird, Nick Whinnet, and
Page 85: VitaFakhrul Alam was born in Dhaka,

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