Simulation of Third Generation CDMA Systems - Virginia Tech

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code can be used by an MS if and only if no other code on the path from the specific code tothe root of the tree or in the sub-tree below the specific code is used by the same MS [5]. Thegeneration method of OVSF can be explained with the help of the following matrixequations:c () 1 = 1!!!1ccccccc224444() 1( 2)() 1( 2)() 3( 4)NcccNN"$# = !"$# = !( N -1)N() 1( 2)..( N)c1() 1 c1()1 1 1c1() 1 c1()1$# = 1 -1cccc"$#2222() 1 c() 1 c( 2)c( 2)c=!2222() 1""#$!"$#1 1 1 1() 1 1 1 1 1( 2)1 1 1 1# = - -- -( 2)1 -1 -1 1ccœœ!() 1 c () 1N/ 2 N/2() 1 c () 1N/ 2 N/2. .. .c ( N / 2) c ( N / 2)N/ 2 N/2c ( N / 2) c ( N)N/ 2 N/2"$#"#$(2.3)In the above matrix notation, an over bar indicates binary complement (e.g.1=- 1 and- 1=1) and N is an integral power of two.The OVSF codes do not have a single, narrow auto-correlation peak as shown infigure 2.6. As a consequence code-synchronization may become difficult. OVSF codesexhibit perfect orthogonality only at zero lags and even this does not hold for partialsequencecross-correlation. As a result the advantage of using OVSF codes is lost when allthe users are not synchronized to a single time base or when significant multipath is present.16
Figure 2.6: Auto-correlation for Two OVSF Codes of SF=256Figure 2.7 a: pdf of Transition in the Figure 2.7b: pdf of Transition in theSignal Constellation with Proper Code Constellation for Arbitrary CodeSelectionSelectionThe first code of any code tree as described in this section is used to spread theDPCCH. This is a sequence of all 1’s for any SF. The first DPDCH is spread by the codenumber (SF/4+1) where SF is the spreading factor for the data channel. As for example, the5 th code is used for spreading the first DPDCH for a spreading factor of 16. So the spreadingcode for the first DPDCH is always a repetition of {1,1, -1, -1}. Subsequently addedDPDCHs for multi-code transmission are spread by codes in ascending order starting fromcode number 2 excepting the code used for the first DPDCH. Code selection in this orderlymanner along with the proper choice of scrambling code increases the spectral efficiency bylimiting the diagonal transitions in the signal constellation. This also results into efficient use17
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: 2.4 Uplink Spreading CodesThe sprea
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 and 52: e -jϕ1FrameAlignmentResamplingDesc
Page 53 and 54: 3.2.7 BER CounterThe bit error rate
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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