1. 1 Wideband DS-CDMA for Next-Generation Mobile Communications Systems Reporter : Vincent Chen Advisor : Prof. Li-Chun Wang 2000/8/13 Reference:IEEE Communication Magazine,1998.9

2. 2 Introduction: Second-Generation cellular system: Adopted digital technology Limited basic service Low-bit-rate Third-Generation cellular system: ITU:IMT-2000,2Mb/s Wideband DS-CDMA FDD,Air interface standard

3. 3 The difference between IS95 and WDS-CDMA IS95: Base on narrowband DS-CDMA Optimized for basic service The difference between second and third generation Isolated cell case Sectored cell: Overcome the interference program

4. 4 Content: The important concepts: Intercell asynchronous operation Pilot channel associated with individual data channels 1:Coherent Detection 2:Interference Cancellation 3:Adaptive antenna array (can be viewed as Adaptive cell sectorization) W-CDMA Technology

5. 5 The technical features: Fast transmit power control Coherent spreading code tracking Coherent rake receiver Orthogonal multispreading factor forward link Variable-rate transmission with blind rate detection Field experiment

6. 6 Enhanced Radio Transmission Techniques Multi-Stage Interference Canceller An Adaptive Antenna Array Combined with A Rake Receiver Matched Filter Rake Receiver Turbo Codes

7. 7 Design Concept: W-CDMA Technology Channel Coding Modulate 10ms Data Add Header QPSK Spread 2GHZ MF Rake Combiner Viterbi Decoder 10ms Data Transmiter Receiver Subtract Header

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10. 10 Fast Cell Search Under Intercell Asynchronous Operation Cell search algorithm: 1: Detect scramble mask timing of best cell (least sum of propagation path loss plus shadowing) 2: Identify the scramble code group 3: Search for the scramble code

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12. 12 Fast TPC

13. 13 Coherent spreading code tracking

14. 14 Coherent Rake Combining

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18. 18 Orthogonal multi-spreading factor forward link

19. 19 Variable-rate transmission with blind rate detection Discontinuous:Keep same Symbol rate Continuous:Keep same Chip rate Cyclic Redundancy Check Decoding Data rata=MSpreading code=01 Data rata=M/2 Spreading code=0011

20. 20 Field experiment System set-up for 32kb/s data transmission

21. 21 Measurement course characterization

22. 22 The effect of spreading bandwidth

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24. 24 High-speed(1.92 Mb/s) data transmission

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26. 26 Enhanced Radio Transmission Techniques Multi-Stage Interference Canceller COMSIC: COherent Multi-Stage IC CEIGU:Channel Estimation-and-Interference Generation Unit

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29. 29 An Adaptive antenna array combined with a Rake receiver CAAAR Receiver: Coherent Adaptive Antenna Array Rake Receiver

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31. 31 Matched Filter Rake Receiver

32. 32 Turbo Codes The main difference between Turbo codes and Conventional code Concatenating two or more recursive systematic codes Using a pseudo-random interleaver Iterative decoding algorithm

33. 33 RSC:Recursive system convolutional encoder

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