Performance Analysis and Improvement of Multi-user Detector Using Probabilistic Data Association in CDMA systems
碩士 === 國立臺北科技大學 === 電機工程系所 === 93 === The main purpose of this thesis is to improve the performance of multi-user detector using probabilistic data association in CDMA systems by reducing its computational complexity. The performance of multi-user detector using probabilistic data association is clo...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
2005
|
| Online Access: | http://ndltd.ncl.edu.tw/handle/2v45m8 |
| Summary: | 碩士 === 國立臺北科技大學 === 電機工程系所 === 93 === The main purpose of this thesis is to improve the performance of multi-user detector using probabilistic data association in CDMA systems by reducing its computational complexity. The performance of multi-user detector using probabilistic data association is close to optimal multi-user detector, but its computational complexity is still higher than the linear MMSE multi-user detector. To reduce its computational complexity, the different initial settings of probabilistic data association are used in this thesis to analyze the effects of convergence time of this multi-user detector in synchronous and asynchronous CDMA systems. A new method has been proposed in this thesis. We set the initial values of probabilistic data association by using the soft decision of the output signals in MMSE or decorrelating multi-user detectors. It can reduce the computational complexity while maintain the same bit error rate in the CDMA systems. Finally, the new proposed method and other methods of fixed initial values of probability are applied to both the DS-CDMA system and slowly fading flat channel MC-CDMA system to verify its performance.
|
|---|