這篇論文提出一個空間處理的RAKE接收機的架構，利用空間，時間與不同的路徑來分割和解調DS/CDMA多重路徑信號。空間的濾波器是beamforming網路(BFN)並且它的每一個權重是藉著MCMV的方法來取的。BFN在不同的空間位置來使信號分離並且使得 MAI 被壓制。因此每一個beamformer 幾乎只有一條路徑的信號被利用了，並且一個 coherent combiner 提供最大的 SINR。
傳統 RAKE 接收機雖然在單一使用者時是最佳化，但是當使用者數目增多時，它的效能就相對變差了，換句話說，也就是說它無法避免 near-far的問題，所以我們就提出了這個空間處理的 RAKE 接收機，來改善傳統 RAKE 接收機的缺點。分析與模擬的結果顯示了處理空間信號的RAKE接收機比傳統的RAKE接收機在有 MAI 時，提供了較好的性能。

This research proposes a spatial processing RAKE receiver that jointly exploits the spatial, temporal and path diversity to separate and demodulate DS/CDMA multipath signals. Spatial filtering is a beamforming network (BFN) with each weight determined by a multiply constrained minimum variance (MCMV) algorithm. The BFN isolates signals originating from different spatial locations such that multiple access interference (MAI) is suppressed. Since each beamformer places nulls to all but retains one path, a coherent combiner is then provided to maximize output signal to interference and noise ratio (SINR).
Although the conventional RAKE receiver is optimum in single user environment，but users is increases，the performance becomes worse。In the words，it suffer from the near-far problem. Hence we propose the spatial processing RAKE receiver to improve the performance of the conventional RAKE receiver in multiuser environment.Analysis and simulation results show that the spatial processing RAKE receiver offers much better performance than the conventional RAKE receiver in the presence of MAI.

封面內頁
簽名頁
授權書………………………………………………………………iii
中文摘要……………………………………………………………iv
英文摘要……………………………………………………………v
誌謝……………………………………………………………vi
目錄……………………………………………………………vii
圖目錄……………………………………………………………ix
表目錄………………………………………………………………x
第一章 緒論…………………………………………………………1
1. 1現代無線通訊…………………………………………1
1.1.1簡介…………………………………………………1
1.1.2展頻通訊……………………………………………4
1.2 問題規格和方法綜述…………………………………5
第二章RAKE 接收機的基本原理……………………………7
2.1 The Tapped Delay Line Channel………………………7
2.2最佳化的同調(coherent)Rake Receiver………………9
2.3 差分偵測(Differential Detection)的RAKE接收機……13
2.4 Decorrelating RAKE 接收機…………………………15
2.4.1簡介…………………………………………………15
2.4.2 Decorrelating-RAKE 接收機……………………17
第三章Beamformer的基本原理………………………………21
3.1簡介………………………………………………21
3.2 Beamformer Networks………………………………22
3.3 MVDR Beamformer…………………………………23
3.4 MCMV Beamformer…………………………………25
第四章 系統模型與性能分析……………………………………27
4.1簡介……………………………………………………27
4.2 性能分析……………………………………………29
4.2.1所提出架構的性能分析…………………………29
4.2.2 傳統 RAKE 接收機的性能分析………………30
第五章 模擬結果………………………………………………35
5.1系統參數………………………………………………35
5.2 模擬結果………………………………………………36
第六章 結論………………………………………………………42
參考文獻……………………………………………………………44
附錄A………………………………………………………………45

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