第三代行動通訊系統是架構在CDMA系統架構下的，這是因為CDMA的系統能夠提供了比TDMA與FDMA系統更多的系統容量。但是在CDMA系統中，當所使用的Pseudo-Noise sequences並不正交時，訊號會受到所謂的Multiple Access Interference(MAI)的干擾。 本篇論文因此分析使用M-ary 正交調變的DS-CDMA系統效能，並且使用四種的PIC的接收技術去消除MAI的干擾影響，此外還利用三種的編碼方式增加系統效能，以及使用RAKE接收架構與Channel Estimation抵抗多路徑通道的衰落的效應。 論文中的模擬結果顯示，使用了以上所述的技術後，可以得到較好的效能結果。 The 3th generation mobile communication system will base on CDMA system, because CDMA system can provide more capacity than TDMA and FDMA systems. But because the pseudo-noise sequences are not exatly orthogonal, signal will suffer from the interference called Multiple Access Interference (MAI). This thesis analyzes the performance of DS-CDMA system with M-ary orthogonal Modulation, using four types of PIC receiver to cancel the MAI effect, tow kinds of channel codes to increasing the system performance. RAKE structure and Channel Estimation are also used to fight multipath fading. The simulation results show that we have can improve the performance using PIC, Coding, and channel estimation technique.
