在第三代行動通訊發展中，著重在現實行動系統中能夠結合高、中和低速率傳輸。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。 在本篇論文中我們分析與模擬不同的干擾消除機制(IC)去消除MAI的干擾影響，在探討這些干擾消除機制時，將可瞭解平行干擾消除機制(PIC)、團體方式平行干擾消除機制(GPIC)與團體方式串聯干擾消除機制(GSIC)的優缺點。同時我們也考慮了兩種團體方式混合干擾消除機制(GHIC)，因為它能夠改善GPIC與GSIC的缺點。 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。 In the development of third mobile telecommunication systems, attention for the realization of mobile systems, which are able to integrate high, medium and low rate transmission is increasing day by day. But because that the pseudo-noise sequences are not exactly orthogonal, signal will suffer from the interference called Multiple Access Interference (MAI). In this thesis, we analyze and simulate different kinds of interference cancellation (IC) schemes to overcome MAI in multi-rate MPG DS/CDMA. Among ICs, we can see the advantage and disadvantage of traditional parallel interference cancellation (PIC) 、 groupwise parallel interference cancellation (GPIC) and groupwise serial interference cancellation (GSIC). Two kinds of groupwise hybrid interference cancellation (GHIC) by combining GSIC and GPIC is also considered. It can improve the disadvantage of PIC 、GPIC and GSIC. The simulation results show that the performance enhancement can be achieved through weighting factors and Improved IC technique.
