未來第三代無線通訊系統為了滿足人們的需求，除了語音服務之外， 甚至提供影像與數據的傳送。在這樣的前提下，寬頻分碼多工 ( Wideband Code Division Multiple Access ; WCDMA ) 系統成為未來發展趨勢。目前使用 中的CDMA系統比起過去的無線通訊系統 ( TDMA或FDMA系統 ) 有許多的 優點,其中最大的優點是能提升系統容量，但使用者增加的同時也相對增加 了彼此間的干擾，這種干擾又稱為多重擷取干擾 ( Multiple Access Interference ; MAI )。所以本篇論文的目的在於針對這種干擾提出改善的方法，我們利 用平行干擾消除法( Parallel Interference Cancellation ; PIC ) 來增加系統效能。另 外，我們將IS-95的上鍵路徑 ( Up-link ) 調變部份做討論與模擬,並且有鑑於 系統在衰落與多路徑環境下的效能並非很理想,因此除了使用雷克 ( RAKE ) 接收器來抵抗多路徑衰減 ( Multipath Fading ) 之外，還加入了通道參數估測 器( Channel Parameter Estimation ) 以改善系統效能。 最後根據我們分析與模擬的結果顯示，PIC技術確實能改善系統效能。 The 3th generation mobile communication system provides not only voice but also video and data services for satisfy human request. On the premise that wideband CDMA system becomes more improvement in the future trend. Comparisons of CDMA, TDMA and FDMA systems, there are many advantages using CDMA in the cellular system. The most of these advantages is increasing the system capacity. System interference will increase by large capacity. This interference is called Multiple Access Interference ( MAI ). In this thesis, we use Parallel Interference Cancellation Schemes to increase system performance. We will discuss and simulate the IS-95 standard's modulator in Up-link path. In the receiver design, we use RAKE structure to fight multipath fading and also join the Channel Parameter Estimation to improve system performance. Finally, according to our simulation results that the PIC technique is improving system performance indeed.
