在本論文中，我們在正交碼跳躍多工(Orthogonal Code Hopping Multiplxing, OCHM)系統架構下，使用完美序列(Perfect Sequence)做訊號展頻，以降低系統在多重路徑衰減通道中之干擾。傳統之OCHM系統，均是使用Walsh-Hadamard序列作訊號展頻，然而Walsh-Hadamard序列在多重路徑衰減通道中會失去正交性，因此會產生嚴重的干擾。而完美序列在多重路徑衰減通道中，依然會保持正交的特性，因此極適合使用在OCHM系統。在本論文之中，我們除了用理論分析在多用戶系統中的訊號對干擾比值(Signal to Interference Ratio, SIR)，也用電腦模擬得到系統的位元錯誤率(Bit Error Rate)。

In this thesis, the perfect sequence is adopted for the multi-path interference cancellation in orthogonal code hopping multiplexing (OCHM) systems. In traditional OCHM systems, Walsh-Hadamard sequences are adopted for signal spreading. Unfortunately, orthogonality of the Walsh-Hadamard sequences is lost in multi-path fading channels, leading to significant increase in interference. On the other hand, perfect sequences maintain their orthogonality even if synchronization is lost in multi-path fading channels. In this thesis, the signal to interference ratio (SIR) is analyzed mathematically for systems with multiple users. In addition, simulation experiments are conducted to obtain the bit error rate.

致謝 ............................................................................................................................. Ⅰ
論文摘要 ..................................................................................................................... Ⅱ
Abstract....................................................................................................................... Ⅲ
目錄..............................................................................................................................Ⅳ
圖表目錄......................................................................................................................Ⅵ
第一章　導論................................................................................................................1
1.1研究動機..........................................................................................................1
1.2論文架構..........................................................................................................2
第二章 分碼多工存取系統之簡介............................................................................3
2.0引言..................................................................................................................3
2.1分碼多工存取系統簡介..................................................................................3
2.2虛擬雜訊..........................................................................................................5
2.3跳躍式正交碼多工系統簡介..........................................................................8
2.4跳躍式正交碼多工系統的碰撞情形簡介.....................................................11
第三章 訊號衰減與完美序列特性簡介..................................................................15
3.0引言................................................................................................................15
3.1通道衰減因素簡介........................................................................................15
3.2多重路徑衰減效應........................................................................................17
3.3耙狀接收機....................................................................................................18
3.4完美序列特性簡介........................................................................................21
第四章 SIR分析在OCHM系統下使用完美序列.................................................23
4.0引言................................................................................................................23
4.1消除部份干擾之完美序列特性簡介............................................................23
4.2訊號干擾功率比值數學分析........................................................................24
第五章 電腦模擬結果..............................................................................................36
第六章
結論.............................................................................................................41
參考文獻.....................................................................................................................42

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