展頻系統是現在無線通訊最常用的多重存取技術，它可以很容易的設計及解碼。展頻系統在對抗人為惡意干擾上可以有很不錯的表現，但是在使用者人數增加時，錯誤率會大大的增加。我們稱之為多重存取干擾(multiple access interference)，而這種影響是不會隨著訊號強度而變好，進而形成通訊系統的難題。我們利用迴旋編碼(convolutional code)來做為多重存取的傳輸方式，迴旋編碼式之無線多重接取是針對多重存取通道的技術，每個使用者利用不同迴旋編碼器編碼，並且利用最大相似正確地解出傳送的資訊來避免多重存取干擾。如何設計有效的編碼讓系統的錯誤率降低並且擁有較高的傳送效率是這個論文的主要研究課題。

無線通訊是現在普遍的傳輸通訊方式，但無線通訊的傳輸環境卻有許多干擾的因素，除了受到雜訊的影響，在傳輸的過程中，也會產生衰減(fading)的現象，發生相位位移及訊號強度的不穩定。在這篇論文中，我們試著利用卡式濾波器(Kalman Filter)去估測衰減的影響，找出最佳近似的衰減影響，以此來找出最近似的信號。我們以高斯-馬可夫(Gaussian-Markov)訊號模型來模擬我們的傳輸環境，在論文中，試著找出編碼的效能界限以發現編碼的基本原則，以達成最佳的效能以及較高的資訊傳輸效率來建構我們的多重存取系統，並且經由電腦模擬分析與傳統的傳輸方式來做比較。

E±cient use of transmission facilities often requires the sharing of resources. We propose a
approach to design a multiple access system over Rayleigh fading channel. We present in
detail the coding scheme based on convolutional codes. Good performance and high data
rate of each user are the two chief goals of our code construction.

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