在行動通訊系統中，經過了展頻的分碼多重接取系統訊號頻寬會變得相當大，頻寬若大於通道的同調頻寬時，通道成了頻率選擇衰減(frequency selective fading) 通道，多重延遲路徑將造成接收端的訊號的失真。多載波分碼多重接取(Multi-Carrier Code Division Multiple Access, MC-CDMA)技術的訊號頻寬將變窄，若頻寬小於通道的同調頻寬時，通道便成了頻率非選擇衰減(frequency nonselective fading) 通道。除此之外，多載波分碼多重接取系統在資料的傳輸速度上較分碼多重接取系統快。
多載波分碼多重接取系統若使用一般傳統的組合性偵測方式，就必須先估測出使用者的通道參數，估測通道參數誤差會導致偵測器性能的下降，盲目適應性偵測方式則不需要估測通道參數，且對干擾的消除具有強健性，對於部分頻帶干擾(partial-band interference)此偵測方式可以利用遞迴的方式將部分頻帶干擾頻帶的影響減低。除此之外，此偵測方式兼可以使用於上行(uplink)和下行(downlink)，這些都是組合性偵測方式所沒有的優點。
本論文中，我們發現此盲目適應性偵測方式存在鏡像問題，我們提出了三種方法以解決鏡像問題，並分析與比較三種方法的優缺點，並以電腦模擬驗證解決鏡像問題後的性能。

In mobile radio systems, the bandwidth of spread spectrum signals for CDMA system is very wide. If the bandwidth exceeds the coherence bandwidth of the channel, the signal is transmitted in the frequency-selective channel, and the signal is severely distorted by the multiple propagation paths. Each bandwidth of the signals for Multi-Carrier CDMA system is smaller. If the bandwidth is smaller than the coherence bandwidth of the channel, the channel is said to be frequency-nonselective. Besides, the data rate of Multi-carrier-CDMA is higher than the data rate of CDMA.
If the traditional combing detector is used for Multi-Carrier CDMA system, the channel coefficients have to be estimated first. The error of the estimated channel coefficients will result in the performance of detector degrade. The blind adaptive algorithm doesn

感謝詞

[1] P. Jung, P. W. Basier, and A. Steil,