近年來無線通訊系統發展迅速,為了達到人們的需求,多輸出多輸入(MIMO)系統的維度(dimension)也不斷增加來提供高的吞吐量(throuput),因此低錯誤率且低複雜度的多輸出多輸入(MIMO)偵測器變成一個熱門的議題.然而隨著天線數不斷的增加,訊號處理的複雜度跟著提高,訊號之間的干擾(ICI)以及每根天線都搭載著一個RF-chain,這使得電路體積龐大且功率號損嚴重,於是就有人提出了空間調變多輸入多輸出(spatial modulation system)的系統,它為單一RF-chain的概念(single RF-chain),限制RF-chain的數目用來解決功率損號以及電路龐大的問題,還可以化簡傳送端與接收端的複雜度.空間調變多輸入多輸出(spatial modulation system)的系統利用獨特的調變方式不同於傳統的多輸出多輸入(MIMO)系統,將接收到的二位元訊號mapping到訊號星座圖上以及空間星座圖上,借此可以提高吞吐量,本論文使用空間調變多輸入多輸出(spatial modulation system)的系統.
本論文重點在於低運算複雜度的偵測器,首先我們可以設定一個可以接受的錯誤率,再根據不同接收到的訊雜比去選取最低複雜度的偵測器來使用,來提供可接受的錯誤率(JAER),傳統的ML偵測器複雜度過高不適合來實踐在硬體上,且sphere decoding 偵測器雖然可以降低複雜度但是由於偵測器無法固定運算的吞吐量所以本論文提出一個modified k-best 的演算法來做為偵測器.論文中介紹兩種偵測器分別是single k-best偵測器以及multiple k-best 偵測器,根據不同的參數有不同的複雜度,接著我們提出algorithm selection(選取演算法)的方法,來選擇低複雜度的偵測器提供可接受的錯誤率.

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