本論文著重在降低傳統K最佳演算法的複雜度及改善效能，並加入位元對數相似比(Bit level Log Likelihood Ratio, LLR)以利軟性解調多輸入多輸出偵測器之位元錯誤率效能提升。減少運算複雜度的方法為使用分散式K最佳演算法，因其能夠減少每一層樹狀搜尋的搜尋點數，且避免了排序電路的使用。文獻中，傳統作法是加入額外路徑產生器來改善多輸入多輸出系統之效能。由於額外路徑多應用於傳統K最佳演法，且受限於星座調變點數及K值，本論文所提出之額外路徑能應用於離散K最佳演算法，且不受限於星座調變解數及K值，使其能產生相同的額外路徑數來進入候選列表模組以利進一步改善效能。在硬體實現上，採用了管線式架構來設計以提高硬體操作頻率增加產出量，且將其設計成能支援各種天線組態。此設計可支援於2×2、4×4和8×8三種不同天線組態，並支援64-QAM、16-QAM、QPSK三種不同的調變方法。

This thesis focuses on reducing complexity of MIMO detector with soft-output by using traditional K-best algorithm and improving its performance by using bit level log likelihood ratio (LLR) to induce bit error rate. In order to reduce the complexity of MIMO detector, the distributed K-best (DKB) algorithm is employed to reduce the number of visited nodes at each layer and to avoid the sorting circuit. In the literature, additional tree search paths are usually used to achieve soft-output for enhancing bit error rate, but they are usually used for traditional K-best algorithm and limited by modulation method and K value. This thesis presents a generating method of additional paths, which can be used with the DKB algorithm. Besides, the proposed method generates the same number of additional paths for various modulation methods and different K values and sends to the candidate lists module to further improve performance. We use pipeline architecture to realize the proposed MIMO detector with soft-output. It is able to provide high clock rate and throughput with multi-antenna configurations. This soft-output MIMO detector supports not only three antenna modes of 2×2, 4×4 and 8×8, but also three modulation methods of QPSK, 16QAM and 64QAM.

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