4×4多輸入多輸出之表列舉球面解碼之晶片設計

Abstract

在這篇論文中，我們利用查表的方式來列舉星座點實現一個比較低複雜度的球面解碼器。對於每個星座點，我們提出只要在周圍均勻切成四個子區域，再加上在最上層下一個搜尋點數的限制所得的解碼器可以達到滿意的吞吐量且符元錯誤率只有0.5dB的損失。此外我們結合了事先縮小範圍的演算法來降低搜尋點數。在硬體架構上，我們不需要用到任何的乘法器並且支援BPSK、QPSK、16-QAM和64-QAM。以TSMC90um的製程，在高訊雜比下，平均的吞吐量可達411.3Mpbs。

In this thesis, we implement sphere decoder with low complexity. The decoder uses table to save the enumeration order of different constellations. For each constellation point, we propose to use only 4 sub-regions. Together with the constraint on the top level, the decoder can achieve satisfactory throughput performance while the performance degradation is only around 0.5 dB. In addition, we use admissible set elimination (ASE) algorithm to further decrease the number of searching nodes. In hardware design, we proposed an architecture that does not need multiplier to shorten the critical path. This proposed architecture can support BPSK, QPSK, 16-QAM and 64-QAM. The average throughput of the proposed architecture can achieves a throughput up to 411.3Mbps for 64-QAM modulation in high SNR.