位元交錯調變碼之效能分析

Abstract

位元交錯調變碼（BICM）保有籬笆碼之有效利用頻寬之特性，並擁有更多的分集階數，所以廣泛的應用在瑞雷衰退通道中，在本篇論文中，我們推導了位元交錯調變碼在加成性白色高斯雜訊通道與瑞雷衰退通道的系統效能分析，我們同時考慮了軟式與硬式解碼器。有鑑於灰色編碼的QAM調變在位元交錯調變碼擁有最佳的系統效能，我們特別針對它應用在位元交錯調變碼使用隨機標籤位址（BICM-RLP）與位元交錯調變碼使用固定標籤位址（BICM-FLP）這兩種架構提出一個更精準的分析。在使用軟式解碼器的BICM-RLP架構中，我們的分析比前人的精準，另一方面，BICM-FLP的架構則是全新的分析。

Bit-interleaved coded modulation (BICM) is a bandwidth-efficient scheme with a diversity order higher than the Ungerboeck’s trellis-coded modulation over fading channels. In this thesis, we investigate the performance of punctured BICM with soft and hard decoding over additive white Gaussian and Rayleigh fading channels. Tight BER upper bounds are derived for QAM constellation with gray labeling, which is known to have the best performance and constitutes a large portion of the practical applications of BICM systems. Both BICM with random (BICM-RLP) and fixed label position (BICM-FLP) mapping are analyzed. For BICM-RLP with soft decoding, the new upper bound is tighter than the well-known BICM Union and the Expurgated Bound proposed in [4]. The tight upper bounds for hard decision and for BICM-FLP with soft decision are newly derived results.