平行串接變動長度碼及迴旋碼 其遞迴型整合式訊源/通道循序解碼演算法

Iterative Joint Source-Channel Sequential Decoding Algorithms for Parallel Concatenated Variable Length Code and Convolutional Code

林煜星(Yu-Hsing Lin)

指導教授 ： 黃育銘

國立暨南國際大學/科技學院/通訊工程研究所/碩士(2009年)

摘要

由於系統複雜度(complexity)與系統延遲(delay)時間的限制，分離式解碼的效能往往無法達到理論上的最佳值。為了改善傳統分離式解碼的效能，在解碼過程中，有效利用壓縮過後所殘留的剩餘資訊(residual redundancy)，同時運用訊源(source)與通道(channel)的統計資訊，同時進行訊源解碼及通道解碼。這種解碼技術稱為整合式訊源/通道解碼(Joint Source -Channel Decoding; JSCD)。
文獻上，應用在遞迴型整合式訊源/通道解碼之Modified-BCJR (M-BCJR)解碼演算法，當所有可用之訊源或通道資訊均予以考量時，往往所建構出的格狀圖(trellis diagram)相當龐大，雖然解碼效能可達到最佳，但其解碼複雜度相當高。本論文裡，首先提出低複雜度之SISO (soft-input-soft-output)整合式訊源/通道循序解碼演算法，接著探討此SISO循序解碼演算法應用在遞迴型(iterative)整合式訊源/通道解碼(I-JSCD)時其效能及複雜度之分析。

關鍵字

整合式訊源通道解碼 ； 格狀圖 ； 循序式解碼

並列摘要

Due to the constraints on complexity and delay, the performance of separate decoding is usually not optimal. In the past, in order to further improve the performance of separate decoding, the residual redundancy left after compression, the source priori information, and the channel statistical information are exploited and fully utilized for presenting a so-called joint source-channel decoding (JSCD) scheme.
In tradition, the trellis of the modified BCJR decoding algorithm adopted in iterative joint source/channel decoding will become tremendously large while all the source and channel information are utilized. Although the decoding performance is optimal, the decoding complexity becomes quite expensive. Therefore, it is not practical. In this work, we propose a low complexity soft-input-soft-output joint source/channel sequential decoding algorithm and apply it in iterative joint source/channel decoding.

並列關鍵字

iterative joint source/channel decoding, source priori information, BCJR, soft-input-soft-output

參考文獻

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