In this paper, we propose using a generic protograph to design joint source-channel codes (JSCCs). We present a generalized algorithm, called protograph extrinsic information transfer for JSCC algorithm (PEXIT-JSCC algorithm), for analyzing the channel threshold of the proposed JSCC. We also propose a source generic protograph EXIT (SGP-EXIT) algorithm, which is more appropriate than the generalized source protograph extrinsic information transfer (GSP-EXIT) algorithm, for evaluating the source threshold of a generic protograph. Moreover, a collaborative optimization method based on the SGP-EXIT and PEXIT-JSCC algorithms is proposed to construct generic-protograph JSCCs with good source and channel thresholds. Finally, we construct generic-protograph JSCCs, analyze their decoding thresholds, and compare their theoretical and error performance with JSCC systems based on optimized double-protographs. Results show that our proposed codes can attain channel thresholds within 1 dB from the Shannon limit and outperform double-protograph-based JSCCs.
翻译:在本文中,我们提议使用通用程序表来设计联合源-渠道代码(JSCCs),我们提出一种通用算法,称为JSCs算法(PEXIT-JSCC算法),用于分析拟议的JSCs的频道阈值;我们还提议使用一种通用程序表ExIT(SGP-EXIT)算法,这比通用程序表外部信息传输(GSP-EXIT)算法更适合用来评价通用程序表的源阈值;此外,我们提议采用基于SGP-EXIT和PEXIT-JSC算法的合作优化方法,用良好的源和频道阈值来建立通用程序化JSCs;最后,我们建立通用程序表JSCs,分析其分解阈值,并根据最佳的双程序图谱将其理论和错误性表现与JSCscocs系统进行比较;结果显示,我们提议的代码可以在1 dB 范围内从香农限值和超出以双程序为基础的双程序基JSCs达到频道阈值。