Jia Zhan | Searcharxiv

arXiv2023

Joint Design of Source-Channel Codes with Linear Source Encoding Complexity and Good Channel Thresholds Based on Double-Protograph LDPC Codes

We propose the use of a lower or upper triangular sub-base matrix to replace the identity matrix in the source-check-channel-variable linking protomatrix of a double-protograph low-density parity-check joint-source-channel code (DP-LDPC JSCC). The elements along the diagonal of the proposed lower or upper triangular sub-base matrix are assigned as "1" and the other non-zero elements can take any non-negative integral values. Compared with the traditional DP-LDPC JSCC designs, the new designs show a theoretical channel threshold improvement of up to 0.41 dB and a simulated source symbol error rate improvement of up to 0.5 dB at an error rate of 1e-6.

cs.IT↗

arXiv2022

Design of Joint Source-Channel Codes Based on a Generic Protograph

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.

cs.IT↗