Joint Source-Channel Codes Based on a Single Protograph

In this paper, we propose using a single 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. Using the classic AR3A and AR4JA protographs, we construct AR3A-JSCC and AR4JA-JSCC codes. We analyze their decoding thresholds and compare their performance with JSCC systems using optimized double protograph low-density-party-check codes.