Parallel Concatenated Joint Source-Channel Coding

In this letter we present a novel approach for robust source transmission where variablelength source and channel encoding are concatenated in parallel. Simulation results show that for waveform source signals the proposed scheme shows a strong increase in decoding performance compared to the typically applied serially concatenated scheme. Introduction: Recently, joint source-channel coding (JSCC) approaches have emerged as a good alternative to the strict application of Shannon’s source-channel separation principle for delayconstrained transmission scenarios. A subset of these techniques is given by joint source-channel decoding, where residual source redundancy increases the error-correction capability of the decoder (see e.g., [1, 2]). Especially, the serial concatenation of implicit source redundancy and explicit redundancy from a channel code can be decoded in an iterative fashion analog to the decoding of serially concatenated channel codes [3, 4]. However, parallel concatenated JSCC (PCJSCC) schemes could be an alternative to serially concatenated approaches when one aims to increase the decoding performance especially for high bit error rates [5]. In this letter a novel joint source-channel coding scheme for the reliable transmission of variable-length encoded waveform signals over additive white Gaussian noise (AWGN) channels is proposed. Instead of using a standard serial concatenation of source and channel encoder we employ a parallel concatenation of variable-length codes (VLCs) and channel encoding. Simulations results show that this new scheme outperforms a previously published serially concatenated VLC JSCC approach [6] in terms of reconstruction signal-to-noise ratio (RSNR). The transmission model is shown in Fig. 1. The vector represents a packet of correlated source symbols , where after quantization with bits we obtain the resulting index vector ! " # %$ with & ' ,