Design of distributed jointed source-channel coding schemes in wireless sensor networks for seismic exploration based on QC-LDPC codes

摘要

In this paper, we employ distributed jointed source-channel (DJSC) coding based on quasi-cyclic low-density parity-check (QC-LDPC) codes in our wireless sensor network (WSN) for seismic exploration. In order to reduce the latency of jointed decoding, we propose a parallel structure of jointed decoding, and decoders of multiple sources can decode simultaneously. We make use of the soft information of a posteriori probability (APP) returned by decoders of other sources and let decoders re-initialize once during iterations. To make decoders with parallel structure work more efficiently, layered logarithm belief propagation (Log-BP) algorithm is employed. In addition, since the data collected by sensors in our WSN has its own features, we modify the regular coding scheme. Simulation results show that, decoders with the proposed parallel structure can achieve a performance as good as, or even better than that of decoders with serial structures, while the latency of them can be reduced nearly a half, and the modification of encoding scheme has a performance gain compared with that of the regular one.