Precoded Batched Sparse Codes Transmission Based on Low-Density Parity-Check Codes

In this paper, a batched sparse(BATS) code transmission scheme based on Low-density Parity-check(LDPC) precoding over GF(2) is studied. At the transmitter, a source file is first segmented into several packets, which are then precoded with LDPC to generate more packets. The precoded packets are encoded with the outer coding of the conventional BATS codes before they are transmitted to the intermediate nodes, which apply inner coding to the received packets and forward them to the next node. At the sink node, only a portion of received packets need to be decoded successfully to recover the source file. Moreover a one-step BP decoder is then proposed which achieves the same performance as the two-step BP decoder. The simulation results show that compared with the conventional BATS codes, less transmission batches are required by using the LDPC precoding. Meanwhile, one step decoder achieves the same transmission performance as the two step decoder, which decodes BATS codes and LDPC codes successively.