Chunked BATS Codes under Time-invariant and Time-variant Channels

In this paper, a batched sparse(BATS) code transmission scheme based on chunked outer code is proposed. At the source node, a source file is first segmented into K number packets, then all the packets are divided into N chunks, each of which contains the same number of packets except for the last one if K can not be divided by N. The chunks are encoded with the chunked outer code of BATS codes before transmitted to the next node. At the destination node, only the decodable batches need to be decoded to recover the input packets, and undecodable batches are abandoned directly to save the storage resources. In the aspect of the decoding, a simplified decoder is proposed, which is based on Gaussian elimination decoding. The consumed number of batches with a source file successfully transmitted by using the proposed scheme is analyzed under both time-invariant and time-variant channels. The simulation results show that compared with conventional BATS codes, less number of batches are consumed by applying the proposed chunked outer code.