Partitioned Analog Fountain Codes for Short Packet Communications

Abstract

Short analog fountain code (AFC) is a promising channel code for short packet communications, particularly in ultra-reliable and low latency communications (URLLC) scenarios. This letter proposes a short partitioned transmission strategy based on AFC (PT-AFC) to further enhance the error rate and latency performance of AFC at short block lengths. The key idea is to partition the information block into multiple short blocks, each being encoded using an AFC, and then concatenate the AFC coded symbols. The partitioning of the message allows for parallel decoding of various partitions at the receiver, which significantly reduces the overall latency. Additionally, this letter provides an analytical framework to minimize the number of short cycles in the bipartite graph of the respective code, where we determine an upper bound on the number of partitions, given the information block length and code rate. Simulation results show that PT-AFC outperforms existing AFC schemes with significantly reduced latency.