Distributed SR‐LDPC codes over multiple‐access relay channel and its applications in cloud storage

Summary Digital fountain techniques have received significant academics and industry attention in the past years because of their rateless, robust, and real‐time characteristics used in networks and storage systems such as cloud data storage. Semi‐Random low‐density parity‐check (SR‐LDPC) codes are a kind of digital fountain codes with linear encoding and decoding complexity. In this paper, We propose a novel encoding procedure to realize codes that resemble SR‐LDPC codes (rateless codes for erasure correction) in both structure and performance. For the case of two sources communicating with a single destination via a common relay, the two sources separately encode their own symbols of information using SR‐LDPC codes. The relay then makes Exclusive OR (XOR) for the two sequences received from the two sources. The destination can recover the information bits of the two sources using the sequences received directively from the two sources and the sequence received from the relay. It is shown that the sequences received by the destination are still SR‐LDPC codes. Iterative decoding can be used by the destination using the sequences received from both the relay and the sources and obtain good performance.