Generalized Channel Coding and Decoding With Natural Redundancy in Protocols

Mainstream wireless communication networks mostly adopt the layered protocol encapsulation mechanism, which inevitably introduces natural redundancy into protocols. To fully exploit the abundant natural redundancy in protocols (NRP), this paper provides a novel cross-frame and cross-layer perspective for channel coding and decoding (CCD). First, a generalized CCD architecture is developed for the first time to describe the NRP and artificial redundancy in channel codes (ARC) uniformly. The concept of equivalent code rate is proposed correspondingly to evaluate the potential gain of NRP. Second, we summarize the types of NRP, and for each of them, factor graphs and sum-product algorithms (SPAs) are adopted to model and solve the correlation between it and ARC. On this basis, the joint decoding of multi-class NRP and ARC is further considered, and a general SPA-based joint protocol-channel decoding (JPCD) scheme is presented. Finally, tests on the 802.11n TCP/IP/MAC protocol stack demonstrate that the JPCD scheme can significantly improve the decoding performance of both the packet header and payload with a relatively small computational cost. Our work shows great promise in reducing error retransmission, bandwidth overhead, and the difficulty of source recovery.