English

On the BCJR Algorithm for Asynchronous Physical-layer Network Coding

Information Theory 2011-05-25 v1 math.IT

Abstract

In practical asynchronous bi-directional relaying, symbols transmitted by two source nodes cannot arrive at the relay with perfect symbol alignment and the symbol-asynchronous multiple-access channel (MAC) should be seriously considered. Recently, Lu et al. proposed a Tanner-graph representation of symbol-asynchronous MAC with rectangular-pulse shaping and further developed the message-passing algorithm for optimal decoding of the asynchronous physical-layer network coding. In this paper, we present a general channel model for the asynchronous multiple-access channel with arbitrary pulse-shaping. Then, the Bahl, Cocke, Jelinek, and Raviv (BCJR) algorithm is developed for optimal decoding of asynchronous MAC channel. This formulation can be well employed to develop various low-complexity algorithms, such as Log-MAP algorithm, Max-Log-MAP algorithm, which are favorable in practice.

Cite

@article{arxiv.1105.4683,
  title  = {On the BCJR Algorithm for Asynchronous Physical-layer Network Coding},
  author = {Xiaofu Wu and Chunming Zhao and Xiaohu You},
  journal= {arXiv preprint arXiv:1105.4683},
  year   = {2011}
}

Comments

3 pages

R2 v1 2026-06-21T18:11:36.297Z