Joint weighted bit-flipping decoder for use in diversity network coding

Abstract

A new joint message-passing decoder is presented for use in a two-user cooperative wireless network. This decoder is designed for use with the diversity network coding scheme of Xiao et al. , which uses nonbinary network codes together with channel coding to achieve high diversity gains. The proposed joint decoder, together with appropriate modifications to the cooperative protocol of Xiao and Skoglund (2010), significantly reduces the required implementation complexity both at the relay nodes and at the receiver. The destination's joint decoder structure consists of two parallel weighted bit flipping (PWBF) decoders which exchange extrinsic soft/hard information regarding the two users' packets. It is demonstrated through simulations that the proposed joint decoder achieves not only the same diversity gain as in the work of Xiao and Skoglund (2010), but also approximately 5dB of additional coding gain. It is also notable that a significant improvement in system performance can be achieved after only two joint decoding iterations.