Performance of Joint Channel and Physical Network Coding Based on Alamouti STBC

TL;DR

This paper analyzes the performance of a joint channel and physical network coding scheme using Alamouti STBC over Nakagami-fading two-way relay channels, proposing a novel precoding and simplified decoding method with theoretical BER analysis.

Contribution

It introduces a new precoding scheme and a simplified LLR update rule for efficient decoding in joint channel and PNC systems with Alamouti coding.

Findings

The proposed scheme achieves BER performance consistent with simulations.

The theoretical analysis has lower computational complexity than existing methods.

The approach facilitates design and evaluation of JCNC in wireless networks.

Abstract

This work considers the protograph-coded physical network coding (PNC) based on Alamouti space-time block coding (STBC) over Nakagami-fading two-way relay channels, in which both the two sources and relay possess two antennas. We first propose a novel precoding scheme at the two sources so as to implement the iterative decoder efficiently at the relay. We further address a simplified updating rule of the log-likelihood-ratio (LLR) in such a decoder. Based on the simplified LLR-updating rule and Gaussian approximation, we analyze the theoretical bit-error-rate (BER) of the system, which is shown to be consistent with the decoding thresholds and simulated results. Moreover, the theoretical analysis has lower computational complexity than the protograph extrinsic information transfer (PEXIT) algorithm. Consequently, the analysis not only provides a simple way to evaluate the error performance but also facilitates the design of the joint channel-and-PNC (JCNC) in wireless communication scenarios.