an open access repository of Middlesex University research http://eprints.mdx.ac.uk Vien, Quoc-Tuan; Nguyen, Huan X., 2012. Network coding based CQI reporting for two-way multi-relay networks. Available from Middlesex University's Research Repository.
Copyright:Middlesex University Research Repository makes the University's research available electronically.Copyright and moral rights to this work are retained by the author and/or other copyright owners. No part of the work may be sold or exploited commercially in any format or medium without the prior written permission of the copyright holder(s). A copy may be downloaded for personal, noncommercial, research or study without prior permission and without charge. Any use of the work for private study or research must be properly acknowledged with reference to the work's full bibliographic details.This work may not be reproduced in any format or medium, or extensive quotations taken from it, or its content changed in any way, without first obtaining permission in writing from the copyright holder(s).If you believe that any material held in the repository infringes copyright law, please contact the Repository Team at Middlesex University via the following email address: eprints@mdx.ac.ukThe item will be removed from the repository while any claim is being investigated. This results in a significant improvement of system throughput especially when the number of relays is large. Upper and lower bounds of the mean square error (MSE) of the estimated CQI are derived to study performance behaviour of our proposed scheme. It is found that the MSE of the estimated CQI increases proportionally with the square of the cardinality of CQI level sets though an increased number of CQI levels would eventually lead to a higher data-rate transmission. Based on the derived bounds, a low-complexity relay selection (RS) scheme is then proposed. Simulation results show that, in comparison with optimal methods, our suboptimal bound-based RS scheme achieves satisfactory performance while reducing the complexity at least three times in case of large number of relays.Quoc-Tuan Vien is with School of Engineering and Built Environment,