Tham khảo luận văn - đề án 'báo cáo hóa học: " research article practical quantize-and-forward schemes for the frequency division relay channel"', luận văn - báo cáo phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID 20258 11 pages doi 2007 20258 Research Article Practical Quantize-and-Forward Schemes for the Frequency Division Relay Channel B. Djeumou 1 S. Lasaulce 1 and A. G. Klein2 1 CNRS Supeléc Paris 11 3 rue Joliot-Curie 91190 Gif-sur-Yvette France 2 Worcester Polytechnic Institute 100 Institute Road Worcester MA 01609-2280 USA Received 6 April 2007 Revised 22 August 2007 Accepted 13 November 2007 Recommended by Mohamed H. Ahmed We consider relay channels in which the source-destination and relay-destination signals are assumed to be orthogonal and thus have to be recombined at the destination. Assuming memoryless signals at the destination and relay we propose a low-complexity quantize-and-forward QF relaying scheme which exploits the knowledge of the SNRs of the source-relay and relay-destination channels. Both in static and quasistatic channels the quantization noise introduced by the relay is shown to be significant in certain scenarios. We therefore propose a maximum likelihood ML combiner at the destination which is shown to compensate for these degradations and to provide significant performance gains. The proposed association which comprises the QF protocol and ML detector can be seen in particular as a solution for implementing a simple relaying protocol in a digital relay in contrast with the amplify-and-forward protocol which is an analog solution. Copyright 2007 B. Djeumou et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION The channels under investigation in this paper are quasistatic orthogonal relay channels for which orthogonality is defined accordingly to 1 . Since the source-destination channel is assumed to be orthogonal to the relay-destination channel .
