Open Access

Practical Quantize-and-Forward Schemes for the Frequency Division Relay Channel

EURASIP Journal on Wireless Communications and Networking20082007:020258

DOI: 10.1155/2007/20258

Received: 6 April 2007

Accepted: 13 November 2007

Published: 8 January 2008


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.


Authors’ Affiliations

CNRS, Supéléc
Worcester Polytechnic Institute


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© B. Djeumou et al. 2007

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