This work considers the problem of relaying spatially multiplexed signals between a source and a destination using a non-regenerative relay equipped with multiple antennas. In addition to the usual power amplification, the relay is assumed to process the received data vector before forwarding it to the destination. We present two linear filtering techniques that perform this processing in an optimal manner when channel state information (CSI) on the backward and forward channels is available at the relay. Firstly, we derive the relay filter that minimizes the pairwise error probability (PEP) assuming maximum-likelihood (ML) detection at the destination. Secondly, we simultaneously optimize the relay and destination filters in the mean-square error (MSE) sense. The proposed relaying techniques are shown to achieve error performance improvements, especially when the number of antennas at the relay is increased.
By: Pedro Coronel; Wolfgang Schott
Published in: in 2006
LIMITED DISTRIBUTION NOTICE:
This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.
Questions about this service can be mailed to reports@us.ibm.com .