On the Performance of MIMO Spatial Multiplexing Relay Channels

In this paper we discuss and compare different signalling and relaying methods for multiple-input multiple-output (MIMO) relay networks in terms of network capacity, where every terminal is equipped with multiple antennas. We propose a new relaying mode called hybrid relaying, by which the MIMO relay channels can be decomposed into several point-to-point parallel channels without decoding the desired signals at the relay. We show that the proposed hybrid relaying algorithms outperform the conventional analogue relaying scheme. They can be good suboptimal choices compared with digital relying schemes, providing an attractive tradeoff between performance and complexity, especially when larger numbers of antennas are deployed at the relay than at the source and destination.