Compress-And-Forward Cooperative Relaying in MIMO-OFDM Systems

Abstract

In this paper, we investigate the capacity of compress-and-forward (C&F) cooperative relaying scheme when the C&F relay operates in time division duplex (TDD). In our evaluation we consider MIMO-OFDM transmission. An achievable rate was previously derived in (A. Host-Madsen et al., 2005) assuming scalar channel. We extend this Wyner-Ziv bound to MIMO-OFDM, by applying results from Bayesian vector estimation and rate-distortion coding theory. Then we derive the mutual information of a sub-optimum relaying scheme in which the relay applies Karhunen-Loeve transform to the signal received from the source before quantizing it and forwarding it to the destination as a new codeword. Finally, we illustrate by simulations (in an environment similar to IEEE 802.16) the fact that for some scenarios, the C&F approach outperforms other known relaying techniques. This remains true even if the C&F sub-optimum scheme is considered