MIMO relaying for multiaccess communication in cellular networks

We study an amplify and forward (AF) relaying scheme that uses a multiple-input-multiple-output (MIMO) relay to improve the performance of multi-point to point communication in cellular networks. With the assumption that perfect channel state information (CSI) is known, the MIMO relay and the base station (BS) receiver are jointly optimized. The objective is to minimize the sum mean-square error (MSE) while keeping the total transmit power of the relay constant. This problem is solved suboptimally using iterative as well as non-iterative methods. Computer simulations show the performance improvements of the proposed methods over conventional all-pass MIMO relay.