Iterative LMMSE transceiver design for dual-hop AF MIMO relay systems under channel uncertainties

This paper considers the problem of robust linear transceiver design for a dual-hop amplify-and-forward (AF) MIMO relay system, with Gaussian random channel uncertainties in both hops. By taking the channel uncertainties into account, an iterative algorithm is proposed to minimize the mean-square-error (MSE) of the output signal at the destination. Simulation results show that the proposed algorithm reduces the sensitivity of the AF MIMO relay systems to channel estimation errors, and performs better than the algorithm based on estimated channels only.