  In this paper, robust transceiver design based on minimum-mean-square-error
(MMSE) criterion for dual-hop amplify-and-forward MIMO relay systems is
investigated. The channel estimation errors are modeled as Gaussian random
variables, and then the effect are incorporated into the robust transceiver
based on the Bayesian framework. An iterative algorithm is proposed to jointly
design the precoder at the source, the forward matrix at the relay and the
equalizer at the destination, and the joint design problem can be efficiently
solved by quadratic matrix programming (QMP).
