Performance of relay based interference alignment with imperfect channel state estimation

In this paper, we consider a multiusers´ (MUs) interference network, where exist K relay-destination (R-D) pairs, and each user has a single transmit antenna and each relay has K receive antennas. To estimate the CSI of K destination-relay/relay-destination pairs, the maximum likelihood based channel estimator is proposed in K distributed relay stations. Meanwhile, by considering the estimation error in the uplink, the upper bond of sum rate loss for relay based space-time interference alignment scheme is derived in K pairs relay-destination interference network. The simulation results of sum rate performance are analyzed under different outdated CSIT scenarios.