“…This case also can be justified by the fact that the true channel evolves over time by the addition of an independent matrix with C(O, 1) entries where a is a forgetting factor which describes the rate of evolution of the channel matrix. However, the case when CSI-T and CSI-R are both imperfect (Case II) can be associated to the practical scenario when the channel estimation at the receiver is not perfect, while the feedback channel is perfect and instantaneous [4] , [20] , We suppose that the channel matrix H in both cases can be expressed as [4] , [20] H = �II + yaH, (5) where H is the channel matrix described in (1), II is the estimate of H where the entries are assumed to be CN(O, 1), H is the error matrix independent of II where the entries are assumed to be CN(O, 1), and a E [0, 1] is the estimation error variance due to the noisy feedback channel (Case I) or the channel estimation at the receiver (Case II). Note that in Case II, we consider the case when we have the same channel estimate at the transmitter and the receiver.…”