A Degrees-of-Freedom-Achieving Scheme for the Temporally Correlated MIMO Interference Channel with Delayed CSIT

A simple scheme is proposed to achieve the optimal degrees of freedom (DoF) of the temporally correlated two-user multiple-input-multiple-output interference channel with delayed channel state information at the transmitter (CSIT). The delayed CSIT is exploited for temporal alignment at the transmitters and spatial zero-forcing of interference at the receivers. The transmitters estimate the current CSIT using perfect delayed CSIT. For most antenna configurations, the proposed scheme achieves the optimal DoF-region of this channel by precoding (resp. decoding) over a finite number of time slots at each transmitter (resp. receiver). This is an improvement over existing achievable methods, which require infinite channel extensions (hence, infinite decoding delay) and involve complicated encoding and decoding procedures.