CSI feedback delay and degrees of freedom gain trade-off for the MISO interference channel

Channel state information at the transmitter (CSIT) plays a significant role in managing interference for the multiple-input-single-output (MISO) interference channel. Because of channel state information (CSI) feedback delay and time-variation in the wireless channel, perfect CSIT may be difficult to obtain, which results in the system performance degradation. In this paper, a CSI feedback delay-DoF gain trade-off is characterized for the MISO interference by using space-time interference alignment that exploits current and outdated CSI jointly. From this trade-off characterization, insight is provided the interplay between CSI feedback delay and DoF gain in the MISO interference channel.