Capacity analysis of cognitive MISO multicast network

In this paper, we consider a scenario where a secondary base station (SBS) with K antennas utilizes the licensed spectrum of a single primary user (PU) to send the same information to N secondary users (SUs). The SBS selects only one antenna out of the K antennas by using maximum signal power to leak interference power ratio strategy (SLIR). Using asymptotic analysis, we first derive the average capacity of multicast transmission scheme with perfect channel state information from the SBS to the PU (interference CSI) available at the SBS. Then, we characterize its capacity loss in the case that perfect interference CSI is not always available at the SBS.