Transmit Beamforming for MIMO Multicast Channels
In this paper, the authors study the optimum Transmit (Tx) beamforming for a MIMO multicast channel where the multi-antenna base station (BS) sends common messages to K multi-antenna users, which is motivated by the modern cellular network where the support of multimedia multicast service is required. This research problem has received a considerable amount of attention in recent years. In the Tx beamforming vector is chosen to maximize the average SNR of the users. Since the multicasting performance is limited by the user(s) with the lowest SNR, the optimization should focus on those bottleneck users.