Multicast performance of large-scale antenna systems

A multicast large-scale antenna system (LSAS) provides distinct programs simultaneously to different groups of users. We analyze the performance of using a common reverselink pilot sequence for the estimation of user channels receiving the same program, and derive an optimal reverse/forward-link combined power control scheme that equalizes the throughput among all users. Equal throughput to all users is effected through a combination of proper forward-link power allocation among user groups and power control on the reverse-link pilots of each individual user. The power control scheme is optimal in the sense that the equalized per-user throughput is maximized. Compared with an LSAS that uses a distinct pilot sequence for each user, our approach provides the following advantages: simultaneously support of many more users; substantially higher throughput per-user; lower user terminal power consumption.