Abstract: Abstract: User scheduling and power allocation are investigated for the downlink of MIMO systems with limited feedback. Corresponding algorithms are proposed based on the idea of opportunistic multiple beamforming. The proposed algorithm feeds the first and the second maximum SINRs of each user and indices of the corresponding beamforming back to the base station only. Simulations show that, compared with previous methods, it can better acquire tradeoff between feedback overhead and total throughput. The proposed power allocation algorithm makes full use of the partial channel state information. Numerical results show that this method can obtain higher throughput under the constraint of available transmit power compared to conventional methods. When the proposed user scheduling and power allocation algorithms are combined, better performance can be obtained without increasing feedback overhead.

Key words: user scheduling, power allocation, downlink of MIMO system, limited feedback, opportunistic beamforming