Low Complexity Multiuser Scheduling in MIMO Broadcast Channel with Limited Feedback

Abstract — This paper deals with the design and analysis of low complexity user scheduling algorithm in multi-antenna broadcast (downlink) systems under zero-forcing multiplexing with limited feedback. By using quantization technology, the channel matrix can be divided into serval unoverlapped channel regions. Based on the quantized channel regions, we can get semi-orthogonal region sets. Then the transmitter can carry out user scheduling by using the feedback channel direction information (CDI), channel quality information (CQI) and the quantized semi-orthogonal channel region sets. Simulation results show that the presented user scheduling algorithm can achieve a sum rate close to the full searching algorithms while with much lower complexity than those of the previous algorithms. I