SPC05-6: Performance of Opportunistic Beamforming with Quantized Feedback

Opportunistic beamforming has been shown to achieve true beamforming gains with unquantized signal-to-interference ratio (SNR) feedback when there are sufficient users in the system [1], [2]. In this paper we investigate the performance of opportunistic beamforming with an SNR quantization scheme that maximizes the expected system throughput. To show that the opportunistic beamforming can still be beneficially employed with quantized SNR feedback, we derive the SNR statistics and the system throughput to optimize the SNR quantization with respect to thresholds separating quantization levels. Numerical results are used to illustrate the impact of the optimum threshold levels and the number of thresholds.