Multiuser Zero-Forcing Beamforming with Limited Feedback in Wireless Ad Hoc Networks

The effect of limited feedback on point-to-multipoint communication is investigated in multi-antenna wireless ad hoc networks. We consider zero-forcing beamforming with quantized channel direction information and derive new closed-form expressions for the outage probability, throughput, transmission capacity, and average user rate. Expressions for the performance degradation due to finite rate feedback, the optimal number of streams, and the required feedback rate scaling are provided. Our results indicate that the optimized system operating points depend on different network parameters such as pathloss exponent, node density, and outage constraints.