Performance Analysis of Distributed Transmit Beamforming with Quantized Channel Feedback

Abstract

Distributed transmit beamforming (DTBF) is an efficient technique to increase the transmission coverage in a situation where distributed nodes have limited hardware capabilities such as transmit power or the number of equipped antennas. This scenario is quite typical in tactical communication systems. The DTBF precodes transmit signals based on feedback information. In practice, continuous channel phase information is quantized based on codebook to reduce feedback overhead. In this paper, we will analyze the effect of channel quantization in the DTBF and show a small number of bits are enough to encode channel feedback information to achieve comparable performance compared to the DTBF without channel quantization. We will also derive approximated probability density function of the received SNR, which is very useful to further derive the performance of the DTBF in terms of channel capacity, outage probability, and error rates