Performance Analysis of Distributed Beamforming in Wireless Networks: The Effect of Synchronization and Doppler spread

Abstract

Distributed Beam-Forming (DBF) is a promising technique for increasing range and throughput in cooperative wireless networks. It is known, however, that DBF is sensitive to carrier-synchronization (“synch”) errors among the spatially separated RF oscillators in the distinct transmitting radios as well as errors due to independently occurring Doppler spread (fading) in each contributing link. We analyze here the statistical behavior of the resulting time-dependent beamforming gain as a function of these synch errors and dynamics-induced Doppler spread. A Gamma-distribution approximation is employed and compared to simulation for the resulting gains and system performance. The proposed statistics can subsequently be employed for optimizing the design parameters of a DBF protocol (frame period, pilot length, resynch period) for given pre-specified capacity or link-outage constraints.