Sensitivity Analysis of Beamforming Techniques for Periodic Broadcast V2V Communication

In this work, we extend the results of two previously proposed transmit beamforming techniques for periodic, broadcast, vehicle-to-vehicle communication with a common fixed broadcast period, to the scenario where vehicular users (VUs) use different, and potentially varying, broadcast periods. The two techniques, analog beamforming network (ABN) of phase shifters and antenna switching network (ASN), were previously developed in accordance with a multiple antenna receiver that employs an analog combining network (ACN) of phase shifters. To accommodate the use of multiple broadcast periods, we propose the design of phase shifter parameters of ABN-ACN and ASN-ACN systems using a design period T
d
. Then, we analytically derive sets of broadcast periods that sustain optimality, in the sense that the sum signal-to-noise ratio (SNR) of K consecutive packets for any receiving VU is maximized. Next, we provide guidelines on how to set T
d
to ensure a sufficient granularity of the sets of optimal broadcast periods. Finally, we investigate using numerical computations the effect of certain design choices on the sensitivity of ABN/ASN-ACN systems to small variations of the broadcast period.