Performance Analysis of 60 GHz Wireless Access with Beam Misalignment

High speed wireless access on 60 GHz spectrum relies on highly directional antenna beams to overcome the serve signal attenuation. However, perfect transmit-receive antenna beam alignment is rare in practice and overheard signals from concurrent transmissions may cause significant interference. In this paper we analyze the impact of antenna beam misalignment and beam patterns on the system performance of 60 GHz wireless access. We focus on two main-lobe beamwidth dependent parameters, namely, the half-power (3 dB) beamwidth to main-lobe beamwidth ratio and the beam misalignment deviation to main-lobe beamwidth ratio. We quantify the signal power loss from beam misalignment and the accumulated interference power from neighboring concurrent transmission links whose signals are leaked either via the main-beam in the similar direction or via side-lobe emission, and derive the probability distribution of the signal to interference plus noise power ratio. We evaluate the sensitivity of average throughput and outage probability against the above two parameters via numerical simulations of randomly deployed nodes inside a circular hall.