Beamwidth Design for Beam Scanning in Millimeter-Wave Cellular Networks

In this paper, we analyze the coverage probability and average rate of millimeter-wave (mmWave) communication systems with directional cell discovery based on beam scanning. We first model the system and derive the coverage probability and average rate using stochastic geometry. We then show that the appropriate beamwidth can balance cell search delay and beamforming gains, improving average rate. Finally, we design the beamwidth that achieves a near-optimal average rate, which is approximately $\text{1.5}\%$ less than the maximum average rate, and verify it by simulation. Furthermore, some useful remarks, which serve guidelines for mmWave beamforming system design, are provided.