A Bidirectional Channel Access Method in Millimeter Wave Dense Deployment Scenario

Due to the high path loss, directional transmission and reception are adopted in millimeter wave band which provides the possibility for spatial multiplexing. Traditional microwave access technologies usually use omnidirectional channel assessment to avoid transmission interference. But this will greatly suppress the spatial multiplexing in beam-based transmission, and the transmitter only needs to perform carrier sensing at the direction of the target receiver. However, directional carrier sensing may lead to potential hidden terminal problems. This paper proposes a bidirectional carrier sensing scheme, which aims to reduce the interference caused by the hidden terminal while ensuring the spatial reuse rate of the directional transmission. The key idea is to perform carrier sensing in the direction of the receiver and the opposite direction at the same time before the transmitter accesses the channel. Numerical results prove that proposed scheme can effectively reduce hidden terminals, avoid interference, and improve system throughput.