Multi-Beam Multiple Access Scheme for Uplink Traffic of Wireless Virtual Reality with Millimeter-Wave Analog Beamforming

Wireless Virtual Reality (VR) is a new-arising technology to enable the untethered connection between VR server and VR client, whose traffic characteristics include both ultra-high data rate in downlink and periodic small-size data packets in uplink. The downlink requires ultra-wide bandwidth and hence leads to the usage of millimeter-wave (mmWave) spectrum with analog beamforming; however, this causes difficulty for the uplink: the efficient multiple access of small-packet users in the same mmWave carrier by time-division duplex (TDD). Therefore, this paper proposes a multi-beam multi-access scheme for the uplink traffic of multiple VR users with mmWave analog beamforming. Specifically, this scheme contains an analog beamforming weight determination function and a frequency-division user scheduling function, which are executed iteratively with the increasing number of selected users. Therein, the proposed multi-beam analog beamforming pattern generation method is able to generate arbitrary number of beams with flexible beam directions, beam widths and beamforming gain ratios, by the constant-modulus weights with one radio-frequency chain. It is demonstrated by the simulation results that the proposed multi-beam multi-access scheme increases 200% for the maximum number of simultaneously served VR uplink users than the traditional single-beam multi-access scheme in 5G systems with mmWave analog beamforming.