Outdoor Experimental Trials of Millimeter-Wave Base Station Cooperation with Digital Beamforming in High-Mobility Environments for 5G Evolution

Outdoor Experimental Trials of Millimeter-Wave Base Station Cooperation with Digital Beamforming in High-Mobility Environments for 5G Evolution

연구 분야: Networking

학회: 2020 IEEE 92nd Vehicular Technology Conference (VTC2020-Fall)

The fifth-generation (5G) mobile communications system initially introduced massive multiple-input multiple-output (M-MIMO) with analog beamforming (BF) to compensate for the larger path-loss in millimeter-wave (mmW) bands. 5G Evolution (5GE), which should be actualized around 2025, will replace analog BF with hybrid or fully digital BF that improves the mmW-band downlink/uplink transmission performance. In addition, 5GE requires base station (BS) cooperation technologies to provide stable and reliable cell-edge transmission in the mmW bands, even when mobile stations (MSs) travel at high speed. This paper introduces our developed 28-GHz-band trial equipment employing a novel BS cooperation technology with digital BF to track the MS mobility. We present evaluation results of outdoor experimental trials at a MS velocity of 90 km/h. Two M-MIMO antennas are deployed in the trials, and the BS cooperation selects one M-MIMO antenna based on the maximum received power criterion of a reference signal transmitted by the MS. The trials clarify that the BS cooperation maintains the maximum throughput in a wider area than non-BS cooperation at 90 km/h.