5G trial system coverage evaluation utilizing multi-point transmission in 15 GHz frequency band

The downlink coverage of a 5G trial system operating within the 15 GHz frequency band is evaluated in this paper with the help of drive test measurements. Key 5G features, such as beamforming, beam tracking and multi-point transmission have been utilized during the measurements. The results indicate that multi-point transmission provides a clear improvement to the downlink coverage. Received signal strength is improved due to the macro diversity offered by the utilization of multiple transmission points. Furthermore, distributed MIMO, i.e. the possibility for the user equipment (UE) to simultaneously receive independent data streams from multiple transmission points, results in large improvements in the average rank values. This is the case in particular for the locations in between the transmission points, where the UE has sufficiently good links towards the serving nodes. Finally, as a result of both the improved signal strength and higher rank values, the average downlink throughput is improved by 33–46% (whole area) or 39–42% (busy square). All in all, the trial system is able to maintain a very high downlink throughput, varying from 4 to 13 Gbps, towards a UE moving within the busy square, which demonstrates the benefit of seamless mobility between the different beams and transmission points.