Throughput performance of local 5G downlink in SU-MIMO under outdoor environments

We evaluated the throughput performance, including received power, in 4×4 single-user multiple-input multiple-output (SU-MIMO) transmission for synchronous time division duplex (TDD) and downlink data channels in comparison with single-input single-output (SISO) transmission in an environment where a local 5G wireless base station was installed on the roof of a research building at our university. After showing a simulation method for evaluating throughput characteristics in MIMO, we compared the results with experimental results. The cumulative distribution function (CDF) of the transmission throughput shows that, at a CDF of 50%, in SISO transmission, the simulated value is approximately 115 Mbps, and the experimental value is 105 Mbps, within a difference of approximately 10 Mbps. By contrast, in MIMO transmission, the simulation value is 380 Mbps, and the experimental value is approximately 420 Mbps, which is a difference of approximately 40 Mbps. It was shown that the transmission throughput characteristics can be predicted with sufficient accuracy by obtaining the delay profile and the system model at each reception point using the both ray tracing and MIMO simulation methods in actual environments.