Single-port measurement scheme: An alternative approach to system calibration for 5G massive MIMO base station conformance testing

To calibrate the test system of fifth-generation (5G) massive multiple-input multiple-output (MIMO) base station (BS), this paper proposes a promising single-port measurement scheme, which is more cost-effective and convenient than conventional scheme. The conventional scheme first requires the disconnection of the measurement equipment from the BS test system, and then uses a costly vector network analyzer (VNA) for the system calibration measurement, which is cumbersome, slow, and inconvenient. Instead, the proposed scheme can conduct the system calibration with low cost directly based on the existing measurement equipment in the original test system, i.e. no need for the extra expensive VNA. The accuracy performance of the proposed scheme is evaluated by the frequency response error measured between the proposed and the conventional schemes, e.g. with an amplitude error range of [-0.45, 0.14] dB and a phase error range of [-0.2¤, 2.5¤]. Therefore, the superiority is that the proposed single-port scheme in this paper accomplished the equivalent measurement as the conventional scheme, and further reduced the cost and inconvenience for the test industry. Finally, the reduced cost and complexity by the proposed measurement scheme is beneficial to both the industry and academic scientific world in terms of faster and more efficient testing as well as increased reproducibility of research findings.