Abstract
Massive multiple-input multiple-output (MIMO) is
seen as an essential feature for the fifth-generation (5G) communication
systems. To ensure the array performance for beamforming
or nulling, it is important to conduct array calibration
beforehand. Since 5G massive MIMO base stations (BSs) are
expected to be highly integrated, i.e. the antenna arrays are
directly integrated with the transceiver front ends, there may be
no antenna connectors reserved for calibration purpose. In this
case, array calibration will be done fully over-the-air (OTA). In
this work, we propose a fast and short-distance OTA calibration
method for massive MIMO BSs based on digital beamforming
structures. Specifically, the correlation-based sounding technique
is utilized for simultaneous measurements, and phase deviation
due to the spherical wavefront at short distance is corrected with
the known propagation geometry. Moreover, a multipath cancellation
scheme is adopted to improve the calibration accuracy. An
experiment is conducted in an open laboratory environment to
assess the validity and robustness of the proposed calibration
method.
seen as an essential feature for the fifth-generation (5G) communication
systems. To ensure the array performance for beamforming
or nulling, it is important to conduct array calibration
beforehand. Since 5G massive MIMO base stations (BSs) are
expected to be highly integrated, i.e. the antenna arrays are
directly integrated with the transceiver front ends, there may be
no antenna connectors reserved for calibration purpose. In this
case, array calibration will be done fully over-the-air (OTA). In
this work, we propose a fast and short-distance OTA calibration
method for massive MIMO BSs based on digital beamforming
structures. Specifically, the correlation-based sounding technique
is utilized for simultaneous measurements, and phase deviation
due to the spherical wavefront at short distance is corrected with
the known propagation geometry. Moreover, a multipath cancellation
scheme is adopted to improve the calibration accuracy. An
experiment is conducted in an open laboratory environment to
assess the validity and robustness of the proposed calibration
method.
| Original language | English |
|---|---|
| Article number | 9446096 |
| Journal | I E E E Antennas and Propagation Magazine |
| Volume | 63 |
| Issue number | 3 |
| Pages (from-to) | 102-111 |
| Number of pages | 10 |
| ISSN | 1045-9243 |
| DOIs | |
| Publication status | Published - 1 Jun 2021 |