Over the Air Calibration of Massive MIMO TDD Arrays for 5G Applications

Technical Publications
Monday, July 31, 2017

This paper addresses the problem of how to accurately calibrate Massive MIMO systems using time-division duplexing (TDD). In practical MIMO array implementations the transmission and reception path are different and hence a calibration mechanism, linking optimum receive array coefficients to optimum transmit coefficients is needed. We propose an Over-the-Air OTA calibration technique based on post-processing of the measured transmit and receive beam. The method is described and uncertainties linked to the method are investigated. A demonstration measurement on a representative array is presented to illustrate the application of the calibration method to realistic MIMO systems.