US Patent 11411778 Time-division duplex multiple input multiple output calibration

Aspects of this disclosure relate to a time-division duplex (TDD) multiple-input multiple-output (MIMO) system that includes a plurality of nodes. The plurality of nodes collectively includes antennas divided into groups. Reference signals can be transmitted from each group of antennas to one or more other groups of antennas during respective time slots. Channel estimates can be generated based on the received reference signals. The channel estimates can be jointly processed to generate calibration coefficients. Each calibration coefficient can represent a ratio associated with a transmit coefficient and a receive coefficient. Example algorithms for the joint processing are disclosed.