Systems and methods for radio frequency calibration exploiting channel reciprocity in distributed input distributed output wireless communications

A method implemented within a RAN comprising:

• sharing a same 3GPP standard protocol time/frequency reference among a plurality of BTSs distributed throughout a coverage area without cells;
• sending a plurality of training signals between the plurality of BTSs;
• and
• processing the training signals to estimate a plurality of RF calibration coefficients.

A system comprising:

• a plurality of wireless transceiver devices (BTSs) of a RAN, the plurality of BTSs distributed throughout a coverage area without cells,
• wherein one or more of the plurality of BTSs are configured to send a plurality of training signals between them, the training signals processed to estimate a plurality of radio frequency (RF) calibration coefficients;
• and
• wherein a DL CSI is derived from a UL CSI using the RF calibration coefficients and exploiting UL and DL channel reciprocity.

A method implemented within a RAN comprising:

• sending a plurality of training signals between the plurality of BTSs distributed throughout a coverage area without cells;
• processing the training signals to estimate a plurality of RF calibration coefficients;
• and
• deriving a DL CSI from a UL CSI using the RF calibration coefficients and exploiting UL and DL channel reciprocity.