Systems, methods and devices for joint calibration of transmit and receive IQ mismatch

A system comprising:

• a quadrature transceiver having a transmit path with a quadrature up-converter, a receive path with a quadrature down-converter, and a loopback path coupled between the up-converter and the down-converter;
• a signal generator arranged to apply first and second pilot signals to the transmit path;
• a signal observer arranged to capture the first and second pilot signals received from the receive path;
• a phase shifter arranged to apply a phase shift to at least one of the first and second pilot signals between the up-converter and the down-converter;
• and
• a processor configured to:
• obtain estimated in-phase (I) and quadrature (Q) mismatch (IQMM) parameters for the transmit path and the receive path by estimating the phase shift;
• and
• estimate one or more compensation coefficients for the quadrature transceiver based on the estimated IQMM parameters.

A method comprising:

• estimating an initial value of a phase mismatch for a receive (RX) path of a quadrature transceiver;
• estimating an initial value of a cross multiplication factor for a real-value compensator (RVC) for the RX path based on the initial value of the RX phase mismatch;
• obtaining a re-estimate of the RX phase mismatch;
• and
• correcting the initial value of the cross multiplication factor based on the re-estimate of the RX phase mismatch.