Triggering digital predistortion training using a reverse signal

A method performed by an apparatus, the method comprising:

• generating a set of digital samples of a reverse signal that is based at least in part on at least one of:
• crosstalk that is associated with an antenna panel, or
• a reflection that is based at least in part on the antenna panel and a forward signal that is associated with a multiple-input-multiple-output (MIMO) communication via the antenna panel;
• and
• computing, selectively, one or more digital predistortion (DPD) coefficients based at least in part on a DPD training trigger decision, the DPD training trigger decision being based at least in part on the set of digital samples of the reverse signal.

An apparatus comprising:

• a plurality of transmit chains each comprising a power amplifier, the plurality of transmit chains coupled to an antenna array comprising a plurality of antennas;
• one or more feedback circuits, each of the one or more feedback circuits comprising an electrical isolation circuit that is configured to capture at least a portion of a signal between the power amplifier of at least one of the plurality of transmit chains and the antenna array and output a reverse signal corresponding to a signal passing in a direction from the antenna array towards the power amplifier, each of the one or more feedback circuits configured to output a feedback signal based on the reverse signal;
• and
• a digital predistortion circuit included as a part of one or more of the plurality of transmit chains or coupled to the one or more of the plurality of transmit chains, the digital predistortion circuit configured to receive the feedback signal that is based on the reverse signal from the one or more feedback circuits.