Low complexity all-digital PIM compensator

摘要

The present disclosure relates to compensation for Passive Intermodulation (PIM) distortion in a receiver. In one embodiment, a communication device includes a transmitter that is configured to receive a digital input signal and output a radio frequency transmit signal, a main receiver configured to receive a radio frequency receive signal and output a digital output signal, and a PIM compensation subsystem. The radio frequency receive signal includes PIM distortion that is a non-linear function of the radio frequency transmit signal output by the transmitter. In order to compensate for the PIM distortion, a PIM compensation subsystem receives the digital input signal of the transmitter, generates a digital PIM estimate signal that is an estimate of the PIM distortion in the digital output signal of the main receiver, and subtracts the digital PIM estimate signal from the digital output signal of the main receiver.

主权项

1. A communication device comprising:
a transmitter configured to receive a digital input signal and output a radio frequency transmit signal that is transmitted by the communication device; a main receiver configured to receive a radio frequency receive signal and output a digital output signal, the digital output signal comprising passive intermodulation distortion that is a non-linear function of the radio frequency transmit signal output by the transmitter; a combined digital predistortion and passive intermodulation estimate generation subsystem configured to:
receive the digital input signal of the transmitter;predistort the digital input signal of the transmitter according to a behavioral model of an inverse of a nonlinearity of the transmitter; andgenerate a digital passive intermodulation estimate signal that is an estimate of the passive intermodulation distortion in the digital output signal of the main receiver based on the digital input signal of the transmitter according to a behavioral model of the transmitter, a source of the passive intermodulation distortion, and the main receiver; andsubtraction circuitry configured to subtract the digital passive intermodulation estimate signal from the digital output signal of the main receiver to thereby provide a compensated digital output signal.