Active interference cancellation

摘要

Antenna structures and methods of operating the same are described. One apparatus includes a processing device that executes an active interference cancellation (AIC) algorithm and radio frequency front-end (RFFE) circuitry coupled to the processing device. The RFFE circuitry includes two RF couplers, and a programmable-delay filter and a vector modulator disposed along electrical path. The AIC algorithm is operable to control the programmable-delay filter to match a delay of the electrical path to a propagation delay in an antenna path. The AIC algorithm is operable to control the vector modulator to adjust a phase, an amplitude or both of a copy of a first RF signal transmitted via the first antenna to generate a second RF signal. The second RF signal is added to a third RF signal via the second RF coupler to remove from the third RF signal interference caused by the first RF signal.

主权项

1. An apparatus comprising:
a processing device; and radio frequency front-end (RFFE) circuitry coupled to the processing device, the RFFE circuitry comprising
a vector modulator disposed along an electrical path between a transmit path to a first antenna and a receive path from a second antenna, wherein the processing device is operable to match a delay in the electrical path to a propagation delay in an antenna path, wherein the processing device is operable to control the vector modulator to adjust a phase, an amplitude or both of a copy of a first RF signal to generate a third RF signal that is added to a second RF signal received via the second antenna to remove interference caused by the first RF signal transmitted via the first antenna, wherein the processing device is operable to determine a phase and an amplitude for the third RF signal that results in a minimum power by the second RF signal by:
setting a phase resolution to a first value;determining a first phase of the third RF signal with the phase resolution set to the first value;setting an amplitude resolution to a second value;determining a second amplitude of the third RF signal with the amplitude resolution set to the second value;setting the phase resolution to a third value;determining the phase of the third RF signal with the phase resolution set to the third value;setting the amplitude resolution to a fourth value;determining the amplitude of the third RF signal with the amplitude resolution set to the fourth value;setting the phase resolution to a fifth value;determining the phase of the third RF signal with the phase resolution set to the fifth value;setting the amplitude resolution to a sixth value; anddetermining the amplitude of the third RF signal with the amplitude resolution set to the sixth value.