Systems and Methods for Adaptive Interference Cancellation

A method for cancelling interference in a communications system, the method comprising:

• receiving a radio frequency (RF) signal with an RF receiver located at an antenna site, the signal comprising a desired signal component and an interference signal component, the interference signal component originating from an RF transmitter also located at the antenna site;
• inputting the received RF signal from the RF receiver into a first phase modulator located at the antenna site;
• generating with a signal generator an inverse RF interference signal that is the inverse of the interference signal component;
• inputting the inverse interference RF signal into a second phase modulator;
• modulating an optical carrier signal with the second phase modulator relative to the inverse RF interference signal to generate a modulated optical signal;
• transmitting the modulated optical signal from the second phase modulator to the first phase modulator;
• modulating the optical carrier signal with the first phase modulator relative to the received RF signal and the modulated optical signal to generate a resulting optical signal;
• transmitting the resulting optical signal from the first phase modulator to a detector;
• and
• detecting the desired signal component with the detector.

A communications system comprising:

• an RF receiver that receives a desired signal and an interference signal;
• a first phase modulator that receives the desired signal and the interference signal from the RF receiver and that generates a resulting optical signal;
• a second phase modulator that generates a modulated optical signal relative to an inverse interference signal and that transmits the modulated optical signal to the first phase modulator;
• and
• a detector that receives the resulting optical signal from the first phase modulator and detects the desired signal, wherein the resulting optical signal comprises a modulated optical signal generated by the first phase modulator relative to the desired signal and the interference signal received from the RF receiver and further relative to the modulated optical signal received from the second phase modulator.

A radio-optical communications system that incorporates adaptive interference cancellation, the system comprising:

• an antenna site including:
• a radio frequency (RF) transmitter that transmits an interference signal,
• an RF receiver that receives a desired signal and the interference signal transmitted by the RF transmitter, and
• a first phase modulator that receives the desired signal and the interference signal from the RF receiver and that generates a resulting optical signal;
• and
• a control center including:
• a signal generator that generates an inverse interference signal that is the inverse of the interference signal transmitted by the RF transmitter,
• a second phase modulator that receives the inverse interference signal from the signal generator, generates a modulated optical signal relative to the inverse interference signal, and transmits the modulated optical signal to the first phase modulator, and
• a detector that receives the resulting optical signal from the first phase modulator and detects the desired signal, wherein the resulting optical signal comprises a modulated optical signal generated by the first phase modulator relative to the desired signal and the interference signal received from the RF receiver and further relative to the modulated optical signal received from the second phase modulator.