Adaptive method and apparatus for eliminating interference between radio transceivers

Apparatus for reducing interference between a plurality of transceivers, each of the plurality of transceivers having a communication port alternately providing a transmission signal to and receiving a received signal from a first antenna, each transceiver having an operating frequency, the apparatus comprising:

• a) a plurality of filter circuits, each of the plurality of filter circuits being electrically coupled to a corresponding transceiver for receiving a corresponding transmission signal therefrom, each filter circuit filtering a corresponding transmission signal, each of the plurality of filter circuits also having an output port for providing the filtered transmission signal thereon;
• b) a coupling device being electrically coupled to each of the plurality of filter circuits for receiving filtered transmission signals from each of the plurality of filter circuits, the coupling device also being electrically coupled to the first antenna for one of providing the transmission signals to and receiving the received signal from the first antenna, the coupling device having a reception channel port for providing the received signal to a transmission line;
• and
• c) a first power splitter being electrically coupled to the transmission line for acquiring a portion of the received signal, the power splitter dividing the portion of the received signal among a plurality of first power splitter output ports;
• d) a plurality of cancellation devices, each of the plurality of cancellation devices having a reference input port and a sample input port, the reference input port of each cancellation device being coupled to an output port of a corresponding filter circuit for receiving a sample of the corresponding transmission signal, the sample input port of each cancellation device being electrically coupled to a corresponding first power splitter output port to receive a sample of the received signal, the received signal sample having an error portion and a non-error portion, each cancellation device further having an output port and generating thereon a cancellation signal which is substantially equal to and opposite in phase to the error portion of the received signal attributed to a corresponding filter circuit output port;
• e) a power combiner being electrically coupled to the output port of each of the plurality of cancellation devices so as to receive each of the cancellation signals, the power combiner effectively combining the cancellation signals to provide a combined cancellation signal, the power combiner injecting the combined cancellation signal onto the transmission line so as to substantially eliminate the error portion from the received signal to provide a modified received signal;
• and
• f) a second power splitter being electrically coupled to the transmission line for receiving the modified received signal, the second power splitter dividing the modified received signal among a plurality of second power splitter output ports, each of the plurality of second power splitter output ports being coupled to a corresponding filter circuit for providing a corresponding second power splitter output signal thereto for processing therein.

A method for eliminating, from a received signal, a transmitter noise and distortion signal component generated by a transceiver, the method comprising:

• a) adjusting a frequency tunable filter circuit to an operating frequency of a corresponding transceiver;
• b) filtering a transmitter output signal with the frequency tunable filter;
• c) sampling the filtered transmitter output signal;
• d) providing the sample of the filtered transmitter output signal to an interference canceler;
• e) sampling a received signal, the received signal including a substantially undistorted signal component and a transmitter noise and distortion signal component;
• f) providing the sample of the received signal to the interference canceler;
• g) comparing the filtered transmitter output signal and the received signal and generating a cancellation signal which is substantially equal to and opposite in phase to the transmitter noise and distortion signal component;
• h) combining the cancellation signal with the received signal so as to effectively eliminate the transmitter noise and distortion signal component from the received signal thereby leaving substantially only the undistorted signal component, the undistorted signal component including a main signal component and a secondary signal component generated by the transmitter output signal, the secondary signal component having a frequency that is proximate to the frequency of the main signal component;
• i) filtering the undistorted signal component with the frequency tunable filter circuit to effectively eliminate the secondary signal component from the undistorted signal component thereby leaving substantially only the main signal component;
• and
• j) providing the main signal component to the corresponding transceiver for processing.