Transceiver with hybrid adaptive self-interference canceller for removing transmitter generated noise to prevent modem jamming

• US 7,869,527 B2
• Filed: 10/15/2007
• Issued: 01/11/2011
• Est. Priority Date: 10/17/2006
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Kazakevich, Leonid, Vetter, Kurt G.
• Primary Examiner(s): Ahn; Sam K
• Application Number:
  US11/872,101
• Publication Number:
  US 20080089397A1
• Time in Patent Office: 1,184 Days
• Field of Search: 375/219, 375/221, 375/222, 375/278, 375/284, 375/285, 375/295, 375/296, 375/297, 375/316, 375/346, 375/220, 375/259, 455/63.1, 455/114.2, 455/278.1, 455/296
• US Class Current: 375/259
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04L 27/366 Arrangements for compensating undesirable properties of the transmission path between the modulator and the demodulator

Abstract

A self-interference canceller (SIC) is incorporated into a transceiver to reduce or eliminate modem jamming when a transmitter in the transceiver transmits at high power levels. The SIC is configured to receive at a first input a transmitter noise reference signal including a self-interfering signal component generated by the transmitter, to receive at a second input a corrupted signal including the self-interfering signal component and a desired signal component generated by the transmitter, and to output a correction signal that resembles the self-interfering signal component. The correction signal is subtracted from the corrupted signal to generate a processed signal that is input to the modem. The SIC may be disabled when the output power of the transmitter is at a level below a predetermined threshold. The invention may be applied to a multi-radio access technology (RAT) transceiver.

Claims

1. A wireless transmit/receive unit (WTRU) comprising:

a transmitter configured to generate a desired transmit signal on a transmit band which incidentally generates a self-interfering signal which corrupts a receive signal in a receive band, wherein the transmitter is transmitting and the receiver is receiving on different channels within the same radio access technologies (RATs);

a receiver configured to receive the corrupted receive signal on at least one channel in the receive band;

a self-interference canceller (SIC) configured to;

receive a reference signal generated by filtering the desired transmit signal to pass the receive band and to attenuate the transmit band;

receive the corrupted receive signal including the self-interfering signal from the receiver;

filter and extract a correction signal that resembles the self-interfering signal; and

subtract the correction signal from the corrupted receive signal to generate a desired receive signal.

2. The WTRU of claim 1 wherein the SIC further comprises:

a delay unit configured to receive and delay the reference signal;

a first correlator configured to correlate the delayed reference signal with the processed signal to generate a first correlation signal;

an equalizer configured to receive the delayed reference signal and generate the correction signal;

a minimum least mean square (LMS) algorithm unit configured to output a first weight vector signal to the equalizer based on the processed signal and the first correlation signal;

a second correlator configured to correlate the corrupted receive signal with the correction signal to generate a second correlation signal;

a maximum least mean square (LMS) algorithm unit configured to output a second weight vector signal to the equalizer based on the second correlation signal; and

an LMS algorithm selection unit configured to input a weight select vector signal to the equalizer based on the first and second correlation signals to determine which of the first and second weight vector signals should be used by the equalizer to generate the correction signal.

3. The WTRU of claim 2 wherein the SIC is disabled on a condition that the transmit power of the transmitter falls below a predetermined threshold.

4. A wireless transmit/receive unit (WTRU) comprising:

a plurality of transmitters associated with the different radio access technologies (RATs), each of the transmitters generating desired transmit signals and incidentally generating cross RAT interfering signals that corrupt receive signals;

a plurality of receivers associated with the different RATs;

a self-interference canceller (SIC) configured to;

receive a plurality of reference signals including the cross RAT interfering signals in receive bands;

receive the corrupted receive signals from the receivers including respective self-interfering signal components and desired signal components; and

filter and extract correction signals from the reference signals; and

a plurality of adders configured to subtract the correction signals from the corrupted receive signals to generate desired signals, wherein the transmitters are transmitting and the receivers are receiving on different channels.

5. A base station comprising:

a transmitter configured to generate a desired transmit signal which corrupts a receive signal, wherein the corrupted receive signal includes a self-interfering signal in a receive band, wherein the transmitter is transmitting and the receiver is receiving on different channels within the same radio access technologies (RATs);

a receiver configured to receive the corrupted receive signal;

a self-interference canceller (SIC) configured to;

receive a reference signal from the transmitter including the self-interfering signal in the receive band;

receive the corrupted receive signal from the receiver including the self-interfering signal and a desired receive signal;

filter and extract a correction signal that resembles the self-interfering signal; and

an adder configured to subtract the correction signal from the corrupted receive signal to extract the desired receive signal.

6. The base station of claim 5 wherein the SIC further comprises:

a delay unit configured to receive and delay the reference signal;

a first correlator configured to correlate the delayed reference signal with the processed signal to generate a first correlation signal;

an equalizer configured to receive the delayed reference signal and generate the correction signal;

a minimum least mean square (LMS) algorithm unit configured to output a first weight vector signal to the equalizer based on the processed signal and the first correlation signal;

a second correlator configured to correlate the corrupted receive signal with the correction signal to generate a second correlation signal;

a maximum least mean square (LMS) algorithm unit configured to output a second weight vector signal to the equalizer based on the second correlation signal; and

an LMS algorithm selection unit configured to input a weight select vector signal to the equalizer based on the first and second correlation signals to determine which of the first and second weight vector signals should be used by the equalizer to generate the correction signals.

7. The base station of claim 6 wherein the SIC is disabled on a condition that the transmit power of the transmitter falls below a predetermined threshold.

8. A base station comprising:

a plurality of transmitters associated with the different RATs, each of the transmitters configured to generate transmit signals which produces a cross RAT interfering signal that corrupts receive signals;

a plurality of receivers associated with different RATs which receives the corrupted receive signals;

a self-interference canceller (SIC) configured to;

receive a plurality of reference signals including the cross RAT interfering signal in receive bands;

receive the corrupted receive signals from the plurality of receivers including the respective self-interfering signals;

filter and extract a plurality of correction signals from the plurality of reference signals; and

a plurality of adders configured to subtract the correction signals from the respective corrupted receive signals to generate a plurality of desired receive signals, wherein the transmitters are transmitting and the receivers are receiving on different channels.

9. A self-interference canceller (SIC) for removing noise from a received signal, the noise generated by a transmitter, the SIC comprising:

a delay unit configured to receive and delay a reference signal;

an adder configured to receive a corrupted receive signal, output a processed signal by subtracting a correction signal from the corrupted signal;

a first correlator configured to correlate the delayed reference signal with the processed signal to generate a first correlation signal;

an equalizer configured to receive the delayed reference signal and generate the correction signal;

a minimum least mean square (LMS) algorithm unit configured to output a first weight vector signal to the equalizer based on the processed signal and the first correlation signal;

a second correlator configured to correlate the corrupted signal with the correction signal to generate a second correlation signal;

a maximum least mean square (LMS) algorithm unit configured to output a second weight vector signal to the equalizer based on the second correlation signal; and

an LMS algorithm selection unit that inputs a weight select vector signal to the equalizer based on the first and second correlation signals to determine which of the first and second weight vector signals should be used by the equalizer to generate the correction signal.

10. The SIC of claim 9 wherein the SIC is disabled on a condition that the transmit power of the transmitter falls below a predetermined threshold.

11. A method of removing a self-interfering signal generated by a transmitter, the method comprising:

receiving and delaying by a delay unit a transmitter noise reference signal including the self-interfering signal;

generating a correction signal by an equalizer based on the delayed transmitter noise reference signal;

receiving by a receiver a corrupted signal including the self-interfering signal and a desired signal;

subtracting the correction signal from the corrupted signal by an adder to generate a processed signal;

correlating the delayed transmitter noise reference signal by a first correlator with the processed signal to generate a first correlation signal;

generating a first weight vector signal by the equalizer based on the processed signal and the first correlation signal;

correlating the corrupted signal with the correction signal by a second correlator to generate a second correlation signal;

generating a second weight vector signal by the equalizer based on the second correlation signal; and

determining which of the first and second weight vector signals should be used to generate the correction signal by an LMS algorithm selection unit.