TRANSCEIVER WITH HYBRID ADAPTIVE SELF-INTERFERENCE CANCELLER FOR REMOVING TRANSMITTER GENERATED NOISE TO PREVENT MODEM JAMMING

• US 20080089397A1
• Filed: 10/15/2007
• Published: 04/17/2008
• Est. Priority Date: 10/17/2006
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Vetter, Kurt, Kazakevich, Leonid
• Granted Patent: US 7,869,527 B2
• Time in Patent Office: Days
• US Class Current: 375/220
• 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) a modem;

(b) a transmitter that unintentionally generates a corrupted signal including a self-interfering signal component and a desired signal component;

(c) a self-interference canceller (SIC) configured to receive a transmitter noise reference signal including the self-interfering signal component, to receive the corrupted signal including the self-interfering signal component and the desired signal component, and to output a correction signal that resembles the self-interfering signal component; and

(d) an adder configured to subtract the correction signal from the corrupted signal to generate a processed signal that is input to the modem.

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

(c1) a delay unit configured to receive and delay the transmitter noise reference signal;

(c2) a first correlator configured to correlate the delayed transmitter noise reference signal with the processed signal to generate a first correlation signal;

(c3) an equalizer configured to receive the delayed transmitter noise reference signal and generate the correction signal;

(c4) 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;

(c5) a second correlator configured to correlate the corrupted signal with the correction signal to generate a second correlation signal;

(c6) 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

(c7) 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 LMS algorithm selection unit is disabled if the transmit power of the transmitter falls below a predetermined threshold.

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

(a) a plurality of modems associated with different radio access technologies (RATs);

(b) a plurality of transmitters associated with the different RATs, each of the transmitters generating signals including a self-interfering signal component and a desired signal component;

(c) a self-interference canceller (SIC) configured to receive a plurality of transmitter noise reference signals including the respective self-interfering signal components, to receive the corrupted signals including the respective self-interfering signal components and the desired signal components, and to output a plurality of correction signals that resemble the respective self-interfering signal components; and

(d) a plurality of adders configured to subtract the correction signals from the respective corrupted signals to generate a plurality of processed signals that are input to the respective modems.

5. A base station comprising:

(a) a modem;

(b) a transmitter that generates a corrupted signal including a self-interfering signal component and a desired signal component;

(c) a self-interference canceller (SIC) configured to receive a transmitter noise reference signal including the self-interfering signal component, to receive the corrupted signal including the self-interfering signal component and the desired signal component, and to output a correction signal that resembles the self-interfering signal component; and

(d) an adder configured to subtract the correction signal from the corrupted signal to generate a processed signal that is input to the modem.

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

(c1) a delay unit configured to receive and delay the transmitter noise reference signal;

(c2) a first correlator configured to correlate the delayed transmitter noise reference signal with the processed signal to generate a first correlation signal;

(c3) an equalizer configured to receive the delayed transmitter noise reference signal and generate the correction signal;

(c4) 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;

(c5) a second correlator configured to correlate the corrupted signal with the correction signal to generate a second correlation signal;

(c6) 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

(c7) 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 LMS algorithm selection unit is disabled if the transmit power of the transmitter falls below a predetermined threshold.

8. A base station comprising:

(a) a plurality of modems associated with different radio access technologies (RATs);

(b) a plurality of transmitters associated with the different RATs, each of the transmitters generating signals including a self-interfering signal component and a desired signal component;

(c) a self-interference canceller (SIC) configured to receive a plurality of transmitter noise reference signals including the respective self-interfering signal components, to receive the corrupted signals including the respective self-interfering signal components and the desired signal components, and to output a plurality of correction signals that resemble the respective self-interfering signal components; and

(d) a plurality of adders configured to subtract the correction signals from the respective corrupted signals to generate a plurality of processed signals that are input to the respective modems.

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

(a) a delay unit configured to receive and delay a transmitter noise reference signal including a self-interfering signal component;

(b) an adder configured to receive a corrupted signal generated by the transmitter and output a processed signal by subtracting a correction signal from the corrupted signal;

(c) a first correlator configured to correlate the delayed transmitter noise reference signal with the processed signal to generate a first correlation signal;

(d) an equalizer configured to receive the delayed transmitter noise reference signal and generate the correction signal;

(e) 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;

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

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

(h) 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 LMS algorithm selection unit is disabled if the transmit power of the transmitter falls below a predetermined threshold.

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

receiving and delaying a transmitter noise reference signal including the self-interfering signal component;

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

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

subtracting the correction signal from the corrupted signal to generate a processed signal.

12. The method of claim 11 further comprising:

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

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

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

generating a second weight vector signal 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.