Full Division Duplex System and a Leakage Cancellation Method

• US 20100271987A1
• Filed: 07/02/2010
• Published: 10/28/2010
• Est. Priority Date: 02/27/2008
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Wu, Chun-Pang, Chiu, Chinq-Shiun
• Granted Patent: US 8,385,235 B2
• Time in Patent Office: Days
• US Class Current: 370/278
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 1/7097 Interference-related aspects

Abstract

An exemplary embodiment of a full division duplex system comprises a receiver, a transmitter and an auxiliary circuit. The receiver receives an inbound RF signal of a first band to generate an inbound baseband signal, and the transmitter up converts an outbound baseband signal by an oscillation signal to generate an outbound RF signal of a second band for transmission. The auxiliary circuit calculates leakages from the outbound RF signal to generate a blocker replica, in which a LNA is coupled to a non-conductive coupling path extended from the input of receiver to collect leakages from the outbound RF signal to produce an induction signal. The induction signal is down converted to perform an adjustment, and thereafter up converted again to generate the blocker replica. In this way, the inbound baseband signal is generated from a subtraction of the inbound RF signal and the blocker replica.

Claims

1. A full division duplex system, comprising:

a transmitter, up converting an outbound baseband signal by an oscillation signal to generate an outbound RF signal of a first band;

an auxiliary circuit, generating a blocker replica associated with leakages from the outbound RF signal by the oscillation signal of the transmitter; and

a receiver, receiving an inbound RF signal of a second band and subtracting the blocker replica from the received inbound RF signal.

2. The full division duplex system as claimed in claim 1, wherein the auxiliary circuit is arranged to calculate the leakages from the outbound RF signal to generate a first baseband signal, and up convert the first baseband signal by the oscillation signal to generate the blocker replica.

3. The full division duplex system as claimed in claim 2, wherein the auxiliary circuit is arranged to produce an induction signal according to the leakages from the outbound RF signal, down convert the induction signal by the oscillation signal to generate a preliminary baseband signal, and adjust the preliminary baseband signal to generate the first baseband signal.

4. The full division duplex system as claimed in claim 3, wherein the auxiliary circuit is arranged to adjust at least one of phase, gain and DC offset of the preliminary baseband signal to generate the first baseband signal.

5. The full division duplex system as claimed in claim 2, wherein the auxiliary circuit is arranged to receive an induction signal from the receiver, and down convert the induction signal by the oscillation signal to generate a preliminary baseband signal, compare the preliminary baseband signal with an outbound baseband signal for the transmitter to calculate a set of error parameters indicating path delay, phase imbalance and gain error of the leakages from the outbound RF signal, and compensate the outbound baseband signal according to the error parameters to generate the first baseband signal.

6. The full division duplex system as claimed in claim 2, wherein the receiver is further arranged to down convert a subtraction result of the received inbound RF signal and the blocker replica to generate an inbound baseband signal.

7. The full division duplex system as claimed in claim 6, wherein the auxiliary circuit is arranged to compare the inbound baseband signal with the outbound baseband signal to calculate a set of error parameters indicating path delay, phase imbalance and gain error of the leakages from the outbound RF signal, and compensate the outbound baseband signal according to the error parameters to generate the first baseband signal.

8. A leakage cancellation method for a full division duplex system, comprising:

up converting an outbound baseband signal by an oscillation signal of a transmitter to generate an outbound RF signal of a first band;

generating a blocker replica associated with leakages from the outbound RF signal by the oscillation signal;

receiving an inbound RF signal of a second band; and

subtracting the blocker replica from the received inbound RF signal.

9. The leakage cancellation method as claimed in claim 8, wherein generation of the blocker replica comprises:

calculating the leakages from the outbound RF signal to generate a first baseband signal; and

up converting the first baseband signal by the oscillation signal to generate the blocker replica.

10. The leakage cancellation method as claimed in claim 9, wherein generation of the first baseband signal comprises:

collecting the leakages from the outbound RF signal by a non-conductive coupling path extended from an input of the receiver to produce an induction signal;

down converting the induction signal by the oscillation signal of the transmitter to generate a preliminary baseband signal; and

adjusting the preliminary baseband signal to output the first baseband signal.

11. The leakage cancellation method as claimed in claim 10, wherein adjustment of the preliminary baseband signal comprises adjusting at least one of phase, gain and DC offset of the preliminary baseband signal to generate the first baseband signal.

12. The leakage cancellation method as claimed in claim 9, further comprising down converting a subtraction result of the received inbound RF signal and the blocker replica to generate an inbound baseband signal.

13. The leakage cancellation method as claimed in claim 12, wherein generation of the first baseband signal comprises:

receiving the subtraction result of the received inbound RF signal and the blocker replica to serve as an induction signal;

down converting the induction signal by the oscillation signal of the transmitter to generate a preliminary baseband signal;

comparing the preliminary baseband signal with an outbound baseband signal for the transmitter to calculate a set of error parameters indicating path delay, phase imbalance and gain error of the leakages from the outbound RF signal; and

compensating the outbound baseband signal by the error parameters to generate the first baseband signal.

14. The leakage cancellation method as claimed in claim 12, wherein generation of the first baseband signal comprises:

comparing the inbound baseband signal with an outbound baseband signal for the transmitter to calculating a set of error parameters indicating path delay, phase imbalance and gain error of the leakages from the outbound RF signal; and

compensating the outbound baseband signal according to the error parameters to generate the first baseband signal.

15. A full division duplex system, comprising:

a receiver, receiving an inbound RF signal of a first band to generate an inbound baseband signal;

a transmitter, up converting an outbound baseband signal by an oscillation signal to generate an outbound RF signal of a second band; and

an auxiliary circuit, having a first signal path from the transmitter which is arranged to receive the oscillation signal of the transmitter and a second signal path from the receiver which is arranged to obtain information associated with leakages from the outbound RF signal, and generating a blocker replica according to the oscillation signal and the obtained information;

wherein the receiver is arranged to subtract the blocker replica from the received inbound RF signal.

16. The full division duplex system as claimed in claim 15, wherein the receiver is further arranged to down convert a subtraction result of the received inbound RF signal and the blocker replica to generate the inbound baseband signal.

17. The full division duplex system as claimed in claim 15, wherein the second signal path is a non-conductive coupling path extended from the input of the receiver to a low noise amplifier in the auxiliary circuit, and is arranged to collect the leakages from the outbound RF signal.

18. The full division duplex system as claimed in claim 15, wherein the first signal path is arranged to transmit the oscillation signal of the transmitter to a down converter and an up down converter in the auxiliary circuit.

19. The full division duplex system as claimed in claim 15, wherein the second signal path is a non-conductive coupling path arranged to transmit an indication signal with the information from an output of a low noise amplifier in the receiver to an input of an up converter in the auxiliary circuit.

20. The full division duplex system as claimed in claim 15, wherein the auxiliary circuit further comprises a third signal path connected to an input of the transmitter, and the third signal path is arranged to receive the outbound baseband signal.

21. The full division duplex system as claimed in claim 15, wherein the second signal path is arranged to transmit the inbound baseband signal from the receiver to an error estimator in the auxiliary circuit, and the first signal path is arranged to transmit the oscillation signal of the transmitter to an up down converter in the auxiliary circuit.

22. A leakage cancellation method for a full division duplex system, comprising:

receiving an oscillation signal of a transmitter by a first signal path from the transmitter;

obtaining information associated with leakages from an outbound RF signal of a first band generated by the transmitter by a second signal path from the receiver;

generating a blocker replica according to the oscillation signal and the obtained information; and

subtracting the blocker replica from an inbound RF signal of a second band received by the receiver.

23. The leakage cancellation method as claimed in claim 22, wherein the obtainment of the information associated with leakages from the outbound RF signal comprises:

collecting the leakages from the outbound RF signal by a non-conductive coupling path extended from an input of the receiver to produce an induction signal with the information.

24. The leakage cancellation method as claimed in claim 22, further comprising down converting a subtraction result of the inbound RF signal and the blocker replica to generate an inbound baseband signal.

25. The leakage cancellation method as claimed in claim 24, wherein obtainment of the information associated with leakages from the outbound RF signal comprises:

receiving the subtraction result of the received inbound RF signal and the blocker replica by a non-conductive coupling path extended from the receiver to serve as an induction signal with the information.

26. The leakage cancellation method as claimed in claim 24, wherein the obtainment of the information associated with leakages from the outbound RF signal comprises:

receiving the inbound baseband signal by the second signal path from the receiver;

receiving an outbound baseband signal for the transmitter by a third signal path connected to an input of the transmitter; and

comparing the inbound baseband signal with the outbound baseband signal to obtain a set of error parameters with the information.