IQ Imbalance Image Compensation in Multi-Carrier Wireless Communication Systems

• US 20120213096A1
• Filed: 02/21/2011
• Published: 08/23/2012
• Est. Priority Date: 02/21/2011
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Krishnamurthy, Sandeep H., Frank, Colin D.
• Granted Patent: US 8,503,322 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 27/3863 Compensation for quadrature error in the received signal
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/00 Local resource management

Abstract

A method in a wireless communication terminal includes receiving an aggregated carrier including a first component carrier and a second component carrier, measuring leakage of a reference signal from the first component carrier onto the second component carrier, receiving a signal on the aggregated carrier, and compensating for leakage of the signal from the first component carrier to the second component carrier based on the measurement of the leakage of the reference signal.

Claims

1. A method in a wireless communication terminal, the method comprising:

receiving, at the terminal, an aggregated carrier including a first component carrier and a second component carrier, the first component carrier including a reference signal (RS);

measuring leakage of the reference signal from the first component carrier onto the second component carrier;

receiving a signal on the aggregated carrier;

compensating for leakage of the signal from the first component carrier to the second component carrier based on the measurement of the leakage of the reference signal.

2. The method of claim 1 further comprising

generating a parameter based on the measurement of the leakage of the reference signal from the first component carrier to the second component carrier,

compensating for leakage of the signal from the first component carrier to the second component carrier by applying a transformation of the parameter to the received signal.

3. The method of claim 2, wherein the transformation of the parameter to the received signal is a linear combination of the received signal scaled by a first coefficient and a complex conjugate of the received signal scaled by a second coefficient, and wherein the first and second coefficients of the linear combination are a function of the parameter generated.

4. The method of claim 2, compensating for leakage of the signal from the first component carrier to the second component carrier by applying a time domain transformation of the parameter to the received signal.

5. The method of claim 2, compensating for leakage of the signal from the first component carrier to the second component carrier by applying a frequency domain transformation of the parameter to the received signal.

6. The method of claim 1 further comprising receiving scheduling information indicating when the reference signal will be transmitted on the first component carrier,

receiving the reference signal (RS) on a time slot of the first component carrier, and

measuring the leakage of the reference signal from the first component carrier onto a corresponding time slot on the second component carrier.

7. The method of claim 1, receiving the aggregated carrier including the reference signal on the first component carrier and measuring leakage of the reference signal from the first component carrier onto the second component carrier before receiving the signal on the aggregated carrier.

8. The method of claim 1 wherein the signal received on the aggregated carrier is selected from a group comprising:

a physical downlink control channel (PDCCH);

a physical downlink shared data channel (PDSCH), a synchronization channel (SCH);

a physical broadcast channel (PBCH);

a cell-specific reference signal;

a demodulation reference signal;

a CSI reference signal;

a physical hybrid-ARQ indicator channel (PHICH);

a physical control format indicator channel (PCFICH); and

physical multicast channel (PMCH).

9. A method in a base station configured to transmit an aggregated signal that includes at least two component carriers, the method comprising:

transmitting scheduling information indicating when a reference signal will be transmitted on a first component carrier, wherein the scheduling information includes at least one time slot on the first component carrier where the reference signal can be transmitted;

transmitting the reference signal on at least one of the indicated time slots; and

blanking a data signal transmission on a second component carrier on a time slot that at least partially overlaps in time with the time slot where the reference signal is transmitted on the first component carrier.

13. The method of claim 9, transmitting the scheduling information indicating when the reference signal will be transmitted in response to receiving a user-specific request from a wireless terminal being served by the base station.

10. The method of claim 10,

wherein the scheduling information corresponds to a time pattern such that transmission of the reference signal on the first component carrier and blanking of the data signal on the second component carrier repeat with a certain periodicity,

the method further comprising transmitting the periodicity associated with transmission of the reference signal on the first component carrier and blanking of the data signal on the second component carrier in a system information message or a user-specific message.

11. The method of claim 10 further comprising transmitting a time offset of the first time slot such that there is transmission of the reference signal on the first component carrier and blanking of the data signal on the second component carrier relative to a time reference in a system information message or a user-specific message.

12. The method of claim 11, wherein the time reference is the start of the radio frame with a system frame number (SFN) equal to zero.