IQ Imbalance Image Compensation in Multi-Carrier Wireless Communication Systems

• US 20120213095A1
• 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 8,619,716 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 24/02 Arrangements for optimising operational condition

Abstract

A method in a wireless communication terminal includes receiving an aggregated carrier including a first component carrier and a second component carrier, determining a level of interference from a signal received on the first component carrier to a signal on the second component carrier based on a signal characteristic of the first component carrier and a signal characteristic of the second component carrier, and providing signal interference information to a serving base station if the determined interference level satisfies a condition.

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;

determining a signal characteristic of the first component carrier and a signal characteristic of the second component carrier;

determining a level of interference from a signal received on the first component carrier to a signal on the second component carrier based on the signal characteristic of the first component carrier and the signal characteristic of the second component carrier;

providing signal interference information to a serving base station if the determined interference level satisfies a condition.

2. The method of claim 1 further comprising,

determining a reference signal received power (RSRP) of the first component carrier and a reference signal received power (RSRP) of the second component carrier,

determining a ratio of the RSRP of the first component carrier with respect to the RSRP of the second component carrier;

determining the level of interference based on the ratio.

3. The method of claim 1 wherein the signal characteristic of the component carriers is selected from a group comprising:

a reference signal received power (RSRP);

a reference signal strength indicator (RSSI);

a total received power;

a total received power;

a channel quality indicator (CQI); and

a hypothetical block error rate (BLER) applicable to a packet-coded transmission.

4. The method of claim 2, indicating the signal interference information to the base station upon determining that a difference between RSRP of the first component and the RSRP of the second component carrier exceeds the threshold.

5. The method of claim 1, wherein the second component carrier is configured as a primary serving cell and the first component carrier is configured as a secondary serving cell, the method further comprising,

receiving a primary serving cell change command from the serving base station in response to sending the signal interference information to the serving base station

configuring a third component carrier as a new primary serving cell in response to receiving the command.

6. The method of claim 5, wherein the first component carrier is configured as the primary serving cell and the second component carrier is configured as the secondary serving cell.

7. The method of claim 1 further comprising

receiving a DCI grant indicating transmission of a sequence of information symbols according to a modulation order and a coding scheme on the second component carrier,

determining a level of interference that the sequence of information symbols is subject to from the first component carrier based on the signal characteristic of the first component carrier and the signal characteristic of the second component carrier,

indicating the signal interference information to the base station only if the level of interference satisfies a condition.

8. The method of claim 1, indicating the signal interference information to the base station only if the determined interference level satisfies a condition and only upon determining that a modulation coding scheme scheduled on the second component carrier is subject to a specified level of interference from the first component carrier.

9. The method of claim 8 of determining that the modulation coding scheme scheduled on the second component carrier is subject to a specified level of interference from the first component carrier based on determining that the modulation coding scheme scheduled on the second component carrier is within a pre-determined range.

10. The method of claim 1, indicating the signal interference information to the base station only if the determined interference level satisfies a condition and only upon determining that a transmission rank in a spatial multiplexing scheme scheduled on the second component carrier is subject to a specified level of interference from the first component carrier.

11. The method of claim 10 of determining that the transmission rank in a spatial multiplexing scheme scheduled on the second component carrier is subject to a specified level of interference from the first component carrier based on determining that the transmission rank on the second component carrier belong to a pre-determined range.

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

receiving a message from a wireless terminal being served by the base station indicating that an impairment from a signal transmitted on a first component carrier to a signal transmitted on the second component carrier exceeds a certain level,

wherein the second component carrier is a secondary cell component carrier and the first component carrier is a primary cell component carrier;

configuring a third component carrier as a new primary cell component carrier in response to receiving the message.

13. The method of claim 12 further comprising sending a user-specific message to the wireless terminal indicating that the third component carrier has been configured as the new primary cell component carrier.

14. The method of claim 12 wherein the third component carrier and the second component carrier correspond to the same component carrier, the method further comprising

configuring the second component carrier as the new primary cell component carrier in response to receiving the message.

15. The method of claim 12 wherein the message indicating that the impairment from the signal transmitted on a first component carrier to the signal transmitted on the second component carrier exceeds a certain level includes the signal characteristic of the first component carrier and the signal characteristic of the second component carrier.

16. The method of claim 15 wherein the signal characteristic of the component carriers is selected from a group comprising:

a reference signal received power (RSRP);

a reference signal strength indicator (RSSI);

a total received power;

a total received power;

a channel quality indicator (CQI); and

a hypothetical block error rate (BLER) applicable to a packet-coded transmission.

17. The method of claim 12 wherein the impairment from the signal transmitted on a first component carrier to the signal transmitted on the second component carrier is due to at least one of a I/Q gain and phase imbalance impairment, a phase noise impairment, a carrier offset impairment or some other wireless terminal receiver impairment.

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

receiving a request from a serving base station for capability information from the wireless communication terminal;

sending capability information to the serving base station, wherein the capability information includes a Adjacent Channel Interference Rejection Ratio (ACIRR) at at least one carrier frequency as part of the RRC capability information exchange.

19. The method of claim 18 further comprising sending ACIRR at a frequency pair together with either a band combination or a carrier aggregation bandwidth class.

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

receiving an information from a wireless terminal being served by the base station wherein the information includes an Adjacent Channel Interference Rejection Ratio (ACIRR) at at least one carrier frequency;

selecting at least one of a modulation order, a coding scheme, a transport block size (TBS), a precoding matrix, a transmission rank and a transmission scheme, wherein the transmission scheme is one of a transmit diversity method and a spatial multiplexing scheme;

transmitting a codeword containing information bits based on the said selection.

21. The method of claim 20 wherein the transmitted codeword corresponds to one of a payload for a physical downlink shared channel (PDSCH) and a physical multicast channel (PMCH).