SYSTEM AND METHOD FOR REDUCING BLIND DECODING FOR CARRIER AGGREGATION

• US 20100303036A1
• Filed: 06/02/2010
• Published: 12/02/2010
• Est. Priority Date: 06/02/2009
• Status: Active Grant

• Current Assignee: Blackberry Limited
• Original Assignee: Blackberry Limited
• Inventors: McBeath, Sean, Earnshaw, Mark, Heo, Youn Hyoung, Fong, Mo-Han, Cai, Zhijun
• Granted Patent: US 8,660,023 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 1/0053 specially adapted for power saving
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/0005 Time-frequency
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/248 where transmission power control commands are generated based on a path parameter
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management

Abstract

A method for processing a control channel at a user agent (UA) to identify at least one of an uplink and a downlink resource grant within a wireless communication system wherein resource grants are received using control channel element (CCE) subsets wherein each CCE subset is a control channel candidate, wherein the UA is configured to decode up to M control channel candidates per time period for single carrier operation, the method comprising the steps of, at the user agent, identifying N control channel candidates that are distributed among C carriers wherein N is less than M×C, attempting to decode each of the N identified control channel candidates to identify at least one of an uplink and a downlink resource grant and where a control channel candidate is successfully decoded, using the one of the uplink grant and the downlink grant to facilitate communication.

Claims

1. A method for processing a control channel at a user agent (UA) to identify at least one of an uplink and a downlink resource grant within a wireless communication system wherein resource grants are received using control channel element (CCE) subsets wherein each CCE subset is a control channel candidate, wherein the UA is configured to decode up to M control channel candidates per time period for single carrier operation, the method comprising the steps of, at the user agent:

identifying N control channel candidates that are distributed among C carriers wherein N is less than M×

C;

attempting to decode each of the N identified control channel candidates to identify at least one of an uplink and a downlink resource grant; and

where a control channel candidate is successfully decoded, using the one of the uplink grant and the downlink grant to facilitate communication.

2. The method of claim 1 wherein the step of identifying N control channel candidates includes identifying candidates that are evenly distributed among the C carriers.

3. The method of claim 1 wherein the step of identifying N control channel candidates includes identifying candidates that are unevenly distributed among the C carriers.

4. The method of claim 1 wherein one of the carriers is designated as an anchor carrier and other carriers are non-anchor active carriers and wherein the step of identifying includes, for the anchor carrier, identifying a total of P control channel candidates and, for all the non-anchor active carriers, identifying a total of R control channel candidates, where the R control channel candidates are distributed among the non-anchor active carriers and wherein the sum of P and R is equal to N.

5. The method of claim 4 wherein the R candidates are evenly distributed among the non-anchor active carriers.

6. The method of claim 4 wherein the N control channel candidates are evenly distributed among all of the carriers.

7. The method of claim 4 wherein the total number P of control channel candidates identified for the anchor carrier is M.

8. The method of claim 1 wherein the step of identifying includes identifying a different set of control channel candidates for each of the carriers.

9. The method of claim 1 wherein control channel candidates include at least first aggregation level and second aggregation level candidates, each first aggregation level candidate including a first number of the CCEs and each second aggregation level candidate including a second number of CCEs that is different than the first number of CCEs and wherein the step of identifying includes identifying specific control channels for each aggregation level and each active carrier.

10. The method of claim 1 wherein N is greater than M.

11. The method of claim 1 wherein the step of identifying N control channels includes dynamically identifying the N control channel candidates.

12. The method of claim 11 wherein the step of dynamically identifying includes receiving data from an access device indicating control channel candidates.

13. The method of claim 12 wherein the step of receiving data from an access device includes receiving one of a DCI formatted message, a MAC formatted message and an RRC formatted message.

14. The method of claim 1 wherein the step of identifying includes identifying no more than M control channel candidates to be decoded for each of the carriers.

15. The method of claim 1 wherein one of the carriers is an anchor carrier and the other carriers are non-anchor active carriers and wherein the step of identifying includes identifying less than M candidates for each non-anchor active carrier.

16. An apparatus for processing a control channel at a user agent (UA) to identify at least one of an uplink and a downlink resource grant within a wireless communication system wherein resource grants are received using control channel element (CCE) subsets wherein each CCE subset is a control channel candidate, wherein the UA is configured to decode up to M control channel candidates per time period for single carrier operation, the apparatus comprising:

a processor programmed to perform the steps of;

identifying N control channel candidates that are distributed among C carriers wherein N is less than M×

C;

attempting to decode each of the N identified control channel candidates to identify at least one of an uplink and a downlink resource grant; and

where a control channel candidate is successfully decoded, using the one of the uplink grant and the downlink grant to facilitate communication.

17. The apparatus of claim 16 wherein the processor is programmed to perform the step of identifying N control channel candidates by identifying candidates that are evenly distributed among the C carriers.

18. The apparatus of claim 16 wherein the processor is programmed to perform the step of identifying N control channel candidates by identifying candidates that are unevenly distributed among the C carriers.

19. The apparatus of claim 16 wherein one of the carriers is designated as an anchor carrier and other carriers are non-anchor active carriers and wherein the processor is programmed to perform the step of identifying by, for the anchor carrier, identifying a total of P control channel candidates and, for all the non-anchor active carriers, identifying a total of R control channel candidates, where the R control channel candidates are distributed among the active carriers and wherein the sum of P and R is equal to N.

20. The apparatus of claim 19 wherein the R candidates are evenly distributed among the non-anchor active carriers.

21. The apparatus of claim 19 wherein the total number P of control channel candidates identified for the anchor carrier is M.

22. The apparatus of claim 16 wherein N is greater than M.

23. The apparatus of claim 16 wherein the processor is programmed to perform the step of identifying by receiving data from an access device indicating control channel candidates for the carriers.

24. The apparatus of claim 23 wherein the step of receiving data from an access device includes receiving one of a DCI formatted message, a MAC formatted message and an RRC formatted message.

25. A method for processing a control channel at an access device to transmit at least one of an uplink and a downlink resource grant within a wireless communication system to a user agent wherein resource grants are specified by control channel element (CCE) subsets wherein each CCE subset is a control channel candidate, wherein a UA is configured to decode up to M control channel candidates per time period for single carrier operation to identify a resource grant, the method comprising the steps of, at the access device:

(i) identifying N control channel candidates to be associated with the C carriers wherein N is less than M×

C;

(ii) selecting at least one of the N control channel candidate subset candidates to code at least one of an uplink grant and a downlink grant for at least one of the C carriers to be used by a UA;

(iii) using the selected control channel candidate to code the at least one an uplink grant and a downlink grant; and

(iv) transmitting the grant to the UA via the selected control channel candidate.

26. The method of claim 25 wherein the step of selecting includes selecting at least one of the N control channel candidates for each of the C carriers, the step of using includes using the selected control channel candidates to code at least one of an uplink and a downlink grant for each of the C carriers and the step of transmitting includes transmitting the grants to the UA via the selected control channel candidates.

27. The method of claim 26 wherein the N control channel candidates include N/C candidates on each of the C carriers.

28. The method of claim 27 wherein the step of selecting at least one control channel candidate for a carrier includes selecting a control channel candidate on the carrier.