Pilot signal set management in a multi-carrier communication system

• US 9,131,420 B2
• Filed: 10/09/2013
• Issued: 09/08/2015
• Est. Priority Date: 05/20/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rezaiifar, Ramin, Lott, Christopher Gerard, Ghosh, Donna, Black, Peter John, Attar, Rashid Ahmed Akbar
• Primary Examiner(s): Lugo, David B.
• Application Number:
  US14/050,008
• Publication Number:
  US 20140036875A1
• Time in Patent Office: 699 Days
• Field of Search: 375/260, 375/267
• US Class Current: 1/1
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/302 due to low signal strength

Abstract

In a wireless communication system where different frequency bands are deployed to generate various communication zones, pilot signal set management for a plurality of pilot signals generated from an additional coverage zone is based on identifying a preselected signal set from the plurality of pilot signals and determining whether a predetermined criterion is met.

Claims

1. A method of communications operable by an infrastructure entity, comprising:

receiving, from an access terminal, information associated with multiple pilot signal sets from an additional coverage zone, wherein the additional coverage zone operates under multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over one designated area;

determining that a deployment associated with the additional coverage zone meets at least one predetermined condition if the multiple frequency bands that respectively correspond to the multiple pilot signal sets are centered at carrier frequencies having sufficient separation to not cause substantial adjacent channel interference; and

instructing the access terminal to independently add individual pilot signal sets from the additional coverage zone that meet a predetermined criterion to an active set maintained at the access terminal in response to determining that the deployment associated with the additional coverage zone meets the at least one predetermined condition.

2. The method recited in claim 1, wherein the multiple pilot signal sets from the additional coverage zone comprise at least a first pilot signal set having a first signal strength that exceeds a predetermined threshold and a second pilot signal set having a second signal strength that does not exceed the predetermined threshold.

3. The method recited in claim 2, wherein instructing the access terminal to independently add the individual pilot signal sets from the additional coverage zone to the active set causes the access terminal to add the first pilot signal set to the active set.

4. The method recited in claim 3, wherein instructing the access terminal to independently add the individual pilot signal sets from the additional coverage zone to the active set maintained at the access terminal further causes the access terminal to subsequently add the second pilot signal set to the active set when the second signal strength crosses the predetermined threshold.

5. The method recited in claim 1, further comprising:

instructing the access terminal to independently drop the individual pilot signal sets from the additional coverage zone that were added to the active set in response to determining that the deployment associated with the additional coverage zone meets the at least one predetermined condition.

6. The method recited in claim 5, wherein instructing the access terminal to independently add and drop the individual pilot signal sets causes the access terminal to add a first pilot signal set from the additional coverage zone that has a signal strength above a predetermined threshold to the active set and subsequently drop the first pilot signal set from the active set when the signal strength associated therewith falls below the predetermined threshold.

7. The method recited in claim 1, further comprising:

constraining a power that the access terminal uses to transmit across adjacent carriers according to an allowable transmit power differential based at least in part on the deployment associated with the additional coverage zone and the separation between the center carrier frequencies associated with the multiple frequency bands.

8. The method recited in claim 1, wherein the deployment associated with the additional coverage zone comprises a heterogeneous deployment in which the additional coverage zone is deployed over at least one existent carrier that serves a geographic area that includes the additional coverage zone.

9. The method recited in claim 1, wherein the deployment associated with the additional coverage zone comprises a macro-cellular deployment in which multiple additional coverage zones operate under the multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over a geographic area that includes the designated areas corresponding to each additional coverage zone.

10. The method recited in claim 1, wherein the multiple pilot signal sets each comprise an identifier associated with a sector or a cell that corresponds to the designated area and a center carrier frequency associated with the frequency band under which the sector or cell operates.

11. An infrastructure entity operable in a communication system, comprising:

means for receiving, from an access terminal, information associated with multiple pilot signal sets from an additional coverage zone, wherein the additional coverage zone operates under multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over one designated area;

means for determining that a deployment associated with the additional coverage zone meets at least one predetermined condition if the multiple frequency bands that respectively correspond to the multiple pilot signal sets are centered at carrier frequencies having sufficient separation to not cause substantial adjacent channel interference; and

means for instructing the access terminal to independently add individual pilot signal sets from the additional coverage zone that meet a predetermined criterion to an active set maintained at the access terminal in response to determining that the deployment associated with the additional coverage zone meets the at least one predetermined condition.

12. The infrastructure entity recited in claim 11, wherein the multiple pilot signal sets from the additional coverage zone comprise at least a first pilot signal set having a first signal strength that exceeds a predetermined threshold and a second pilot signal set having a second signal strength that does not exceed the predetermined threshold.

13. The infrastructure entity recited in claim 12, wherein the means for instructing the access terminal to independently add the individual pilot signal sets from the additional coverage zone to the active set causes the access terminal to add the first pilot signal set to the active set.

14. The infrastructure entity recited in claim 13, wherein the means for instructing the access terminal to independently add the individual pilot signal sets from the additional coverage zone to the active set maintained at the access terminal further causes the access terminal to subsequently add the second pilot signal set to the active set when the second signal strength crosses the predetermined threshold.

15. The infrastructure entity recited in claim 11, further comprising:

means for instructing the access terminal to independently drop the individual pilot signal sets from the additional coverage zone that were added to the active set in response to determining that the deployment associated with the additional coverage zone meets the at least one predetermined condition.

16. The infrastructure entity recited in claim 15, wherein the means for instructing the access terminal to independently add and drop the individual pilot signal sets causes the access terminal to add a first pilot signal set from the additional coverage zone that has a signal strength above a predetermined threshold to the active set and subsequently drop the first pilot signal set from the active set when the signal strength associated therewith falls below the predetermined threshold.

17. The infrastructure entity recited in claim 11, further comprising:

means for constraining a power that the access terminal uses to transmit across adjacent carriers according to an allowable transmit power differential based at least in part on the deployment associated with the additional coverage zone and the separation between the center carrier frequencies associated with the multiple frequency bands.

18. The infrastructure entity recited in claim 11, wherein the deployment associated with the additional coverage zone comprises a heterogeneous deployment in which the additional coverage zone is deployed over at least one existent carrier that serves a geographic area that includes the additional coverage zone.

19. The infrastructure entity recited in claim 11, wherein the deployment associated with the additional coverage zone comprises a macro-cellular deployment in which multiple additional coverage zones operate under the multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over a geographic area that includes the designated areas corresponding to each additional coverage zone.

20. The infrastructure entity recited in claim 11, wherein the multiple pilot signal sets each comprise an identifier associated with a sector or a cell that corresponds to the designated area and a center carrier frequency associated with the frequency band under which the sector or cell operates.

21. An apparatus operable in a communication system, comprising circuitry configured to:

receive, from an access terminal, information associated with multiple pilot signal sets from an additional coverage zone, wherein the additional coverage zone operates under multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over one designated area;

determine that a deployment associated with the additional coverage zone meets at least one predetermined condition if the multiple frequency bands that respectively correspond to the multiple pilot signal sets are centered at carrier frequencies having sufficient separation to not cause substantial adjacent channel interference; and

instruct the access terminal to independently add individual pilot signal sets from the additional coverage zone that meet a predetermined criterion to an active set maintained at the access terminal in response to determining that the deployment associated with the additional coverage zone meets the at least one predetermined condition.

22. A non-transitory computer-readable medium having computer-executable instructions recorded thereon, wherein executing the computer-executable instructions on one or more processors causes the one or more processors to:

receive, from an access terminal, information associated with multiple pilot signal sets from an additional coverage zone, wherein the additional coverage zone operates under multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over one designated area;

determine that a deployment associated with the additional coverage zone meets at least one predetermined condition if the multiple frequency bands that respectively correspond to the multiple pilot signal sets are centered at carrier frequencies having sufficient separation to not cause substantial adjacent channel interference; and

instruct the access terminal to independently add individual pilot signal sets from the additional coverage zone that meet a predetermined criterion to an active set maintained at the access terminal in response to determining that the deployment associated with the additional coverage zone meets the at least one predetermined condition.

23. A method of communications operable by an access terminal, comprising:

sending information associated with multiple pilot signal sets from an additional coverage zone to an infrastructure entity, wherein the additional coverage zone operates under multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over one designated area; and

receiving, from the infrastructure entity, instructions to independently add individual pilot signal sets from the additional coverage zone that meet a predetermined criterion to an active set maintained at the access terminal, wherein the infrastructure entity sends the instructions to independently add the individual pilot signal sets from the additional coverage zone to the active set if the additional coverage zone has a deployment in which the multiple frequency bands that respectively correspond to the multiple pilot signal sets are centered at carrier frequencies having sufficient separation to not cause substantial adjacent channel interference.

24. The method recited in claim 23, wherein the multiple pilot signal sets from the additional coverage zone comprise at least a first pilot signal set having a first signal strength that exceeds a predetermined threshold and a second pilot signal set having a second signal strength that does not exceed the predetermined threshold.

25. The method recited in claim 24, further comprising:

adding the first pilot signal set to the active set in response to receiving the instructions to independently add the individual pilot signal sets from the additional coverage zone that meet the predetermined criterion to the active set.

26. The method recited in claim 25, further comprising:

adding the second pilot signal set to the active set in response to determining that the second signal strength subsequently crosses the predetermined threshold.

27. The method recited in claim 23, further comprising:

receiving, from the infrastructure entity, instructions to independently drop the individual pilot signal sets from the additional coverage zone that were added to the active set.

28. The method recited in claim 27, further comprising:

adding a first pilot signal set from the additional coverage zone that has a signal strength above a predetermined threshold to the active set in response to the instructions to independently add the individual pilot signal sets from the additional coverage zone that meet the predetermined criterion to the active set; and

dropping the first pilot signal set from the active set in response to determining that the signal strength associated therewith subsequently falls below the predetermined threshold in response to the instructions to independently drop the individual pilot signal sets from the additional coverage zone that were added to the active set.

29. The method recited in claim 23, further comprising:

constraining a transmit power used across adjacent carriers according to an allowable transmit power differential based at least in part on the deployment associated with the additional coverage zone and the separation between the center carrier frequencies associated with the multiple frequency bands.

30. The method recited in claim 23, wherein the deployment associated with the additional coverage zone comprises a heterogeneous deployment in which the additional coverage zone is deployed over at least one existent carrier that serves a geographic area that includes the additional coverage zone.

31. The method recited in claim 23, wherein the deployment associated with the additional coverage zone comprises a macro-cellular deployment in which multiple additional coverage zones operate under the multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over a geographic area that includes the designated areas corresponding to each additional coverage zone.

32. The method recited in claim 23, wherein the multiple pilot signal sets each comprise an identifier associated with a sector or a cell that corresponds to the designated area and a center carrier frequency associated with the frequency band under which the sector or cell operates.

33. The method recited in claim 23, wherein the access terminal comprises a multi-frequency device that can process multiple frequencies at a time.

34. The method recited in claim 23, wherein the access terminal comprises a single-frequency device that can process one frequency at a time.

35. The method recited in claim 34, further comprising monitoring the multiple pilot signal sets from the additional coverage zone, wherein monitoring the multiple pilot signal sets from the additional coverage zone comprises:

switching from a current serving frequency to a different frequency;

detecting an individual pilot signal set from the additional coverage zone; and

performing a frequency transition from the current serving frequency to a center carrier frequency associated with the detected pilot signal set from the additional coverage zone in response to determining that the detected pilot signal set has a signal strength that exceeds a predetermined threshold.

36. An access terminal operable in a communication system, comprising:

means for sending information associated with multiple pilot signal sets from an additional coverage zone to an infrastructure entity, wherein the additional coverage zone operates under multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over one designated area; and

means for receiving, from the infrastructure entity, instructions to independently add individual pilot signal sets from the additional coverage zone that meet a predetermined criterion to an active set maintained at the access terminal, wherein the infrastructure entity sends the instructions to independently add the individual pilot signal sets from the additional coverage zone to the active set if the additional coverage zone has a deployment in which the multiple frequency bands that respectively correspond to the multiple pilot signal sets are centered at carrier frequencies having sufficient separation to not cause substantial adjacent channel interference.

37. The access terminal recited in claim 36, wherein the multiple pilot signal sets from the additional coverage zone comprise at least a first pilot signal set having a first signal strength that exceeds a predetermined threshold and a second pilot signal set having a second signal strength that does not exceed the predetermined threshold.

38. The access terminal recited in claim 37, further comprising:

means for adding the first pilot signal set to the active set in response to receiving the instructions to independently add the individual pilot signal sets from the additional coverage zone that meet the predetermined criterion to the active set.

39. The access terminal recited in claim 38, further comprising:

means for adding the second pilot signal set to the active set in response to determining that the second signal strength subsequently crosses the predetermined threshold.

40. The access terminal recited in claim 36, further comprising:

means for receiving, from the infrastructure entity, instructions to independently drop the individual pilot signal sets from the additional coverage zone that were added to the active set.

41. The access terminal recited in claim 40, further comprising:

means for adding a first pilot signal set from the additional coverage zone that has a signal strength above a predetermined threshold to the active set in response to the instructions to independently add the individual pilot signal sets from the additional coverage zone that meet the predetermined criterion to the active set; and

means for dropping the first pilot signal set from the active set in response to determining that the signal strength associated therewith subsequently falls below the predetermined threshold in response to the instructions to independently drop the individual pilot signal sets from the additional coverage zone that were added to the active set.

42. The access terminal recited in claim 36, further comprising:

means for constraining a transmit power used across adjacent carriers according to an allowable transmit power differential based at least in part on the deployment associated with the additional coverage zone and the separation between the center carrier frequencies associated with the multiple frequency bands.

43. The access terminal recited in claim 36, wherein the deployment associated with the additional coverage zone comprises a heterogeneous deployment in which the additional coverage zone is deployed over at least one existent carrier that serves a geographic area that includes the additional coverage zone.

44. The access terminal recited in claim 36, wherein the deployment associated with the additional coverage zone comprises a macro-cellular deployment in which multiple additional coverage zones operate under the multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over a geographic area that includes the designated areas corresponding to each additional coverage zone.

45. The access terminal recited in claim 36, wherein the multiple pilot signal sets each comprise an identifier associated with a sector or a cell that corresponds to the designated area and a center carrier frequency associated with the frequency band under which the sector or cell operates.

46. The access terminal recited in claim 36, wherein the access terminal comprises a multi-frequency device that can process multiple frequencies at a time.

47. The access terminal recited in claim 36, wherein the access terminal comprises a single-frequency device that can process one frequency at a time.

48. The access terminal recited in claim 47, further comprising means for monitoring the multiple pilot signal sets from the additional coverage zone, wherein the means for monitoring the multiple pilot signal sets from the additional coverage zone comprises:

means for switching from a current serving frequency to a different frequency;

means for detecting an individual pilot signal set from the additional coverage zone; and

means for performing a frequency transition from the current serving frequency to a center carrier frequency associated with the detected pilot signal set from the additional coverage zone in response to determining that the detected pilot signal set has a signal strength that exceeds a predetermined threshold.

49. An apparatus operable in a communication system, comprising circuitry configured to:

send information associated with multiple pilot signal sets from an additional coverage zone to an infrastructure entity, wherein the additional coverage zone operates under multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over one designated area; and

receive, from the infrastructure entity, instructions to independently add individual pilot signal sets from the additional coverage zone that meet a predetermined criterion to an active set maintained at the apparatus, wherein the infrastructure entity sends the instructions to independently add the individual pilot signal sets from the additional coverage zone to the active set if the additional coverage zone has a deployment in which the multiple frequency bands that respectively correspond to the multiple pilot signal sets are centered at carrier frequencies having sufficient separation to not cause substantial adjacent channel interference.

50. A non-transitory computer-readable medium having computer-executable instructions recorded thereon, wherein executing the computer-executable instructions on an access terminal causes the access terminal to:

send information associated with multiple pilot signal sets from an additional coverage zone to an infrastructure entity, wherein the additional coverage zone operates under multiple frequency bands that respectively correspond to the multiple pilot signal sets to generate multi-carrier coverage over one designated area; and

receive, from the infrastructure entity, instructions to independently add individual pilot signal sets from the additional coverage zone that meet a predetermined criterion to an active set maintained at the access terminal, wherein the infrastructure entity sends the instructions to independently add the individual pilot signal sets from the additional coverage zone to the active set if the additional coverage zone has a deployment in which the multiple frequency bands that respectively correspond to the multiple pilot signal sets are centered at carrier frequencies having sufficient separation to not cause substantial adjacent channel interference.