Method and apparatus for managing finger resources in a communication system

• US 20020101909A1
• Filed: 01/29/2001
• Published: 08/01/2002
• Est. Priority Date: 01/29/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tiedemann, Edward G. Jr., Wang, Jun, Chen, Tao, Willenegger, Serge
• Granted Patent: US 7,085,310 B2
• Time in Patent Office: Days
• US Class Current: 375/147
• CPC Class Codes: H04B 1/70755 Setting of lock conditions, e.g. threshold
• CPC Class Codes: H04B 1/7117 Selection, re-selection, allocation or re-allocation of paths to fingers, e.g. timing offset control of allocated fingers
• CPC Class Codes: H04B 1/712 Weighting of fingers for combining, e.g. amplitude control or phase rotation using an inner loop

Abstract

In a communication system, a method and an accompanying apparatus determine a number of available fingers (110A-N) in a receiver (100). A controller (121) adjusts a threshold based on the determined number of the available fingers (110). The adjusted threshold may be one of, or any combination of, a pilot signal search threshold, a lock/unlock threshold, and a combine/un-combine threshold. The number of available fingers (110) may change after the threshold is adjusted.

Claims

1. In a communication system, a method comprising:

determining a number of available fingers in a receiver of said communication system;

adjusting a threshold based on said number of available fingers.

2. The method as recited in claim 1, wherein said threshold is a pilot signal search window threshold.

3. The method as recited in claim 2 further comprising:

receiving a signal;

assigning at least a finger from said number of available fingers to said received signal;

wherein said adjusting of said pilot signal search window threshold allows assigning more or less of fingers to said received signal.

4. The method as recited in claim 3 further comprising:

assigning more or less of fingers to said received signal after said adjusting said pilot signal search window threshold.

5. The method as recited in claim 2 further comprising:

receiving a pilot signal;

correlating with said received pilot signal within a search window;

comparing correlation energy of said received pilot signal to said adjusted search window threshold.

6. The method as recited in claim 5 further comprising:

accepting or denying a processing of a received signal based on whether said received pilot signal meets said adjusted search window threshold in said comparing.

7. The method as recited in claim 6, wherein said received signal is associated with said received pilot signal.

8. The method as recited in claim 1 wherein said threshold is a lock/unlock threshold.

9. The method as recited in claim 8 further comprising:

receiving a signal;

assigning at least a finger from said number of available fingers to said received signal;

wherein said adjusting of said lock/unlock threshold allows more or less of said least assigned finger to switch from a lock condition to a unlock condition or from said unlock condition to said lock condition.

10. The method as recited in claim 9 further comprising:

switching at least said least assigned finger from said lock condition to said unlock condition or from said unlock condition to said lock condition.

11. The method as recited in claim 1, wherein said determining includes:

determining a number of fingers in a lock/unlock condition;

wherein said determining of said number of available fingers is based on said number of fingers in said lock/unlock condition.

12. The method as recited in claim 1, wherein said determining includes:

determining a time period of lock/unlock condition of a number of fingers in a lock/unlock condition;

wherein said determining of said number of available fingers is based on said time period of lock/unlock condition of said number of fingers in said lock/unlock condition.

13. The method as recited in claim 1 wherein said threshold is a combine/un-combine threshold.

14. The method as recited in claim 13 further comprising:

receiving a signal;

assigning at least a finger to said received signal;

wherein said adjusting of said combine/un-combine threshold allows more or less of said least assigned finger to switch from a combine condition to a un-combine condition or from said un-combine condition to said combine condition.

15. The method as recited in claim 14 further comprising:

switching at least said least assigned finger from said combine condition to said un-combine condition or from said un-combine condition to said combine condition.

16. The method as recited in claim 1, wherein said determining includes:

determining a number of fingers in a combine/un-combine condition;

wherein said determining of said number of available fingers is based on said number of fingers in said combine/un-combine condition.

17. The method as recited in claim 1, wherein said determining includes:

determining a time period of combine/un-combine condition of a number of fingers in a combine/un-combine condition;

wherein said determining of said number of available fingers is based on said time period of combine/un-combine condition of said number of fingers in said combine/un-combine condition.

18. The method as recited in claim 1, wherein said determining includes:

determining a number of fingers in an assign/un-assign condition;

wherein said determining of said number of available fingers is based on said number of fingers in said assign/un-assign condition.

19. The method as recited in claim 1 further comprising:

determining at least one of Active set, Candidate set, and Neighbor set of base stations in said communication system, wherein each set identifies a set of base stations for communication with a mobile station in said communication system, wherein said Active set identifies a set of base stations assigned for communication with said mobile station, wherein said Candidate set identifies a set of base stations with sufficient pilot signal strength at said mobile station and for communication with said mobile station, wherein said Active set is exclusive of said Candidate set, wherein said Neighbor set identifies a set of base stations for possible communication with said mobile station, wherein said Neighbor set is exclusive of said Active and Candidate sets;

moving at least one base station from one set to another set among said Active, Candidate and Neighbor sets of base stations based on said adjusting said threshold based on said number of available fingers.

20. The method as recited in claim 1 wherein said threshold is at least one of an add-threshold and a drop-threshold.

21. The method as recited in claim 20 wherein at least one of said add-threshold and said drop-threshold is associated with at least one of Active set, Candidate set, and Neighbor set of base stations in said communication system, wherein each set identifies a set of base stations for communication with a mobile station in said communication system, wherein said Active set identifies a set of base stations assigned for communication with said mobile station, wherein said Candidate set identifies a set of base stations with sufficient pilot signal strength at said mobile station and for communication with said mobile station, wherein said Active set is exclusive of said Candidate set, wherein said Neighbor set identifies a set of base stations for possible communication with said mobile station, wherein said Neighbor set is exclusive of said Active and Candidate sets.

22. The method as recited in claim 20 wherein at least one of said add-threshold and said drop-threshold is associated with determining a number of fingers in a lock/unlock condition.

23. The method as recited in claim 20 wherein at least one of said add-threshold and said drop-threshold is associated with determining a number of fingers in a combine/un-combine condition.

24. The method as recited in claim 20 wherein at least one of said add-threshold and said drop-threshold is associated with correlation of a pilot signal in a search window.

26. The apparatus as recited in claim 25 wherein said threshold is a pilot signal search window threshold.

27. The apparatus as recited in claim 26 further comprising:

a pilot signal searcher configured for searching for pilot signals, and further configured for comparing signal energies of said searched pilot signals with said adjusted pilot signal search window threshold.

28. The apparatus as recited in claim 25 wherein said threshold is a lock/unlock threshold.

29. The apparatus as recited in claim 28 further comprising:

at least a finger resource configured for correlating with at least one received signal;

wherein a condition of said least finger is either a lock condition or a unlock condition, said least finger is further configured to switch from said lock condition to said unlock condition or from said unlock to said lock condition based on whether signal energy of said received signal meets said adjusted lock/unlock threshold.

30. The apparatus as recited in claim 25 wherein said threshold is a combine/un-combine threshold.

31. The apparatus as recited in claim 30 further comprising:

at least a finger resource configured for correlating with at least one received signal;

wherein a condition of said least finger is either a combine condition or a un-combine condition, wherein said least finger is further configured to switch from said combine condition to said un-combine condition or from said un-combine condition to said combine condition based on whether signal energy of said received signal meets said adjusted combine/un-combine threshold.

32. The apparatus as recited in claim 25 wherein said controller further is configured to determine at least one of Active set, Candidate set, and Neighbor set of base stations in said communication system, wherein each set identifies a set of base stations for communication with a mobile station in said communication system, wherein said Active set identifies a set of base stations assigned for communication with said mobile station, wherein said Candidate set identifies a set of base stations with sufficient pilot signal strength at said mobile station and for communication with said mobile station, wherein said Active set is exclusive of said Candidate set, wherein said Neighbor set identifies a set of base stations for possible communication with said mobile station, wherein said Neighbor set is exclusive of said Active and Candidate sets;

wherein said controller is further configured for moving at least one base station from one set to another set among said Active, Candidate and Neighbor sets of base stations based on said adjusting said threshold based on said number of available fingers.

25. An apparatus in a communication system comprising:

a controller configured for determining a number of available fingers in said communication system, wherein said controller further is configured for adjusting a threshold based on said number of available fingers.

33. In a communication system, a method comprising:

determining a number of available fingers in a receiver of said communication system;

adjusting a pilot signal search window threshold based on said number of available fingers;

correlating with a received pilot signal within a search window;

comparing correlation energy of said received pilot signal to said adjusted search window threshold;

determining an assigned number of fingers, from said number of available fingers, to a received signal after said adjusting said pilot signal search window threshold.

34. An apparatus in a communication system comprising:

a controller configured for determining a number of available fingers in said communication system, wherein said controller further is configured for adjusting a pilot signal search window threshold based on said number of available fingers;

a pilot signal searcher configured for searching for pilot signals, and further configured for comparing signal energies of said searched pilot signals to said adjusted pilot signal search window threshold.