Dynamically adjusting integration interval based on a signal strength

• US 6,477,162 B1
• Filed: 03/31/2000
• Issued: 11/05/2002
• Est. Priority Date: 03/31/2000
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Hughes, Robbin, Bayley, Gwain
• Primary Examiner(s): Yao, Kwang Bin
• Assistant Examiner(s): Harper, Kevin C.
• Application Number:
  US09/540,798
• Time in Patent Office: 949 Days
• Field of Search: 370/328, 370/335, 370/342, 370/441, 370/331-333, 455/434, 375/130, 375/140-142, 375/149-150, 375/152
• US Class Current: 370/342
• CPC Class Codes: H04B 1/70752 Partial correlation
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects
• CPC Class Codes: H04W 48/20 Selecting an access point

Abstract

A method and apparatus for improving searching in a remote unit of a slotted mode, wireless, communication system. In a slotted mode communication system, the remote unit is in an “active state” during its assigned slot. While in the active state, a controller in the remote unit passes selected sets of search parameters to a search engine. The integration interval of the searches performed is based on the measured signal strength of another base station. The search engine performs searches using the integration interval. Searching continues as long as the remote unit is in the active state. When the remote unit enters the inactive state, searching ceases.

Claims

1. A method of determining an integration interval used by a remote unit for use in a wireless communication system comprising:

measuring the strength of a signal, received by a remote unit, that was transmitted by a first base station;

selecting an integration interval in response to said signal strength; and

using said selected integration interval when monitoring a signal transmitted by at least one other base station.

2. The method of claim 1 wherein said first base station is a preferred base station.

3. The method of claim 1 wherein said selected integration interval is used when monitoring a plurality of other base stations.

4. The method of claim 1 wherein said signal from the first base station is a pilot signal.

5. The method of claim 1 wherein said signal from said at least one other base station is a pilot signal.

6. The method of claim 1 wherein said signal from the first base station is a synchronization signal.

7. The method of claim 1 wherein said signal from said at least one other base station is a synchronization signal.

8. The remote unit of claim 1 wherein said controller is further configured such that there are a plurality of thresholds and said integration interval is changed each time said determined signal strength crosses one of said threshold levels.

9. The method of claim 1 wherein said selected base station is a preferred base station.

10. The method of claim 1 wherein said at least one non selected base station comprises a plurality of neighboring base stations.

11. The method of claim 1 wherein said signal from the selected base station is a pilot signal.

12. The method of claim 1 wherein said signals from said at least one non selected base stations are pilot signals.

13. The method of claim 1 wherein said signal from the selected base station is a synchronization signal.

14. The method of claim 1 wherein said signals from said at least one non selected base stations are synchronization signals.

15. The method of claim 1 wherein if said signal strength is below a threshold level a first integration interval is selected, and if said signal strength is equal to or exceeds said threshold level, a second integration interval is selected.

16. The method of claim 1 wherein there are a plurality of thresholds and said integration interval is changed each time said signal strength crosses a threshold.

17. The method of claim 1 wherein said coded signal is a synchronization signal.

18. The method of claim 1 wherein said first base station is a preferred base station.

19. The remote unit of claim 1 wherein said controller is further configured such that said integration interval is selected in response to said determined signal strength.

20. The remote unit of claim 1 wherein said controller is further configured such that if said determined signal strength is below a threshold level a first integration interval is selected, and if said determined signal strength is equal to or exceeds said threshold level a second integration interval is selected.

21. The method of claim 1 wherein said at least one other base station is a plurality of neighboring base stations.

22. A method of determining an integration interval used by a remote unit in a wireless communication system with a plurality of base stations, each base station configured to transmit a PN encoded signal at a time offset different that neighboring base stations, and at least one remote unit configured to receive said PN encoded signals transmitted by base stations, the method comprising:

measuring a signal strength of a signal transmitted by a selected base station and received by a remote unit;

selecting an integration interval in response to said signal strength; and

using said selected integration interval when monitoring signals transmitted by at least one non selected base station.

23. A remote unit for use in a wireless communication system comprising:

means for measuring a signal strength of a signal transmitted by a base station and received by a remote unit;

means for selecting an integration interval in response to said signal strength; and

means for monitoring a signal transmitted by at least one non selected base station using said selected integration interval.

24. A remote unit for use in a wireless communication system comprising:

a search engine configured to determine a signal strength of a received signals and perform searches for signal transmitted by base stations; and

a controller in communication with said search engine configured to;

pass selected search parameters to the search engine,

receive search results,

evaluate said determined signal strength of said received signal,

select an integration interval used to search for signals transmitted by base stations.

25. A method of determining an integration interval used by a remote unit for use in a wireless communication system comprising:

receiving a coded signal by a remote unit that was transmitted by a first base station;

decoding said coded signal;

determining a number of bit errors in said coded signal;

selecting an integration interval in response to said number of bit errors; and

using said integration interval when monitoring a signal transmitted by at least one other base station.