Acquisition of a gated pilot by avoiding partial correlation peaks

• US 20030007468A1
• Filed: 06/29/2001
• Published: 01/09/2003
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Neufeld, Arthur James, Glazko, Serguei A., Joshi, Abhay
• Granted Patent: US 7,065,129 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 1/70753 Partial phase search
• CPC Class Codes: H04B 1/70755 Setting of lock conditions, e.g. threshold
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects

Abstract

Systems and techniques are disclosed wherein a gated pilot signal can be acquired faster by checking the neighbor pilot signals of the target pilot signal. A subscriber station may frequency lock onto a wrong pilot burst because a partial correlation exists between the wrong pilot burst and an adjacent pilot burst. Comparing the strength of the target pilot signal with the strength of neighbor pilot signals enables the selection of the strongest pilot signal before the timely process of frequency locking and demodulation are initiated. Grouping pilot signals with the same symbol sequence and a pseudo-random noise increment apart enables quick acquisition of a gated pilot signal.

Claims

1. A method of acquiring a gated pilot signal, comprising:

selecting a strongest pilot peak from a plurality of pilot peaks;

evaluating the strength of pilot peaks adjacent to the strongest pilot peak; and

selecting a maximum pilot peak from the adjacent pilot peaks and the strongest pilot peak.

2. The method of claim 1, wherein the adjacent pilot peaks overlap in pseudo-random noise (PN) space the strongest pilot peak.

3. The method of claim 1, wherein the adjacent pilot peaks overlap in time the strongest pilot peak.

4. The method of claim 1, wherein the selecting a strongest pilot peak from a plurality of pilot peaks comprises receiving a signal, evaluating the plurality of pilot peaks from the signal, and selecting the strongest pilot peak from the plurality of pilot peaks.

5. The method claim 1, wherein the adjacent pilot peaks are in a different coset than the strongest pilot peak.

6. The method of claim 5, wherein a coset is a set of pilot peaks with the same symbol sequence, but separated by a PN increment.

7. The method of claim 6, wherein a PN increment is a number of chips.

8. A receiver, comprising:

a searcher configured to search for a plurality of pilot peaks; and

a processor coupled to the searcher and configured to select a strongest pilot peak from the plurality of pilot peaks, evaluate the strength of pilot peaks adjacent to the strongest pilot peak, and select a maximum pilot peak from the adjacent pilot peaks and the strongest pilot peak.

9. The receiver of claim 8, wherein the adjacent pilot peaks overlap in PN space the strongest pilot peak.

10. The receiver of claim 8, wherein the adjacent pilot peaks overlap in time the strongest pilot peak.

11. The receiver of claim 8, further comprising an antenna for receiving a signal comprising the plurality of pilot peaks.

13. The computer-readable medium of claim 12, wherein the adjacent pilot peaks overlap in PN space the strongest pilot peak.

14. The computer-readable medium of claim 12, wherein the adjacent pilot peaks overlap in time the strongest pilot peak.

15. The computer-readable medium of claim 12, wherein the selecting a strongest pilot peak from a plurality of pilot peaks comprises receiving a signal, evaluating the plurality of pilot peaks from the signal, and selecting the strongest pilot peak from the plurality of pilot peaks.

16. The computer-readable medium of claim 12, wherein the adjacent pilot peaks are in a different coset than the strongest pilot peak.

12. A computer-readable medium embodying a program of instructions executable by a computer to perform a method of acquiring a gated pilot signal, the method comprising:

selecting a strongest pilot peak from a plurality of pilot peaks;

evaluating the strength of pilot peaks adjacent to the strongest pilot peak; and

selecting a maximum pilot peak from the adjacent pilot peaks and the strongest pilot peak.