Method of and apparatus for pilot set maintenance

• US 6,160,799 A
• Filed: 09/06/1996
• Issued: 12/12/2000
• Est. Priority Date: 09/06/1996
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Krause, David J., Taranowski, William F., Storm, Brian D., Eberhardt, Michael A.
• Primary Examiner(s): NGO, RICKY QUOC
• Application Number:
  US08/709,432
• Time in Patent Office: 1,558 Days
• Field of Search: 370/252, 370/311, 370/335, 370/342, 370/441, 370/479, 370/514, 370/515, 375/367, 375/147, 375/316, 375/349, 455/434, 455/436, 455/32.1, 455/442
• US Class Current: 370/335
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

An apparatus (100) maintains a Pilot Set in a digital communication system that utilizes Code Division Multiple Access. The apparatus comprises a logic and control circuit (113) for providing instructions to a searcher receiver (109). The searcher receiver, in response to the instructions, sequentially scans active pilots, then candidate pilots, and then pre-candidate pilots. The scan of the pre-candidate pilots continues until all but a predetermined number of pre-candidate pilots have been promoted or demoted. Then the searcher receiver alternately scans the predetermined number of pre-candidate pilots and the neighbor pilots. The searcher receiver terminates alternate scans of the predetermined number of pre-candidate pilots and the neighbor pilots when a one of the neighbor pilots is promoted, and resumes the scan of the pre-candidate pilots.

Claims

1. A method of maintaining a Pilot Set in a digital communication system that utilizes Code Division Multiple Access, the Pilot Set including an Active Set of active pilots, a Candidate Set of candidate pilots, a Pre-candidate Set of pre-candidate pilots, and a Neighbor Set of neighbor pilots, the method comprising the steps of:

scanning the entire Active Set of active pilots;

scanning the entire Candidate Set of candidate pilots after scanning the entire Active Set; and

scanning the pre-candidate pilots without intervening scans of the active pilots or candidate pilots until all but a predetermined number of pre-candidate pilots have been promoted to the Candidate Set or demoted to the Neighbor Set.

2. The method of claim 1 further comprising the step of alternately scanning the predetermined number of pre-candidate pilots and the neighbor pilots.

3. The method of claim 2, wherein the predetermined number of pre-candidate pilots and the neighbor pilots are alternately scanned until one of the neighbor pilots is promoted to the Pre-candidate Set.

4. The method of claim 3, wherein the step of scanning the pre-candidate pilots until all but a predetermined number of pre-candidate pilots have been promoted to the Candidate Set or demoted to the Neighbor Set is repeated when a one of the neighbor pilots is promoted to the Pre-Candidate Set.

5. The method of claim 2, wherein the predetermined number of pre-candidate pilots and the neighbor pilots are alternately scanned until a one of the predetermined number of pre-candidate pilots is promoted to the Candidate Set or demoted to the Neighbor Set.

6. The method of claim 5 further comprising the step of scanning the neighbor pilots until a one of the neighbor pilots is promoted to the Pre-candidate Set or all of the neighbor pilots have been scanned, when the one of the predetermined number of pre-candidate pilots has been promoted to the Candidate Set or demoted to the Neighbor Set.

7. The method of claim 6, wherein the step of alternately scanning the predetermined number of pre-candidate pilots and the neighbor pilots is repeated when the one of the neighbor pilots has been promoted.

8. The method of claim 6, the Pilot Set further includes a Remaining Set of remaining pilots, the method further comprises the step of scanning a remaining pilot when all of the neighbor pilots have been scanned.

9. The method of claim 8, wherein the step of scanning the neighbor pilots until a one of the neighbor pilots is promoted to the Pre-candidate Set or all of the neighbor pilots have been scanned is repeated when the remaining pilot has not been promoted to the Pre-candidate Set.

10. The method of claim 7, wherein the step of alternately scanning the predetermined number of pre-candidate pilots and the neighbor pilots is repeated when the remaining pilot has been promoted to the Pre-candidate Set.

11. The method of claim 2 wherein the predetermined number of pre-candidate pilots and the neighbor pilots are alternately scanned until all of the neighbor pilots have been scanned.

12. The method of claim 11, the Pilot Set further includes a Remaining Set of remaining pilots, the method further comprises the step of scanning a remaining pilot when all of the neighbor pilots have been scanned.

13. The method of claim 12, wherein the step of scanning the pre-candidate pilots until all but predetermined number of pre-candidate pilots have been promoted to the Candidate Set or demoted to the Neighbor Set is repeated when the remaining pilot has been promoted to the Pre-candidate Set.

14. The method of claim 12, wherein the step of step of alternately scanning the predetermined number of pre-candidate pilots and the neighbor pilots is repeated when the remaining pilot has not been promoted to the Pre-candidate Set.

15. A method of maintaining a Pilot Set in a digital communication system that utilizes Code Division Multiple Access, the Pilot Set including an Active Set of active pilots, a Candidate Set of candidate pilots, a Pre-candidate Set of pre-candidate pilots, and a Neighbor Set of neighbor pilots, the method comprising the steps of:

(a) scanning the entire Active Set;

(b) scanning the entire Candidate Set after scanning the entire Active Set;

(c) scanning at least a subset of the Pre-candidate Set and the Neighbor Set without intervening scans of the Active Set or the Candidate Set after scanning the entire Candidate Set, until an initiation event occurs; and

(d) repeating steps (a) through (c) when the initiation event occurs.

16. The method of claim 15, wherein step (c) further comprises the substep of scanning the Pre-candidate Set until all but a predetermined number of pre-candidate pilots have been promoted to the Candidate Set or demoted to the Neighbor Set.

17. The method of claim 16, wherein step (c) further comprises the substep of alternately scanning the predetermined number of pre-candidate pilots and the neighbor pilots.

18. The method of claim 15, wherein the initiation event is the expiration of a predetermined time duration that commences upon initiating step (a).

19. An apparatus for maintaining a Pilot Set in a digital communication system that utilizes Code Division Multiple Access, the Pilot Set including an Active Set of active pilots, a Candidate Set of candidate pilots, a Pre-candidate Set of pre-candidate pilots, and a Neighbor Set of neighbor pilots, the apparatus comprising:

a logic and control circuit for providing instructions; and

a searcher receiver, responsive to the instructions, to sequentially scan the entire Active Set of active pilots, then the entire Candidate Set of candidate pilots, and then the pre-candidate pilots without intervening scans of the Active Set or Candidate Set, wherein the scan of the pre-candidate pilots continues until all but a predetermined number of pre-candidate pilots have been promoted to the Candidate Set or demoted to the Neighbor Set.

20. The apparatus of claim 19, wherein the searcher receiver alternately scans the predetermined number of pre-candidate pilots and the neighbor pilots.

21. The apparatus of claim 20, wherein the searcher receiver terminates alternate scans of the predetermined number of pre-candidate pilots and the neighbor pilots when a one of the neighbor pilots is promoted to the Pre-candidate Set, and resumes the scan of the pre-candidate pilots.