Method and apparatus for configuring PN-offsets for a non-uniform CDMA cellular network

• US 6,049,564 A
• Filed: 12/22/1997
• Issued: 04/11/2000
• Est. Priority Date: 04/28/1997
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Chang, Churui
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US08/995,510
• Time in Patent Office: 841 Days
• Field of Search: 375/206, 375/200, 375/208, 370/335, 370/342, 455/422, 455/522, 455/429, 455/438, 455/446, 455/447, 455/448
• US Class Current: 375/130
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/0074 Code shifting or hopping
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 16/12 Fixed resource partitioning

Abstract

A method for configuring a spread spectrum cellular network for small-cell inclusion, by providing a finite series of PN-offsets, each PN-offset is separated by a constant value that is allotted to the spread spectrum cellular network. The finite series is portioned into a first and a second set. The second set subsequent to the first set and having sufficient PN-offset elements for a PN-offset reuse pattern having a plurality of cells, each cell having similar transmission characteristics. The second set is assigned to the PN-offset reuse pattern, deploying the cellular reuse pattern for a cellular network. Small cells are insertable into the spread spectrum cellular network by assigning the first set to a PN-offset reuse pattern having a plurality of small cells arranged in a small-cell reuse pattern, and deploying the small-cell reuse pattern. In another aspect, the method for configuring the spread spectrum cellular network involves sectoring each cell of the plurality of cells into a plurality of sectors. The sectored cells are assigned PN-offsets adjacent in the finite series together in each sector of the sectored cell while maintaining sufficient distance between cells that reuse an assigned PN-offset.

Claims

1. A method for configuring a spread spectrum cellular network for small-cell inclusion, the method comprising the steps of:

providing a finite series of PN-offsets, each of the PN-offsets being separated by a constant value that is allotted to the spread spectrum cellular network;

portioning the series of PN-offsets into a first and a second set, the second set subsequent to the first set and having sufficient PN-offset elements for a PN-offset reuse pattern having a plurality of cells, each cell having similar transmission characteristics;

assigning the second set to the PN-offset reuse pattern; and

deploying the cellular reuse pattern.

2. The method for configuring a spread spectrum cellular network of claim 1 wherein the constant value is PILOT_-- INC.

3. The method for configuring a spread spectrum cellular network of claim 1 wherein the first and the second set are disjointed.

4. The method for configuring a spread spectrum cellular network of claim 1 wherein the series of PN-offsets is defined by an industry standard.

5. The method for configuring a spread spectrum cellular network of claim 4 wherein the industry standard is IS-95.

6. The method for configuring a spread spectrum cellular network of claim 1 wherein said step of providing a finite set of PN-offsets further comprises the step of:

further separating each of the PN-offsets of the second set by a multiple of the constant value, the multiple having a value greater than unity.

7. The method for configuring a spread spectrum cellular network of claim 1 further comprising the steps of:

assigning the first set to a PN-offset reuse pattern having a plurality of small cells arranged in a small-cell reuse pattern; and

deploying the small-cell reuse pattern in close proximity to the first cellular reuse pattern.

8. The method for configuring a spread spectrum cellular network of claim 7 wherein said step of providing a finite set of PN-offsets further comprises the step of:

further separating each of the PN-offsets of the second set by a multiple of the constant value, the multiple having a value greater than unity.

9. The method for configuring a spread spectrum cellular network of claim 7 wherein the constant value is PILOT_-- INC.

10. The method for configuring a spread spectrum cellular network of claim 7 wherein the first and the second set are disjointed.

11. The method for configuring a spread spectrum cellular network of claim 7 wherein the series is defined by an industry standard.

12. The method for configuring a spread spectrum cellular network of claim 11 wherein the industry standard is IS-95.

13. The method for configuring a spread spectrum cellular network of claim 1 further comprising the steps of:

sectoring each cell of said plurality of cells into a plurality of sectors; and

assigning PN-offsets adjacent in the finite series together in each adjacent sector of the sectored cell while maintaining sufficient distance between cells that reuse an assigned PN-offset.

14. An apparatus for configuring a spread spectrum cellular network for small-cell inclusion, the apparatus comprising:

means for providing a finite series of PN-offsets, each of the PN-offsets being separated by a constant value that is allotted to the spread spectrum cellular network;

means for portioning the series of PN-offsets into a first and a second set, the second set subsequent to the first set and having sufficient PN-offset elements for a PN-offset reuse pattern having a plurality of cells, each cell having similar transmission characteristics;

means for assigning the second set to the PN-offset reuse pattern; and

means for deploying the cellular reuse pattern.

15. The apparatus for configuring a spread spectrum cellular network of claim 14 wherein the providing means further comprises:

means for further separating each of the PN-offsets of the second set by a multiple of the constant value, the multiple having a value greater than unity.

16. The apparatus for configuring a spread spectrum cellular network of claim 14 further comprising:

means for assigning the first set to a PN-offset reuse pattern having a plurality of small cells arranged in a small-cell reuse pattern; and

means for deploying the small-cell reuse pattern in close proximity to the first cellular reuse pattern.

17. The apparatus for configuring a spread spectrum cellular network of claim 16 wherein said providing means further comprises:

means for further separating each of the PN-offsets of the second set by a multiple of the constant value, the multiple having a value greater than unity.

18. The apparatus for configuring a spread spectrum cellular network of claim 14 further comprising:

means for sectoring each cell of said plurality of cells into a plurality of sectors; and

means for assigning PN-offsets adjacent in the finite series together in each adjacent sector of the sectored cell while maintaining sufficient distance between cells that reuse an assigned PN-offset.

19. A method of minimizing adjacent PN-offset confusion in a sectored CDMA cell, the method comprising the steps of:

providing a series having a plurality of PN-offsets, each PN-offset of the plurality of PN-offsets separated by a constant value allotted for the cellular network;

disjointing the first set from the second set and the second set is subsequent to the first set; and

further separating the PN-offsets of the second set by a multiple of the constant value, the multiple having a value greater than unity.

20. The method of minimizing adjacent PN-offset confusion of claim 19 wherein the constant value is PILOT_-- INC.

21. The method of minimizing adjacent PN-offset confusion of claim 19 wherein the series is defined in part by an industry standard.

22. The method of minimizing adjacent PN-offset confusion of claim 21 wherein the industry standard is IS-95.

23. The method of minimizing adjacent PN-offset confusion of claim 19 wherein the multiple is an integer.

24. A method of minimizing PN-offset confusion between a plurality of large cells and a plurality of small cells in a spread spectrum cellular network, the large cells and the small cells each arranged in a respective reuse pattern, the method comprising the steps of:

providing a finite series of PN-offsets, each PN-offset separated by a constant value that is allotted to the spread spectrum cellular network;

minimizing co-PN-offset confusion between the small cells and the large cells by portioning the series of PN-offsets into a first and a second set, and assigning the PN-offsets from the first set to the small cells and assigning the PN-offsets from the second set to the large cells; and

minimizing adjacent PN-offset confusion by disjointing the first set from the second set and the second set is subsequent to the first set, and further separating the PN-offsets of the second set by a multiple of the constant value, the multiple having a value greater than unity.

25. The method of minimizing PN-offset confusion of claim 24 wherein the multiple is an integer.

26. A method of inserting a plurality of small cells into a spread spectrum cellular network, the method comprising the steps of:

deploying a plurality of mobile small cells in a small-cell reuse pattern, the small cells having a plurality of PN-offsets unrelated to a second plurality of PN-offsets of the spread spectrum cellular network; and

decreasing a cellular traffic coverage provided by a cell in the spread spectrum cellular network while transferring cellular traffic coverage to at least one small cell of the plurality of deployed mobile small cells.

27. The method of inserting a plurality of small cells into a spread spectrum cellular network of claim 26, wherein the step of decreasing a cellular traffic coverage further comprises the steps of:

reducing the transmission power of a preexisting cell; and

desensitizing the receiver of the preexisting cell.

28. A spread spectrum cellular communication system wherein pseudo-random noise offsets (PN-offset) of a cell base transmission station identification code are used in adjacent cells comprising in combination:

a plurality of base transmission stations each defining a large cell;

at least one base transmission station defining a small cell; and

means in each of said at least one base transmission station defining a small cell for establishing a PN-offset that precedes any PN-offset established in a base transmission station of said plurality of base transmission stations defining a large cell.