Method and apparatus for improving link performance and capacity of a sectorized CDMA cellular communication network

• US 6,188,914 B1
• Filed: 10/22/1997
• Issued: 02/13/2001
• Est. Priority Date: 10/22/1997
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Chheda, Ashvin
• Primary Examiner(s): Le, Thanh Cong
• Assistant Examiner(s): PHAM, DIEP N
• Application Number:
  US08/956,296
• Time in Patent Office: 1,210 Days
• Field of Search: 455/562, 455/522, 455/277.1, 455/277.2, 455/449, 455/446, 455/561
• US Class Current: 455/562.1
• CPC Class Codes: H04W 16/00 Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
• CPC Class Codes: H04W 16/24 Cell structures

Abstract

A system and method for improving link performance and network capacity of a CDMA network is described. In a preferred embodiment, at each sector site, antennas having a relatively narrow horizontal beamwidth are used as transmit antennas, while antennas having a relatively wide horizontal beamwidth are used as receive antennas. Narrow beamwidth antennas are also used to implement hybrid transmit/receive antennas.

Claims

1. A method of improving link capacity of a sectorized code division multiple access (“

CDMA”

) network, the method comprising steps of;

(a) installing at at least one sector site of said CDMA network a first antenna having a first beamwidth; and

(b) installing at said at least one sector site of said CDMA network a second antenna having a second beamwidth;

wherein said first beamwidth is greater than said second beamwidth; and

wherein said first antenna is a receive-only antenna and said second antenna is a transmit-only antenna.

2. The method of claim 1 further comprising:

(c) installing at said at least one sector site of said CDMA network a third antenna having beamwidth equal to said first beamwidth, wherein said third antenna is a receive-only antenna.

3. The method of claim 1 wherein a sectorization of said CDMA network is three and wherein said first and second beamwidths are approximately 90°

and 60°

, respectively.

4. The method of claim 1 wherein a sectorization of said CDMA network is four and wherein said first and second beamwidths are approximately 60°

and 40°

, respectively.

5. The method of claim 1 wherein a sectorization of said CDMA network is six and wherein said first and second beamwidths are approximately 45°

and 30°

, respectively.

6. The method of claim 1 wherein said step (a) further comprises installing at each sector site of said CDMA network a first antenna having a beamwidth equal to said first beamwidth.

7. The method of claim 1 wherein said step (b) further comprises installing at each sector site of said CDMA network a second antenna having a beamwidth equal to said second beamwidth.

8. The method of claim 2 wherein said step (c) further comprises installing at each sector site of said CDMA network a third antenna having a beamwidth equal to said first beamwidth.

9. A code division multiple access (“

CDMA”

) network having improved link capacity and performance, the CDMA network comprising;

a plurality of cells each comprising a plurality of sectors, wherein each of said sectors includes a sector site;

a first antenna installed at each of said sector sites; and

a second antenna installed at each of said sector sites;

wherein at each sector site, a beamwidth of said first antenna of said sector site is greater than a beamwidth of said second antenna of said sector site; and

wherein said first antenna is a receive-only antenna and said second antenna is a transmit-only antenna.

10. The CDMA network of claim 9 further comprising:

a third antenna installed at each of said sector sites;

wherein a beamwidth of each of said third antennas is equal to that of each of said first antennas and wherein the third antenna is a receive-only antenna.

11. The CDMA network of claim 9 wherein a sectorization of said CDMA network is three and wherein said beamwidths of each said first and second antennas are approximately 90°

and 60°

, respectively.

12. The CDMA network of claim 9 wherein a sectorization of said CDMA network is four and wherein said beamwidths of each said first and second antennas are approximately 60°

and 40°

, respectively.

13. The CDMA network of claim 9 wherein a sectorization of said CDMA network is six and wherein said beamwidths of each first and second antennas are approximately 45°

and 30°

, respectively.

14. A method of improving link capacity of a sectorized code division multiple access (“

CDMA”

) network, the method comprising steps of;

(a) installing at at least one sector site of said CDMA network a first antenna having a first beamwidth; and

(b) installing at said at least one sector site of said CDMA network a second antenna having a second beamwidth equal to two-thirds of said first beamwidth; and

wherein said first antenna is a receive-only antenna and said second antenna is a transmit-only antenna.

15. A code division multiple access (“

CDMA”

) network having improved link capacity and performance, the CDMA network comprising;

a plurality of cells each comprising a plurality of sectors, wherein each of said sectors includes a sector site;

a first antenna installed at each of said sector sites; and

a second antenna installed at each of said sector sites;

wherein at each sector site, a beamwidth of said second antenna of said sector site is equal to two thirds the beamwidth of first second antenna of said sector site; and

wherein said first antenna is a receive-only antenna and said second antenna is a transmit-only antenna.