Use of sectorized polarization diversity as a means of increasing capacity in cellular wireless systems

• US 6,445,926 B1
• Filed: 10/14/1998
• Issued: 09/03/2002
• Est. Priority Date: 05/06/1998
• Status: Expired due to Term

• Current Assignee: Alcatel Canada Inc. (Nokia Corporation)
• Original Assignee: Alcatel Canada Inc. (Nokia Corporation)
• Inventors: Herscovich, Bernard, Boch, Erik H.
• Primary Examiner(s): Vo, Nguyen T.
• Assistant Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US09/170,723
• Time in Patent Office: 1,420 Days
• Field of Search: 455/561, 455/562, 455/447, 455/454, 455/450, 455/101, 455/500, 455/422, 370/328, 370/338, 343/797
• US Class Current: 455/447
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H04L 2012/5607 Radio
• 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 system and method for increasing the use of frequency licenses in a cellular, multipoint wireless access system with non-mobile customer sites. The cell coverage of a base station is divided into sectors, for example 4, and orthogonal polarization between adjacent sectors is employed. For bi-directional communication uplink and downlink signals within each sector also employs orthogonal polarization.

Claims

1. A system for optimizing frequency re-use within a cell of a cellular wireless communications system comprising:

a base station within the cell and having a sectored antenna dividing the cell into four sectors, the sectored antenna transmitting point to multipoint communications to customer premise equipment (CPE) at sites within said sectors;

a directional antenna at each CPE for receiving communications from said sectored antenna and for transmitting point to point communications to said base station;

polarization means at said base station for transmitting and receiving orthogonally polarized radiation; and

polarization means at said CPE directional antennas for receiving and transmitting orthogonally polarized radiation, said CPE directional antenna having a cross polarization rejection ratio in the order of 20 to 40 dB;

wherein orthogonally polarized radiation is employed between adjacent sectors and radiation between adjacent sectors have a common carrier frequency,

wherein said orthogonal radiation comprises linear −

45 degree polarization and linear +45 degree polarization relative to vertical linear.

2. A system as defined in claim 1 wherein said communications is broadband digital.

3. A system as defined in claim 2 wherein said communications system is an asynchronous transfer mode (ATM) network.

4. A system as defined in claim 3 wherein said base station is connected to an ATM backbone network.

5. A system as defined in claim 4 wherein said base station is hard wired to said backbone network.

6. A system as defined in claim 4 wherein said base station is connected to said backbone network via a wireless link.

7. A system as defined in claim 3 wherein said base station is connected to an Internet Protocol (IP) network.

8. A system as defined in claim 1 wherein a plurality of cells are adjacently arranged to cover a larger geographical area.

9. A method of optimizing frequency re-use within a cell of a cellular wireless communications system, said cell having a base station with a sectored antenna dividing the cell into four sectors, the sectored antenna transmitting point to multipoint communications to customer premise equipment (CPE) at sites within said sectors each CPE having a directional antenna for receiving communications from said sectored antenna and for transmitting point to point communications to said base station, the method comprising:

providing polarization means at said base station whereby said sectored antenna transmits and receives orthogonally polarized radiation;

providing polarization means at said CPE directional antennas for receiving and transmitting orthogonally polarized radiation said CPE directional antenna having a cross polarization rejection ratio in the order of 20 to 40 dB; and

employing orthogonally polarized radiation between adjacent sectors said radiation between adjacent sectors having a common carrier frequency, said orthogonally polarized radiation comprising linear −

45 degree and linear +45 degree polarization relative to vertical linear.

10. A method as defined in claim 9 for broadband digital communications over an asynchronous transfer mode (ATM) network.

11. A method as defined in claim 9 for broadband digital communications over an Internet Protocol (IP) network.