Use of sectorized polarization diversity as a means of increasing capacity in cellular wireless systems
AssigneeAlcatel Canada Inc.
InventorsErik H. Boch, Bernard Herscovich
Life of this patent
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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.
Claims11
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.
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.
Dependencies are inferred from the claim text.