Antenna assembly and associated method for radio communication device

• US 5,924,020 A
• Filed: 12/15/1995
• Issued: 07/13/1999
• Est. Priority Date: 12/15/1995
• Status: Expired due to Term

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Johannisson, Bjorn, Forssen, Ulf, Anderson, Soren
• Primary Examiner(s): Rao, Anand S.
• Application Number:
  US08/573,280
• Time in Patent Office: 1,306 Days
• Field of Search: 455/562, 455/277.1, 455/277.2, 455/272, 455/33.1, 455/33.2, 455/33.3, 455/33.4, 455/561, 455/422, 455/443, 455/129, 342/372, 342/373, 342/374, 342/375, 342/354
• US Class Current: 455/129
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/40 with phasing matrix

Abstract

An antenna assembly, and an associated method, which exhibits a selected the antenna beam configuration. The direction of a primary lobe and of a null is selected to improve the signal-to-noise and signal-to-interference ratios of communication signals transmitted between two communication stations. When implemented to form a portion of a base station of a cellular communication system, the traffic capacity of the communication system can be increased and the infrastructure costs of the system can be reduced.

Claims

1. In a radio transceiver having an array of transceiver elements operable to transceive radio frequency signals, an improvement of an antenna assembly which exhibits a selected directional antenna beam pattern having an elongated lobe extending in a first direction and a null extending in a second direction, said antenna assembly comprising:

a first antenna array formed of a first selected number of antenna elements;

a second antenna array formed of a second selected number of antenna elements;

a beamforming matrix device for causing the formation of the elongated lobe, said beamforming matrix device including a first and second matrix beamformer respectively coupled to the first and second antenna arrays, said first and second matrix beamformers operable to respectively cause the formation of a first and second polarized antenna beam pattern, where said first and second polarized antenna beam patterns are substantially orthogonal to one another and interleaved by said beamforming matrix device to cause the formation of the null for attenuating energy due to interference; and

a processor coupled to each transceiver element of the array of transceiver elements and to said beamforming matrix device, said processor for processing signals provided thereto by the transceiver elements to determine the first direction in which the elongated lobe is to extend and the second direction in which the null is to extend, said processor further for providing indications of the first and second directions, respectively, determined thereat to said beamforming matrix device.

2. The antenna assembly of claim 1, wherein the first matrix beamformer and the second matrix beamformer are separated by at least a minimum separation distance.

3. The antenna assembly of claim 2 wherein the radio transceiver is formed of a radio base station of a cellular communication network operable to communicate with at least one mobile station and wherein said antenna array is operative to transmit downlink signals to, and to receive uplink signals transmitted by, said at least one mobile station.

4. The antenna assembly of claim 1 wherein said processor further computes direction-of-arrival indications responsive to the signals received by said array of transceiver elements.

5. The antenna assembly of claim 1 further comprising a memory look-up device coupled to said processor, said memory look-up device for storing data associated with at least one direction in which the first elongated lobe of the selected antenna pattern can extend.

6. The antenna assembly of claim 5 wherein said processor accesses the data stored in said memory look-up device to determine the first direction in which the elongated lobe of the antenna pattern is to extend.

7. An antenna assembly used in a cellular communication system for exhibiting a selected antenna beam pattern consisting of a lobe extending toward a mobile station and a null extending toward a location where an interfering signal is transmitted, said antenna assembly comprising:

a first antenna array having a plurality of antennas;

a second antenna array having a plurality of antennas;

a beamforming device for causing the formation of the lobe, said beamforming device including a first and second matrix beamformer respectively coupled to the first and second antenna arrays, said first and second matrix beamformers for respectively causing the formation of a first and second polarized antenna beam pattern, where said first and second polarized antenna beam patterns are substantially orthogonal to one another and interleaved by said beamforming matrix device to cause the formation of the null for attenuating energy due to said interfering signal; and

a transceiver array coupled to the beamforming device; and

a processor coupled to the transceiver array, said processor including;

a direction-of-arrival determiner responsive to receiving a signal from the transceiver array for determining a first direction for extending the lobe and a second direction for extending the null;

a look-up table for storing data; and

a beam configuration determiner coupled to the look-up table and the direction-of-arrival determiner, said beam configuration determiner for accessing the stored data in response to the determined first and second directions to provide indications of the first and second directions to said beamforming device.

8. The antenna assembly of claim 7, further comprising an input and output device coupled to the processor.

9. The antenna assembly of claim 7, wherein said transceiver array includes a plurality of transceivers and a plurality of receivers, where each transceiver includes a modulator and up-converter and each receiver includes a demodulator and down-converter.

10. The antenna assembly of claim 7, wherein said processor includes means for updating the selected antenna beam pattern in response to receiving a subsequent signal from the transceiver array.

11. A method used in a cellular communication system for exhibiting a selected antenna beam pattern consisting of a lobe extending toward a mobile station and a null extending toward a location where an interfering signal is transmitted, said method comprising the steps of:

transmitting an initial antenna beam pattern;

receiving a signal;

determining, responsive to the received signals, a first direction for extending the lobe and a second direction for extending the null;

forming the selected antenna beam pattern in response to determining the first and second directions, said step of forming further including the steps of;

forming the lobe, a first antenna beam pattern and a second antenna beam pattern;

orthogonally polarizing the first antenna beam pattern and a second antenna beam pattern; and

interleaving the orthogonally polarized first and second antenna beam patterns so as to cause the formation of the null for attenuating energy due to the interfering signal;

transmitting the selected antenna beam pattern; and

updating, responsive to receiving a subsequent signal, the formed selected antenna beam pattern.

12. The method of claim 11, wherein said step of updating includes:

determining, responsive to the received subsequent signal, an updated first direction for extending the lobe and an updated second direction for extending the null; and

forming, responsive to the determined updated first and second directions, the formed selected antenna beam pattern.

13. In a method for communicating in a radio communication system having a communication station including transceiver circuitry having an array of transceiver elements, an improvement of a method for transceiving communication signals at the communication station, said method comprising the steps of:

determining, responsive to signals received at the array of transceiver elements, a first direction in which an elongated lobe is to extend and a second direction in which a null is to extend of an antenna beam pattern to be exhibited by an antenna array, including using one of the first and second directions to determine the other of the first and second directions;

providing indications of the determined first direction and the determined second direction to a beamforming matrix device for causing the formation of the elongated lobe, said beamforming device including a first and second matrix beamformer respectively coupled to a first and second antenna array of the antenna array, said first and second matrix beamformers for respectively causing the formation of a first and second polarized antenna beam pattern, where said first and second polarized antenna beam patterns are substantially orthogonal to one another and interleaved by said beamforming matrix device to cause the formation of the null for attenuating energy due to interference; and

forming the antenna beam pattern to be exhibited by the antenna array.

14. In a radio transceiver having an array of transceiver elements operable to transceive radio frequency signals, an improvement of an antenna assembly which exhibits a selected directional antenna beam pattern having an elongated lobe extending in a first direction and a null extending in a second direction, said antenna assembly comprising:

a first antenna array formed of a first plurality of antenna elements;

a second antenna array formed of a second plurality of antenna elements;

a beamforming matrix device for causing the formation of the elongated lobe, said beamforming matrix device including a first and second matrix beamformer respectively coupled to the first and second antenna arrays, said first and second matrix beamformers operable to respectively cause the formation of a first and second polarized antenna beam pattern, where said first and second polarized antenna beam patterns are substantially orthogonal to one another and interleaved by said beamforming matrix device to cause the formation of the null for attenuating energy due to interference; and

a processor coupled to each transceiver element of the array of transceiver elements and to said beamforming matrix device, said processor for processing signals provided thereto by the transceiver elements to determine the first direction in which the elongated lobe is to extend and the second direction in which the null is to extend, where one of the first and second directions is used to determine the other of the first and second directions, said processor further for providing indications of the first and second directions to said beamforming matrix device.