Communication system and method utilizing an antenna having adaptive characteristics

• US 5,680,142 A
• Filed: 11/07/1995
• Issued: 10/21/1997
• Est. Priority Date: 11/07/1995
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Smith, David Anthony, Rinnback, Lennart Hans
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): PHAN, DAO LINDA
• Application Number:
  US08/554,524
• Time in Patent Office: 714 Days
• Field of Search: 342/372, 342/375, 455/65
• US Class Current: 342/372
• CPC Class Codes: H04B 7/0845 per branch equalization, e.g. by an FIR-filter or RAKE receiver per antenna branch rake receivers as such H04B1/7115
• CPC Class Codes: H04B 7/086 using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming

Abstract

An apparatus, and an associated method, for facilitating reception and transmission of signals in a communication system, such as a cellular communication system. An antenna having an antenna pattern adaptively responsive to propagation characteristics extending between communication stations of the communication system. The antenna pattern of the antenna is selected responsive to the propagation characteristics. When the propagation characteristics are indicative of a channel exhibiting only insignificant multipath components, the antenna pattern is selected to be highly directional, and when the propagation characteristics are indicative of a channel exhibiting significant multipath components, the antenna pattern is altered to become less directional.

Claims

1. In a radio communication system having a first communication station and at least a second communication station, an improvement of an apparatus coupled to the first communication station for facilitating transmission of communication signals upon a radio communication channel between the first communication station and the second communication station, said apparatus comprising:

a propagation characteristic determiner for determining propagation characteristics of the radio communication channel upon which the communication signals are transmitted between the first communication station and the second communication station; and

an antenna assembly coupled to receive indications of the propagation characteristics determined by said propagation characteristic determiner, said antenna assembly forming an antenna beam pattern at least alternately exhibiting at least a first lobe geometry and a second lobe geometry, selection of the antenna beam pattern exhibited by said antenna assembly determined by said propagation characteristic determiner.

2. The apparatus of claim 1 wherein said propagation characteristic determiner determines propagation delays of the communication signals transmitted upon the radio communication channel between the first and second communication stations, respectively.

3. The apparatus of claim 2 wherein a communication signal transmitted by the second communication station to the first communication station defines an uplink signal, wherein a communication signal transmitted by the first communication station to the second communication station defines a downlink signal, and wherein the propagation delays determined by said propagation characteristic determiner is determined by determining an indication of a time period between transmission of a selected downlink signal by the first communication station and reception of a selected uplink signal responsive thereto at the first communication station.

4. The apparatus of claim 1 wherein said propagation characteristic determiner determines a value representative of angular energy spreading of the communication signals transmitted upon the radio communication channel between the first and second communication stations, respectively.

5. The apparatus of claim 4 wherein a communication signal transmitted by the second communication station to the first communication station defines an uplink signal and wherein the value determined by said propagation characteristic determiner is representative of the angular energy spreading of the uplink signal.

6. The apparatus of claim 1 wherein said propagation characteristic determiner determines a value representative of signal quality of the communication signals transmitted upon the radio communication channel between the first and second communication stations, respectively.

7. The apparatus of claim 6 wherein a communication signal transmitted by the second communication station to the first communication station defines an uplink signal and wherein the value determined by said propagation characteristic determiner is representative of the signal quality of the uplink signal.

8. The apparatus of claim 1 wherein said propagation characteristic determiner determines a value representative of signal strength of the communication signals transmitted upon the radio communication channel between the first and second communication stations, respectively.

9. The apparatus of claim 8 wherein a communication signal transmitted by the second communication station to the first communication station defines an uplink signal and wherein the value determined by said propagation characteristic determiner is representative of the signal strength of the uplink signal.

10. The apparatus of claim 1 wherein the lobe geometry exhibited by said antenna assembly is adaptively selectable responsive to the propagation characteristics.

11. The apparatus of claim 1 wherein the antenna beam pattern exhibited by said antenna assembly comprises a plurality of lobe geometries, each lobe geometry defining a primary lobe of the antenna beam pattern, configuration of the primary lobe adaptively selectable responsive to the propagation characteristics determined by said propagation characteristic determiner.

12. The apparatus of claim 11 wherein the lobe geometry of the primary lobe is adaptively selectable to form at least either an elongated primary lobe or a non-elongated primary lobe.

13. The apparatus of claim 12 wherein the lobe geometry of the primary lobe is adaptively selectable further to form a selected primary lobe of a shape between the elongated primary lobe and the non-elongated primary lobe.

14. The apparatus of claim 1 wherein the first communication station forms a radio base station, wherein the second communication station forms a moveably-positionable transceiver, and wherein said propagation characteristic determiner is coupled to the radio base station to form a portion thereof.

15. The apparatus of claim 14 wherein said antenna assembly is coupled to the radio base station.

16. The apparatus of claim 1 wherein said antenna assembly comprises an antenna array formed of a plurality of antenna elements, the plurality of antenna elements having elemental characteristics which together define the antenna beam pattern exhibited said antenna assembly.

17. The apparatus of claim 15 wherein the antenna bean pattern exhibited by said antenna array is formed by superpositioning of fields of each antenna element of the antenna array.

18. The apparatus of claim 16 wherein the antenna beam pattern exhibit said antenna array is adaptively altered by adaptively altering numbers of the antenna elements which form the antenna array.

19. The apparatus of claim 18 wherein the antenna beam pattern exhibited by said antenna array is adaptively altered by altering phases of signals applied to selected ones of the antenna elements of the antenna array.

20. The apparatus of claim 18 wherein the antenna beam pattern exhibited by said antenna array is adaptively altered by altering amplitudes of signals applied to selected ones of the antenna elements of the antenna array.

21. The apparatus of claim 1 wherein the radio communication channel comprises an uplink channel and a downlink channel and wherein said propagation characteristic determiner determines the propagation chacteristics of the uplink channel.

22. In a method for communicating in a radio communication system having a first communication station and at least a second communication station and a radio communication channel upon which radio communication signals are transmitted between the first and second communication stations, respectively, an improvement of a method for at least receiving communication signals generated by the second communication station, said method comprising the steps of:

determining propagation characteristics of a communication signal transmitted between the first communication station and the second communication station upon the radio communication channel; and

adaptively selecting an antenna beam pattern to be exhibited by an antenna assembly responsive to the propagation characteristics determined during said step of determining, the antenna beam pattern selected to be at least alternately of a first lobe geometry and of a second lobe geometry.

23. A radio base station for transmitting downlink signals to, and receiving uplink signals from, at least one subscriber unit, said radio base station comprising:

transceiver circuitry for generating the downlink signals and for processing the uplink signals;

a propagation characteristic determiner operative responsive to selected uplink signals processed by said transceiver circuitry, said propagation characteristic determiner for determining a value representative of the propagation characteristics of a radio communication channel upon which a communication signal is transmitted between the subscriber unit and the transceiver circuitry; and

an antenna assembly coupled to said transceiver circuitry, said antenna assembly exhibiting an antenna beam pattern at least alternately exhibiting at least a first lobe geometry and a second lobe geometry, selection of the antenna beam pattern exhibited by said antenna assembly responsive to the value determined by said propagation characteristic determiner.