Using beamforming and closed loop transmit diversity in a multi-beam antenna system

• US 20040121810A1
• Filed: 12/23/2002
• Published: 06/24/2004
• Est. Priority Date: 12/23/2002
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Goransson, Bo, Logothetis, Andrew, Hagerman, Bo
• Granted Patent: US 7,151,951 B2
• Time in Patent Office: Days
• US Class Current: 455/562.1
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients

Abstract

In controlling a multi-beam antenna system for downlink wireless communication, beamforming and closed loop transmit diversity signaling are combined. Each beam signal is adjusted at the transmitter based on feedback from a wireless mobile communication station such that the signals received at the wireless mobile communication station can be coherently combined.

Claims

1. An apparatus for supporting downlink wireless communication to wireless mobile communication stations via a multi-beam antenna system, comprising:

an input for receiving a data stream associated with a wireless mobile communication station;

a divider coupled to said input for producing from said data stream a set of beam signals;

an adjuster coupled to said divider for receiving said beam signals, said adjuster including an input for receiving feedback information that the wireless mobile communication station has provided via a wireless communication link, said adjuster operable for adjusting at least one of said beam signals based on said feedback information to produce an adjusted set of beam signals;

a beamforming unit coupled to said adjuster for receiving therefrom said adjusted set of beam signals, said beamforming unit having an input for receiving beamforming control information, and said beamforming unit responsive to said adjusted set of beam signals and said beamforming control information for producing antenna information for the multi-beam antenna system; and

an output coupled to said beamforming unit for providing said antenna information to the multi-beam antenna system.

2. The apparatus of claim 1, wherein said adjuster is for phase-adjusting said at least one beam signal.

3. The apparatus of claim 2, wherein said adjuster is further for amplitude-adjusting said at least one beam signal.

4. The apparatus of claim 1, wherein said adjuster is for amplitude-adjusting said at least one beam signal.

5. The apparatus of claim 1, including a beam pattern determiner for determining a number of beams in a beam pattern to be implemented by the multi-beam antenna system, said beam pattern determiner coupled to said divider for providing thereto beam number information indicative of said number of beams, said divider responsive to said beam number information for providing said set of beam signals with a number of said beam signals equal to the number of beams.

6. The apparatus of claim 5, wherein said beam pattern determiner is further coupled to said beamforming unit input for providing thereto said beamforming control information.

7. The apparatus of claim 6, wherein said beam pattern determiner includes an input for receiving measurement information obtained from a wireless communication link, said beam pattern determiner responsive to said measurement information for determining said number of beams and for providing said beamforming control information.

8. The apparatus of claim 1, wherein said beamforming control information includes antenna weights.

9. The apparatus of claim 1, provided in a WCDMA base station, and wherein said feedback information is provided by the wireless mobile communication station using one of FBI and FSM.

10. The apparatus of claim 1, wherein said beamforming unit includes a plurality of beamformers for respectively receiving the beam signals of said adjusted set of beam signals, each said beamformer operable for producing in response to the associated beam signal and said beamforming control information a plurality of beamformer output signals, said beamforming unit further including a combiner coupled to said beamformers for combining said pluralities of beamformer output signals to produce said antenna information.

11. The apparatus of claim 1, wherein said beamforming unit includes a plurality of combiners, each said combiner for receiving each said beam signal of said adjusted set of beam signals, each said combiner responsive to the received beam signals for producing a corresponding combiner output signal, said beamforming unit including a beamforming network coupled to said combiners and responsive to said combiner output signals for producing said antenna information.

12. The apparatus of claim 1, wherein said adjuster includes a multiplier and said feedback information includes complex beam weights.

13. The apparatus of claim 1, including a plurality of said inputs, a plurality of said dividers, and a plurality of said adjusters, each said divider coupled to a corresponding one of said inputs, each said adjuster coupled to a corresponding one of said dividers, and said beamforming unit coupled to each of said adjusters.

14. A method of effectuating downlink wireless communication to a wireless mobile communication station via a multi-beam antenna system, comprising:

receiving a data stream associated with the wireless mobile communication station;

producing from said data stream a set of beam signals;

based on feedback information received from the wireless mobile communication station via a wireless communication link, adjusting at least one of said beam signals to produce an adjusted set of beam signals;

using the adjusted set of beam signals to perform a beamforming operation, including combining the adjusted set of beam signals with beamforming control information; and

in response to said beamforming operation, operating the multi-beam antenna system for downlink wireless communication to the wireless mobile communication station.

15. The method of claim 14, wherein said adjusting step includes one of phase-adjusting and amplitude-adjusting said at least one beam signal.

16. The method of claim 14, wherein said adjusting step includes phase-adjusting and amplitude-adjusting said at least one beam signal.

17. The method of claim 14, including determining a number of beams in a beam pattern to be implemented by the multi-beam antenna system, said producing step including providing said set of beam signals with a number of said beam signals equal to the number of beams.

18. The method of claim 17, wherein said determining step includes determining said number of beams in response to measurement information obtained from a wireless communication link, and including providing said beamforming control information in response to said measurement information.

19. The method of claim 18, wherein said measurement information includes one of uplink power measurement information and uplink quality measurement information.

20. The method of claim 14, including the wireless mobile communication station transmitting the feedback information via a WCDMA wireless communication link using one of FBI and FSM.

21. The method of claim 14, wherein said adjusting step includes multiplying said at least one beam signal by a complex beam weight.

22. An apparatus for performing downlink wireless communication to wireless mobile communication stations, comprising:

an input for receiving a data stream associated with a wireless mobile communication station;

a divider coupled to said input for producing from said data stream a set of beam signals;

an adjuster coupled to said divider for receiving said beam signals, said adjuster including an input for receiving feedback information that the wireless mobile communication station has provided via a wireless communication link, said adjuster operable for adjusting at least one of said beam signals based on said feedback information to produce an adjusted set of beam signals;

a beamforming unit coupled to said adjuster for receiving therefrom said adjusted set of beam signals, said beamforming unit having an input for receiving beamforming control information, and said beamforming unit responsive to said adjusted set of beam signals and said beamforming control information for producing antenna information; and

a multi-beam antenna system coupled to said beamforming unit and responsive to said antenna information for downlink transmitting to the wireless mobile communication station.

23. The apparatus of claim 22, provided as a WCDMA base station.

24. The apparatus of claim 23, wherein said feedback information is provided by the wireless mobile communication station using one of FBI and FSM.

25. The apparatus of claim 22, wherein said adjuster is for one of phase-adjusting and amplitude-adjusting said at least one beam signal.

26. The apparatus of claim 22, wherein said adjuster is for phase-adjusting and amplitude-adjusting said at least one beam signal.

27. The apparatus of claim 22, wherein said beamforming unit includes a plurality of beamformers for respectively receiving the beam signals of said adjusted set of beam signals, each said beamformer operable for producing in response to the associated beam signal and said beamforming control information a plurality of beamformer output signals, said beamforming unit further including a combiner coupled to said beamformers for combining said pluralities of beamformer output signals to produce said antenna information.

28. The apparatus of claim 22, wherein said beamforming unit includes a plurality of combiners, each said combiner for receiving each said beam signal of said adjusted set of beam signals, each said combiner responsive to the received beam signals for producing a corresponding combiner output signal, said beamforming unit including a beamforming network coupled to said combiners and responsive to said combiner output signals for producing said antenna information.

29. The apparatus of claim 22, wherein said adjuster includes a multiplier and said feedback information includes complex beam weights.

30. The apparatus of claim 22, including a plurality of said inputs, a plurality of said dividers, and a plurality of said adjusters, each said divider coupled to a corresponding one of said inputs, each said adjuster coupled to a corresponding one of said dividers, and said beamforming unit coupled to each of said adjusters.