Methods and apparatus of enhancing performance in wireless communication systems

• US 9,049,722 B2
• Filed: 11/15/2006
• Issued: 06/02/2015
• Est. Priority Date: 04/23/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Laroia, Rajiv, Srinivasan, Murari, Li, Junyi
• Primary Examiner(s): NGUYEN, KHAI MINH
• Application Number:
  US11/599,837
• Publication Number:
  US 20070064641A1
• Time in Patent Office: 3,121 Days
• Field of Search: 455/450, 455/422.1, 455/452.1, 455/452.2, 455/454, 455/464, 455/441, 455/434, 455/418, 455/552.1, 455/414.1, 455/435.3, 455/419, 455/440, 455/458, 455/404.2, 370/320, 370/338, 370/328, 370/329, 370/341, 370/431, 370/253, 370/252
• US Class Current: 1/1
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 72/51 based on terminal or device properties

Abstract

Methods and apparatus for supporting and using multiple communications channels corresponding to different transmit technologies and/or access technologies in parallel within a cell of a wireless communications system are described. Mobile nodes support multiple technologies and can switch between the technology being used at a particular point in time, e.g., from a first channel corresponding to a first technology to a second channel corresponding to a different technology which provides better transmission characteristics, e.g., a better perceived channel quality. Mobiles maintain at least two sets of channel quality information at any one point in time. Mobiles select the better channel and communicate the channel selection to the base station or communicate channel quality information for multiple channels to the base station and allow the base station to select the channel corresponding to the technology providing the better conditions for the mobile. Different mobiles in the same cell may support different technologies.

Claims

1. A method of operating a wireless terminal, the method comprising:

maintaining a set of communications quality information for a plurality of different wireless communications channels which can be used to communicate information between a base station and said wireless terminal, at least one of the base station and wireless terminal including multiple antennas, said plurality of different wireless communications channels including at least a first communications channel and a second communications channel, the first and second communications channels having different quality characteristics which are a function of first and second communications technologies used to establish said first and second communications channels, respectively, said first and second communications technologies being different;

determining a rate of motion of said wireless terminal; and

selecting a communications channel for use in communicating with said base station as a function of the determined rate of motion of said wireless terminal.

2. The method of claim 1, further comprising:

transmitting communications channel quality information corresponding to said first and said second communications channels to said base station.

3. The method of claim 1, wherein said first and second communications technologies are different incompatible communications technologies.

4. The method of claim 3, where the different communications technologies include CDMA, OFDM, and narrowband signal carrier technologies.

5. The method of claim 3, where each of the different communications technologies corresponds to a different technology standard which defines requirements for complying with the particular communications technology, said different communications technologies being incompatible as indicated by the technology standard corresponding to one of said different communications technologies defining communications requirements which violate the defined requirements of the other different communications technologies.

6. The method of claim 1, wherein at least one of said first and second communications technologies is an orthogonal frequency division multiplexed communication technology.

7. The method of claim 1, wherein the step of selecting a communications channel includes:

selecting the first communications technology when said determined rate of motion indicates a first rate of wireless terminal movement, said first communications technology providing a first amount of frequency diversity to the wireless terminal; and

selecting a communications channel corresponding to the second communications technology when said determined rate of motion indicates a second rate of wireless terminal movement, the second communications technology using antenna beam forming as a function of feedback information received from the wireless terminal, said second rate of wireless terminal movement being slower than said first rate of wireless terminal movement.

8. The method of claim 1, wherein determining a rate of motion includes making a measurement indicative of a rate of motion of said wireless terminal by measuring a Doppler shift in a signal transmitted between said base station and said wireless terminal.

9. The method of claim 1, wherein said step of determining a rate of motion of said wireless terminal includes measuring at least one of:

a rate of change in timing control signals which are used to instruct the wireless terminal to make a clock timing change;

a rate at which power in a periodically transmitted signal from the wireless terminal changes over time;

a rate of change in a measured quality of a communications channel; and

a rate of change in a channel fading measurement.

10. The method of claim 1, wherein the step of selecting a communications channel includes:

selecting the first communications technology when said determined rate of motion indicates a first rate of wireless terminal movement, said first communications technology using a first amount of channel quality feedback signaling from said wireless terminal to said base station; and

selecting a communications channel corresponding to the second communications technology when said determined rate of motion indicates a second rate of wireless terminal movement, the second rate of wireless terminal movement being lower than said first rate of wireless terminal movement, the second communications technology using a second amount of channel feedback, the second amount of channel feedback being greater than said first amount of channel quality feedback.

11. The method of claim 10, wherein said first communications technology uses two fixed antennas and is a technology which used an Alamouti transmission method, said first communications technology using zero channel quality feedback signaling to said base station to control the antenna pattern used to transmit signals from said base station.

12. The method of claim 10, wherein said second communications technology uses a beam forming transmission method which involves forming beams as a function of channel quality feedback received from said wireless terminal.

13. The method of claim 10, wherein both the base station and the wireless terminal include multiple antennas, said second communications technology using a multiple-input, multiple-output technique.

14. The method of claim 1, wherein the step of selecting a communications channel includes:

selecting the first communications technology when said determined rate of motion indicates a first rate of wireless terminal movement, said first communications technology providing at least one of a higher frequency diversity and a time diversity than a second communications channel; and

selecting the second communications channel corresponding to the second communications technology when said determined rate of motion indicates a second rate of wireless terminal movement, the second rate of wireless terminal movement being lower than said first rate of wireless terminal movement, the second communications technology providing a high spatial diversity than is available from the first communications channel corresponding to the first communications technology.

15. The method of claim 1, wherein the step of selecting a communications channel includes:

selecting a communications channel in said plurality of communications channels which provides a higher frequency or time diversity than is available from the non-selected communications channels in said plurality of channels when changes in channel conditions are occurring at a rapid rate; and

selecting another communications channel in said plurality of communications channels which provides higher spatial diversity than said communications channel which is selected when changes in communications channel conditions are occurring at said rapid rate, said another communications channel being selected when changes in channel conditions are occurring at a slow rate, said slow rate being a rate which is slower than said rapid rate.

16. The method of claim 1, wherein said plurality of communications channels are fixed.

17. The method of claim 16, wherein at least some of said plurality of fixed communications channels are periodic in nature with different combinations of communications channels existing at different points in time, the combination of communications channels exiting at any point in time being predictable due to the periodic nature of the communications channels.

18. A wireless terminal comprising a processor configured to control said wireless terminal to implement a method, the method comprising:

maintaining a set of communications quality information for a plurality of different wireless communications channels which can be used to communicate information between a base station and said wireless terminal, at least one of the base station and wireless terminal including multiple antennas, said plurality of different wireless communications channels including at least a first communications channel and a second communications channel, the first and second communications channels having different quality characteristics which are a function of first and second communications technologies used to establish said first and second communications channels, respectively, said first and second communications technologies being different;

determining a rate of motion of said wireless terminal; and

selecting a communications channel for use in communicating to said base station as a function of the determined rate of motion of said wireless terminal.

19. The wireless terminal of claim 18, wherein the method further comprises:

transmitting communications channel quality information corresponding to said first and said second communications channels to said base station.

20. The wireless terminal of claim 18, wherein said first and second communications technologies are different incompatible communications technologies.

21. A non-transitory computer readable medium embodying machine executable instruction for controlling a wireless terminal to implement a method, the method comprising:

maintaining a set of communications quality information for a plurality of different wireless communications channels which can be used to communicate information between a base station and said wireless terminal, at least one of the base station and wireless terminal including multiple antennas, said plurality of different wireless communications channels including at least a first communications channel and a second communications channel, the first and second communications channels having different quality characteristics which are a function of first and second communications technologies used to establish said first and second communications channels, respectively, said first and second communications technologies being different;

determining a rate of motion of said wireless terminal; and

selecting a communications channel for use in communicating to said base station as a function of the determined rate of motion of said wireless terminal.

22. The non-transitory computer readable medium of claim 21, wherein the method further comprises:

transmitting communications channel quality information corresponding to said first and said second communications channels to said base station.

23. The non-transitory computer readable medium of claim 21, wherein said first and second communications technologies are different incompatible communications technologies.

24. A wireless terminal comprising:

means for storing a set of communications quality information for a plurality of different wireless communications channels which can be used to communicate information between a base station and said wireless terminal, at least one of the base station and wireless terminal including multiple antennas, said plurality of different wireless communications channels including at least a first communications channel and a second communications channel, the first and second communications channels having different quality characteristics which are a function of first and second communications technologies used to establish said first and second communications channels, respectively, said first and second communications technologies being different;

means for determining a rate of motion of said wireless terminal; and

means for selecting a communications channel for use in communicating to said base station as a function of the determined rate of motion of said wireless terminal.

25. The wireless terminal of claim 24, further comprising:

means for transmitting communications channel quality information corresponding to said first and said second communications channels to said base station.

26. The wireless terminal of claim 24, wherein said first and second communications technologies are different incompatible communications technologies.

27. A wireless terminal comprising:

a memory including a set of communications quality information for a plurality of different wireless communications channels which can be used to communicate information between a base station and said wireless terminal, at least one of the base station and wireless terminal including multiple antennas, said plurality of different wireless communications channels including at least a first communications channel and a second communications channel, the first and second communications channels having different quality characteristics which are a function of first and second communications technologies used to establish said first and second communications channels, respectively, said first and second communications technologies being different;

a processor configured to determine a rate of motion of said wireless terminal; and

a selection module configured to select a communications channel for use in communicating to said base station as a function of the determined rate of motion of said wireless terminal.

28. The wireless terminal of claim 27, further comprising:

a transmitter configured to transmit communications channel quality information corresponding to said first and said second communications channels to said base station.

29. The wireless terminal of claim 27, wherein said first and second communications technologies are different incompatible communications technologies.