METHODS AND APPARATUS FOR USING MULTIPLE ANTENNAS HAVING DIFFERENT POLARIZATION

• US 20090207093A1
• Filed: 02/15/2008
• Published: 08/20/2009
• Est. Priority Date: 02/15/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wu, Xinzhou, Anreddy, Vikram Reddy
• Granted Patent: US 8,306,473 B2
• Time in Patent Office: Days
• US Class Current: 343/876
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0602 using antenna switching H04B7/0686 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/0805 with single receiver and antenna switching H04B7/0822 takes precedence
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity

Abstract

A MIMO wireless communications device supports a dual polarized mode of antenna operation and a single polarized mode of antenna operation. Antenna mode selection is performed as a function of signal to noise ratio information and/or rank information corresponding to a communications channel matrix. One of a communications device'"'"'s processing chains is switched between first and second polarization orientation antennas, e.g., vertical and horizontally polarized antennas, as a function of the antenna mode selection. In various embodiments, the dual polarized mode is advantageously used for high SNR users, while in the low SNR regime, where the capacity is limited by received power, the single polarized antenna configuration, sometimes referred to as the spatial MIMO configuration, is used.

Claims

1. A communications device comprising:

a first antenna element polarized in a first direction;

a second antenna element polarized in a second direction, said first and second directions being different by at least 45 degrees;

a first signal processing module coupled to said first antenna element; and

a second signal processing module coupled to said second antenna element.

2. The communications device of claim 1, wherein said first and second signal processing modules are used for one of:

i) recovering data from first and second received signals having the same frequency but different polarizations and ii) generating first and second signals having the same frequency to be transmitted with different polarizations.

3. The communications device of claim 1, further comprising:

a third antenna element polarized in said first direction;

an antenna switching module used to couple said second and third antenna elements to said second signal processing module, said antenna switching module selectively passing signals between one of;

i) said second antenna element and ii) said third antenna element and said second processing module at any given time.

4. The communications device of claim 3, further comprising:

a channel quality determination module for generating channel quality indicators from received signals, said channel quality indicators including a signal to noise ratio value.

5. The communications device of claim 4, further comprising:

a channel quality information transmission control module for controlling transmission of channel quality information, said channel quality information including said signal to noise ratio value and one of i) rank information for a channel matrix between transmitter antennas used to transmit to said communications device and receive antennas included in said communications device having a polarization which is the same as the transmitter antennas and ii) additional signal to noise ratio information.

6. The communications device of claim 5, further comprising:

an antenna mode indicator signal detection module for detecting receipt of an antenna mode indicator signal and for recovering information indicating one of a dual polarized mode of operation and a single polarized mode of operation.

7. The communications device of claim 4, further comprising:

an antenna mode selection module for selecting between a dual polarized mode of operation and a single polarized mode of operation as a function of said generated channel quality indicators.

8. The communications device of claim 7, further comprising:

an antenna mode indicator signal generation module for generating a signal indicating the selected antenna mode of operation; and

an antenna mode indicator signal transmission control module for controlling transmission of said antenna mode indicator signal.

9. The communications device of claim 4,

wherein when said dual polarized mode of operation is selected, said antenna switching module is controlled to couple said second antenna element to said second signal processing module;

and

wherein when said single polarized mode of operation is selected, said antenna switching module is controlled to couple said third antenna element to said second signal processing module.

10. The communications device of claim 9,

wherein said first direction is a vertical direction;

and

wherein said second direction is a horizontal direction.

11. The communications device of claim 2, further comprising:

an antenna mode selection module for selecting between a dual polarized mode of operation and a single polarized mode of operation as a function of received channel quality information;

wherein when said dual polarized mode of operation is selected signals from said first and second antenna are used to support communications; and

wherein when said single polarized mode of operation is selected, said first and said third antenna elements are used to support communications.

12. The communications device of claim 2, wherein said communications device is a transceiver, the communications device further comprising:

a transmitter/receiver mode control module for controlling whether said communications device operates in a transmit or receive mode of operation; and

an antenna mode selection module for selecting between a dual polarized mode of operation and a single polarized mode of operation as a function of a received signal;

wherein the said antenna mode selection module selects the dual polarized or single polarized mode of operation based on the said antenna mode indicator signal.

13. The communications device of claim 12, wherein said received signal is an antenna mode indicator signal.

14. The communications device of claim 12,

wherein said received signal is a signal from which a channel quality estimate is made;

and

wherein said antenna mode selection module selects the dual polarized mode of operation when said channel quality estimate indicates a first channel quality and selects the single polarized mode of operation when said channel quality estimate indicates a second channel quality which is lower than said first channel quality.

15. The communications device of claim 14, further comprising

an antenna mode indicator signal generation module for generating a signal indicating the selected antenna mode of operation;

and

an antenna mode indicator signal transmission control module for controlling transmission of said antenna mode indicator signal.

16. A method of operating a wireless communications device, the method comprising:

operating during a first period of time in a dual polarized mode of antenna operation; and

operating during a second period of time in a single polarized mode of antenna operation, said first and second periods of time being different.

17. The method of claim 16, further comprising:

selecting between said dual polarized mode of antenna operation and said single polarized mode of antenna operation based on one of;

i) a channel quality estimate and ii) a received antenna mode indicator signal.

18. The method of claim 17, further comprising:

switching between said dual polarized mode of antenna operation and said single polarized mode of antenna operation when said selecting step selects a different one of said dual polarized mode of antenna operation and said single polarized mode of antenna operation than a current mode of operation in which the wireless communications device is operating.

19. The method of claim 18, wherein when said selecting is based on a channel quality estimate, the method further comprises:

generating rank information for a channel matrix between transmitter antennas used to transmit to said wireless communications device and receive antennas included in said wireless communications device having a polarization which is the same as the polarization of the transmitter antennas; and

making a selection between said dual polarized mode of antenna operation and said single polarized mode of antenna operation based on both the channel quality estimate and said generated rank information.

20. The method of claim 19, further comprising:

transmitting an antenna mode indicator signal over an airlink.

21. The method of claim 18, wherein when said selecting is based on a received antenna mode indicator signal, said selecting includes detecting an antenna mode of operation indicated by the received antenna mode indicator signal and selecting the antenna mode of operation indicated by the received signal.

22. The method of claim 17,

wherein when said dual polarized mode of operation is selected, the method further comprises:

recovering data from signals output by first and second antennas polarized at more than 75 degrees to each other; and

wherein when said single polarized mode of operation is selected, the method further comprises;

recovering data from signals output by multiple antennas polarized in the first direction without using the output of an antenna polarized in a different direction.

23. The method of claim 22, wherein the first and second directions are vertical and horizontal directions, respectively.

24. The method of claim 17,

wherein when said dual polarized mode of operation is selected, the method further comprises:

transmitting data from a first antenna and a second antenna, the first and second antennas being polarized at more than 75 degrees to each other; and

wherein when said single polarized mode of operation is selected, the method further comprises;

transmitting data from multiple antennas polarized in the first direction without transmitting data on an antenna polarized in a different direction.

25. The method of claim 18, wherein said switching is performed at specific points in time within a predetermined timing structure at which said wireless communications device is permitted to switch between said dual polarized mode of operation and said single polarized mode of operation.

26. A communications device comprising:

means for operating the said device during a first period of time in a dual polarized mode of antenna operation; and

operating the device during a second period of time in a single polarized mode of antenna operation, said first and second periods of time being different.

27. The device of claim 26, further comprising:

means for selecting between dual polarized mode of antenna operation and said single polarized mode of antenna based on one of;

i) a channel quality estimate and ii) a received antenna mode indicator signal.

28. The device of claim 27, wherein switching is performed between said dual polarized mode of antenna operation and said single polarized mode of antenna operation when said selecting step selects a different one of said dual polarized mode of antenna operation and said single polarized mode of antenna than a current mode of operation in which the wireless communications device is operating.

29. A computer readable medium embodying machine executable instructions for controlling a device to implement a method, the method comprising:

operating during a first period of time in a dual polarized mode of antenna operation; and

operating during a second period of time in a single polarized mode of antenna operation, said first and second periods of time being different

30. The computer readable medium of claim 29, wherein the method further comprising:

selecting between said dual polarized mode of antenna operation and said single polarized mode of antenna operation based on one of;

i) a channel quality estimate and ii) a received antenna mode indicator signal.

31. The computer readable medium of claim 30, wherein the method further comprising:

switching between said dual polarized mode of antenna operation and said single polarized mode of antenna operation when said selecting step selects a different one of said dual polarized mode of antenna operation and said single polarized mode of antenna than a current mode of operation in which the wireless communications device is operating.

32. A wireless communications device comprising:

a processor configured to control said device to;

operate during a first period of time in a dual polarized mode of antenna operation; and

operate during a second period of time in a single polarized mode of antenna operation, said first and second periods of time being different.

33. The device of claim 32, wherein the processor is further configured to:

select between said first and second modes of operation based on one of;

i) a channel quality estimate and ii) a received antenna mode indicator signal.

34. The device of claim 33, wherein the processor is further configured to:

switch between said dual polarized mode of antenna operation and said single polarized mode of antenna operation when said selecting step selects a different one of said first and second modes of operation than a current mode of operation in which the wireless communications device is operating.