METHOD AND APPARATUS FOR ANTENNA SELECTION IN WIRELESS COMMUNICATIONS SYSTEMS

• US 20120300717A1
• Filed: 05/23/2012
• Published: 11/29/2012
• Est. Priority Date: 05/24/2011
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: CEPEDA LOPEZ, Rafael Arcangel, Coon, Justin
• Granted Patent: US 9,025,618 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

According to one embodiment there is provided a wireless communication device comprising a plurality of antennas and operable to transmit data on a plurality of subcarriers from one or more of said plurality of antennas over a communication channel, the device comprising a receiver configured to receive signals via each of said plurality of antennas, a processor configured to determine the number of subcarriers that can be allocated to one or more of said plurality of antennas for data transmission on the basis of received signal metrics associated with said received signals, and an antenna selector configured to select one or more of said plurality of antennas for transmitting data on said plurality of subcarriers based on said determination.

Claims

1. A wireless communication device comprising a plurality of antennas and operable to transmit data on a plurality of subcarriers from one or more of said plurality of antennas over a communication channel, the device comprising

a receiver configured to receive signals via each of said plurality of antennas;

a processor configured to determine the number of subcarriers that can be allocated to one or more of said plurality of antennas for data transmission on the basis of received signal metrics associated with said received signals; and

an antenna selector configured to select one or more of said plurality of antennas for transmitting data on said plurality of subcarriers based on said determination.

2. A device according to claim 1, wherein said received signal metrics include any one of the following:

total received energy of said received signals;

peak received power of said received signals; and

root mean square (RMS) delay spread of said received signals.

3. A device according to claim 1 or claim 2, wherein said processor is further configured to perform said determination on the basis of a function defining a relationship between said received signal metrics and subcarriers that can be allocated to said one or more of said plurality of antennas;

4. A device according to claim 3, wherein said function includes a linear regression defining said relationship, and is expressible in the form:

y=α

+β

x

where α

is the intersection point and β

is the slope factor.

5. A device according any one of the preceding claims, wherein said processor is further configured to arrange said plurality of antennas in descending order by the number of subcarriers that can be allocated to each of said plurality of antennas.

6. A device according to claim 5, wherein said antenna selector is configured to select a set of antennas from said arranged antennas, such that the total number subcarriers allocated to said set of antennas is equal to or greater than said plurality of subcarriers.

7. A device according to claim 6, further comprising radio frequency (RF) modules connected to each of said plurality of antennas, and said processor being operable to switch off said RF modules corresponding to antennas other than said selected antennas.

8. A method of operating a wireless communication device comprising a plurality of antennas and operable to transmit data on a plurality of subcarriers from one or more of said plurality of antennas over a communication channel, the method comprising:

receiving signals via each of said plurality of antennas;

determining the number of subcarriers that can be allocated to one or more of said plurality of antennas for data transmission on the basis of received signal metrics associated with said received signals;

selecting one or more of said plurality of antennas for transmitting data on said plurality of subcarriers based on said determination.

9. A method according to claim 8, wherein said received signal metrics include any one of the following:

total received energy of said received signals;

peak received power of said received signals; and

root mean square (RMS) delay spread of said received signals.

10. A method according to claim 8 or claim 9, further comprising determining the number of subcarriers that can be allocated to one or more of said plurality of antennas for data transmission on the basis of a function defining a relationship between said received signal metrics and subcarriers that can be allocated to said one or more of said plurality of antennas;

11. A method according to claim 10, wherein said function includes a linear regression defining said relationship, and is expressible in the form:

y=α

+β

x

where α

is the intersection point and β

is the slope factor.

12. A method according to any one of claims 8 to 11, further comprising arranging said plurality of antennas in descending order by the number of subcarriers that can be allocated to each of said plurality of antennas.

13. A method according to claim 12, further comprising selecting a set of antennas from said arranged antennas, and wherein the total number subcarriers allocated to said set of antennas is equal to or greater than said plurality of subcarriers.

14. A method according to claim 13, wherein said wireless communication device further comprising radio frequency (RF) modules connected to each of said plurality of antennas, and the method further comprising switching off said RF modules corresponding to antennas other than said selected antennas.

15. A computer program product comprising computer executable instructions operable to configure a general purpose programmable communications device to perform a method according to any one of claims 8 to 14.