Systems and methods of antenna selection

• US 8,068,877 B1
• Filed: 07/20/2007
• Issued: 11/29/2011
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Clearwire Ip Holdings LLC (Deutsche Telekom AG)
• Original Assignee: Clear Wireless LLC (Deutsche Telekom AG)
• Inventors: Mansour, Nagi A.
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US11/780,783
• Time in Patent Office: 1,593 Days
• Field of Search: 455/561, 455/562.1, 455/101, 455/103, 455/129
• US Class Current: 455/562.1
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H04B 7/0447 utilizing uniform distribution
• CPC Class Codes: H04B 7/0608 Antenna selection according to transmission parameters
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

Systems and methods of controlling transmission of communications from a base station to a wireless communication station are provided. When the signal quality of communications between the base station and the wireless communication station are above a predetermined signal quality level, multiple antennas are employed for transmitting such communications. When the signal quality of transmissions by the base station to the wireless communication station are below a predetermined signal quality level, a single antenna is employed for transmitting such communications.

Claims

1. A method of communicating with a wireless communication station, the method comprising the acts of:

transmitting, by a base station to the wireless communication station, communication signals in a first communication mode, wherein the base station transmits the communication signals over multiple antennas in the first communication mode;

determining a signal quality measure of the communications with the wireless communication station in the first communication mode;

determining a distance between the base station and the wireless communication station; and

transmitting, by the base station to the wireless communication station, communication signals in a second communication mode when the determined signal quality measure is less than a predetermined signal quality measure and when there is a predetermined distance between the base station and the wireless communication station, wherein the base station transmits the communication signals over a single one of the plurality of antennas in the second communication mode,

wherein the base station transmits the communication signals at a same power level over each of the multiple antennas in the first communication mode and the base station transmits the communication signals over the single antenna at a power level equal to a sum of the power levels used for transmission over the multiple antennas in the second communication mode.

2. The method of claim 1, wherein the base station and wireless communication station communicate in accordance with WiMAX protocols.

3. The method of claim 1, wherein the first communication mode involves multiple input multiple output (MIMO) processing.

4. The method of claim 1, further comprising the act of:

determining whether the determined signal quality measure is less than a predetermined signal quality measure for a predetermined amount of time, wherein the base station transmits communication signals in the second communication mode when the determined signal quality measure is less than a predetermined signal quality measure for a predetermined amount of time.

5. The method of claim 1, further comprising the acts of:

determining a signal quality measure of the communications in the second communication mode; and

switching, by the base station, transmissions to the wireless communication station from the second communication mode to the first communication mode when the determined signal quality measure in the second communication mode exceeds the predetermined signal quality measure by a predetermined amount.

6. A base station, comprising:

a transceiver;

at least two antennas coupled to the transceiver;

a memory; and

a processor coupled to the transceiver and memory, wherein the processor includes

transmission mode controlling logic to control transmissions, by the base station to a wireless communication station, of communication signals in a first communication mode, wherein the base station transmits the communication signals over the at least two antennas in the first communication mode;

distance determination logic that determines a distance between the base station and the wireless communication station; and

signal quality determination logic that determines a signal quality measure of the communications with the wireless communication station in the first communication mode, wherein the transmission mode controlling logic controls transmissions, by the base station to the wireless communication station, of communication signals in a second communication mode when the determined signal quality measure is less than a predetermined signal quality measure and when there is a predetermined distance between the base station and the wireless communication station, wherein the base station transmits the communication signals over a single antenna in the second communication mode,

wherein the base station transmits the communication signals at a same power level over each of the at least two antennas in the first communication mode and the base station transmits the communication signals over the single antenna at a power level equal to a sum of the power levels used for transmission over the at least two antennas in the second communication mode.

7. The base station of claim 6, wherein the base station and wireless communication station communicate in accordance with WiMAX protocols.

8. The base station of claim 6, wherein the first communication mode involves multiple input multiple output (MIMO) processing.

9. The base station of claim 6, wherein the signal quality determination logic determines whether the determined signal quality measure is less than a predetermined signal quality measure for a predetermined amount of time, wherein the base station transmits communication signals in the second communication mode when the determined signal quality measure is less than a predetermined signal quality measure for a predetermined amount of time.

10. The base station of claim 6, wherein the signal quality determination logic determines a signal quality measure of the communications in the second communication mode, and the transmission mode controlling logic switches transmissions from the base station to the wireless communication station from the second communication mode to the first communication mode when the determined signal quality in the second communication mode exceeds the predetermined signal quality measure by a predetermined amount.

11. A method of communicating with a wireless communication station, the method comprising the acts of:

transmitting, by a base station to the wireless communication station, communication signals in a first communication mode, wherein the base station transmits the communication signals over multiple antennas in the first communication mode;

determining a signal quality measure of the communications with the wireless communication station in the first communication mode;

determining a distance between the base station and the wireless communication station; and

transmitting, by the base station to the wireless communication station, communication signals in a second communication mode when the determined signal quality measure is less than a predetermined signal quality measure and when there is a predetermined distance between the base station and the wireless communication station, wherein the base station transmits the communication signals over a single one of the plurality of antennas in the second communication mode.

12. The method of claim 11, wherein the base station transmits the communication signals at a same power level over each of the multiple antennas in the first communication mode and the base station transmits the communication signals over the single antenna at a power level equal to a sum of the power levels used for transmission over the multiple antennas in the second communication mode.

13. The method of claim 12, wherein the base station and wireless communication station communicate in accordance with WiMAX protocols.

14. The method of claim 12, wherein the first communication mode involves multiple input multiple output (MIMO) processing.

15. The method of claim 12, further comprising the act of:

determining whether the determined signal quality measure is less than a predetermined signal quality measure for a predetermined amount of time, wherein the base station transmits communication signals in the second communication mode when the determined signal quality measure is less than a predetermined signal quality measure for a predetermined amount of time.