Power control with signal quality estimation for smart antenna communications systems

• US 20070173277A1
• Filed: 03/15/2006
• Published: 07/26/2007
• Est. Priority Date: 10/11/1996
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Yun, Louid
• Granted Patent: US 8,064,944 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04B 7/0848 Joint weighting
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

A method for power control with signal quality estimation for smart antenna communication systems is described. The method, for example, starts with a transmit power assignment. Receive weight vector determination is carried out with this assigned transmit power, and the new weights used. An estimate of the resulting received signal quality is obtained and used for another power adjustment.

Claims

1. A method comprising:

receiving, at a second radio station, a first radio signal from a first radio station, the first signal being transmitted with a first assigned power level and a first transmit spatial weight vector;

determining a quality of the received first signal;

receiving a second radio signal from the first station, the second signal being transmitted using a second assigned power level and a second transmit spatial weight vector, the second assigned power level being determined based on the determined quality of the received first signal; and

determining the quality of the received second signal.

2. The method of claim 1, further comprising communicating the determined quality of the first and second received radio signals to the first radio station.

3. The method of claim 1, further comprising determining the second power assignment at the second radio based on the determined quality of the first received radio signal and communicating the second power assignment to the first station before receiving the second signal.

4. The method of claim 1, further comprising:

determining the second transmit spatial weight vector at the second station based on the determined quality of the first signal;

communicating the second transmit spatial weight vector to the first station; and

receiving the second signal from the first station using the second power assignment and the second transmit spatial weight vector.

5. The method of claim 4, further comprising repeating at least a portion of:

receiving a signal from the first station;

determining a quality of the signal;

determining a power assignment based on the determined quality;

determining a transmit spatial weight vector based on the determined quality;

communicating the second power assignment to the first station;

communicating the second transmit weight vector to the first station; and

receiving a second signal from the first station using the second power assignment and the second transmit spatial weight vector.

6. A machine-readable medium comprising data that when operated on by the machine cause the machine to perform operations comprising:

receiving at second radio station a first radio signal from a first radio station, the first signal being transmitted with a first assigned power level and a first transmit spatial weight vector;

determining a quality of the received first signal;

receiving a second radio signal from the first radio station, the second signal being transmitted using a second assigned power level and a second transmit spatial weight vector, the second assigned power level being determined based on the determined quality of the received first signal; and

determining the quality of the received second signal.

7. The medium of claim 6, the operations further comprising communicating the determined quality of the first and second received radio signals to the first radio station.

8. The medium of claim 6, the operations further comprising repeating at least a portion of:

receiving a signal from the first station;

determining a quality of the signal;

determining a power assignment based on the determined quality;

determining a transmit spatial weight vector based on the determined quality;

communicating the second power assignment to the first station;

communicating the second transmit weight vector to the first station; and

receiving a second signal from the first station using the second power assignment and the second transmit spatial weight vector.

9. A radio station comprising:

a receiver to receive a first radio signal from a second radio station, the first signal being transmitted with a first assigned power level and a first transmit spatial weight vector;

a signal processor to determine a quality of the received first signal;

the receiver further to receive a second radio signal from the first radio station, the second signal being transmitted using a second assigned power level and a second transmit spatial weight vector, the second assigned power level being determined based on the determined quality of the received first signal; and

the signal processor further to determine the quality of the received second signal.

10. The radio station of claim 9, wherein the signal processor further determines the second transmit spatial weight vector based on the determined quality of the first signal, further comprising a transmitter to communicate the second transmit spatial weight vector to the first station, and wherein the receiver further receives the second signal from the first station using the second power assignment and the second transmit spatial weight vector.

11. The radio station of claim 9, wherein the receiver receives on a downlink channel and the transmitter transmits on an uplink channel.

12. The radio station of claim 9, wherein the radio station comprises a component of a mobile cellular telephone.

13. A method comprising:

transmitting a first radio signal from a first radio station to a second radio station, the first signal being sent according to a first power assignment and a first spatial weight vector;

receiving from the second station a quality of the first signal;

determining at the first station a second power assignment based on the received quality of the first signal; and

transmitting a second radio signal from the first station to the second station using the second power assignment.

14. The method of claim 13, further comprising:

determining a second spatial weight vector at the first station based on the received quality of the first signal; and

wherein transmitting the second signal comprises transmitting the second signal using the second power assignment and the second spatial weight vector.

15. The method of claim 13, further comprising:

setting up an initial power assignment and spatial weight vector as the first power assignment and the first spatial weight vector, the initial assignments being the same for all radios to which the first station transmits a first signal.

16. The method of claim 13, wherein the second power assignment is applied as a scaling factor to the second spatial weight vector.

17. The method of claim 13, wherein receiving from the second station comprises receiving an uplink signal.

18. A machine-readable medium comprising data that when operated on by the machine cause the machine to perform operations comprising:

transmitting a first radio signal from a first radio station to a second radio station, the first signal being sent according to a first power assignment and a first spatial weight vector;

receiving from the second radio station a quality of the first signal;

determining a second power assignment based on the received quality of the first signal; and

transmitting a second radio signal from the first radio station to the second radio station using the second power assignment.

19. The medium of claim 18, the operations further comprising:

determining a second spatial weight vector at the first station based on the received quality of the first signal; and

wherein transmitting the second signal comprises transmitting the second signal using the second power assignment and the second spatial weight vector.

20. The medium of claim 18, the operations further comprising:

repeating at least a portion of;

transmitting an additional radio signal to the second station;

receiving a quality of the additional signal from the second station;

determining an additional power assignment based on the received quality;

determining an additional spatial weight vector based on the received quality; and

transmitting an additional signal to the second station using the determined additional power assignment and the determined additional spatial weight vector.

21. A radio station comprising:

a transmitter to transmit a first radio signal from the radio station to a second radio station, the first signal being sent according to a first power assignment and a first spatial weight vector;

a receiver to receive from the second radio station a quality of the first signal;

a signal processor to determine a second power assignment based on the received quality of the first signal; and

the transmitter further to transmit a second radio signal from the first radio station to the second radio station using the second power assignment.

22. The radio station of claim 21, wherein the signal processor is further to determine a second spatial weight vector based on the received quality of the first signal, and wherein the transmitter is further to transmit the second signal using the second power assignment and the second spatial weight vector.

23. The radio station of claim 21, wherein the transmitter transmits to a plurality of second radio stations as a base station in cellular radio communication system and wherein the signal processor further sets up an initial power assignment and spatial weight vector as the first power assignment and the first spatial weight vector, the initial assignments being the same for all radios to which the transmitter transmits a first signal.

24. The radio station of claim 21, wherein the signal processor applies the second power assignment as a scaling factor to the second spatial weight vector.