Granted Patent B2

US 7,548,527 · App. 10/448,466 · Granted Jun 16, 2009

Abstract

Claims (102)

1. A method, comprising:

using at least one beam specific pilot for channel estimation, the beam specific pilot being transmitted using a plurality of antenna elements of an antenna array of a base transceiver station;

determining, at the base transceiver station, a calibration quality indicator describing the quality of calibration of the antenna array;

checking whether the determined calibration quality indicator resides below a calibration quality threshold value, the calibration quality threshold value being a predetermined value; and

switching over to using an antenna element specific pilot when the calibration quality indicator resides below the calibration quality threshold value.

2. The method of claim 1 , wherein the method further comprises:

transmitting to a terminal device, from the base transceiver station, a command to change pilots when the calibration quality indicator resides below the calibration quality threshold value prior to a switch-over to using an antenna element specific pilot;

switching over to using an antenna element specific pilot according to the command to change pilots.

3. The method of claim 1 , wherein the method further comprises:

receiving, from a terminal device, a signal at the base transceiver station; and

determining, at the base transceiver station, a calibration quality indicator for the antenna array on the basis of the received signal.

4. The method of claim 1 , wherein the method further comprises:

receiving, from a terminal device, a signal at the base transceiver station;

determining, at the base transceiver station, a direction estimate for the terminal device on the basis of the transmitted signal; and

determining, at the base transceiver station, a calibration quality indicator for the antenna array on the basis of the determined direction estimate.

5. The method of claim 1 , wherein the method further comprises:

measuring, at the base transceiver station, a signal of the antenna array; and

determining, at the base transceiver station, a calibration quality indicator for the antenna array on the basis of the measured signal.

6. The method of claim 1 , wherein the method further comprises:

switching over to using an antenna element specific pilot when the calibration quality indicator resides below the calibration quality threshold value such that the pilot is transmitted using any one of the least loaded antenna elements of the antenna array.

7. The method of claim 1 , wherein the method further comprises:

switching over to using an antenna element specific wideband code division multiple access system primary common pilot channel pilot when the calibration quality indicator resides below the calibration quality threshold value such that the pilot is transmitted using at least one middle antenna element of the antenna array.

8. A system, comprising:

a base transceiver station including an antenna array including a plurality of antenna elements configured to transmit at least one beam specific pilot; and

at least one terminal device configured to use the pilot in channel estimation, wherein

the base transceiver station is configured to determine a calibration quality indicator describing the quality of calibration of the antenna array;

the base transceiver station is configured to check whether the determined calibration quality indicator resides below a calibration quality threshold value, the calibration quality threshold value being a predetermined value; and

the base transceiver station and the terminal device are configured to use an antenna element specific pilot when the calibration quality indicator resides below the calibration quality threshold value.

9. The system of claim 8 , wherein

the base transceiver station is configured to transmit a command to change pilots when the calibration quality indicator resides below the calibration quality threshold value prior to a switch-over to transmitting a pilot from the base transceiver station antenna-element-specifically;

the terminal device is configured to receive the command to change pilots;

the terminal device is configured to transmit an acknowledgement of the command to change pilots to the base transceiver station;

the base transceiver station is configured to receive the acknowledgement; and

the base transceiver station and the terminal device are configured to switch over to using a pilot according to the command to change pilots.

10. The system of claim 8 , wherein

the terminal device is configured to transmit a signal;

the base transceiver station is configured to receive the signal; and

the base transceiver station is configured to determine a calibration quality indicator for the antenna array on the basis of the received signal.

11. The system of claim 8 , wherein

the terminal device is configured to transmit a signal;

the base transceiver station is configured to receive the signal;

the base transceiver station is configured to determine a direction estimate for the terminal device on the basis of the transmitted signal; and

the base transceiver station is configured to determine a calibration quality indicator for the antenna array on the basis of the determined direction estimate.

12. The system of claim 8 , wherein

the base transceiver station is configured to measure the signal of the antenna array; and

the base transceiver station is configured to determine a calibration quality indicator for the antenna array on the basis of the measured signal.

13. The system of claim 8 , wherein

the base transceiver station is configured to transmit an antenna element specific pilot by using any one of the least loaded antenna elements of the antenna array when the calibration quality indicator resides below the calibration quality threshold value.

14. The system of claim 8 , wherein

the base transceiver station is configured to transmit an antenna element specific wideband code division multiple access system primary common pilot channel pilot by using at least one middle antenna element of the antenna array when the calibration quality indicator resides below the calibration quality threshold value.

15. A system, comprising:

a base transceiver station including an array including a plurality of elements configured to transmit at least one beam specific pilot; and

at least one terminal device configured to use the pilot in channel estimation, wherein

the base transceiver station is configured to determine a calibration quality indicator describing the quality of calibration of an element array;

the base transceiver station is configured to check whether the determined calibration quality indicator resides below a calibration quality threshold value, the calibration quality threshold value being a predetermined value; and

the base transceiver station and the terminal device are configured to use an element specific pilot when the calibration quality indicator resides below the calibration quality threshold value.

16. An apparatus, comprising:

a processor configured to

use a beam specific pilot for transmitting using a plurality of antenna elements of an antenna array of a base transceiver station;

determine a calibration quality indicator describing the quality of calibration of the antenna element array;

check whether the determined calibration quality indicator resides below a calibration quality threshold value, the calibration quality threshold value being a predetermined value; and

use an antenna element specific pilot when the calibration quality indicator resides below the calibration quality threshold value.

17. An apparatus, comprising:

a first using means for using a beam specific pilot for transmitting using a plurality of antenna element means of an antenna array of a base transceiver station:

a determining means for determining a calibration quality indicator describing the quality of calibration of the antenna element means for transmitting and receiving signals;

a checking means for checking whether the determined calibration quality indicator resides below a calibration quality threshold value, the calibration quality threshold value being a predetermined value; and

a second using means for using an antenna element means specific pilot when the calibration quality indicator resides below the calibration quality threshold value.

18. A method, comprising:

using a beam specific pilot for transmitting using a plurality of antenna elements of an antenna array of a base transceiver station;

determining a calibration quality indicator describing the quality of calibration of the antenna element array;

checking whether the determined calibration quality indicator resides below a calibration quality threshold value, the calibration quality threshold value being a predetermined value; and

using an antenna element specific pilot when the calibration quality indicator resides below the calibration quality threshold value.

19. The method of claim 18 , further comprising:

transmitting a command to a terminal device to change pilots when the calibration quality indicator resides below the calibration quality threshold value prior to a switch-over to using the antenna element specific pilot.

20. The method of claim 18 , further comprising:

receiving a signal from a terminal device; and

determining a calibration quality indicator for the antenna array on the basis of the received signal.

21. The method of claim 18 , further comprising:

receiving a signal from a terminal device;

determining a direction estimate for the terminal device on the basis of the transmitted signal; and

determining a calibration quality indicator for the antenna array on the basis of the determined direction estimate.

22. The method of claim 18 , further comprising:

measuring the signal of the antenna array; and

determining a calibration quality indicator for the antenna array on the basis of the measured signal.

23. The method of claim 18 , further comprising:

switching over to using an antenna element specific pilot when the calibration quality indicator resides below the calibration quality threshold value such that the pilot is transmitted using any one of the least loaded antenna elements of the antenna array.

24. The method of claim 18 , further comprising:

switching over to using an antenna element specific wideband code division multiple access system primary common pilot channel pilot when the calibration quality indicator resides below the calibration quality threshold value such that the pilot is transmitted using at least one middle antenna element of the antenna array.

25. The apparatus of claim 16 , further comprising:

a transmitter configured to transmit a command to a terminal device to change pilots when the calibration quality indicator resides below the calibration quality threshold value prior to a switch-over to using an antenna element specific pilot.

26. The apparatus of claim 16 , further comprising:

a receiver configured to receive a signal from a terminal device, wherein the processor is configured to determine a calibration quality indicator for the antenna array on the basis of the received signal.

27. The apparatus of claim 16 , further comprising:

a receiver configured to receive a signal from a terminal device, wherein the processor is configured to determine a direction estimate for the terminal device on the basis of the transmitted signal and determine a calibration quality indicator for the antenna array on the basis of the determined direction estimate.

28. The apparatus of claim 16 , wherein the processor is further configured to measure the signal of the antenna array and determine a calibration quality indicator for the antenna array on the basis of the measured signal.

29. The apparatus of claim 16 , wherein the processor is configured to issue one or more commands for switching over to using an antenna element specific pilot when the calibration quality indicator resides below the calibration quality threshold value such that the pilot is transmitted using any one of the least loaded antenna elements of the antenna array.

30. The apparatus of claim 18 , wherein the processor is configured to issue one or more commands for switching over to using an antenna element specific wideband code division multiple access system primary common pilot channel pilot when the calibration quality indicator resides below the calibration quality threshold value such that the pilot is transmitted using at least one middle antenna element of the antenna array.

31. A computer program embodied on a computer-readable medium, the computer program configured to control a processor to perform operations comprising:

using a beam specific pilot for transmitting using a plurality of antenna elements of an antenna array of a base transceiver station;

determining a calibration quality indicator describing the quality of calibration of the antenna element array;

checking whether the determined calibration quality indicator resides below a calibration quality threshold value, the calibration quality threshold value being a predetermined value; and

using an antenna element specific pilot when the calibration quality indicator resides below the calibration quality threshold value.

Assignments (9)