Determining a calibration function using at least one remote terminal

• US 6,654,590 B2
• Filed: 04/29/2002
• Issued: 11/25/2003
• Est. Priority Date: 05/01/1998
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: ArrayComm LLC (Ygomi LLC)
• Inventors: Boros, Tibor, Barratt, Craig H., Uhlik, Christopher R., Trott, Mitchell D.
• Primary Examiner(s): Banks-Harold, Marsha D.
• Assistant Examiner(s): MOORE, JAMES K
• Application Number:
  US10/136,049
• Publication Number:
  US 20030032423A1
• Time in Patent Office: 575 Days
• Field of Search: 455/67.1, 455/67.4, 455/562, 455/67.11, 455/67.14, 455/67.16, 455/562.1, 370/310, 370/328, 342/174, 342/378
• US Class Current: 455/67.14
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H04B 17/10 of transmitters
• CPC Class Codes: H04B 17/11 for calibration
• CPC Class Codes: H04B 17/12 of transmit antennas, e.g. of the amplitude or phase
• CPC Class Codes: H04B 17/14 of the whole transmission and reception path, e.g. self-test loop-back
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 7/005 Control of transmission; Equalising
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0842 Weighted combining
• CPC Class Codes: H04B 7/0848 Joint weighting
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end

Abstract

A calibration function for calibrating a base station can be determined using one or more remote terminals. In one embodiment of the present invention, determining the calibration function includes transmitting a calibration signal, using an array of antenna elements of a first radio, to a second radio, and receiving, at the first radio, a downlink spatial signature related signal from the second radio containing information related to a second radio downlink spatial signature, the information being calculated using the calibration signal. Then, a second radio downlink spatial signature may be determined using the downlink spatial signature related signal. Also, a second radio uplink spatial signature may be determined using an uplink spatial signature signal from the second radio to the first radio. The calibration function may then be determined using the second radio downlink spatial signature and the second radio uplink spatial signature. Furthermore, one embodiment of the present invention may include determining a third radio downlink weight vector for a third radio using a third radio uplink weight vector and the calibration function.

Claims

1. A method comprising:

transmitting a calibration signal, using an array of antenna elements of a first radio, to a second radio;

receiving, at the first radio, a downlink spatial signature related signal from the second radio containing information related to a second radio downlink spatial signature, the information being calculated using the calibration signal;

determining a second radio downlink spatial signature using the downlink spatial signature related signal;

determining a second radio uplink spatial signature using an uplink spatial signature signal from the second radio to the first radio;

determining a calibration function using the second radio downlink spatial signature and the second radio uplink spatial signature; and

determining a third radio downlink weight vector for a third radio using a third radio uplink weight vector and the calibration function.

2. The method of claim 1, further comprising:

transmitting a second calibration signal from the first radio to a fourth radio;

receiving, at the first radio, a fourth radio downlink spatial signature related signal from the fourth radio, the fourth radio downlink spatial signature related signal containing information related to a fourth radio downlink spatial signature, the information being calculated using the second calibration signal;

determining a fourth radio downlink spatial signature using the fourth radio downlink spatial signature related signal; and

determining a fourth radio uplink spatial signature using a fourth radio uplink spatial signature signal from the fourth radio to the first radio.

3. The method of claim 2, wherein determining the calibration function comprises determining the calibration function using the second radio downlink spatial signature, the second radio uplink spatial signature, the fourth radio downlink spatial signature, and the fourth radio uplink spatial signature.

4. The method of claim 2, wherein determining the fourth radio uplink spatial signature comprises determining the fourth radio uplink spatial signature using the fourth radio downlink spatial signature related signal.

5. The method of claim 1, wherein determining the second radio uplink spatial signature comprises determining the second radio uplink spatial signature using the downlink spatial signature related signal.

6. The method of claim 1, wherein receiving the downlink spatial signature related signal from the second radio comprises receiving the downlink spatial signature related signal, the downlink spatial signature related signal including the second radio downlink spatial signature, the second radio downlink spatial signature being calculated using the calibration signal.

7. The method of claim 1, wherein transmitting a calibration signal from an array of antenna elements comprises:

transmitting a combined signal using a first antenna element of the antenna array, the combined signal comprising a first signal and a second signal;

transmitting the first signal using the first antenna element; and

transmitting the second signal using a second antenna element of the array of antenna elements.

8. The method of claim 1, wherein determining the calibration function using the second radio downlink spatial signature and the second radio uplink spatial signature comprises dividing the second radio uplink spatial signature by the second radio downlink spatial signature.

9. The method of claim 1, wherein determining the third radio downlink weight vector using the third radio uplink weight vector and the calibration function comprises:

receiving a signal from the third radio at the array of antenna elements of the first radio;

determining the third radio uplink weight vector using a first portion of the received signal, the third radio uplink weight vector facilitating spatial processing of a second portion of the received signal; and

determining the third radio downlink weight vector by mathematically combining the third radio uplink weight vector with the calibration vector.

10. The method of claim 1, wherein the first radio comprises a base station in a wireless radio communications system, and the second and third radios comprise remote terminals in the wireless radio communications system.

11. The method of claim 1, further comprising transmitting a communications signal from the first radio to the third radio using the third radio downlink weight vector.

12. A machine-readable medium having stored thereon data representing instructions that, when executed by a processor, cause the processor to perform operations comprising:

transmitting a calibration signal, using an array of antenna elements of a first radio, to a second radio;

receiving, at the first radio, a downlink spatial signature related signal from the second radio containing information related to a second radio downlink spatial signature, the information being calculated using the calibration signal;

determining a second radio downlink spatial signature using the downlink spatial signature related signal;

determining a second radio uplink spatial signature using an uplink spatial signature signal from the second radio to the first radio;

determining a calibration function using the second radio downlink spatial signature and the second radio uplink spatial signature; and

determining a third radio downlink weight vector for a third radio using a third radio uplink weight vector and the calibration function.

13. The machine-readable medium of claim 12, wherein the instructions further cause the processor to perform operations comprising:

transmitting a second calibration signal from the first radio to a fourth radio;

receiving, at the first radio, a fourth radio downlink spatial signature related signal from the fourth radio, the fourth radio downlink spatial signature related signal containing information related to a fourth radio downlink spatial signature, the information being calculated using the second calibration signal;

determining a fourth radio downlink spatial signature using the fourth radio downlink spatial signature related signal; and

determining a fourth radio uplink spatial signature using a fourth radio uplink spatial signature signal from the fourth radio to the first radio.

14. The machine-readable medium of claim 13, wherein determining the calibration function comprises determining the calibration function using the second radio downlink spatial signature, the second radio uplink spatial signature, the fourth radio downlink spatial signature, and the fourth radio uplink spatial signature.

15. The machine-readable medium of claim 13, wherein determining the fourth radio uplink spatial signature comprises determining the fourth radio uplink spatial signature using the fourth radio downlink spatial signature related signal.

16. The machine-readable medium of claim 12, wherein determining the second radio uplink spatial signature comprises determining the second radio uplink spatial signature using the downlink spatial signature related signal.

17. The machine-readable medium of claim 12, wherein receiving the downlink spatial signature related signal from the second radio comprises receiving the downlink spatial signature related signal, the downlink spatial signature related signal including the second radio downlink spatial signature, the second radio downlink spatial signature being calculated using the calibration signal.

18. The machine-readable medium of claim 12, wherein transmitting a calibration signal from an array of antenna elements comprises:

transmitting a combined signal using a first antenna element of the antenna array, the combined signal comprising a first signal and a second signal;

transmitting the first signal using the first antenna element; and

transmitting the second signal using a second antenna element of the array of antenna elements.

19. The machine-readable medium of claim 12, wherein determining the calibration function using the second radio downlink spatial signature and the second radio uplink spatial signature comprises dividing the second radio uplink spatial signature by the second radio downlink spatial signature.

20. The machine-readable medium of claim 12, wherein determining the third radio downlink weight vector using the third radio uplink weight vector and the calibration function comprises:

receiving a signal from the third radio at the array of antenna elements of the first radio;

determining the third radio uplink weight vector using a first portion of the received signal, the third radio uplink weight vector facilitating spatial processing of a second portion of the received signal; and

determining the third radio downlink weight vector by mathematically combining the third radio uplink weight vector with the calibration vector.

21. The machine-readable medium of claim 12, wherein the first radio comprises a base station in a wireless radio communications system, and the second and third radios comprise remote terminals in the wireless radio communications system.

22. The machine-readable medium of claim 12, the operations further comprising transmitting a communications signal from the first radio to the third radio using the third radio downlink weight vector.

23. A radio comprising:

a transmitter coupled to an array of antenna elements for transmitting a calibration signal, using the array of antenna elements to a second radio;

a receiver for receiving a downlink spatial signature related signal from the second radio containing information related to a second radio downlink spatial signature, the information being calculated using the calibration signal;

a processor coupled to the receiver for;

determining a second radio downlink spatial signature using the downlink spatial signature related signal;

determining a second radio uplink spatial signature using an uplink spatial signature signal from the second radio;

determining a calibration function using the second radio downlink spatial signature and the second radio uplink spatial signature; and

determining a third radio downlink weight vector for a third radio using a third radio uplink weight vector and the calibration function.

24. The radio of claim 23, wherein:

the transmitter is further for transmitting a second calibration signal to a fourth radio;

the receiver is further for receiving a fourth radio downlink spatial signature related signal from the fourth radio, the fourth radio downlink spatial signature related signal containing information related to a fourth radio downlink spatial signature, the information being calculated using the second calibration signal; and

the processor is further for;

determining a fourth radio downlink spatial signature using the fourth radio downlink spatial signature related signal; and

determining a fourth radio uplink spatial signature using a fourth radio uplink spatial signature signal from the fourth radio.

25. The radio of claim 24, wherein determining the calibration function comprises determining the calibration function using the second radio downlink spatial signature, the second radio uplink spatial signature, the fourth radio downlink spatial signature, and the fourth radio uplink spatial signature.

26. The radio of claim 24, wherein determining the fourth radio uplink spatial signature comprises determining the fourth radio uplink spatial signature using the fourth radio downlink spatial signature related signal.

27. The radio of claim 23, wherein determining the second radio uplink spatial signature comprises determining the second radio uplink spatial signature using the downlink spatial signature related signal.

28. The radio of claim 23, wherein receiving the downlink spatial signature related signal from the second radio comprises receiving the downlink spatial signature related signal, the downlink spatial signature related signal including the second radio downlink spatial signature, the second radio downlink spatial signature being calculated using the calibration signal.

29. The radio of claim 23, wherein transmitting a calibration signal from an array of antenna elements comprises using the transmitter for:

transmitting a combined signal using a first antenna element of the antenna array, the combined signal comprising a first signal and a second signal;

transmitting the first signal using the first antenna element; and

transmitting the second signal using a second antenna element of the array of antenna elements.

30. The radio of claim 23, wherein determining the calibration function using the second radio downlink spatial signature and the second radio uplink spatial signature comprises dividing the second radio uplink spatial signature by the second radio downlink spatial signature.

31. The radio of claim 23, wherein determining the third radio downlink weight vector using the third radio uplink weight vector and the calibration function comprises:

receiving a signal from the third radio at the receiver; and

using the processor for;

determining the third radio uplink weight vector using a first portion of the received signal, the third radio uplink weight vector facilitating spatial processing of a second portion of the received signal; and

determining the third radio downlink weight vector by mathematically combining the third radio uplink weight vector with the calibration vector.

32. The radio of claim 23, wherein the communications device comprises a base station in a wireless radio communications system, and the second and third radios comprise remote terminals in the wireless radio communications system.

33. The radio of claim 23, wherein the transmitter is further for transmitting a communications signal to the third radio using the third radio downlink weight vector.