Tuning a station

• US 20030053561A1
• Filed: 06/27/2002
• Published: 03/20/2003
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Kuiri, Tapio, Savolainen, Jorma, Salmi, Ville
• Granted Patent: US 7,403,747 B2
• Time in Patent Office: Days
• US Class Current: 375/316
• CPC Class Codes: H03C 3/406 using a feedback loop containing mixers or demodulators
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control
• CPC Class Codes: H04L 2027/0016 Stabilisation of local oscillators
• CPC Class Codes: H04L 27/364 Arrangements for overcoming imperfections in the modulator, e.g. quadrature error or unbalanced I and Q levels

Abstract

A method of tuning a station is disclosed, wherein a first pilot signal is applied on a circuit of the station and the resulting output power of the signal circuit is subsequently detected. A second pilot signal is then applied to the circuit and the resulting output power of the circuit is detected. The offset of the circuit is then tuned based on information of the resulting output power detected for the first and second signals. A station that is adapted to implement the method may be tuned by the manufacturer thereof or later after having already been taken into use. The tuning may occur automatically as response to a predefined event.

Claims

1. A method of tuning a station comprising the steps of:

a) applying a first signal to a circuit of the station and subsequently detecting the resulting output power of the said circuit;

b) applying a second signal to the circuit and subsequently detecting the resulting output power of the circuit, said second signal being provided by changing the polarity of the first signal; and

c) compensating an offset of the circuit based on information of the resulting output power detected in steps a) and b).

2. The method of claim 1, wherein steps a) to c) are repeated at least once.

3. The method of claim 1, wherein the signal comprises a reference voltage.

4. The method of claim 2, wherein the signal comprises a reference voltage.

5. The method of claim 1, wherein said signal is a pilot signal.

6. The method of claim 2, wherein said signal is a pilot signal.

7. The method of claim 3, wherein said signal is a pilot signal.

8. The method of claim 1, wherein the offset is tuned until substantially equal resulting output power is detected subsequent to the application of said first and second signals.

9. The method of claim 1, wherein the output power comprise output power of modulator means of the circuit.

10. The method of claim 1, wherein the tuning is accomplished based on the difference determined for the resulting output power in steps a) and b).

11. The method of claim 1, wherein the circuit comprises an in-phase (I) branch and/or a quadrature phase (Q) branch of a IQ modulator for a transmitter.

12. The method of claim 11, wherein the steps a) to c) are applied at least once for both of said in-phase and quadrature branches.

13. The method of claim 1, wherein the output power are detected by envelope detector means.

14. The method of claim 1, wherein the tuning is based on information regarding detected carrier leakage in the station.

15. The method of claim 1, wherein at least one further error is compensated by tuning the station.

16. The method of claim 1, wherein the tuning is controlled by a digital signal processor.

17. The method of claim 1, wherein the station comprises a mobile station of a cellular communication system.

18. The method of claim 17, wherein the tuning is accomplished during the manufacture of the mobile station.

19. The method of claim 17, wherein the tuning is accomplished in response to an event after the mobile station has been taken in use.

20. The method of claim 18, wherein the tuning is accomplished in response to an event after the mobile station has been taken in use.

21. The method of claim 19, wherein the event comprises one of:

expiry of a predefined time period;

change in the operational status of the station;

change in the operation environment of the station;

a message from another station;

action taken by the user.

22. The method of claim 20, wherein the event comprises one of:

expiry of a predefined time period;

change in the operational status of the station;

change in the operation environment of the station;

a message from another station;

action taken by the user.

23. The method of claim 19, wherein the tuning is triggered automatically in response to the event.

24. The method of claim 20, wherein the tuning is triggered automatically in response to the event.

25. The method of claim 21, wherein the tuning is triggered automatically in response to the event.

26. The method of claim 22, wherein the tuning is triggered automatically in response to the event.

27. The method of claim 1, wherein the first pilot signal is selected such that the tuning of the station does not substantially interfere with the operation of other stations.

28. The method of claim 1, wherein said offset is an DC offset.

29. The method of claim 1, wherein said offset is a gain offset.

30. A station comprising:

signal means for applying signals to a modulator circuit of the station, said signal means being adapted to change the polarity of a first signal to produce a second signal;

detector means for detecting resulting output power; and

means for tuning the offset of the modulator circuit based on information of said output power detected by the detector means.

31. The station of claim 30, wherein the station comprises a mobile station for communication via a cellular communication system.

32. The station of claim 30, wherein the modulator circuit comprises an in-phase (I) signal branch and/or a quadrature phase (Q) signal branch.

33. The station of claim 31, wherein the modulator circuit comprises an in-phase (I) signal branch and/or a quadrature phase (Q) signal branch.

34. The station of claim 30, wherein the detector means comprise an envelope detector.

35. The station of claim 31, wherein the detector means comprise an envelope detector.

36. The station of claim 32, wherein the detector means comprise an envelope detector.

37. The station of claim 33, wherein the detector means comprise an envelope detector.

38. The station of claim 30, further comprising a digital signal processor adapted for controlling the tuning of the station.

39. The station of claim 31, further comprising a digital signal processor adapted for controlling the tuning of the station.

40. The station of claim 32, further comprising a digital signal processor adapted for controlling the tuning of the station.

41. The station of claim 33, further comprising a digital signal processor adapted for controlling the tuning of the station.

42. The station of claim 34, further comprising a digital signal processor adapted for controlling the tuning of the station.

43. The station of claim 35, further comprising a digital signal processor adapted for controlling the tuning of the station.

44. The station of claim 36, further comprising a digital signal processor adapted for controlling the tuning of the station.

45. The station of claim 37, further comprising a digital signal processor adapted for controlling the tuning of the station.

46. The station of claim 30, wherein the station is adapted to tune itself in response to an event.

47. The station of claim 46, wherein the event comprises one of:

expiry of a predefined time period;

change in the operational status of the station;

change in the operation environment of the station;

a message from another station; and

action taken by the user of the station.

48. A method of tuning a station comprising the steps of:

a) applying a first signal to a first part of a circuit of the station and subsequently detecting the resulting output power of the said circuit;

b) applying a second signal to a second part of said circuit and subsequently detecting the resulting output power of the circuit,; and

c) compensating a gain of the circuit based on information of the resulting output power detected in steps a) and b).

49. The method of claim 48, wherein the gain of one of said first and second parts is tuned until an output power of said first and second parts are substantially the same.

50. A method of tuning a station comprising the steps of:

a) applying a first signal to a circuit of the station and subsequently detecting the resulting output power of the said circuit;

b) applying a second signal to the circuit and subsequently detecting the resulting output power of the circuit, said second signal being provided by changing the polarity of the first signal; and

c) compensating phase offset of the circuit based on information of the resulting output power detected in steps a) and b).

51. The method of claim 50, wherein said circuit comprises first and second parts, said first signal being applied to said first and second parts and said second signal being applied to at least one of said first and second parts.

52. The method of claim 51, further comprising the step of calibrating said phase offset so that different amounts of predistortion are added to said first and second parts of said circuit.

53. A station comprising:

signal means for applying signals to a modulator circuit of the station,;

detector means for detecting resulting output power; and

means for tuning a gain of the modulator circuit based on information of said output power detected by the detector means.

54. A station comprising:

signal means for applying signals to a modulator circuit of the station, said signal means being adapted to change the polarity of a first signal to produce a second signal;

detector means for detecting resulting output power; and

means for tuning a phase offset of the modulator circuit based on information of said output power detected by the detector means.