MINIMIZING ESTIMATION TIME FOR RAKE FINGERS WITH HELP OF A SPEED SENSOR

• US 20080037612A1
• Filed: 08/08/2006
• Published: 02/14/2008
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: Sony Ericsson Mobile Communications AB (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications AB (Sony Group Corp.)
• Inventors: Tudosoiu, Bogdan
• Granted Patent: US 7,848,388 B2
• Time in Patent Office: Days
• US Class Current: 375/147
• CPC Class Codes: H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
• CPC Class Codes: H04B 1/7117 Selection, re-selection, allocation or re-allocation of paths to fingers, e.g. timing offset control of allocated fingers

Abstract

An electronic equipment includes a RAKE receiver that includes at least one finger having a settable delay, a transducer operable to provide a signal indicative of motion of the electronic equipment, and a delay estimator circuit operative to calculate a duration between fading nulls of a received signal based on the motion signal of the electronic equipment. The time delay of the at least one finger is set based on the duration between fading nulls.

Claims

1. An electronic equipment, comprising:

a RAKE receiver for receiving a signal, said receiver including at least one finger having a settable time delay;

a transducer operable to provide a signal indicative of motion of the electronic equipment; and

a delay estimator circuit operative to calculate a duration between fading nulls of the signal based on the motion signal, wherein the time delay of the at least one finger is set based on the duration between fading nulls.

2. The electronic equipment of claim 1, wherein the duration between fading nulls is calculated using the formula

3. The electronic equipment of claim 1, wherein the time delay of the at least one finger is set such that the at least one finger avoids searching in areas of the signal where fading nulls are present that have a magnitude greater than a predefined level.

4. The electronic equipment of claim 1, further comprising a path probability circuit operative to receive the calculated duration between fading nulls and to set the time delay of the at least one finger based on the duration between fading nulls.

5. The electronic equipment of claim 1, further comprising a motion signal processing circuit operable to determine a velocity of the electronic equipment from the motion signal.

6. The electronic equipment of claim 5, wherein the transducer is operable to generate a motion signal that corresponds to acceleration and/or deceleration of the electronic equipment.

7. The electronic equipment of claim 5, said motion signal processing circuit comprising a signal conditioning circuit to filter out signals that do not meet a predetermined threshold.

8. The electronic equipment of claim 7, said signal conditioning circuit comprising a low pass filter.

9. The electronic equipment of claim 5, wherein the motion signal processing circuit is operative to provide a motion signal indicative of duration of the motion, amplitude of the motion, and/or frequency of the motion.

10. The electronic equipment of claim 9, wherein the motion signal processing circuit includes at least one of a low pass filter, a threshold detector, an amplitude detector or a frequency detector.

11. The electronic equipment of claim 1, said transducer comprising an accelerometer, a velocimeter, a GPS receiver or a signal detector.

12. The electronic equipment of claim 1, said transducer operable to detect at least one of acceleration, velocity, position, rotation or proximity.

13. The electronic equipment of claim 1, wherein said electronic equipment is a mobile phone.

14. The electronic equipment of claim 1, wherein said electronic equipment is at least one of a personal audio device, a personal video device or a personal digital assistant.

15. A method of minimizing estimation time for at least one finger of a RAKE receiver in electronic equipment, comprising:

determining a velocity of the electronic equipment;

using the velocity to determine a duration between fading nulls of a signal receivable by the RAKE receiver; and

setting a time delay of the at least one finger based on the duration between fading nulls.

16. The method of claim 15, wherein using the velocity to determine the duration between fading nulls includes using the formula

17. The method of claim 15, wherein setting includes setting the time delay such that the at least one finger avoids searching in areas of the signal where fading nulls are present that have a magnitude greater than a predefined level.

18. The method of claim 15, wherein determining a velocity includes using a transducer in the electronic equipment, said transducer operable to detect motion of the electronic equipment.

19. The method of claim 15, wherein determining a velocity includes:

generating a motion signal that corresponds to acceleration and/or deceleration of the electronic equipment; and

determining the velocity of the electronic equipment from the motion signal.

20. The method of claim 15, wherein determining a velocity includes using a GPS receiver to determine the velocity.

21. The method of claim 15, wherein determining the velocity includes filtering out signals that do not meet a predetermined threshold.

22. A computer program embodied on a computer readable medium and operable in electronic equipment for minimizing estimation time for at least one finger of a RAKE receiver in the electronic equipment, comprising:

code that determines a velocity of the electronic equipment;

code that uses the velocity to determine a duration between fading nulls of a signal receivable by the RAKE receiver; and

code that sets a time delay of the at least one finger based on the duration between fading nulls.