Method and device for managing power consumption of a receiver in stand-by mode

• US 6,381,450 B1
• Filed: 04/02/1999
• Issued: 04/30/2002
• Est. Priority Date: 04/02/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: DSPC Technologies Limited
• Inventors: Shamai, Shlomo, Rainish, Doron, Perets, Yona
• Primary Examiner(s): LE, THANH C
• Application Number:
  US09/285,274
• Time in Patent Office: 1,124 Days
• Field of Search: 455/422, 455/517, 455/62, 455/68, 455/550, 455/575, 455/572, 455/573, 455/574, 455/343, 375/224, 375/225
• US Class Current: 455/343.3
• CPC Class Codes: H04W 52/0238 where the received signal is an unwanted signal, e.g. interference or idle signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A device for power management of a receiver includes a soft decoder and a power reducer. The receiver receives repetitions of a word containing a message possibly addressed to the receiver. The soft decoder soft decodes at least one of the repetitions to produce a codeword, and the power reducer reduces power to the receiver when the message contained in the codeword is not addressed to the receiver. The receiver may be a mobile telephone, a wireless local loop, a pager, or a cordless telephone. A method for managing power in a receiver includes the steps of receiving a repetition of a word containing a message possibly addressed to the receiver and combining the repetition with previous repetitions of the word. Candidates are generated from information contained in the combination, and a best candidate is selected from the generated candidates. The probable reliability of the best candidate is determined. If the best candidate is probably reliable and the message contained therein is not addressed to the receiver, power to the receiver is reduced. If the best candidate is probably not reliable, all of the steps are repeated until either the best candidate is probably reliable or no further repetitions of the word are received.

Claims

1. A device for power management of a receiver which receives repetitions of a word containing a message possibly addressed to said receiver, the device comprising:

a soft decoder for soft decoding at least one of said repetitions to produce a codeword; and

a power reducer for reducing power to said receiver when said message contained in said codeword is not addressed to said receiver.

2. A device according to claim 1, wherein said soft decoder comprises:

a candidate generator for generating candidates based upon at least one of said repetitions; and

a selector for selecting a best candidate from said generated candidates as said codeword.

3. A device according to claim 2, wherein said selector comprises a correlation metric calculator for calculating a correlation metric, and said best candidate is the candidate which minimizes said correlation metric.

4. A device according to claim 2, wherein said candidate generator comprises:

a locator for identifying the location of low confidence bits in said at least one repetition;

a pattern template generator for generating pattern templates based upon said locations;

a test pattern generator for generating test patterns based upon said at least one repetition and said pattern templates; and

an algebraic decoder for decoding said test patterns as candidates.

5. A device according to claim 4, herein said locator includes means for using said soft decision variables for identification of said low confidence bits.

6. A device according to claim 4, wherein said locator includes means for using received signal strength indicator (RSSI) information for identification of said low confidence bits.

7. A device according to claim 1, the device further comprising:

a determiner for determining the probable reliability of said codeword.

8. A device according to claim 7, wherein said determiner determines said probable reliability based upon output of said soft decoder.

9. A device according to claim 7, wherein said determiner comprises:

an estimator for producing an average bit level estimate and a signal to noise ratio estimate for said at least one repetition;

a calculator for calculating a probability associated with said codeword, based upon said estimates; and

a decision block for deciding the reliability of said codeword based upon said probability.

10. A device according to claim 1, wherein said receiver is one of a group comprising a mobile telephone, a local loop, a pager and a cordless telephone.

11. A method for managing power in a receiver, the method comprising the steps of:

receiving a repetition of a word containing a message possibly addressed to said receiver;

combining said repetition with previous repetitions of said word;

generating candidates from information contained in said combination;

selecting a best candidate from said generated candidates;

determining the probable reliability of said best candidate;

if said best candidate is probably reliable and said message contained therein is not addressed to said receiver, reducing power to said receiver; and

if said best candidate is probably not reliable, repeating all of said steps until either said best candidate is probably reliable or no further repetitions of said word are received.

12. A method according to claim 11, wherein said step of combining includes the steps of:

multiplying bits of said repetitions by weight factors to produce products; and

accumulating said products.

13. A method according to claim 12, wherein said weight factors are based upon RSSI information for identification of said low confidence bits.

14. A method according to claim 11, wherein said step of generating comprises the steps of:

identifying the location of low confidence bits of said combination;

generating pattern templates based upon said locations;

generating test patterns based upon said combination and said pattern templates; and

decoding said test patterns.

15. A method according to claim 14, wherein said receiver generates soft decision variables associated with bits of said received repetitions, and wherein said step of identifying uses said soft decision variables for identification of said low confidence bits.

16. A method according to claim 14, wherein said step of identifying uses RSSI information for identification of said low confidence bits.

17. A method according to claim 11, wherein said step of selecting comprises the steps of:

calculating a correlation metric for each candidate; and

choosing the candidate which minimizes said calculated correlation metric as best candidate.

18. A method according to claim 11, wherein said receiver generates soft decision variables associated with bits of said received repetitions, and wherein said probable reliability is based on said soft decision variables.

19. A method according to claim 11, wherein said probable reliability is based on the a posterior probability (APP) for said best candidate.

20. A method according claim 11, wherein said method further comprises the step of:

restoring power to said receiver when a timer reaches a predetermined time, independent of at what time said step of reducing power occurred.

21. A method according to claim 11, wherein said receiver is one of a group comprising a mobile telephone, a local loop, a pager and a cordless telephone.

22. A mobile telephone comprising:

a transmitter;

a receiver which receives repetitions of a word containing a message possibly addressed to said mobile telephone;

a soft decoder for soft decoding at least one of said repetitions to produce a codeword; and

a power reducer for reducing power to said receiver when said message contained in said codeword is not addressed to said mobile telephone.

23. A mobile telephone according to claim 22, wherein said soft decoder comprises:

a candidate generator for generating candidates based upon at least one of said repetitions; and

a selector for selecting a best candidate from said generated candidates as said codeword.

24. A mobile telephone according to claim 23, wherein said selector comprises a correlation metric calculator for calculating a correlation metric, and said best candidate is the candidate which minimizes said correlation metric.

25. A mobile telephone according to claim 23, wherein said candidate generator comprises:

a locator for identifying the location of low confidence bits in said at least one repetition;

a pattern template generator for generating pattern templates based upon said locations;

a test pattern generator for generating test patterns based upon said at least one repetition and said pattern templates; and

an algebraic decoder for decoding said test patterns as candidates.

26. A mobile telephone according to claim 25, wherein said locator includes means for using said soft decision variables for identification of said low confidence bits.

27. A mobile telephone according to claim 25, wherein said locator includes means for using received signal strength indicator (RSSI) information for identification of said low confidence bits.

28. A mobile telephone according to claim 22, the mobile telephone further comprising:

a determiner for determining the probable reliability of said codeword.

29. A mobile telephone according to claim 28, wherein said determiner determines said probable reliability based upon output of said soft decoder.

30. A mobile telephone according to claim 28, wherein said determiner comprises:

an estimator for producing an average bit level estimate and a signal to noise ratio estimate for said at least one repetition;

a calculator for calculating a probability associated with said codeword, based upon said estimates; and

a decision block for deciding the reliability of said codeword based upon said probability.