Synchronization judging circuit capable of operating moderately

• US 7,519,040 B2
• Filed: 09/09/2004
• Issued: 04/14/2009
• Est. Priority Date: 09/10/2003
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Masuda, Shuji
• Primary Examiner(s): Harper, Vincent P.
• Assistant Examiner(s): Santiago-Cordero, Marivelisse
• Application Number:
  US10/937,630
• Publication Number:
  US 20050054309A1
• Time in Patent Office: 1,678 Days
• Field of Search: 370/342
• US Class Current: 370/342
• CPC Class Codes: H04B 7/2668 Arrangements for Wireless Code-Division Multiple Access [CDMA] System Synchronisation, for code acquisition H04B1/7075, for code tracking H04B1/7085
• CPC Class Codes: H04W 56/008 detecting arrival of signal based on received raw signal

Abstract

In a synchronization judging circuit, a measuring portion measures a signal to interference power ratio of a received signal at each frame. An averaging portion calculates a moving average of a series of signal to interference power ratios for a predetermined number of frames to produce a mean value at each frame. A counter counts a number of consecutive frames each of which the mean value meets a predetermined threshold requirement. The counter further compares a counted value with a predetermined threshold value to decide whether to perform a transmission control operation or not.

Claims

1. A synchronization judging circuit comprising:

a measuring portion for measuring a signal to interference power ratio of a received signal at each frame;

an averaging portion for calculating a moving average of a series of signal to interference power ratios for a predetermined number of frames to produce a mean value at each frame, said averaging portion comprising,

a first calculation portion for calculating a first arithmetic mean of a series of the measured signal interference power ratios for the latest frames of a number represented by a parameter Min; and

a second calculation portion for calculating a second arithmetic mean of the measured signal interference power ratios for the latest frames of a number represented by a parameter Mout; and

a counter for counting a number of consecutive frames each of which the mean value meets a predetermined threshold requirement;

wherein;

said counter compares a counted value with a predetermined threshold value to decide whether to perform a transmission control operation or not.

2. A synchronization judging circuit as claimed in claim 1, wherein the received signal is transmitted through a dedicated physical control channel or a dedicated physical data channel.

3. A synchronization judging circuit as claimed in claim 1, wherein the counter produces a transmission control signal as the transmission control operation when the counted value is equal to the predetermined threshold value.

4. A synchronization judging circuit as claimed in claim 1, wherein:

said counter judges whether the signal to interference power ratio of a frame preceeding by predetermined frame periods meets the predetermined threshold requirement or not before the transmission control operation, and performs the transmission control operation only when the signal to interference power ratio of the frame preceding by the predetermined frame periods meets the predetermined threshold requirement.

5. A synchronization judging circuit as claimed in claim 4, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the signal to interference power ratio is over/under a predetermined limit level are detected, and suspends judgment whether the signal to interference power ratio of the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

6. A synchronization judging circuit as claimed in claim 4, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the mean value is over/under a predetermined limit level are detected, and suspends judgment whether the signal to interference power ratio of the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

7. A synchronization judging circuit as claimed in claim 4, wherein:

said counter is cleared when a difference between continuous two signal to interference power ratios is larger than a predetermined range, and suspends judgment whether the signal to interference power ratio of the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

8. A synchronization judging circuit as claimed in claim 1, wherein:

said counter judges whether the mean value obtained at a frame preceding by predetermined frame periods meets the predetermined threshold requirement or not before the transmission control operation, and performs the transmission control operation only when the mean value obtained at the frame preceding by the predetermined frame periods meets the predetermined threshold requirement.

9. A synchronization judging circuit as claimed in claim 8, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the signal to interference power ratio is over/under a predetermined limit level are detected, and suspends judgment whether the mean value obtained at the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

10. A synchronization judging circuit as claimed in claim 8, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the mean value is over/under a predetermined limit level are detected, and suspends judgment whether the mean value obtained at the frame preceding by predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

11. A synchronization judging circuit as claimed in claim 8, wherein:

said counter is cleared when a difference between continuous two signal to interference power ratios is larger than a predetermined range, and suspends judgment whether the mean value obtained at the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

12. A synchronization judging circuit as claimed in claim 1, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the signal to interference power ratio is over/under a predetermined limit level are detected.

13. A synchronization judging circuit as claimed in claim 1, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the mean value is over/under a predetermined limit level are detected.

14. A synchronization judging circuit as claimed in claim 1, wherein:

said counter is cleared when a difference between continuous two signal to interference power ratios is larger than a predetermined range.

15. A cellular phone including a synchronization judging circuit, said synchronization judging circuit comprising:

a measuring portion for measuring a signal to interference power ratio of a received signal at each frame;

an averaging portion for calculating a moving average of a series of signal to interference power ratios for a predetermined number of frames to produce a mean value at each frame, said averaging portion comprising,

a first calculation portion for calculating a first arithmetic mean of a series of the measured signal interference power ratios for the latest frames of a number represented by a parameter Min; and

a second calculation portion for calculating a second arithmetic mean of the measured signal interference power ratios for the latest frames of a number represented by a parameter Mout; and

a counter for counting a number of consecutive frames each of which the mean value meets a predetermined threshold requirement;

wherein;

said counter compares a counted value with a predetermined threshold value to decide whether to perform a transmission control operation or not.

16. A cellular phone as claimed in claim 15, wherein the received signal is transmitted through a dedicated physical control channel or a dedicated physical data channel.

17. A cellular phone as claimed in claim 15, wherein the counter produces a transmission control signal as the transmission control operation when the counted value is equal to the predetermined threshold value.

18. A cellular phone as claimed in claim 15, wherein:

said counter judges whether the signal to interference power ratio of a frame preceding by predetermined frame periods meets the predetermined threshold requirement or not before the transmission control operation, and performs the transmission control operation only when the signal to interference power ratio of the frame preceding by the predetermined frame periods meets the predetermined threshold requirement.

19. A cellular phone as claimed in claim 18, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the signal to interference power ratio is over/under a predetermined limit level are detected, and suspends judgment whether the signal to interference power ratio of the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

20. A cellular phone as claimed in claim 18, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the mean value is over/under a predetermined limit level are detected, and suspends judgment whether the signal to interference power ratio of the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

21. A cellular phone as claimed in claim 18, wherein:

said counter is cleared when a difference between continuous two signal to interference power ratios is larger than a predetermined range, and suspends judgment whether the signal to interference power ratio of the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

22. A cellular phone as claimed in claim 15, wherein:

said counter judges whether the mean value obtained at a frame preceding by predetermined frame periods meets the predetermined threshold requirement or not before the transmission control operation, and performs the transmission control operation only when the mean value obtained at the frame preceding by the predetermined frame periods meets the predetermined threshold requirement.

23. A cellular phone as claimed in claim 22, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the signal to interference power ratio is over/under a predetermined limit level are detected, and suspends judgment whether the mean value obtained at the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

24. A cellular phone as claimed in claim 22, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the mean value is over/under a predetermined limit level are detected, and suspends judgment whether the mean value obtained at the frame preceding by predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

25. A cellular phone as claimed in claim 22, wherein:

said counter is cleared when a difference between continuous two signal to interference power ratios is larger than a predetermined range, and suspends judgment whether the mean value obtained at the frame preceding by the predetermined frame periods meets the predetermined threshold requirement or not for a predetermined time period.

26. A cellular phone as claimed in claim 15, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the signal to interference power ratio is over/under a predetermined limit level are detected.

27. A cellular phone as claimed in claim 15, wherein:

said counter is cleared when a predetermined number of continuous frames each of which the mean value is over/under a predetermined limit level are detected.

28. A cellular phone as claimed in claim 15, wherein:

said counter is cleared when a difference between continuous two signal to interference power ratios is larger than a predetermined range.