System and method for detecting valid indicator signals

• US 6,856,607 B1
• Filed: 03/26/2001
• Issued: 02/15/2005
• Est. Priority Date: 03/26/2001
• Status: Expired due to Term

• Current Assignee: Synaptics Incorporated
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Ryan, Patrick, Vialle, Jerome, Whitfield, Michael
• Primary Examiner(s): TON, DANG T
• Application Number:
  US09/817,827
• Time in Patent Office: 1,422 Days
• Field of Search: 370/241, 370/245, 370/247, 370/248, 370/251, 370/252, 370/480, 370/319, 370/311, 370/333, 370/332, 370/334, 370/344, 370/350, 370/318, 370/317, 370/401, 370/351, 370/352, 370/465, 455/427, 455/428, 455/452.2, 455/10, 455/9, 455/23, 455/24
• US Class Current: 370/318
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

Disclosed are systems and methods for signal detection. In one embodiment, a method is provided for detecting a signal. In this respect, the method comprises the steps of determining a normalized measure of a first power within a first frequency band relative to a second power within a second frequency band of an input signal in a network gateway, wherein the first frequency band is within the second frequency band; and, comparing the normalized measure of the first power with a predefined power threshold to detect a presence of an anticipated signal in the first frequency band.

Claims

1. A signal detection method, comprising:

determining a normalized measure of a first power within a first frequency band relative to a second power within a second frequency band of an input signal in a network gateway, wherein the first frequency band is within the second frequency band;

comparing the normalized measure of the first power with a predefined power threshold to detect a presence of an anticipated signal in the first frequency band; and

indicating a detection of the anticipated signal after the normalized measure of the first power is at least as great as the predefined power threshold for a period of time.

2. The signal detection method of claim 1, wherein the step of determining the normalized measure of the first power within the first frequency band relative to the second power within the second frequency band of the input signal in the network gateway further comprises:

normalizing the second power of the input signal across the second frequency band, thereby generating a normalized input signal;

isolating the first frequency band from the normalized input signal; and

estimating the first power within the first frequency band, thereby obtaining the normalized measure of the first power.

3. The signal detection method of claim 2, wherein the step of normalizing the second power of the input signal across the second frequency band, further comprises:

applying the input signal to an automatic gain controller; and

adjusting a gain of the automatic gain controller to maintain the second power at an approximate constant level.

4. The signal detection method of claim 2, wherein the step of isolating the first frequency band from the normalized input signal further comprises processing the normalized input signal with a narrowband filter.

5. The signal detection method of claim 2, further comprising recording a pattern in the anticipated signal over a period of time.

6. The signal detection method of claim 5, further comprising:

comparing the pattern in the anticipated signal with at least one predefined pattern to find a match therebetween; and

triggering an execution of an action upon an occurrence of the match.

7. The signal detection method of claim 1, wherein the step of determining the normalized measure of the first power within the first frequency band relative to the second power within the second frequency band of the input signal in the network gateway further comprises:

estimating the second power of the input signal across the second frequency band;

isolating the first frequency band from the input signal;

estimating the first power within the first frequency band; and

calculating the normalized measure of the first power as a ratio between the first power and the second power.

8. The signal detection method of claim 7, wherein the step of isolating the first frequency band from the input signal further comprises processing the input signal with a narrowband filter.

9. The signal detection method of claim 7, further comprising recording a pattern in the anticipated signal over a period of time.

10. The signal detection method of claim 9, further comprising:

comparing the pattern in the anticipated signal with at least one predefined pattern to find a match therebetween; and

triggering an execution of an action upon an occurrence of the match.

11. A program embodied in a machine readable medium, the program comprising:

at least one statement for determining a normalized measure of a first power within a first frequency band relative to a second power within a second frequency band of an input signal in a network gateway, wherein the first frequency band is within the second frequency band;

at least one statement for comparing the normalized measure of the first power with a predefined power threshold to detect a presence of an anticipated signal in the first frequency band; and

at least one statement for indicating a detection of the anticipated signal after the normalized measure of the first power is at least as great as the predefined power threshold for a period of time.

12. The program embodied in a machine readable medium of claim 11, wherein the at least one statement for determining the normalized measure of the first power within the first frequency band relative to the second power within the second frequency band of the input signal in the network gateway further comprises:

at least one statement for normalizing the second power of the input signal across the second frequency band, thereby generating a normalized input signal;

at least one statement for isolating the first frequency band from the normalized input signal; and

at least one statement for estimating the first power within the first frequency band, thereby obtaining the normalized measure of the first power.

13. The program embodied in a machine readable medium of claim 12, wherein the at least one statement for normalizing the second power of the input signal across the second frequency band, further comprises:

at least one statement for applying the input signal to an automatic gain controller; and

at least one statement for adjusting a gain of the automatic gain controller to maintain the second power at an approximate constant level.

14. The program embodied in a machine readable medium of claim 12, wherein the at least one statement for isolating the first frequency band from the normalized input signal further comprises at least one statement for processing the normalized input signal with a narrowband filter.

15. The program embodied in a machine readable medium of claim 12, further comprising at least one statement for recording a pattern in the anticipated signal over a period of time.

16. The program embodied in a machine readable medium of claim 15, further comprising:

at least one statement for comparing the pattern in the anticipated signal with at least one predefined pattern to find a match therebetween; and

at least one statement for triggering an execution of an action upon an occurrence of the match.

17. The program embodied in a machine readable medium of claim 11, wherein the at least one statement for determining the normalized measure of the first power within the first frequency band relative to the second power within the second frequency band of the input signal in the network gateway further comprises:

at least one statement for estimating the second power of the input signal across the second frequency band;

at least one statement for isolating the first frequency band from the input signal;

at least one statement for estimating the first power within the first frequency band; and

at least one statement for calculating the normalized measure of the first power as a ratio between the first power and the second power.

18. The program embodied in a machine readable medium of claim 17, wherein the at least one statement for isolating the first frequency band from the input signal further comprises a narrowband filter.

19. The program embodied in a machine readable medium of claim 17, further comprising at least one statement for recording a pattern in the anticipated signal over a period of time.

20. The program embodied in a machine readable medium of claim 19, further comprising:

at least one statement for comparing the pattern in the anticipated signal with at least one predefined pattern to find a match therebetween; and

at least one statement for triggering an execution of an action upon an occurrence of the match.

21. A system for signal detection, comprising:

means for determining a normalized measure of a first power within a first frequency band relative to a second power within a second frequency band of an input signal in a network gateway, wherein the first frequency band is within the second frequency band;

means for comparing the normalized measure of the first power with a predefined power threshold to detect a presence of an anticipated signal in the first frequency band; and

means for indicating a detection of the anticipated signal after the normalized measure of the first power is at least as great as the predefined power threshold for a period of time.

22. The system of claim 21, wherein the means for determining the normalized measure of the first power within the first frequency band relative to the second power within the second frequency band of the input signal in the network gateway further comprises:

means for normalizing the second power of the input signal across the second frequency band, thereby generating a normalized input signal;

means for isolating the first frequency band from the normalized input signal; and

means for estimating the first power within the first frequency band, thereby obtaining the normalized measure of the first power.

23. The system of claim 22, wherein the means for normalizing the second power of the input signal across the second frequency band, further comprises:

means for applying the input signal to an automatic gain controller; and

means for adjusting a gain of the automatic gain controller to maintain the second power at an approximate constant level.

24. The system of claim 22, wherein the means for isolating the first frequency band from the normalized input signal further comprises means for processing the normalized input signal with a narrowband filter.

25. The system of claim 22, further comprising means for recording a pattern in the anticipated signal over a period of time.

26. The system of claim 25, further comprising:

means for comparing the pattern in the anticipated signal with at least one predefined pattern to find a match therebetween; and

means for triggering an execution of an action upon an occurrence of the match.

27. The system of claim 21, wherein the means for determining the normalized measure of the first power within the first frequency band relative to the second power within the second frequency band of the input signal in the network gateway further comprises:

means for estimating the second power of the input signal across the second frequency band;

means for isolating the first frequency band from the input signal;

means for estimating the first power within the first frequency band; and

means for calculating the normalized measure of the first power as a ratio between the first power and the second power.

28. The system of claim 27, wherein the means for isolating the first frequency band from the input signal further comprises a narrowband filter.

29. The system of claim 27, further comprising means for recording a pattern in the anticipated signal over a period of time.

30. The system of claim 29, further comprising:

means for comparing the pattern in the anticipated signal with at least one predefined pattern to find a match therebetween; and

means for triggering an execution of an action upon an occurrence of the match.

31. A system for signal detection, comprising:

an automatic gain controller adapted to normalize a signal power of an input signal across a predefined frequency spectrum;

a narrowband filter coupled to the automatic gain controller, the narrowband filter being configured to isolate a predefined frequency band of the input signal, wherein an anticipated signal is transmitted in the predefined frequency band;

a power estimator coupled to the narrowband filter for estimating the power within the predefined frequency band; and

a first logical circuit for comparing the power estimated within the predefined frequency band with a predefined power threshold to detect a presence of the anticipated signal; and

a second logical circuit for indicating a detection of the anticipated signal after the power estimated within the predefined frequency band is at least as great as the predefined power threshold for a period of time.

32. A system for signal detection, comprising:

a first estimator adapted to estimate a signal power of an input signal across an input signal frequency band;

a narrowband filter coupled to the first estimator, the narrowband filter being configured to isolate a predefined frequency band within the input signal frequency band, wherein an anticipated signal is transmitted in the predefined frequency band;

a second estimator adapted to estimate a second power within the predefined frequency band;

a first logical circuit to compare a ratio of the second power to the signal power with a predefined ratio threshold; and

a second logical circuit for indicating a detection of the anticipated signal after the ratio is at least as great as the predefined ratio threshold for a period of time.