Automatic slope and gain (ASG) detector technique including a pilot signal

• US 6,587,012 B1
• Filed: 10/02/2000
• Issued: 07/01/2003
• Est. Priority Date: 10/01/1999
• Status: Expired due to Term

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Arris International, Inc. (CommScope Holding Company, Inc.)
• Inventors: Kenny, John J., Farmer, James, Hollabaugh, John S., Stover, Calvin W.
• Primary Examiner(s): Summons, Barbara
• Application Number:
  US09/677,168
• Time in Patent Office: 1,002 Days
• Field of Search: 333/15, 333/16, 327/65, 455/500, 455/68
• US Class Current: 333/15
• CPC Class Codes: H03G 5/005 of digital signals
• CPC Class Codes: H03G 5/22 having semiconductor devices
• CPC Class Codes: H04N 7/102 Circuits therefor, e.g. noise reducers, equalisers, amplifiers H04N7/108 takes precedence

Abstract

An apparatus (7) for switching from a first pilot signal and a second pilot signal on a system transporting a plurality of signals. A tuner (30) receives the signals and provides an output signal to a loop compensation circuit (26). The tuner includes a bandpass filter (22) for removing signals other than the selected pilot signal from the output of the tuner. The output of the bandpass filter is provided to a detector circuit (24, 25). The output of the detector is compared with a reference signal (28) by the loop compensation circuit (28). A microcontroller (39) sends a tuning command to the tuner which causes the tuner to switch from tuning to the first pilot signal to tuning to the second pilot signal and also sends a new reference voltage to the loop compensation circuit. Thus, if the input signal changes from analog to digital modulation on the pilot channel, the set-point, or target level of the reference signal, will automatically change to provide the correct value for operation of the circuit. The microcontroller may change the selected pilot signal based upon a command in the input signal or upon an operator command, such as by setting a switch (not shown).

Claims

1. An ASG system which utilizes a pilot signal and a tuner for maintaining ASG control for a system operable to transport a plurality of station signals, said ASG system comprising:

a controller operable to generate a first control signal for assigning a pilot signal based on a first station signal;

a tuner electronically coupled to said controller operable to receive said first control signal and assign a pilot signal based on said first control signal;

said controller operable to generate a second control signal for assigning a pilot signal based on a second station signal;

said tuner operable to receive said second control signal and assign a pilot signal based on said second control signal; and

said tuner operable to adjust the frequency gain of said assigned pilot signal.

2. The ASG system of claim 1, wherein said tuner has a reference voltage set by said controller based on either said first or said second control signal.

3. The ASG system of claim 1, wherein said first control signal assigns a pilot signal that is a different frequency from the pilot signal assigned by said second control signal.

4. The ASG system of claim 1, wherein said tuner is operable to switch from analog parameters to digital parameters based on said second control signal.

5. The ASG system of claim 1, wherein said tuner is operable to switch from digital parameters to analog parameters based on said second control signal.

6. A method of maintaining ASG control utilizing a pilot signal and a tuner for a system operable to transport a plurality of station signals, said method comprising:

providing a first control signal from a first station signal which can be used for assigning a pilot signal;

providing a second control signal from a second station signal which can be used for assigning a pilot signal;

selecting a pilot signal utilizing said tuner;

providing a controller for instructing said tuner to select either said first or said second control signal for assigning a pilot signal for said system; and

adjusting the frequency gain of said assigned pilot signal utilizing said tuner.

7. The method of claim 6, wherein said tuner has a reference voltage set by said controller based on either said first or said second control signal for adjusting the frequency gain of said assigned pilot signal.

8. The method of claim 6, wherein said second control signal assigns a pilot signal that is a different frequency from said pilot signal assigned by said first control signal.

9. The method of claim 6, wherein said tuner is operable to switch from analog parameters to digital parameters based on said second control signal.

10. The method of claim 6, wherein said tuner is operable to switch from digital parameters to analog parameters based on said second control signal.

11. An ASG system for obtaining a pilot signal for a system operable to transport a plurality of station signals, said system having a tuner utilized to adjust the frequency gain of said pilot signal, said ASG system comprising:

a controller operable to generate a first control signal for assigning a pilot signal based on a first station signal;

a tuner electronically coupled to said controller operable to receive said first control signal and set a pilot signal based on said first control signal;

said controller operable to generate a second control signal for assigning a pilot signal based on a second station signal; and

said tuner operable to receive said second control signal and assign a pilot signal based on said second control signal.

12. The ASG system of claim 11, wherein said tuner has a reference voltage set by said controller based on either said first or said second control signal.

13. The ASG system of claim 11, wherein said first control signal assigns a pilot signal that is a different frequency from said pilot signal assigned by said second control signal.

14. The ASG system of claim 11, wherein said tuner is operable to switch from analog parameters to digital parameters based on said second control signal.

15. The ASG system of claim 11, wherein said tuner is operable to switch from digital parameters to analog parameters based on said second control signal.