KFM frequency tracking system using a digital correlator
First Claim
Patent Images
1. Apparatus for providing a two point phase/frequency modulation system, the apparatus comprising:
- a first network configured to introduce an offset to center a signal applied to a VCO;
a second network configured to set a gain of the VCO; and
a phase tracking network configured to dynamically adjust the offset and the gain.
7 Assignments
0 Petitions
Accused Products
Abstract
An apparatus for providing a two point phase/frequency modulation system is disclosed herein. The apparatus includes a first network configured to introduce an offset to center a signal applied to a VCO. The apparatus further includes a second network configured to set a gain of the VCO. A phase tracking network is configured to dynamically adjust the offset and the gain.
-
Citations
14 Claims
-
1. Apparatus for providing a two point phase/frequency modulation system, the apparatus comprising:
-
a first network configured to introduce an offset to center a signal applied to a VCO; a second network configured to set a gain of the VCO; and a phase tracking network configured to dynamically adjust the offset and the gain. - View Dependent Claims (2)
-
-
3. Apparatus for providing a two point phase/frequency modulation system, the apparatus comprising:
-
a first network configured to introduce an offset to center a signal applied to a VCO; a second network configured to set a gain of the VCO; and a phase tracking network configured to dynamically adjust the offset and the gain; wherein the phase tracking network includes a correlator network operative to track an error signal applied to the VCO and wherein the correlator network includes; a subtracting integrator; a window comparator coupled to an output of the subtracting integrator; and a correlator coupled to an output of the window comparator.
-
-
4. Apparatus for tracking in a two point phase/frequency modulation system to adjust an offset and scale of a signal applied to a VCO, the apparatus comprising:
-
a subtracting integrator configured to capture a dynamic correction signal; a window comparator configured to determine a polarity of an output signal of the integrator; a correlator network configured to project the dynamic correction signal onto a reference modulation signal; and logic configured to generate, based on the output signal of the correlator, a control signal (Voff) to adjust the offset of a signal applied to the VCO and a control signal (Valpha) to scale the signal applied to the VCO. - View Dependent Claims (5, 6)
-
-
7. Apparatus for tracking the operation of a two point phase/frequency modulation system to adjust the offset and/or the scaling applied to the signal driving the VCO, the apparatus comprising:
-
a subtracting integrator configured to capture a dynamic correction signal; an A/D converter for measuring an output of the integrator; a correlator configured to project the dynamic correction signal onto a reference modulation signal and produce a correlation signal; logic configured to generate, based on the output signal of the correlator, a control signal (Voff) to adjust the offset of a signal applied to the VCO and a control signal (Valpha) to scale the signal applied to the VCO.
-
-
8. A phase/frequency modulation system, comprising:
-
a phase-locked loop (PLL) having a VCO including a first port and a second port wherein during operation of the PLL an error signal is received by the first port; a correlator network configured to produce an output signal based upon the error signal and a function of an applied FM modulation signal; and a phase tracking loop which generates, in response to the output signal, a VCO control signal applied to the second port. - View Dependent Claims (9, 10)
-
-
11. A method for providing two point phase/frequency modulation, comprising:
-
generating an offset signal; providing the offset signal to center a modulation signal applied to a VCO element of a phase-locked loop; generating a gain signal; providing the gain signal to set a gain of the VCO; and dynamically tracking, during operation of the phase-locked loop, the offset and the gain of the VCO so as to generate one or more additional correction signals to be applied to the VCO. - View Dependent Claims (12)
-
-
13. A method for tracking the relationship between a direct modulation FM signal applied to a phase-locked loop (PLL) and a PLL feedback signal, comprising:
-
generating, using cross-correlation between the FM signal and feedback signal, a correlation signal that; follows the FM signal when the FM signal is scaled below a first predefined scaling threshold; and moves opposite to the FM signal when the FM signal is scaled above a second predefined threshold; and providing said correlation signal to the PLL so as to adjust the output of a VCO element of the PLL. - View Dependent Claims (14)
-
Specification