BLIND CARRIER TRACKING LOOP

• US 20100284494A1
• Filed: 01/14/2008
• Published: 11/11/2010
• Est. Priority Date: 01/14/2008
• Status: Active Grant

• Current Assignee: InterDigital Madison Patent Holdings (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Belotserkovsky, Maxim
• Granted Patent: US 8,983,004 B2
• Time in Patent Office: Days
• US Class Current: 375/316
• CPC Class Codes: H04L 2027/0024 at the receiver end
• CPC Class Codes: H04L 2027/0044 Control loops for carrier regulation
• CPC Class Codes: H04L 2027/0069 Loop filters
• CPC Class Codes: H04L 27/0014 Carrier regulation of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657
• CPC Class Codes: H04L 7/033 using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop

Abstract

A receiver is an ATSC (Advanced Television Systems Committee)-receiver and comprises a phase lock loop (PLL) for performing carrier tracking of a carrier in a received signal. The PLL includes a detector (160) comprising two pseudo-Hilbert filters (205, 215). The detector uses energy from both band edges of the received ATSC signal for driving the PLL.

Claims

1. Apparatus for use in a carrier tracking loop, the apparatus comprising:

a phase lock loop for performing tracking of a carrier in a received signal;

wherein the phase lock loop comprises

a detector for using energy from both band edges of the received signal for driving the phase lock loop.

2. The apparatus of claim 1, wherein the phase lock loop is for use in providing a downconverted received signal.

3. The apparatus of claim 1 wherein the detector comprises

as least two Hilbert-type filters for use in detecting energy from both band edges of the received signal.

4. The apparatus of claim 3, wherein the Hilbert-type filters are pseudo-Hilbert filters.

5. The apparatus of claim 1, wherein the detector comprises:

a first Hilbert-type filter responsive to a real component of an output signal of the carrier tracking loop for providing a first signal;

a second Hilbert-type filter responsive to an imaginary component of an output signal of the carrier tracking loop for providing a second signal;

a first delay element for delaying the real component of the output signal of the carrier tracking loop for providing a delayed real component;

a second delay element for delaying the imaginary component of the output signal of the carrier tracking loop for providing a delayed imaginary component; and

a first combiner for providing a difference signal representative of a difference between the first signal and the delayed imaginary component;

a second combiner for providing a sum signal representative of a sum of the delayed real component and the second signal; and

a multiplier for multiplying the difference signal and the sum signal for providing an output signal for driving the phase lock loop.

6. The apparatus of claim 5, wherein the Hilbert-type filters are pseudo-Hilbert filters.

7. The apparatus of claim 1, wherein the received signal is an ATSC (Advanced Television Systems Committee) VSB (Vestigial Sideband) modulation signal.

8. A method for use in carrier tracking, the method comprising:

performing tracking of a carrier in a received signal with a phase lock loop; and

driving the phase lock loop as a function of detected energy from both band edges of the received signal for

9. The method of claim 8, further comprising

providing a downconverted received signal.

10. The method of claim 8, wherein the driving step

using at least two Hilbert-type filters for use in detecting energy from both band edges of the received signal.

11. The method of claim 10, wherein the Hilbert-type filters are pseudo-Hilbert filters.

12. The method of claim 8, wherein the driving step comprises:

processing a real component of an output signal of the carrier tracking loop for providing a first signal;

processing an imaginary component of the output signal of the carrier tracking loop for providing a second signal;

delaying the real component of the output signal of the carrier tracking loop for providing a delayed real component;

delaying the imaginary component of the output signal of the carrier tracking loop for providing a delayed imaginary component; and

providing a difference signal representative of a difference between the first signal and the delayed imaginary component;

providing a sum signal representative of a sum of the delayed real component and the second signal; and

multiplying the difference signal and the sum signal for providing an output signal for driving the phase lock loop.

13. The method of claim 12, wherein each processing step performs Hilbert-type filtering.

14. The method of claim 13, wherein the Hilbert-type filtering is a pseudo-Hilbert filtering.

15. The method of claim 8, wherein the received signal is an ATSC (Advanced Television Systems Committee) VSB (Vestigial Sideband) modulation signal.