US 6,803,970 B1Granted

Digital television receiver with match filter responsive to field synchronization code

AssigneeSamsung Electronics Co., Ltd.

InventorsAllen LeRoy Limberg, Chandrakant B. Patel

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Abstract

A radio receiver for receiving a selected digital TV signal uses final intermediate frequency signals the carrier frequencies of which are multiples of symbol rate. The radio receiver has a match filter receptive of rectified samples of digitized intermediate-frequency signal and responsive to the amplitude of the intermediate-frequency carrier being modulated in accordance with the field synchronization code group to generate a pulsed response to the beginning of each data field. This pulsed response is used to determine when data segment synchronization information should occur, so its detection is more certain to be accurate and data segment synchronization is more rapidly determined. Symbol synchronization is rapidly inferred from the field synchronization and data segment synchronization, so that the samples in each data line can be counted. The complex carrier frequencies of the final intermediate frequency signals are generated in response to the samples per data line count, for implementing synchronous detection to baseband. The adjustment of the carrier frequency of the final intermediate frequency signal to be a prescribed multiple of symbol rate is done in response to an automatic-frequency-and-phase-control signal developed from the synchronous detection results.

Claims18

Dependent claims

A radio receiver for receiving digital TV signal having a plurality of successive data fields each including a respective data field synchronization code at the beginning thereof, which said digital TV signal includes symbol codes of various amplitudes in the rest of each of said successive data fields, said radio receiver comprising:

a tuner that selects one of a plurality of channels at different locations in a frequency band of said digital TV signals and performs plural frequency conversion of the selected channel to output a final intermediate-frequency signal in a final intermediate-frequency band;
an adjustable analog tapped delay line responsive to a control signal to delay the final intermediate-frequency signal output from the tuner in order to effect symbol synchronization;
a bandpass analog-to-digital converter for sampling the delayed final intermediate-frequency signal output from the adjustable analog delay line;
an absolute value circuit for rectifying each sample from the bandpass analog-to-digital converter to output an envelope exhibiting amplitude variations in response to data field synchronization codes and to symbol codes of an analog intermediate-frequency carrier of the digital TV signal;
a match filter for responding to the envelope output from the absolute value circuit to indicate whether modulation of the carrier was by a field synchronization code group, said match filter generating a respective pulsed match filter response for conducting a vertical synchronizing signal;
and
kinescope deflection circuitry receiving the vertical synchronizing signal conducted from said match filter.

4 more elements

a tuner that selects one of a plurality of channels at different locations in a frequency band of said digital TV signals and performs plural frequency conversion of the selected channel to output a final intermediate-frequency signal in a final intermediate-frequency band;
an adjustable analog tapped delay line responsive to a control signal to delay the final intermediate-frequency signal output from the tuner in order to effect symbol synchronization;
a bandpass analog-to-digital converter for sampling the delayed final intermediate-frequency signal output from the adjustable analog delay line;
an absolute value circuit for rectifying each sample from the bandpass analog-to-digital converter to output an envelope exhibiting increased and decreased amplitude in accordance with positive and negative excursions of pseudo-random sequences in the data field synchronization code and to symbol codes of an analog intermediate-frequency carrier of the digital TV signal;
a match filter for responding to the envelope output from the absolute value circuit to indicate whether modulation of the carrier was by a field synchronization code group, said match filter generating a respective pulsed match filter response;
and
kinescope deflection circuitry receiving, as a vertical synchronizing signal, the pulsed match filter response generated said match filter.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/337,493Filed 22 Jun 1999 · continuation
Priority: 24 Mar 1994
Granted: 12 Oct 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04N 21/426
Structure of client; Structure of client peripherals: internal components of the client ; Characteristics thereof
H04L 25/03038
Adaptive, i.e. capable of adjustment during data reception: with a non-recursive structure
H04L 27/02
Modulated-carrier systems: amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
H04N 5/08
Synchronising: separation of synchronising signals from picture signals

Family

Application08/216,936Parent of this continuation-in-part · filed 24 Mar 1994
Application60/006,335Us provisional application · filed 8 Nov 1995
Application08/746,294Parent of this continuation-in-part · filed 7 Nov 1996
Application09/262,091Parent of this continuation · filed 4 Mar 1999
Application09/262,091Parent of this continuation-in-part
US 5,648,987 AParent of this continuation-in-part
US 6,803,970 B1This patent

From the US filing history. Foreign family members aren’t listed.