Digital and analog TV common-use receiver having single ghost canceler and ghost cancellation method

• US 6,246,444 B1
• Filed: 10/28/1998
• Issued: 06/12/2001
• Est. Priority Date: 11/21/1997
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Ki-bum
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): NATNAEL, PAULOS M
• Application Number:
  US09/179,842
• Time in Patent Office: 958 Days
• Field of Search: 348/614, 358/905, 375/231, 375/232, 375/229, 375/315, 370/290, 370/291
• US Class Current: 348/614
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/42638 involving a hybrid front-end, e.g. analog and digital tuners
• CPC Class Codes: H04N 5/211 Ghost signal cancellation H04N23/81 takes precedence
• CPC Class Codes: H04N 5/46 for receiving on more than one standard at will deflecting circuits of multi-standard receivers H04N3/27

Abstract

A digital/analog TV common-use receiver having a single ghost canceler, and a ghost cancellation method are provided. The single ghost canceler includes a first filter coefficient generator for generating first filter coefficients using a first reference signal included in the analog TV signal, a second filter coefficient generator for generating second filter coefficients using a second reference signal included in the digital TV signal, and a digital filter for filtering the analog TV signal using the first filter coefficients if the analog TV signal is received, and the digital TV signal using the second filter coefficients if the digital TV signal is received. Since an equalizer used when receiving a terrestrial digital TV broadcast is also used upon receiving a terrestrial analog TV broadcast, the single equalizer can correspond to both digital and analog TV signals.

Claims

1. A digital/analog TV common-use receiver having a single ghost canceler, which can receive both an analog TV signal and a digital TV signal, the single ghost canceler comprising:

a first filter coefficient generator for generating first filter coefficients using a first reference signal included in the analog TV signal;

a second filter coefficient generator for generating second filter coefficients using a second reference signal included in the digital TV signal; and

a digital filter for filtering the analog TV signal using the first filter coefficients if the analog TV signal is received, and filtering the digital TV signal using the second filter coefficients if the digital TV signal is received, according to an analog/digital TV selection signal.

2. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 1, wherein the first reference signal is a ghost cancellation reference signal.

3. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 1, wherein the second reference signal is a predetermined signal included in a field synchronous signal.

4. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 1, further comprising:

a reference signal generator for generating the first reference signal and the second reference signal; and

a selector for selecting filter coefficients generated by either the first or second filter coefficient generator, according to the analog/digital TV selection signal, and applying the selected filter coefficients to the digital filter.

5. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 1, further comprising:

a memory for storing the filter coefficients used by the digital filter, reading the stored filter coefficients, and applying the read filter coefficients to the digital filter, to improve the updating speed of the filter coefficients.

6. A digital/analog TV common-use receiver having a single ghost canceler, comprising:

a tuner for receiving both terrestrial analog and digital TV signals;

first and second demodulators for demodulating the terrestrial analog and digital TV signals into demodulated analog and digital TV signals, respectively;

a single ghost canceler for canceling a ghost from the output of the first or second demodulator selected according to the analog/digital TV selection signal;

first and second signal processors for restoring original analog and digital TV signals from the output of the ghost canceler; and

a single display for displaying the outputs of the first and/or second signal processors,

wherein the single ghost canceler comprises;

a first filter coefficient generator for generating first filter coefficients using a first reference signal included in a baseband signal of the analog TV signal and a predetermined first reference signal;

a second filter coefficient generator for generating second filter coefficients using a second reference signal included in a baseband signal of the digital TV signal and a predetermined second reference signal; and

a digital filter for filtering the baseband signal of the analog TV signal using the first filter coefficients if the analog TV signal is received, and the baseband signal of the digital TV baseband signal using the second filter coefficients if the digital TV signal is received, according to an analog/digital TV selection signal.

7. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 6, wherein the first reference signal is a ghost cancellation reference signal.

8. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 6, wherein the second reference signal is a predetermined signal included in a field synchronous signal.

9. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 6, further comprising:

a reference signal generator for generating the first reference signal and the second reference signal; and

a selector for selecting filter coefficients generated by either the first or second filter coefficient generator, according to the analog/digital TV selection signal, and applying the selected filter coefficients to the digital filter.

10. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 6, further comprising:

a memory for storing filter coefficients used by the digital filter, reading the stored filter coefficients, and applying the read filter coefficients to the digital filter, to improve the updating speed of the filter coefficients.

11. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 6, wherein the first demodulator comprises:

an analog intermediate frequency (IF) converter for converting the terrestrial analog TV signal received by the tuner into the baseband signal of the analog TV signal;

a sync separation and clock generator for separating a synchronous signal from the baseband signal of the analog TV signal supplied from the analog IF converter, generating a first sampling clock signal which is synchronized with the separated synchronous signal, and applying horizontal and vertical synchronous signals; and

a first analog-to-digital converter for converting the output of the analog IF converter into a digitized analog TV baseband signal according to the first sampling clock,

wherein the second demodulator comprises;

a digital IF converter for converting the terrestrial digital TV signal received by the tuner into a baseband signal of the digital TV signal;

a second analog-to-digital converter for converting the output of the digital IF converter into a digitized digital TV baseband signal according to a second sampling clock;

a carrier wave recoverer for recovering a carrier wave from the digitized digital TV baseband signal and supplying a signal having the recovered carrier wave;

a symbol timing recovery and sync detector for detecting a symbol timing and a synchronous signal from the signal having the recovered carrier wave, and applying the second sampling clock signal synchronized with the symbol timing, and the synchronous signal; and

an interference canceler for canceling an NTSC interference component existing in the signal which has a recovered carrier wave and is supplied from the carrier wave recoverer.

12. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 11, further comprising:

a first selector for selecting either the digitized analog TV baseband signal or the signal having the recovered carrier wave output via the interference canceler, according to the analog/digital TV selection signal, and supplying the selected signal to the single ghost canceler; and

a demultiplexer for outputting analog and digital TV signals from which multipath distortion has been removed and which are supplied via the single ghost canceler, according to the analog/digital TV selection signal.

13. The digital/analog TV common-use receiver having a single ghost canceler as claimed in claim 11, wherein the first signal processor comprises:

a digital-to-analog converter for converting the ghost-canceled digitized analog TV signal supplied from the single ghost canceler, into a ghost-canceled analog TV signal according to the first sampling clock signal;

a second selector for selecting either the baseband signal of the analog TV signal or the ghost-canceled analog TV signal supplied from the digital-to-analog converter, according to a ghost cancellation control signal;

an analog video signal processor for processing the selected analog TV signal selected by the second selector; and

a third analog-to-digital converter for converting the output of the analog video signal processor into a digital signal according to the first sampling clock signal,

wherein the second signal processor comprises;

a phase tracker for correcting a residual phase error of a ghost-canceled carrier wave supplied through the single ghost canceler;

a Trellis/FEC (forward error correction) decoder for Trellis-decoding the output of the phase tracker and correcting an error of the digital TV signal generated during transmission;

a transport stream demultiplexer for restoring various data streams from the output of the Trellis/FEC decoder; and

a source decoder for restoring the original digital TV signal by performing variable-length decoding, inverse-quantization and inverse discrete cosine conversion on the data stream.

14. A ghost cancellation method for a digital/analog TV common-use receiver for receiving both an analog TV signal and a digital TV signal, comprising the steps of:

(a) generating first filter coefficients using a first reference signal included in the analog TV signal and a predetermined first reference signal;

(b) generating second filter coefficients using a second reference signal included in the digital TV signal and a predetermined second reference signal; and

(c) filtering the analog TV signal using the first filter coefficients if the analog TV signal is received, and the digital TV signal using the second filter coefficients if the digital TV signal is received, according to an analog/digital TV selection signal.

15. The single ghost cancellation method as claimed in claim 14, wherein the first reference signal is a ghost cancellation reference signal.

16. The single ghost cancellation method as claimed in claim 14, wherein the second reference signal is a predetermined signal included in a field synchronous signal.