JPS63109688A - High-definition television receiver - Google Patents

Abstract

PURPOSE:To miniaturize the circuit of a high-definition TV receiver, by executing integrally the aperture corrections of luminance signals and two kinds of chrominance components with a first aperture correction circuit before the three kinds of signals are separated from each other. CONSTITUTION:The output signals from the wide-band (CW) and narrow-band (CN) of the 1st aperture correcting circuit 5 are sent to a TCI decoder 8 at the transmission sampling rate of 64.8 MHz. The TCI decoder 8 extends timewisely the output signals from CW and CN of the 1st aperture correcting circuit 5 which are time-compressed to 1/4 to the transmission sampling rate of 16.2 MHz which is four times as long as the original sampling rate of 64.8 MHz and, at the same time, performs two-dimensional internal insertion of the data CW and CN of the lines which wait for their turn because of a line sequential transmitting system. Therefore, the bands of the output signals CW and CN of the TCI decoder 8 become 7 MHz and 5.5 MHz, respectively. Consequently, the aperture correcting circuit 5 can be constituted of one piece of digital circuit only and the circuit of this receiver can be miniaturized.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to high-definition television reception in which a high-definition MUSE television signal such as a video signal is regenerated into the original high-definition television signal through digital signal processing. It's about machines.

[Prior art] In order to realize high-definition television broadcasting, the method of transmitting high-definition television signals through satellite broadcasting in the 12GH2 band is
This was explained in detail in the preliminary materials for the lecture on ``New Transmission Methods for High-Definition Television (MUSE) J'', which was presented by the HK Research Institute of Technology and the NHK Broadcasting Chemistry Research Institute in June 1980 to commemorate their founding. .

FIG. 2 is a block diagram showing the configuration of a receiver for such a MUSE type baseband signal. In the figure, (1) is an input terminal for a high-definition television signal, and (2) is an input terminal for the above input signal. The A/D converter (3) that performs A/D conversion is a first image interpolation circuit that inputs the output signal of the A/D converter (2), and is equipped with a frame memory and a two-dimensional digital filter. There is. (4) is the first image interpolation circuit (3
) is a second image interpolation circuit that receives the output signal of the second image interpolation circuit as an input, and is equipped with a frame memory and a two-dimensional digital filter.

(6) converts the output signal of the second image interpolation circuit [4] into D
(13) is a second aperture correction circuit that inputs the output signal of the D/A converter (6); (7) is a D/A conversion circuit that performs /A conversion;
) is an output terminal for a luminance signal (hereinafter referred to as Y signal), and (8) is a TCI decoder that receives the output signal of the second image interpolation circuit (4) and reproduces two types of color signals. , (9) is a D/A converter that inputs the output signal of the TCI decoder (8), and (14) is the D/A converter (9).
) a third aperture correction circuit which receives the output signal of
(lO) is the output terminal of the third aperture correction circuit (14), which is the output terminal of the wideband signal (hereinafter referred to as CW multiplied signal), and (11) is the output terminal of the third aperture correction circuit (14), which receives the output signal of the TCI decoder (8) as input. /A converter, (15) is a fourth aperture correction circuit that receives the output signal of the D/A converter (11), and (12) is a fourth aperture correction circuit (15) that receives the output signal of the D/A converter (11).
) and is an output terminal for a narrowband signal (hereinafter referred to as CN signal).

Next, the operation of the above configuration will be explained.

The signal arriving at the video signal input terminal (1) exhibits a sampling pattern as shown in FIG. That is, it is a sub-Nyquist sampling link that goes around in four fields.

In addition, the CW multiplied signal CN signal of the color signal is line-sequentially compressed in the time axis, and the TCI signal is time-division multiplexed during the horizontal blanking period of the Y signal.The compression ratio of one chromatic signal is 4:1, The signal is not compressed.

FIG. 4 shows the transmission format of the above input signal. When an alog signal arrives at the input terminal (1), this signal is
/D converter (2) transmission sampling rate 16.2
Converted to MB7 digital quantity.

Next, the first image interpolation circuit (3) interpolates data within the same field excluding sampling points that are not transmitted. In other words, in Figure 3, if ○ is transmitted, interpolate O, if mouth is transmitted, interpolate mouth, if 0 is transmitted, interpolate ○, and if mouth is transmitted, interpolate mouth. If so, interpolate the mouth. This first image interpolation circuit (3)
The transmission sampling rate of the output data is 32.4
Becomes MII2.

Subsequently, the second image interpolation circuit (4) interpolates data at sampling points that are not transmitted. In other words,
In FIG. 3, x is interpolated from 01 and 01. However, since the color signal is line sequential, vertical interpolation is performed every two lines. This second image interpolation circuit (4
) The transmission sampling rate of the output data is 64.
8 It becomes MB2.

The TCI decoder (8) time-expands the 1/4 time-compressed color signal to a transmission sampling rate of 16.2 M)12, which is 4 times the time, and converts the Cl and CN of lines that are not transmitted line-sequentially. Performs two-dimensional interpolation of data.

The D/A converter (6) converts the Y digital output of the second image interpolation circuit (4) into an analog quantity at a sampling rate of a4.8Mtlz/4J. D/A converter (9
) with a sampling rate of 16.2 MB2
The CW digital output of the decoder (8) is converted into an analog quantity. D/A converter (11) is 16.2 MB2
The digital output of CN of the TCT decoder (8) is converted into an analog quantity at a sampling rate of .

The characteristics of the amplitude (G) of the output signal of each of the D/A converters (6), (9), and (11) with respect to the frequency (f) are as follows: Then, G=-da717bfu
Since an aperture effect as shown in FIG. 5 is produced from the relational expression, each of the D converters (6), (9), (n)
each aperture correction circuit (13) for each output signal of
The inverse characteristic is applied via (14) and (15) to correct the frequency characteristic to be flat. That is, the second aperture correction circuit (13) corrects the output of the D/A converter (6) to the required band of 22MH2, and the third aperture correction circuit (14) corrects the output of the D/A converter (6) to the required band of 22MH2. 9) to the required band of 7 MH2, and in the fourth aperture correction circuit (15), the D/A converter (1
By correcting the output of 1) to the required band of 5.5 Ml+Z, an analog Y signal with a flat amplitude frequency characteristic up to 22 MIIZ is output to the Y signal output terminal (7) in CW mode.
Is the amplitude frequency characteristic at the signal output terminal (10) 7 MH2?
An analog CN signal whose amplitude frequency characteristic is flat up to 5.5 MH2 is obtained at the CN signal output terminal (12).

[Problems to be solved by the invention] Since the conventional high-definition television receiver is configured as described above, three aperture correction circuits for analog signals are required, and these are configured with analog transversal circuits. In this case, the circuit scale becomes very large and a considerable number of accurate analog delay devices are also required. Furthermore, when the aperture correction circuit is configured with a simple peaking circuit using transistors, there is a problem that a linear frequency characteristic of the phase of the output signal cannot be obtained.

This invention was made to solve the above-mentioned problems, and it is possible to maintain the phase frequency characteristic of the output signal linearly, perform aperture correction of the amplitude frequency characteristic with high precision, and reduce the circuit scale. The purpose is to provide a high-definition television receiver that can be reduced in size.

[Means for Solving the Problems] The high-definition television receiver according to the present invention is capable of calculating the TCI of the original high-definition television signal from the output signal of the first image interpolation circuit.
A first aperture correction circuit for correcting the frequency characteristic of the amplitude of the output signal of the second image interpolation circuit for reproducing the signal is used to separate the luminance signal and the two types of color signals before separating them. It is characterized by performing aperture correction of various signals all at once.

[Operation] According to the present invention, the first image interpolation circuit reproduces the TCI signal subjected to inter-field offset sampling from the input MUSE high-definition television signal, and the first image is generated from the reproduced output signal. The interpolation circuit reproduces the TCI signal of the original high-definition television signal, and the first aperture correction circuit corrects the frequency characteristics of the amplitude of the reproduced TCI output signal. It is possible to perform aperture correction on both signals at once.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the configuration of a high-definition television receiver according to an embodiment of the present invention. In this figure, the same components as in FIG.

In FIG. 1, (5) is a first aperture correction circuit which receives the output signal of the second image interpolation circuit (4);
This is a linear phase digital filter consisting of a symmetrical transversal filter. (6) is a D/A converter that inputs the output signal of the aperture correction circuit (5) and converts it into a Y signal, and (7) is the output terminal of the D/A converter (6) that outputs the Y signal. The terminal (8) is a TCI decoder which receives the output signal of the aperture correction circuit (5) and reproduces two types of color signals of the high-definition television signal;
(9) is a D/A converter that inputs the output signal of the TCI decoder (8) and converts it into D/A, and (10) is the output terminal of the D/A converter (9), which is the CI9 signal output terminal. , (11) is a D/A converter which inputs the output signal of the TCI decoder (8), and (12) is an output terminal of (11), which is a CN signal output terminal.

Next, we will explain the action of the compound.

Until the video signal reaching the input terminal (1) or the sampling points that are not transmitted are interpolated in the second image interpolation circuit (4), the operation is the same as in the conventional case described above, and this operation is ideal. , the second image interpolation circuit (4
) output signal Y band is 221! IH2, and CW and C of the output signals of the second image interpolation circuit (4)
Since the time axis of the N band is compressed to 1/4, 28
MHz, 22 MHz.

Next, the sampling frequency of the first aperture correction circuit (5) is 64.8 MHz, which is the same as the transmission sampling rate of the output signal of the second image interpolation circuit (4). With the amplitude frequency characteristic of (5), each of the above D/A converters (6), (9)
, (11) to correct the aperture effect.

In other words, when the frequency characteristic of the amplitude of the first aperture correction circuit (5) is set to fs-64,8M)IZ in FIG. That is, O
~28 MHz, fs-64,8M) IZw
Vibration @ G = tc(f/fs)/sinπ(f/fs
), the Y output signal of the first aperture correction circuit (5) has a transmission sampling rate of 64.8 MHz,
Band 22 MHz"t' is sent to the D/A converter (6). The sampling frequency of the D/A converter (6) is set to 64 MHz.
．． 8 M) 12, the first aperture correction circuit (5
) is converted by the D converter (6), Y
At the signal output terminal (7), an analog Y signal having a flat amplitude frequency characteristic up to the band 22MIIZ is obtained.

On the other hand, the CW of the first aperture correction circuit (5),
The CN output signal is sent to the TCI decoder (8) at a transmission sampling rate of 64.8 M)+2.

This TCI decoder (8) time-expands the CW and CN output signals of the first aperture correction circuit (5), which have been time-compressed to 1/4, to a transmission sampler rate of 16.2 MHz, which is 4 times as much. , performs two-dimensional interpolation of CW and CN data of lines that are not transmitted line-sequentially.

Expanding the CW and CN data by four times in the time direction using the TCI decoder (8) in this way corresponds to compressing it by 174 in the frequency direction. I want to, TCI
The band of the CW output signal of the decoder (8) is 7MHz,
CM (7) The band of the output signal is 5.5M)IZ.

Similarly, the frequency characteristics of the amplitude given by the digital filter of the first aperture correction circuit (5) are shown in Figure 5.
θ~7 MHz when fs=16.2 MHz
◇The CW output signal of the TCI decoder (8) above is sent to the D/A converter (9), which corresponds to the inverse characteristic of
Sampling frequency of converter (9) Mira 16.2 MH
When the CW output signal of the TCI decoder (8) is D/A converted, the C'# signal output terminal (10) receives
An analog CN signal with a flat frequency characteristic and an amplitude up to 7 MHz can be obtained.

Also, the output signal of CN of the TCI decoder (8) is D
/A converter (11), and this D/A converter (11)
) with a sampling frequency of 16.2 MHz, T
When the CN output signal of the CI decoder (8) is D/A converted, the CN signal output terminal (12) has a band of 5.5
Analog C with flat frequency response of amplitude up to MHz
N signals are obtained.

[Effects of the Invention] As described above, according to the present invention, since the aperture correction circuit can be constructed from one digital circuit, the circuit scale of the receiver can be reduced. Moreover, the aperture correction accuracy is high, and the frequency characteristics of the phase of the output signal can be kept linear.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a high-definition television receiver according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a conventional high-definition television receiver, and FIG. 3 is a sampling pattern of the MUSE method. 4 is a transmission format of a video signal of the MUSE system, and FIG. S is an amplitude characteristic diagram of the aperture effect of a D-H converter. (1) --- Video signal input terminal, (2) --- A/D converter, (3) --- first image interpolation circuit, (4) ---
Second image interpolation circuit, (5)...first aperture correction circuit, (6), (9), (11)...0C converter,
(7)...Y signal output terminal, (8)-T CI decoder, (10)-Cw signal output terminal, (12)...
CN signal output terminal. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) High quality of the MUSE method, which is a TCI method that transmits dot interlaced signals with offset sampling between fields, compresses the line-sequential color signal in the time axis, and time-division multiplexes it during the horizontal blanking period of the luminance signal. In a high-definition television receiver that receives a television signal as an input and reproduces the input signal into the original high-definition television signal through digital signal processing, an A/D converter that converts the input signal from analog to digital; a first image interpolation circuit that reproduces a TCI signal offset-sampled between fields from the output signal of the /D converter;
a second image interpolation circuit that reproduces the TCI signal of the original high-definition television signal from the output signal of the image interpolation circuit; and a second image interpolation circuit that corrects the frequency characteristics of the amplitude of the output signal of the second image interpolation circuit. a first aperture correction circuit; and two parts of the original high-definition television signal from the output signal of the first aperture correction circuit.
a TCI decoder for reproducing a seed color signal; a D/A converter for D/A converting the luminance signal of the output signal of the first aperture correction circuit;
and two D/A converters for A/A conversion, and the first aperture correction circuit performs aperture correction for each of the luminance signal and two types of color signals at once. A high-definition television receiver.