Television signal processing apparatus

A signal processing apparatus in a television signal transmitting system includes: a first group of delay lines for obtaining a first series of parallel signals; a first group of coefficient multipliers for weighting the first series of signals; a first adder for adding outputs of the first group of coefficient multipliers; a second group of delay lines for obtaining a second series of parallel signals; a second group of coefficient multipliers for weighting the second series of signals; a second adder for adding outputs of the second group of coefficient multipliers and one of the first series of signals; and a transmitter for transmitting output signals from the first and second adders. A signal processing apparatus in a television signal receiving system includes: an input circuit for receiving first and second signals; a first group of delay lines for obtaining a first series of parallel signals; a first group of coefficient multipliers for weighting the first series of signals; a first adder for adding outputs of the first group of coefficient multipliers and the second signal; a second group of delay lines for obtaining a second series of parallel signals; a second group of coefficient multipliers for weighting the second series of signals; a coefficient multiplier for weighting one of the first series of signals; a second adder for adding outputs of the second group of coefficient multipliers and the coefficient multiplier; and a signal composer for composing the output signals from the first and second adders.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an apparatus for extracting a specific signal 
from a television signal source, multiplexing it with a television signal, 
transmitting and receiving the multiplexed signal, and extracting the 
specific signal from the multiplexed signal. 
2. Description of the Prior Art. 
More than 35 years have passed since the color television broadcasting of 
the current NTSC (National Television System Committee) system began in 
1954. Recently, in search of finer definition and higher performance 
television systems, several new systems including HDTV (High Definition 
Television) systems have been proposed. At the same time, the contents of 
the programs presented to viewers have been changed from the mere studio 
programs to programs providing higher quality images and more realistic 
feeling such as cinema-size movies. 
The current NTSC broadcasting is standardized by 2:1 interlaced 525 
scanning lines, a luminance signal bandwidth of 4.2 MHz, and an aspect 
ratio of 4:3. (See, for example, Pritchard, "US Color Television 
Fundamentals-A Review", IEEE Trans. Consumer Electron., vol. CE-23, pp. 
467-478, November 1977). 
In this background, several television signal composition methods aiming at 
compatibility with the current broadcasting system and enhancement of 
horizontal resolution have been proposed. One of such examples is 
presented in a paper of Faroudja and Roisen, "Improving NTSC to achieve 
near-RBG performance", SMPTE J., vol. 96, pp. 750-761, August 1987. They 
use a comb filter to split luminance and chrominance signals at the 
transmitting end and avoid crosstalk between them at a receiver. This 
method is useful for eliminating an annoying crosstalk on the received 
image, but horizontal and vertical high frequency components of the 
luminance signal cannot be transmitted, nor can the enhancement of the 
resolution be attained. Another example is presented in a paper of 
Fukinuki and Hirano, "Extended Definition TV Fully Compatible with 
existing Standards", IEEE Trans. Commun., vol. COM-32, pp. 948-953, August 
1984. Considering the NTSC television signal expressed on a 
two-dimensional plane of temporal frequency f1 and vertical frequency f2, 
the chrominance signals C are present in the second and fourth quadrants 
due to their phase relationships to the chrominance subcarrier fsc. The 
Fukinuki et al example uses the vacant first and third quadrants for 
multiplexing the high frequency components of the luminance signal. These 
vacant quadrants are called the "Fukinuki Hole" after the inventor. The 
chrominance signal and the multiplex high frequency components are 
separated and reproduced at the receiving end, thereby enhancing the 
horizontal resolution. In this example, the conventional NTSC receiver 
would be interfered with by the multiplex signal, because the example has 
no ability for separating the chrominance signal from the multiplex high 
frequency components. In the current television broadcast, as is clear 
from the description above, the signal bandwidth is limited by the 
standard, and it is not easy to add some new information with a high 
quality. For example, other methods to enhance the horizontal resolution 
have been proposed (M. Isnardi et al, "A Single Channel NTSC Compatible 
Widescreen EDTV System", HDTV Colloquium in Ottawa, October, 1987), but 
many problems are left unsolved from the viewpoint of the compatibility 
with the current television broadcasting and the deterioration of 
demodulation characteristics of the high frequency components in a moving 
picture. Besides, from the standpoint of effective use of the frequency 
resources, the transmission band cannot be easily extended. 
The present inventors invented a method of superposing a signal by using 
quadrature modulation of the video carrier (U.S. Pat. No. 4,882,614 which 
issued Nov. 21, 1989, or see Yasumoto et al, "An extended definition 
television system using quadrature modulation of the video carrier with 
inverse Nyquist filter", IEEE Trans. Consumer Electron., vol. CE-33, pp. 
173-180, August 1987). By this method, various signals can be transmitted 
using the newly established quadrature channel and the interference to the 
conventional NTSC receiver is very small in principle. But the 
interference can be detected in practice, because of the imperfectness of 
the characteristics of filters at the receiver and transmitter. 
This invention is one solution to avoid imperfectness of those systems 
mentioned above. Even if the imperfectness of such filters/circuits occur, 
the interference to the conventional NTSC receivers can be reduced down to 
an acceptable level. In this sense, this invention is very useful when one 
transmits the multiplex signal using quadrature modulation of the video 
carrier. 
SUMMARY OF THE INVENTION 
It is a primary object of this invention to provide a television signal 
processing apparatus for multiplex transmission of a large quantity of 
information in a limited bandwidth without interference to the current 
receiver. 
According to this invention, quadrature modulation of the video carrier 
with an inverse Nyquist filter for the multiplex signal, hidden portions 
of the main NTSC signal (the portions which are not displayed on a screen 
by over-scanning of a receiver) and the front porch of horizontal 
synchronous signal of the main NTSC signal, and the "Fukinuki Hole", for 
transmitting various multiplex signals are used. 
One method is to transmit the Vertical-Temporal component extracted from 
progressive scanning signal source using the above mentioned quadrature 
modulation of the video carrier. This V-T component can significantly 
enhance the normal NTSC picture which comes from interlace scanning signal 
sources, although the bandwidth of the V-T component can be reduced down 
to about 1 MHz. One merit to transmit the V-T component by using the 
quadrature modulation is that the interference from this signal to the 
conventional receiver is never perceived owing to its correlation to the 
main NTSC picture. 
Another method is to transmit the Vertical-Horizontal component adaptively 
using the "Fukinuki Hole" in order to avoid crosstalk between the 
luminance and chrominance signals as mentioned above. When the picture is 
still, it is unnecessary to transmit the V-H component by using the 
"Fukinuki Hole" because there exists no crosstalk between the luminance 
and chrominance signals if their separation is performed by frame memories 
3 dimensionally. But when the picture is moving, it is desirable to remove 
the V-H component at the transmitting site to avoid the crosstalk. 
Therefore, the V-H component must be transmitted by the other channel in 
order to keep the resolution the same as that of the NTSC signal. 
Still another method is effected by transmitting the high frequency 
component of the luminance signal of the side panels of a wide screen 
picture using quadrature modulation, the low frequency component of the 
luminance and chrominance signals of the side panels by the above 
mentioned hidden portion and/or front porch, the and high frequency 
component of the luminance signal of the center panel and the high 
frequency component of the chrominance signal of the side panels by the 
"Fukinuki Hole". The advantage of this method is the least possible 
interference to the conventional receiver because the most powerful signal 
including DC component is transmitted by the hidden portion and the high 
frequency component of the center panel has a correlation with the main 
NTSC signal which means less visible artifacts to the conventional 
receiver even if the "Fukinuki Hole" is imperfect as a multiplex channel. 
Another similar method is to transmit the first high frequency component of 
the luminance signal and the high frequency component of the chrominance 
signal of the side panels of a wide screen picture using quadrature 
modulation, the low frequency component of the luminance and chrominance 
signals of the side panels by the hidden portion, and the second high 
frequency component of the luminance signal of the side panels and the 
high frequency component of the luminance signal of the center panels by 
the "Fukinuki Hole". 
The above-noted object may be effected by providing a signal processing 
apparatus in a television signal transmitting system, including; a first 
group of delay lines for delaying an input signal to obtain a first series 
of signals in parallel; a first group of coefficient multipliers for 
weighting the first series of signals; a first adder for adding outputs of 
the first group of coefficient multipliers; a second group of delay lines 
for delaying an output signal from said first adder to obtain a second 
series of signals in parallel; a second group of coefficient multipliers 
for weighting the second series of signals; a second adder for adding 
outputs of the second group of coefficient multipliers and one of the 
first series of signals; and a transmitter for transmitting the output 
signal from the first adder and an output signal from the second adder. 
The above noted object may also be effected by providing a signal 
processing apparatus in a television signal receiving system, including: 
an input circuit for receiving a first signal and a second signal; a first 
group of delay lines for delaying the first signal to obtain a first 
series of signals in parallel; a first group of coefficient multipliers 
for weighting the first series of signals; a first adder for adding 
outputs of the first group of coefficient multipliers and the second 
signal; a second group of delay lines for delaying an output signal from 
the first adder to obtain a second series of signals in parallel; a second 
group of coefficient multipliers for weighting the second series of 
signals; a coefficient multiplier for weighting one of the first series of 
signals; a second adder for adding outputs of the second group of 
coefficient multipliers and an output of the coefficient multiplier; and a 
signal composer for composing the output signal from the first adder and 
an output signal from the second adder. 
By employing the above mentioned techniques, when the multiplex signal is 
received by an existing television receiver, there is almost no 
interference due to the multiplex signal. In other words, the 
compatibility with the existing television receivers can be maintained. 
Furthermore, the feature that multiplex transmission of other information 
is possible in a frequency band determined by the standard is very 
advantageous also from the viewpoint of effective use of frequency 
resources.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIGS. 1(a)-(c) are spectral diagrams which show the quadrature modulation 
of the video carrier at the transmission side. More specifically, FIG. 
1(a) is a spectral diagram of a vestigial sideband, amplitude modulated 
television signal in the NTSC television system, in which the lower 
sideband of a video carrier P1 is the vestigial sideband. In this case, 
the signal may be any amplitude modulated television signal, and thus it 
is not limited to the NTSC television signal. 
FIG. 1(b) is a spectrum of a signal which is obtained by amplitude 
modulating a multiplex signal by a carrier P2 which is same in frequency 
as and different in phase by 90 degrees from the video carrier P1 and 
passing the modulated signal through a special filter which is called an 
"inverse Nyquist filter". The frequency characteristic of the inverse 
Nyquist filter is -6 dB at frequency P2, infinite attenuation at P2+1.25 
MHz, and no attenuation at P2-1.25 MHz. Preferably, the carrier P2 is 
removed in the blanking period of the main television signal. 
The signal shown in FIG. 1(b) is multiplexed with the main television 
signal shown in FIG. 1(a) to obtain a composite signal as shown in FIG. 
1(c). The multiplex signal may be either an analog signal or a digital 
signal. 
FIG. 2 is a block diagram showing a television multiplex signal processor 
at the transmission side. A main signal generator 601 generates a main 
signal such as a video baseband signal. A multiplex signal generator 602 
generates a multiplex signal which is either an analog or a digital 
signal. The main and multiplex signals are fed to a multiplex signal 
superposing circuit 513 through input terminals 510 and 511, respectively. 
In the multiplex signal superposing circuit 513, the multiplex signal is 
separated by a signal separator 506 into two parts, one of which is 
multiplexed with the main signal by a time multiplexer 501, and the other 
is amplitude-modulated by an amplitude modulator 507. The first multiplex 
signal from the signal separator 506 is multiplexed at the hidden portions 
of the over-scanning and the front porch of the horizontal synchronous 
signal of the main video baseband signal by the time multiplexer 501. By 
the main signal coming from the time multiplexer 501, the video baseband 
signal multiplexed with a part of the multiplex signal, a carrier P1 
generated by an oscillator 504 is amplitude-modulated by an amplitude 
modulator 502. The modulated signal is filtered by a VSB filter 503 to 
become a vestigial sideband signal, which is fed to an adder 509. The VSB 
filter 503 is a filter used to transform a double sideband signal into a 
vestigial sideband signal. The carrier P1 from the oscillator 504 is 
shifted in phase by 90 degrees by a phase shifter 505 to form a carrier 
P2. 
By the second part of the multiplex signal separated by the signal 
separator 506, the carrier P2 is amplitude-modulated in double sideband by 
the amplitude modulator 507, and preferably in the blanking period, the 
carrier is suppressed. The phase shift direction of the phase shifter 505 
may be either fixed or varied at intervals of the horizontal scanning 
period, field or frame. The modulated multiplex signal is limited in the 
band by an inverse Nyquist filter 508, and then fed to the adder 509. The 
amplitude frequency characteristic of the inverse Nyquist filter 508 is 
symmetrical to an amplitude frequency characteristic immediately before 
video detection at the receiver with respect to the video carrier. 
The output of the adder 509 is a composite signal. That is, the modulated 
multiplex signal is superposed on the modulated video baseband signal by 
the adder 509 to obtain the composite signal. The composite signal 
appearing at an output terminal 512 of the multiplex signal superposing 
circuit 513 is transmitted from a transmitter 558 with an antenna 559. The 
transmission path is not limited to the wireless system, but may be a 
wired system. In this example, the composite signal is obtained by adding 
the outputs of the VSB filter 503 and the inverse Nyquist filter 508, but 
it is also possible to feed the sum of the outputs of the amplitude 
modulator 502 and the inverse Nyquist filter 508 into the VSB filter 503 
to obtain the composite signal. 
FIG. 3(a) is a block diagram of an existing television receiver with a 
synchronous video detector. The signal transmitted from the transmission 
side is received by an antenna 521, converted in frequency to an 
intermediate frequency band by a tuner 522, and limited in the band by a 
Nyquist filter 523. The band-limited signal is fed into a video detector 
524 and a carrier regenerator 525. In the carrier regenerator 525, the 
video carrier I1 for synchronous detection is regenerated. The 
band-limited signal is synchronously detected by the carrier I1 by the 
video detector 524 to obtain the main signal, that is the video baseband 
signal, at an output terminal 526. 
The frequency characteristic of the Nyquist filter 523 is as follows. 
Referring to FIG. 3(b) which shows the frequency characteristic of the 
Nyquist filter 523, the amplitude is attenuated by 6dB at the video 
carrier I1, and the Nyquist filter characteristic possesses nearly an 
odd-symmetrical amplitude property with respect to the video carrier I1. 
On the other hand, as shown in FIG. 1(b), when the multiplex signal is 
limited in band by the inverse Nyquist filter 508 in the transmitter 
having an inverse characteristic to the frequency characteristic of the 
Nyquist filter 523 in the receiver, the multiplex signal components in the 
shaded area in FIG. 3(b) is nearly double sideband. This can be expressed 
by a vector diagram as shown in FIG. 3(c), in which I1 is the video 
carrier of the main signal, that is, the video baseband signal, and I2 is 
the carrier of the multiplex signal which carrier is same in frequency as 
but different in phase by 90 degrees from I1. The video baseband signal is 
a vestigal sideband with respect to the carrier I1, so that the upper and 
lower sidebands are vector aU and vector aL, respectively, which are 
vector a1 and vector a2, respectively, when decomposed into orthogonal 
vectors. Since the upper and lower sidebands of the multiplex signal are 
expressed by vector bU and vector bL, respectively, their synthetic vector 
is b2, which is the only component to intersect with vector I1 
orthogonally. 
That is, when the main signal is synchronously detected by the carrier I1, 
quadrature distortion due to the vector a2, vector b2 components does not 
occur. Thus, the impairment by the multiplex signal to the existing 
television receiver performing video synchronous detection does not occur 
in principle. 
Next, detection of the multiplex signal at the reception side is described 
below. The signal of the video intermediate frequency band which is the 
output of the turner 522 is limited in band by a bandpass filter, as shown 
in FIG. 4(a), so that the main signal, that is, the video baseband signal, 
becomes double sideband. Its vector expression is shown in FIG. 4(b). 
Since the multiplex signal is a vestigial sideband, the upper and lower 
side bands are vector bU and vector bL, respectively, their synthetic 
vector is a1, which is the only component intersecting orthogonally with 
the vector I2. 
That is, when the multiplex signal is synchronously detected by the carrier 
I2, quadrature distortion due to the vector a1, vector b1 components does 
not occur. Thus, only the multiplex signal components can be demodulated. 
FIG. 4(c) shows an example of television multiplex signal processor for 
demodulating the multiplex signal as well as the main signal. The 
multiplexed signal transmitted from the transmission side is received by 
an antenna 531, converted in frequency into an intermediate frequency band 
by a tuner 532, and fed to a multiplex signal separator 544 through an 
input terminal 541 thereof. The fed signal is limited in the band by a 
Nyquist filter 533. The band-limited signal is fed to a video detector 534 
and a carrier regenerator 535. In the carrier regenerator 535, the video 
carrier I1 for synchronous detection is regenerated. The band-limited 
signal is synchronously detected by the carrier I1 in the video detector 
534, and fed to a time demultiplexer 536. In the time demultiplexer 536 
the main signal and the first multiplex signal are separated. This 
processing is just the opposite to that of the time multiplexer 501 in the 
multiplex signal superposing circuit 513 at the transmission side. The 
first multiplex signal is fed into a signal composer 540 and the main 
signal, the baseband video signal, goes to an output terminal 542 of the 
multiplex signal separator 544. 
The main signal is converted into, for example, R, G, B signals by a main 
signal processor 603, and displayed on a CRT screen 1000. 
The output of the tuner 532 is band-limited also as shown in FIG. 4(a) by a 
bandpass filter 537. By the carrier I2 obtained by 90 degrees phase 
shifting the carrier I1 by a phase shifter 538 (that is, by the carrier I2 
in the same phase as the carrier for multiplex signal modulation used at 
the transmission side), the band-limited signal is synchronously detected 
in a multiplex signal detector 539 to obtain the second multiplex signal. 
The second multiplex signal is composed into the original multiplex signal 
together with the first multiplex signal at the signal composer 540. 
The main signal and the multiplex signal are usually correlated to each 
other, and both signals are separated from a signal source. One novel way 
to increase the vertical resolution is to use a progressive scanning 
camera as a signal source. In order to keep the transmission 
compatibility, the progressive scanning signal is once converted to an 
interlace scanning signal at a transmitter and converted again to the 
progressive signal at a receiver. One reason to use a progressive camera 
is its spot size which is small enough to increase the vertical 
resolution. 
But more positive use of the progressive scanning camera is to transmit a 
difference signal between adjacent horizontal scanning lines, which is 
lost at a converter of the transmitter. 
FIG. 5 is a 2-dimensional spectrum of television signal, where the vertical 
axis shows vertical frequency .nu. and horizontal axis shows temporal 
frequency f. When the progressive scanning camera is used to pick up a 
picture, the frequency region of the output signal is a square Region P 
shown in FIG. 5. But conforming to the conventional NTSC format, we can 
transmit only a square Region Q surrounded by 2, 4, 6, and 8 in FIG. 5 
without aliasing. To transmit the progressive scanning signal without 
aliasing, we have to filter it into Region Q from Region P. But to achieve 
high vertical resolution at the receiver, it is necessary to send the 
signal of Region D (D=P-Q) in FIG. 5 by an additional channel. 
FIGS. 6 and 7(a)-7(b) show how to convert a progressive scanning signal to 
a interlace scanning signal at the transmitting end. In FIG. 6, each 
circle and each column means a line and a frame, respectively; therefore, 
the horizontal axis is temporal. Now we focus a line named f in the middle 
of this figure. When we are at line f, line e came just a frame ago, line 
b came just a line ago, and line x will come in just a frame. The frame 
rate is assumed to be 60 Hz in this example. We make a new line F 
according to the following equation: 
EQU F=f/2+(b+e+x+i)/8 (1) 
By following this signal processing, we can convert a line f in Region P to 
a line F in Region Q. By applying the same way to lines c, j, g, etc. and 
discarding lines e, b, i, x, etc., we obtain the 2:1 interlace signal 
shown in FIG. 7(a). In order to extract the signal of Region D mentioned 
earlier, we have a new line X from a line x using the following equation: 
EQU X=x-(C+F+G+J)/4 (2) 
In this equation C, F, G, and J are lines obtained by the previous 
equation. By applying the same way to lines a, b, d, e, etc., we have new 
lines A, B, D, E, etc. shown in FIG. 7(b). After these signal processing, 
lines F, C, G, J etc. shown in FIG. 7(a) are transmitted by the 
conventional NTSC channel and lines A, B, D, E, etc. are transmitted 
through an augmentation channel. When we recover the original progressive 
scanning signal at the receiving end, we obtain line x from the following 
equation; 
EQU x=X+(C+F+G+J)/4 (3) 
As for line f, we use lines F, b, e, x, i and the following equation, 
EQU f=2F-(b+e+x+i)/8 (4) 
By applying the same method to lines C, G, J, and so on, we can recover all 
lines and form the original progressive scanning signal. 
FIG. 8 is a block diagram showing a television multiplex signal processor 
at the transmission side used to obtain the interlace signal and the 
additional signal in Region D as an embodiment of this invention. 
The progressive scanning signal is fed to an input terminal 11, and passes 
through delay lines 12, 14, 16, and 18. These delay lines have a 524 H or 
1 H delay time (H: Horizontal scanning time). From terminals 11, 13, 15, 
17, and 19, signals corresponding to lines h, k, g, d, and x in FIG. 6 are 
obtained at the same time. These signals are fed into coefficient 
multipliers 20, 21, 22, 23, and 24, and multiplied by coefficients of 1/8, 
1/8, 1/2, 1/8, and 1/8, respectively. The outputs of these multipliers are 
all fed into an accumulator 25 by which a signal corresponding to line G 
in FIG. 7(a) is obtained. This processing of multiplying and accumulation 
follows the equation (1). This signal G is fed to a progressive-interlace 
converter 38 and converted from a progressive signal to an interlace 
signal. The actual processing of converter 38 is time-axis expansion. On 
the other hand, the signal corresponding to the line G is fed into a point 
26, and signals corresponding to lines G, J, C, and F are obtained by 
delay lines 27, 29 and 31 at points 26, 28, 30, and 32. These signals are 
again fed to coefficient multipliers 33, 34, 35 and 36. At each multiplier 
the input signal is multiplied by a coefficient -1/4. At an accumulator 
37, these multiplied signals and the signal of line x are all accumulated 
together to produce a signal X, which is an input to a 
progressive-interlace converter 39. At output terminals 40 and 41, 
interlace signals G and X, which are corresponding to Regions Q and D 
respectively, are obtained. These signal processings follow the equations 
(1) and (2). The terminal 40 may be connected to the input terminal 501 in 
FIG. 2. 
FIG. 9 is a block diagram showing another television multiplex signal at 
the transmission side used to obtain the interlace signal and the 
additional signal in Region D as an embodiment of this invention. This 
diagram shows the same signal processing as FIG. 8 but the difference is 
the position of the two progressive-interlace converters. In FIG. 9, these 
two converters are placed at the beginning of the signal processing and 
convert the progressive scanning signals to the interlace scanning signals 
before the processings according to the equations (1) and (2). Therefore, 
the delay time of the delay lines in FIG. 9 is just half of that in FIG. 
8. 
FIG. 10 is a block diagram showing a television multiplex signal processor 
at the receiving side used to obtain the progressive signal of Region P, 
such as lines g and x from lines G and X, as an embodiment of this 
invention. In this figure, an interlace scanning signal to an input 
terminal 101 is fed to a series of delay lines to obtain, at points 101, 
104, 106 and 108, signals which are corresponding to lines G, J, C and F 
shown in FIG. 7(a), respectively. These signals are multiplied by 
coefficients, which are all 1/4, by multipliers 109, 110, 111 and 112. At 
an accumulator 113, another input signal at a terminal 102 and these 
multiplied signals are all accumulated and a signal corresponding to x in 
Region P is obtained at a point 127. 
In the lower part of FIG. 10, this signal corresponding to x is fed to 
another series of delay lines 115, 117 and 119, and signals corresponding 
to lines x, i, b and e are obtained at the same time at points 114, 116, 
118 and 120. These signals are multiplied by coefficients, which are all 
(-1/4), by multipliers 122, 123, 124 and 125. On the other hand, the 
signal corresponding to line F is multiplied by a coefficient 2 by a 
multiplier 121. At an accumulator 126, these signals are accumulated and a 
signal corresponding to line f in Region P is obtained at a point 128. At 
the last portion of this figure, the signals which relate to lines x and f 
are fed to an interlace-progressive converter 129 and converted to a 
progressive scanning signal. An point 130 is a output terminal of this 
signal. 
In order to transmit the signal corresponding to Region D in FIG. 5, one 
can use an additional 6 MHz TV channel, or smaller bandwidth channel after 
applying band compression method to it. Alternatively, it is possible to 
use `Fukinuki Hole` or quadrature modulation of the video carrier to 
transmit a portion of the signal in Region D. In the case of using 
`Fukinuki Hole`, one must restrict the region for transmitting to the area 
shown in FIG. 11. 
When we use `Fukinuki Hole` for transmitting side panels instead of higher 
frequency component of luminance or chrominance signal, the original 
signal occupying the first and third quadrants must be removed to prevent 
crosstalk between them. In order to remove the signal which horizontal 
frequency is between 1.5 MHz and 4.2 MHz, the next processing is performed 
as shown in FIG. 11. 
EQU Z1=Z2=(Y1+Y2)/2 (6) 
Thus, one can reduce the diagonal resolution from Region Q shown in FIG. 5. 
Furthermore, a signal corresponding to a line X will be transmitted. Here 
X is: 
EQU X=(Y1-Y2)/2 (7) 
At the receiving end, by processing as: 
EQU Y1=Z1+X (8) 
EQU Y1=Z1-X (9) 
Y1 and Y2 can be reproduced. As mentioned, the horizontal frequency of the 
signal of line X is 1.5 MHz to 4.2 MHz. Therefore the bandwidth of 2.7 MHz 
is required to be transmitted. But for two lines Z1 and Z2, only one line 
X, is needed. Therefore the bandwidth of the signal of line X may be split 
into two parts, 1.5 MHz to 2.5 MHz (X1), and 2.5 MHz to 3.5 MHz (X2), and 
each part can be transmitted with each line, Z1 or Z2. Both X1 and X2 can 
be transmitted by quadrature modulation of the video carrier, because 
their bandwidth is 1 MHz. Thus, the diagonal resolution can be recovered 
at the receiving end with little degradation to reconstruct lines Y1 and 
Y2 from the received Z1, Z2, X1 and X2. 
FIG. 13 is a block diagram showing still another television multiplex 
signal processor at the transmission side as an embodiment of this 
invention. In this figure, the luminance signal is fed to an input 
terminal 201, and a wideband chrominance signal I and a narrowband 
chrominance signal Q are fed into input terminals 202 and 203, 
respectively. The luminance signal is band limited by a first 
vertical-horizontal (V-H) filter 204 by removing the region of 
horizontally 2.1 MHz to 4.2 MHz and vertically above 525/4 cycle per 
height. But, these V-H filter is not limited to this characteristics. This 
V-H filter is realized, for example, as a combination of horizontal 
bandpass filter and vertical bandpass filter. An example of the V-H filter 
characteristic is shown in FIG. 15, where vertical and horizontal axes 
show their frequencies and units are cph and MHz. In this figure, the 
region with diagonal lines is removed and transmitted as a multiplex 
signal. In FIG. 13, this multiplex signal is obtained as the output of a 
subtractor 205, or alternatively as a direct output of the mentioned first 
V-H filter 204. The multiplex signal is fed to a multiplier 206 and 
multiplied by a carrier fa and converted in frequency. This converted 
signal is fed to a filter 207 and undesired bandwidth is removed to be the 
"Fukinuki Hole". In an adder 208, the output signal from the first V-H 
filter 204 and the signal from the filter 207 are added. At a switch 209, 
this output from the adder and the output from the first V-H filter 204 
are switched according to the moving information of each pixel, for 
example. In other words, the input luminance signal is selected for a 
still or near still pixel and the output from the adder 208 is selected 
for a moving pixel. As for the chrominance signal, I and Q signals are 
filtered by a second V-H filter 210 and the third V-H filter 211, 
respectively, and quadrature modulated by a quadrature modulator 212 in 
the same way as the conventional NTSC encoder. A modulated chrominance 
signal, which is an output of the quadrature modulator 212, and the output 
luminance signal from the switch 209 are added by an adder 213. A 
composite television signal from the adder 213 is obtained at an output 
terminal 214. This composite television signal is, for instance, amplitude 
modulated and transmitted from an antenna. 
FIG. 17 and FIG. 18 are examples of the frequency spectrum of the second 
and third V-H filter, respectively. As explained above, when a still 
picture occurs, no special processing, such as removing the diagonal 
region, will be performed. The reason is that the chrominance and 
luminance signals are perfectly separated without crosstalk by using frame 
memories at the receiving end. 
FIG. 20 shows this reason, where the luminance signal lies in the region 
surrounded by .+-.15 Hz lines and .+-.525/2 cph lines, and the chrominance 
signal lies outside this region. Therefore, as shown in FIG. 13, the 
switch 209 selects the input luminance signal for a still or near still 
pixel and the output signal from the adder 208 for a moving pixel. But, 
for the receiver without the frame Y/C separator, the diagonal region may 
be removed even for a still pixel. 
FIG. 16 shows a 2-dimensional frequency spectrum of the luminance signal 
which is transmitted as in FIG. 13. In this figure, f is the temporal 
frequency and .nu. is the vertical frequency. The third axis coming from 
the face of the paper to a viewer is horizontal frequency and this 
2-dimensional section is that of 2.1 MHz to 4.2 MHz of the horizontal 
frequency. The region with diagonal lines shows the multiplex signal. The 
multiplex signal is converted in frequency by the multiplier 206 shown in 
FIG. 13. By this multiplier, the carrier fa is used for the original 
multiplex signal to convert it so as to lie in the "Fukinuki Hole". 
FIG. 19 shows a 2-dimensional frequency spectrum of the luminance signal, 
where the "Fukinuki Hole" exists in both the first and third quadrants and 
chrominance signal lies in the second and fourth quadrants. 
FIG. 14 is a block diagram showing another television multiplex signal 
processor at the receiving side in accordance with an embodiment of this 
invention. In this figure, 221 is an input terminal of a composite 
television signal, and 228, 229 and 230 are output terminals of a 
demodulated luminance signal, a demodulated wideband chrominance signal I, 
and a demodulated narrowband chrominance signal Q, respectively. The input 
composite signal is first fed to a luminance-chrominance separator 222 and 
separated into luminance and chrominance signals. This chrominance signal 
includes a chrominance signal and a multiplex signal and is fed to a 
chrominance-multiplex separator 223. One of outputs from the separator 
223, which is a multiplex signal, is fed to a multiplier 224 and 
multiplied by a carrier fa. After passing through a filter 225 in order to 
remove the undesired bandwidth which arises in the multiplier, the 
multiplex signal (the diagonal region of luminance signal which is 
separated at the transmitting side) is added by an adder 226 with a 
baseband luminance signal from the separator 222 to become the original 
luminance signal Y. On the other hand, another output from the separator 
223, which is a chrominance signal, is fed to a chrominance demodulator 
227 and demodulated into I and Q signals. The chrominance-multiplex 
separator 223 is designed to separate the multiplex signal in the first 
and third quadrants and the chrominance signal in the second and fourth 
quadrants in FIG. 19. This separator can be realized using field memories. 
Thus, owing to the multiplexing in the diagonal region of the luminance 
signal with the "Fukinuki Hole", the crosstalk between chrominance and 
luminance signals never happens at the receiving end, and the diagonal 
region can be recovered to form the original luminance signal. In other 
words, one can receive the complete luminance signal without crosscolor or 
dot crawling. When this multiplexed television signal is received by the 
conventional television receiver, both the multiplex signal and the 
modulated chrominance signal are demodulated as a chrominance signal, but 
one can hardly detect any degradation of chrominance signal because the 
demodulated phase of the multiplex signal produces alternate colors 
without any visibility. It proves that there is no interference from the 
multiplex signal to the conventional television receiver. 
FIG. 21 is a block diagram showing still another television multiplex 
signal processor at the transmission side in accordance with an embodiment 
of this invention. FIG. 22 is a block diagram showing still another 
television multiplex signal processor at the receiving side in accordance 
with an embodiment of this invention. These block diagrams include 
time-compression at the transmitting end and time-expansion at the 
receiving end. In FIG. 21, 271 is an input terminal of a luminance signal 
Y, and 272 and 273 are input terminals of wideband and narrowband 
chrominance signals I and Q. These Y, I and Q signals are introduced to 
time-compression circuits 274, 275 and 276, and then to horizontal filters 
277, 278 and 279. The time-compressed chrominance signals are modulated in 
quadrature by a quadrature modulator 281, and added to the time-compressed 
luminance signal by an adder 280 to form a composite television signal. In 
FIG. 22, a composite television signal inputted through an input terminal 
283 is fed to a Y/C separator 284. One output from the Y/C separator is a 
luminance signal Y and the other is a modulated chrominance signal C. The 
modulated chrominance signal C is fed to a chrominance demodulator 285 and 
a wideband chrominance signal I and a narrowband chrominance signal Q are 
separated. These Y, I and Q signals are respectively introduced to 
time-expansion circuits 286, 287 and 288. As described above, since this 
multiplex signal processor includes time-expansion at the receiving end, 
dot crawling, which is crosstalk from the chrominance signal to the 
luminance signal, includes low frequency components and is visible than 
that of the normal crawling. The bandwidth limiting by horizontal filters 
at the transmitting end, as shown in FIG. 16 for the luminance signal, and 
FIG. 17 and FIG. 18 for chrominance signals, can eliminate the crosstalk 
just explained before. Even when the multiplex signal processor at the 
transmission end includes time-compression circuits, these horizontal 
filters are useful for eliminating annoying dot crawling at the receiving 
end. 
FIG. 23(a) is a block diagram showing another television multiplex signal 
processor at the transmission side. In FIG. 23(a), R, G and B signals with 
an aspect ratio of 16:9 and 7 MHz bandwidth are fed into a matrix circuit 
301 and are converted to a luminance signal Y, and chrominance signals I 
and Q. These signals are fed into three separators 302, 303 and 304 and a 
center panel, which is three quarters of the whole picture, and side 
panels, which are the rest of it, are split. Three center panels Yc, Ic, 
Qc, which come from the three separators, are fed to a time-axis expander 
305 and are time-expanded to 4/3, then the bandwidth of the luminance 
signal becomes 5.2 MHz, whereas the bandwidths of the chrominance signals 
are 1.5 MHz and 0.5 MHz. The center panel of the luminance signal is then 
fed to a filter 306 and separated into a low frequency component Yc1, 
whose bandwidth is DC to 4.2 MHz, and a high frequency component Ych, 
whose bandwidth is 4.2 MHz to 5.2 MHz. The low frequency component of the 
luminance signal of the center panel is fed to an adder 307, and the 
output of this adder and the chrominance signal of the center panel Ic and 
Qc are all fed into an NTSC encoder 308 and encoded into an NTSC composite 
signal. The high frequency component of the luminance signal of the center 
panel is fed to a frequency shifter 309 and converted in frequency to a 
bandwidth of DC to 1.0 MHz to be called Ych'. On the other hand, the 
luminance signal of the side panels Ys is fed to a filter 310 and 
separated into a low frequency component Ys1, whose bandwidth is DC to 800 
KHz, and a high frequency component Ysh, whose frequency is over 800 KHz. 
The low frequency component Ys1 is fed into a time-axis compressor 311 and 
time compressed by 5, and then superposed at the hidden part of 
overscanning of a receiver and a front porch of the synchronous signal by 
the adder 307. The high frequency component of the luminance signal of the 
side panels Ysh is fed to a time-axis expander 312 and time-expanded by 4, 
then its frequency is 200 KHz to 1.75 MHz. A part of this time-expanded 
signal, whose bandwidth is 200 KHz to 1.2 MHz, can be transmitted by 
quadrature modulation of the video carrier. The chrominance signal of the 
side panels, Is and Qs, are fed to a quadrature modulator 313 and 
modulated to form a modulated chrominance signal Cs. This modulated 
chrominance signal Cs and the frequency shifted high frequency component 
of the luminance signal of the center panel Ych' are fed into a quadrature 
modulator 314 and modulated by a 3.1 MHz carrier, for example. If one 
choosees this carrier as having opposite phase line by line and opposite 
phase at 262nd line in next field, the quadrature modulated signal would 
exist in the first and third quadrants in a 2-dimensional spectrum figure, 
"Fukinuki Hole". The output of the quadrature modulator 314 is added to 
the NTSC composite signal by an adder 315, and the output of this adder is 
fed into a quadrature modulator 316 and modulated by the multiplex signal 
from the time-axis expander 312. 
Especially, if one can modulate the carrier by the high frequency component 
of the luminance signal of the center panel Ych' as the lower sideband and 
the modulated chrominance signal of the side panels Cs as the upper 
sideband in a carrier suppression fashion, there arises a merit to reduce 
interference to the conventional television receiver because the former 
has a correlation with the main NTSC composite signal. As most of the 
conventional receiver use a narrowband chrominance modulator, interference 
caused by the lower sideband of the "Fukinuki Hole" becomes dot crawling 
which moves down and is very annoying. In this sense, it is desirable to 
modulate the carrier in the "Fukinuki Hole" as positioning the correlated 
signal in the lower sideband. 
FIG. 23 (b) is a block diagram showing another television multiplex signal 
processor at the receiving side. In this figure, the input signal is a 
frequency shifted IF video signal from a tuner 320. A quadrature modulator 
321 is a video detector and demodulates a video signal. In this quadrature 
modulator, the input IF signal is demodulated by regenerated carriers 
sin.omega.ct and cos.omega.ct, and then a main NTSC composite signal and a 
multiplex signal are obtained. The detected main signal is next fed to a 
Y/C separator 322, and the multiplex signal is fed into a time-axis 
expander 334 and converted to high frequency component of the luminance 
signal of the side panels. The Y/C separator has 3-dimensional filter for 
a still picture and 2-dimensional filter for a moving picture to separate 
luminance signal Y' and modulated chrominance signal C'. This modulated 
chrominance signal C' includes a chrominance signal and a multiplex signal 
in the first and third quadrants, and is fed to a quadrant separator 323 
to be converted to a chrominance signal of the center panel Cc and a 
multiplex signal. The multiplex signal is modulated by a carrier, for 
instance, of a frequency of 3.1 MHz, and therefore introduced to a 
quadrature demodulator 330, where a high frequency component of the 
luminance signal of the center panel Ych and a modulated chrominance 
signal of the center panel Cc are obtained. The separated modulated 
chrominance signal of the center panel Cc from the quadrant separator 323 
is fed to a quadrature demodulator 329 and chrominance signals Ic and Qc 
are reproduced. This processing is exactly the same as the normal NTSC 
decoder. The modulated chrominance signal of the side panels Cs is fed 
into a quadrature demodulator 331 and chrominance signals Is and Qs are 
reproduced. 
On the other hand, one of the outputs from the Y/C separator 322, Y', is 
fed to a time-axis separator 324 and a low frequency component of the 
luminance signal of the side panels Ys1', which is superposed at the 
hidden portion of overscanning of a receiver and a front porch of 
synchronous signal, is separated, and at the same time, the rest of it is 
separated and expanded in time by 4/3 to be a low frequency component of 
the luminance signal of the center panel Yc1. This Yc1 is fed to an, adder 
327, added to the high frequency component of the luminance signal of the 
center panel Ych, and becomes a luminance signal of the center panel Yc. 
The low freqency component of the luminance signal of the side panels Ys1' 
is fed to an expander 325 and time-expanded to Ys1, and then added to the 
high frequency counterpart Ysh from the time-axis expander 334 by an adder 
326 to be Ys. These signals, luminance and chrominance signals of the, 
center and side panels, are combined by adders 328, 332 and 333 to be Y, I 
and Q. As the last stage, at a matrix circuit 335, these Y, I and Q 
signals are converted to R, G and B signals in order to display on a CRT, 
for example. 
As explained above and shown in FIGS. 24(a)-24(b), the low frequency 
component of the luminance signal of the side panels Ys1 is superposed at 
the hidden portion of overscanning of a receiver and front porch of the 
synchronous signal, the high frequency component of the luminance signal 
of the side panels Ysh is transmitted by quadrature modulation of the 
video carrier, and the chrominance signal of the side panels Cs and the 
high frequency component of the luminance signal of the center panel Ych 
are transmitted by the "Fukinuki Hole". The main merit of this 
transmission is to reduce interference to the conventional receiver by 
transmitting signals in the most appropriate way. 
FIG. 25 (a) is a block diagram showing another television multiplex signal 
processor at the transmission side. In this case, the low frequency 
component of the luminance signal of the side panels is superposed at the 
hidden portion of overscanning of a receiver and front porch of the 
synchronous signal, the first high frequency component of the luminance 
signal of the side panels and the chrominance signal of the side panel are 
transmitted by quadrature modulation of the video carrier, and the second 
high frequency component of the luminance signal of the side panels and 
the high frequency component of the luminance signal of the center panel 
are transmitted by the "Fukinuki Hole". In FIG. 25 (a), R, G and B signals 
with an aspect ratio of 16:9 and 7 MHz bandwidth are fed into a matrix 
circuit 351 and are converted to a luminance signal Y, and chrominance 
signals I and Q. These signals are fed into three separators 352, 353 and 
354 and a center panel, which is three quarters of the whole picture, and 
side panels, which are the rest of it, are split. Three center panels Yc, 
Ic, Qc of Y, I and Q signals, which come from the three separators, are 
fed to a time-axis expander 355 and expanded in time by 4/3, then the 
bandwidth of the luminance signal becomes 5.2 MHz, whereas the bandwidths 
of the chrominance signals are 1.5 MHz and 0.5 MHz. The center panel of 
the luminance signal is then fed to a filter 356 and separated into a low 
frequency component Yc1, whose bandwidth is DC to 4.2 MHz, and a high 
frequency component Ych, whose bandwidth is 4.2 MHz to 5.2 MHz. The low 
frequency component of the luminance signal of the center panel, Yc1 is 
fed to an adder 357, and the output of this adder and the chrominance 
signal of the center panel Ic and Qc are all fed into an NTSC encoder 358 
and encoded into an NTSC composite signal. The high frequency component of 
the luminance signal of the center panel, Ych, is fed to a frequency 
shifter 359 and converted in frequency to a bandwidth of DC to 1.0 MHz to 
be called Ych'. On the other hand, the luminance signal of the side panels 
Ys is fed to a filter 360 and separated into a low frequency component 
Ys1, whose bandwidth is DC to 800 KHz, a first high frequency component 
Ysh1, whose bandwidth is 800 KHz to 4.0 MHz, and a second high frequency 
component Ysh2, whose bandwidth is 4.0 MHz to 5.2 MHz. The low frequency 
component Ys1 is fed into a time-axis compressor 361 and time compressed 
by 5, then can be superposed at the hidden part of overscanning of a 
receiver and a front porch of the synchronous signal at the adder 357. The 
first high frequency component of the luminance signal of the side panels 
Ysh1 is fed to a time-axis expander 362 and time-expanded by 4, then its 
frequency is 200 KHz to 1.0 MHz. This time-expanded signal can be 
transmitted by quadrature modulation of the video carrier. The second high 
frequency component of the luminance signal of the side panels Ysh2 is fed 
to a frequency shifter 367 and converted to a bandwidth of DC to 1.2 MHz. 
Then this signal is fed to a time-axis expander 368 and time expanded by 4 
and its frequency is DC to 0.3 MHz. The chrominance signal of the side 
panels Is and Qs are fed to a quadrature modulator 363 and modulated to be 
a modulated chrominance signal Cs. This modulated chrominance signal Cs 
and the signal Ysh1 are fed to the time-axis expander 362 and combined. 
The output of this expander 362 is fed into a quadrature modulator 366. 
The frequency shifted high frequency component of the luminance signal of 
the center panel, Ych', and the frequency-shifted and time-expanded high 
frequency component of the chrominance signal of the side panels Csh' are 
fed into a quadrature modulator 364 and modulated by 3.9 MHz carrier, for 
example. If one chooses this carrier as having opposite phase line by line 
and opposite phase at 262nd line in next field, the quadrature modulated 
signal would exist in the first and third quadrants in a 2-dimensional 
spectrum figure, "Fukinuki Hole". The output of the quadrature modulator 
364 is added to the NTSC composite signal by an adder 365, and the output 
of this adder is fed into the quadrature modulator 366 and modulated with 
the multiplex signal from the time-axis expander 362. 
Especially, if one can modulate the carrier by the high frequency component 
of the luminance signal of the center panel as the lower sideband and the 
high frequency component of the luminance signal of the side panels as the 
upper sideband in a carrier suppression fashion, there arises a merit to 
reduce interference to the conventional television receiver because the 
former has a correlation with the main NTSC composite signal. As most of 
the conventional receivers use a narrowband chrominance modulator, 
interference caused by the lower sideband of the "Fukinuki Hole" becomes 
dot crawling which moves down and is very annoying. In this sense, it is 
desirable to modulate the carrier in the "Fukinuki Hole" as positioning 
the correlated signal in the lower sideband. 
FIG. 25 (b) is a block diagram showing another television multiplex signal 
processor at the receiving side. In this figure, the input signal is a 
frequency shifted IF video signal from a tuner 370. A quadrature 
demodulator 371 is a video detector and demodulates a video signal. In 
this quadrature modulator, the input IF signal is demodulated by 
regenerated carriers sin.omega.ct and cos.omega.ct, and then a main NTSC 
composite signal and a multiplex signal are obtained. The detected main 
signal is next fed to a Y/C separator 372 and the multiplex signal is fed 
into a Y/C separator 384 and separated to a high frequency component of 
the luminance signal of the side panels and a modulated chrominance signal 
of the side panels. Both Y/C separators have a 3-dimensional filter for a 
still picture and a 2-dimensional filter for a moving picture. 
The modulated chrominance signal Cs of the output of the Y/C separator 384 
is fed to a quadrature demodulator 386, and high frequency components of 
the chrominance signal of side panels Is and Qs are obtained. Both 
chrominance signals, Is, Qs, are then time-compressed in a time-axis 
compressor 387. Another output of the Y/C separator 384 is a high 
frequency component of the luminance signal of the side panels, Ysh and it 
is frequency shifted by a frequency shifter 388. The modulated chrominance 
signal C' of the output of the Y/C separator 372 includes a chrominance 
signal and a multiplex signal in the first and third quadrants, and is fed 
to a quadrant separator 373 to be converted to a luminance signal of the 
center panel and a multiplex signal. The multiplex signal is demodulated 
by a carrier, for instance, of frequency 3.9 MHz, introduced to a 
quadrature demodulator 380, and a high frequency component of the 
luminance signal of the center panel and side panels, Ych and Ysh are 
obtained. The separated modulated chrominance signal of the center panel 
Cc' is fed to a quadrature demodulator 379 and chrominance signals Ic and 
Qc are reproduced. This processing is exactly the same as the normal NTSC 
decoder. 
On the other hand, one of the outputs from the Y/C separator 372, Y, ' is 
fed to a time-axis separator 374 and a low frequency component of the 
luminance signal of the side panels Ys1', which is superposed at the 
hidden portion of overscanning of a receiver and a front porch of 
synchronous signal, is separated, and at the same time, the rest of it is 
separated and expanded in time by 4/3 to be a low frequency component of 
the luminance signal of the center panel Yc1. This Yc1 is fed to an adder 
377, added to the high frequency component of the luminance signal of the 
center panel Ych, and becomes a luminance signal of the center panel Yc. 
The low frequency component of the luminance signal of the side panels 
Ys1' is fed to an expander 375 and time-expanded to Ys1, and then added to 
the first and second high frequency component of the luminance signal of 
the side panels, Ysh1 and Ysh2 by and adder 376 to be Ys. These signals, 
luminance and chrominance signals of the center and side panels, are 
combined by adders 388, 382 and 383 to be Y, I and Q. As the last stage, 
by a matrix circuit 385, these Y, I and Q signals are converted to R, G 
and B signals in order to display on a CRT, for example. 
As explained above and shown in FIGS. 26(a)-26(b) the low frequency 
component of the luminance signal of the side panels is superposed at the 
hidden portion of overscanning of a receiver and front porch of the 
synchronous signal, the high frequency component of the luminance and 
chrominance signal of the side panels is transmitted by quadrature 
modulation of the video carrier, and the high frequency component of the 
luminance signal of the center panel and side panels are transmitted by 
the "Fukinuki Hole". The main merit of this transmission is to reduce 
interference to the conventional receiver by transmitting signals in the 
most appropriate way.