close

Вход

Забыли?

вход по аккаунту

?

JPS5033722

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPS5033722
? 4-channel stereo broadcast type ? Japanese Patent Application No. 45-941670 Application
No. 45 (1970) October 27 @ Takahashi Satoshi Tokyo Kyoto Suginami Ward Izumi 2 14 14 1
Sansui Electric Co., Ltd. 0 Applicant Sansui Electric Co., Ltd. Company 1 Tokyo 14 Sugino-ku
Izumi 2 1 [presence] agent patent attorney Takehiko Suzue 3 persons outside
BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 show different arrangements of
microphones for extracting 4-channel stereo signals according to the present invention, and FIGS.
4 and 5 are blocks showing different embodiments of the present invention. Figures 6a and 6b
are waveform diagrams for explaining the embodiment, and Figures 7 to 9 are vector diagrams
for explaining the embodiment, and Figure 10 is a main carrier according to the method of the
present invention. FIGS. 11 to 13 are diagrams showing modulation spectra, and FIGS. 11 to 13
are block diagrams showing different embodiments for demodulating a four-channel stereo
signal.
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a broadcast
system of four channel stereo signals, and the present invention will be described with reference
to the drawings. First, it is considered that the four-channel stereo signal described here is a
signal detected by microphones at four different places in a certain sound field. That is, as shown
in FIG. 1, when considering a human P at the center of a certain sound field S, the microphone on
the left side diagonally forward viewed from this human P is the microphone on the left side
MFLX diagonally The microphones of the above are MFR and the microphones at the diagonally
rear right side are MRR, and the outputs FL, RL, and FRRR of these microphones are stereo
signals of 4 channels. In addition, as arrangement | positioning of each microphone MFL, MFR,
MRL, and MRR [111111], it is also possible to obtain 5 channel stereo signal as shown in FIG. 2
or FIG. Thus, in FIG. 4, 40 is a first extraction circuit which combines the above-mentioned stereo
09-05-2019
1
signals and extracts a sum signal of A = FL + RL + FR + RR, and 41 is B = (FL + RL)-(FR + RR). And
a second extraction circuit for extracting the left and right information signal. Reference numeral
42 denotes a third extraction circuit for extracting a crossover information signal of C = (FL-RL)(FR-RR)-(FL + RR)-(FRRRL), and 43 denotes D = (FL-RL) + It is the 4th extraction circuit which
extracts a back-and-front information signal which becomes (FR-RR) = (FL ten FR)-(RL + RR). A
pilot signal generation circuit 44 generates a pilot signal of, for example, 19 [kHzJ], and a first
frequency multiplier circuit 45 generates a first subcarrier of 38rkHzj by multiplying the pilot
signal by I-. 46 amplitude modulates the first subcarrier of the multiplier circuit 45 with the
signal B = (FL + RL) ? (FR + RR) of the second extraction circuit 41, and suppresses the carrier of
the first subcarrier. It is a first carrier suppression amplitude modulation circuit that produces a
carrier. 4T is a phase shift circuit for shifting the phase of the pilot signal of the pilot signal
generation circuit 44 by 45 degrees, 48 is the output signal frequency of this phase shift circuit
47 which is doubled, and 90 degrees with the first subcarrier A second frequency multiplier
circuit that generates a 38 second "kHz" subcarrier with a phase difference of 49 amplitudemodulates the second subcarrier of the multiplying circuit 48 with the signal C = (FL?RL) ?
(FR?RR) of the third extracting circuit 42, and suppresses the carrier of the second subcarrier.
There is [111111] EndPage: 1 in the second carrier wave suppression amplitude modulation
circuit that produces the second suppression subcarrier.
50 is, for example, a generation circuit for generating a signal of 76 "kH2", that is, the third
subcarrier, 51 is a signal D = (FL-RL) + of the fourth extraction circuit 43 for the third subcarrier
of the generation circuit 50. It is a frequency modulation circuit that generates a third modulated
wave by frequency modulation with (FR-RR). 52 is a signal A = FL + RL + FR + RR of the first
extraction circuit 40, a first suppression subcarrier of the first carrier suppression amplitude
modulation circuit 46, and a second suppression subcarrier of the second carrier suppression
amplitude modulation circuit 49 And a third modulated wave of the frequency modulation circuit
51 and a pilot signal of the pilot signal generation circuit 44. The output of the modulation
circuit 52 is amplified by the power amplification circuit 53 VC and then radiated from the
transmission antenna. Thus, the first carrier wave suppression amplitude modulation circuit 46
which uses the signal B = (FL ? RL) ? (FR + RR) synthesized by the second extraction circuit 41
as a modulation signal doubles the pilot signal of 19 rkHz J The first subcarrier thus obtained is
amplitude-modulated, and the carrier of this first subcarrier is suppressed to supply only the
double-sideband wave, and the first suppressed subcarrier is supplied to the frequency
modulation circuit 52Vc. Further, the second carrier wave suppression amplitude modulation
circuit 49 which uses a signal of C = (FL?RL) ? (FR?RR) synthesized by the third extraction
circuit 42 as a modulation signal corresponds to the first subcarrier. The second subcarrier with
the same frequency and 90 degree phase difference is amplitude-modulated and the carrier of
this is suppressed to provide only the double sidebands to the frequency modulation circuit 52.
Similarly, the phase relationship between the pilot signal and the first and second suppression
subcarriers at this time is as shown in FIGS. That is, FIG. 6A shows the case where the phase of
09-05-2019
2
the first subcarrier is 90 degrees ahead of the phase of the second subcarrier. Conversely, in FIG.
6A, the phase of the second subcarrier is the first subcarrier. The case is 90 degrees ahead of the
phase of. Therefore, the first and second carrier wave suppression amplitude modulation circuits
46 and 49 which respectively modulate the first and second subcarriers having such a phase
relationship form a so-called quadrature two-phase modulation circuit. Furthermore, the
frequency modulation circuit 51 using the signal of D = (FL?RL) + (FR?RR) synthesized by the
fourth extraction circuit 43 as a modulation signal frequency-modulates the third subcarrier to
obtain a frequency modulation circuit. Supply to 52 The third modulated wave which is the
output of such a frequency modulation circuit 51, the second suppressed subcarrier which is the
output of the second carrier wave suppression amplitude modulation circuit 49, the second
which is the output of the first carrier wave suppression amplitude modulation circuit 46 A
frequency modulation circuit 52 which uses as a modulation signal a composite signal composed
of a pilot signal which is the output of the (1) suppressed subcarrier and the pilot signal
generation circuit 44 and a signal of A = FL + RL + FR О RR synthesized by the extraction circuit
40 has a main carrier frequency Since the signal is modulated and supplied to the power
amplification circuit 53, a radio wave having a modulation spectrum as shown in FIG. 10 is
emitted from the transmitting antenna (not shown).
FIG. 5 shows an embodiment in which the same signal A and the first suppression subcarrier as
described above are obtained by the switching method, and the same reference numerals as in
FIG. 4 denote the same parts in FIG. That is, in the figure, 40 'is a fifth combining circuit for
extracting a signal of A + B = 2 (FL + RL), and 41' is a sixth combining circuit for extracting a
signal of A-B = 2 (FRRRR). is there. Reference numeral 54 denotes a pulse generation circuit
which uses a 38 [kHz J subcarrier as a trigger signal and generates a pulse train of a fixed
amplitude and a fixed pulse width. 55 is a switching circuit between two levels which switches
between two signal levels of the signal (A + B) and the signal (A-B) using the pulse of the pulse
generation circuit 54. Reference numeral 56 denotes a low pass filtering circuit for removing
harmonics from the output signal of this circuit to obtain the same signal A and the first
suppressed subcarrier as described in FIG. Then, 52 'modulates a composite signal comprising
the signal A and the first suppression subcarrier, the second suppression subcarrier which is the
output signal of the second carrier suppression amplitude modulator 49, and the third
modulation wave and the pilot signal. It is a frequency modulation circuit that frequency
modulates the main carrier wave as a signal, and the output signal is amplified by the power
amplification circuit 53 and then supplied to the transmission antenna. Similarly, in FIGS. 4 and
5, the third modulated wave is a signal frequency-modulated by the frequency modulation circuit
51, but may be a carrier wave suppression amplitude modulation signal. Also, the third
subcarrier of 76 rkHzj may be easily obtained by multiplying the pilot signal by four. Also, the
phase shift circuit 47 may be provided at the rear stage of the frequency multiplication circuit
4.8. However, the phase shift characteristic of the phase shift circuit 4T at EndPage: 2 o'clock is
90 degrees. Furthermore, in FIG. 5, the carrier wave suppression amplitude modulation circuit 49
09-05-2019
3
for generating the second suppression subcarrier can be replaced with a switching circuit
between two levels. Next, the separation and demodulation in the case where the 4-channel
stereo broadcast obtained as described above is received by the conventional 2-channel stereo
receiver will be described. First, if the phase of the 38 kHzj carrier is perfectly matched, the
second suppressed subcarrier is detected as shown in the vector diagrams of FIGS. 7a and 7b,
which is inserted into the demodulated first suppressed subcarrier. Since only the first
suppressed subcarrier is detected, a signal of B = (FL + RL)-(FR + RR) occurs at the output. On the
other hand, since the signal A = FL + RL + FR + RR is demodulated, the signal A and the signal B
are passed through a matrix circuit to obtain A + B = 2 (FL + RL). The left signal (1), A?B = 2 (FR
+ RR)... (2) The right signal is separated and demodulated.
Therefore, the result is completely the same as that of the conventional separation and
demodulation of a two-channel stereo signal, and it can be seen that it is completely compatible.
Of course, the same result as described above can be obtained even if the signal A and the first
suppression subcarrier are detected by the switching method. Next, when the phase of the
insertion carrier to be inserted into the first suppression subcarrier is shifted, for example, by ?,
as shown in the vector diagram of FIG. The crosstalk from the second suppressed subcarrier is
Cs1n?. Now, ? is small, so B cos ?-B. Assuming that Cs1n?-?C, the detection output of the
first suppressed subcarrier is B + ?C. Here, assuming that ?C = (?FL??RL) ? (?FR??RR),
the left side output is A 10 B 10 ?C 2 (FL + RL) + (A) by passing through the IJ circuit or
switching circuit as described above. .DELTA.Fl DOO ?RL) - (?FL-?RR) иииииииииииииииииииии (3) in
addition, the right output A- (B + ?C) = 2 (FR + RR) + (.DELTA.FR-.DELTA.RR)-(. DELTA.FL.DELTA.RL)... Therefore, when the ? is small, the signal ?FL??RL or ?FR??RR takes a small
value, and the difference signal ?FL??RL or ?FR??RR becomes crosstalk, so the actual
value is extremely small. Also, even if the phase of the carrier inserted into the first suppression
subcarrier is shifted as shown in FIGS. 9a and 9b, the left output is A + B-.DELTA.C = 2 (FL + RL)-(.
DELTA.FL-.DELTA.RL) + (. DELTA.FR ??RR) (5) Further, the right side output is A? (B??C) = 2
(FR + RR) ? (?FR??'RR) + (.DELTA.FR-.DELTA.RL) (6), and the crosstalk is small as described
above. In any of the above cases, as is apparent from the third to sixth equations, since the left
output and the right output are symmetrical, the crosstalk is equally distributed to the left and
right. Next, the degree of modulation of the main carrier of the quadrature two-phase modulation
by the first and second carrier suppression amplitude modulation circuits 46 and 49 will be
described. Here, since the signal B and the signal C modulate a two-phase carrier wave having a
phase difference of 90 degrees with each other, the size of the combined subcarrier changes with
the signal B and the signal C, and the signal B and the signal C If C simultaneously increases,
there is a concern that the degree of modulation of the main carrier by the combined subcarrier
may become too large.
However, according to the method according to the present invention, there is no concern
09-05-2019
4
because one of the following sea urchins, the signal B and the signal C, becomes larger as the
other becomes smaller. That is, when the signal B is at the maximum level, if FL = 1, RL = 1, FR =
?1, and RR = ?1, the level of the signal B at this time becomes the maximum value 4, but the
level of the signal C Becomes 1-1-((-1)-(-1)) = 0 or zero. Similarly, when the level C of the signal C
is the maximum value 4, the signal B is at the zero level. Also, the main signal, that is, the signal A
also becomes zero in both cases. Furthermore, when the signal B is ▒ 2 (absolute value = 2), the
signal C can only take up to a level of ▒ 2 (absolute value = 2) at the maximum. As described
above, the subcarrier level W1111111EndPage: 3 of the quadrature two-phase modulation does
not exceed the subcarrier level in the compliant 2-channel stereo according to the signal B alone.
It is also apparent from the above description that the main signal, that is, the signal A = FL + RL
+ FR + RR is demodulated when monaural reception is performed. Next, an example of a method
for demodulating and separating the broadcast signal of the four-channel stereo signal will be
described with reference to FIG. In the figure, 110 is a frequency discrimination circuit of a 4channel stereo receiver, 111 is a pilot signal extraction circuit for extracting a 19 rk H 2-pilot
signal from the composite signal demodulated by the discrimination circuit 110 11 c, and 112 is
a pilot signal for amplifying this pilot signal It is an amplifier circuit. A frequency multiplier
circuit 113 receives an amplified pilot signal as an input and doubles the frequency to generate
an insertion carrier of 38 rkHzj, and a carrier amplification circuit 114 amplifies the insertion
carrier. A third modulated wave removal circuit 115 removes only the third modulated wave
from the composite signal, and a composite signal 116 from which the third modulated wave is
removed, ie, the main signal (signal A) and the first and second signals. It is an amplifier circuit
which amplifies a suppression subcarrier. And 117 switches the main signal and the first and
second suppressed subcarriers with the output signal of the carrier amplification circuit 114 in
phase with the first suppressed subcarrier, and generates a sum signal of the main signal and the
first suppressed subcarrier. The switching circuit is a switching circuit that extracts a signal A ?
? B = 2 (FL + RL) which is a difference signal and a signal AB = 2 (FR + RR). A phase shift circuit
118 transposes the output signal of the carrier amplification circuit 114, that is, the phase of the
amplified insertion carrier by 90 degrees, and the first suppression subcarrier determines
whether the phase is advanced or retarded by 90 degrees. It is determined depending on whether
the phase of the second suppressed sub-carrier for A is an early phase or a late phase.
129 is an extraction circuit for extracting only the first and second suppression subcarriers from
the output signal of the amplification circuit 116, and 120 is an output signal of the phase shift
circuit 11B amplified by the amplification circuit 119, that is, the second suppression subcarrier.
The output signal of the extraction circuit 129, that is, the second suppression subcarrier, is
switched by the insertion carrier of the same phase to extract the signal C = (FL?RL) ?
(FR?RR). 121 is a third modulated wave extraction circuit for extracting a third modulated wave
from the composite signal, 122 is an amplification circuit for amplifying the third modulated
wave, and 123 is a third modulated wave amplified by the amplification circuit 122 It is a
frequency discrimination circuit that demodulates a wave and extracts a signal of D = (FL?RL) +
09-05-2019
5
(FR?RR). A matrix circuit 124 separates the target signals FL, RL, FR, and RR from the signals (A
+ B), (A?B), and C and D, respectively. In the four-channel stereo signal demodulator configured
as described above, the main signal and the first suppression subcarrier are obtained by doubling
the pilot signal among the composite signal of the four-channel stereo signal demodulated by the
frequency discrimination circuit 110. Because the first carrier in the same phase as the first
suppression subcarrier is applied to the switching circuit 117 which uses the first carrier as the
switching signal, the output of the switching circuit 117 is (A + B) = 2 (FL ? RL) and (A). The
signal -B) = 2 (FR + RR) is produced. In addition, the second suppression subcarrier in the
composite signal is applied to the detection circuit 120 which uses as a switching signal a second
carrier having the same phase as the second suppression subcarrier which is 90 degrees out of
phase with the first carrier. From this, at the output of this detection circuit 120, a signal of C =
(FL?RL) ? (FR?RR) is generated. Then, the third modulated wave of the composite signal is
demodulated by the frequency discrimination circuit 123 into a signal of D = (FL?RL) + (FR?RR)
and is applied to the matrix circuit 124. In the matrix circuit, the signal FL is taken out by a
circuit satisfying the condition of 1?4 (A + B + C + D), and the signal FR is taken out by a circuit
satisfying the condition of 1?4 (A?B?C + D). Similarly, the signals RL and IRR are taken out by
the circuit of 1/4 (A + B-C-D) and 1/4 (A-B + C-D). Therefore, the desired four channel stereo
signals FL, RL, FR, RR will be produced at the output terminals 125, 126, 127.degree. 12811c,
respectively. FIG. 12 is an embodiment showing another method for separating and
demodulating a composite signal of four-channel stereo signals. The same reference numerals
are given to the same parts as FIG. 11, and the third subject is described below. The main signal,
which is the output signal of the modulation wave removal circuit 115, and the first and second
suppression subcarriers are separated and extracted by the filtering circuits 131 and 132,
respectively.
Then, the first and second suppressed subcarriers as the output of the filtering circuit 132 are
amplified by the amplifier circuit 133 and then supplied to the first and second detection circuits
134120, respectively. As a result, in the second detection circuit 120, in the same manner as
described above, the second suppressed subcarrier is inserted in the insertion carrier in the same
phase as this carrier, EndPage: 4 and C = (FL?RL) ? (FR?). A signal RR is extracted, and this
signal is supplied to the matrix circuit 135. Also, in the first detection circuit 134, the first
suppression subcarrier is switched by the insertion carrier in the same phase as this carrier to
extract the signal B = (FL '+ RL)-(FR + RR), and this signal B is used as a matrix Circuit, 135w
supply. On the other hand, the main signal which is the output signal of the filtering circuit 131,
that is, the sum signal A = FL + RL + FR + RR is amplified by the amplifier circuit 136 and then
supplied to the matrix circuit 135. Since this matrix circuit 135 is formed of a circuit which
satisfies the condition of-(A + B + C + D)-(A + B-C-D), a 4-channel stereo signal FL to be obtained
from output terminals 125, 126, 127, 128 . RL, FR and RR are obtained respectively. When the
third modulated wave is a so-called suppressed subcarrier which is amplitude-modulated with a
signal of D = (FL?RL) + (FR?RR), the same parts as in FIG. As shown in FIG. 13, the output
09-05-2019
6
signal frequency of the carrier amplification circuit 114 is doubled by the frequency
multiplication circuit 137 to make a carrier of 76 rkHzJ, and detection is performed by the
detection circuit 138 which uses this carrier as a switching signal. A signal of RL) + (FR?RR) may
be extracted. According to the first embodiment described above, the 4-channel stereo signal FL
to be broadcasted. ??????????
???????????????????????????????
?????????????????? A signal of D = (FL?RL) + (FR?RR) is synthesized, and
the first subcarrier is amplitude-modulated from the signal BK to obtain a first suppressed
subcarrier, and the first subcarrier is obtained from the signal CLC. And amplitude-modulating
the second subcarrier in a quadrature two-phase relationship with the signal to obtain a second
suppressed subcarrier, and modulating the third subcarrier according to the signal to obtain a
third modulated W4444441 harmonic, the signal and the signal A method of frequencymodulating a main carrier by a composite signal comprising the first and second suppressed
subcarriers, the 1 / n frequency of these subcarriers, and a complex signal consisting of the
signal A, and in the second embodiment According to the above, the four-channel stereo signal is
(A + B) = 2 (FL + RL).
??????????????? ?????????????????? Using the pulse train
obtained based on the first subcarrier, synthesized into the signal D = (FL?RL) + (FR?RR), the
signal (A + B) and (A?B) between the second and third signal pulses Switching is performed to
obtain a signal A and a first suppressed subcarrier, and from the signal ClIC, amplitude
modulation is performed on a second subcarrier having a quadrature two-phase relationship with
the first subcarrier to obtain a second suppressed subcarrier. The third subcarrier is modulated
by a signal to obtain a third modulated wave, and this signal, the first and second suppressed
subcarriers of the signal A1, and a pilot signal having a frequency 1 / n of these subcarriers are
obtained. Since the 4-channel stereo broadcast can be performed by the frequency modulation of
the main carrier by the composite signal, it is possible to provide a 4-channel stereo broadcast
system which can be received even by a conventional 2-channel stereo receiver.
09-05-2019
7
Документ
Категория
Без категории
Просмотров
0
Размер файла
19 Кб
Теги
jps5033722
1/--страниц
Пожаловаться на содержимое документа