JP2821116B2 - Transmission signal transmission method and apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission signal transmission method and apparatus effective for multiplexing and transmitting a multiplexed signal, particularly a PCM audio signal digitally encoded into a video signal. [Prior Art] For a method of multiplexing a digitally encoded PCM audio signal and a video signal, see "Report on Satellite Broadcasting Receiving Technology Study Group 1" 5.7272 MHz subcarriers are multiplexed on the current NTSC video signal, so it does not satisfy the current terrestrial television broadcasting band. It is difficult to use for broadcasting. On the other hand, regarding the possibility of multiplex transmission to current terrestrial television broadcasting, the Broadcasting Technology Book 2 edited by the Japan Broadcasting Corporation published by the Japan Broadcasting Corporation in January 1983
Pp. 205-208, there is no description of a method capable of securing a transmission capacity of about 1 Mbit / s for transmitting two channels of high quality audio. [Problems to be Solved by the Invention] In the above-mentioned conventional technology, there is no method for multiplexing and transmitting a high-quality PCM audio signal to the current terrestrial television broadcast. An object of the present invention is to provide a transmission signal transmission method and apparatus for multiplexing and transmitting a high quality digitally encoded signal such as a PCM audio signal to a current television broadcast. [Means for Solving the Problems] The object of the present invention is to provide a PCM audio signal which is digitally encoded within a band in which both sidebands of a carrier are transmitted, at least a video information period including video information in a video signal. This is achieved by transmitting a signal of high importance, such as a synchronization signal and a control signal, in a period other than the video signal period, by modulating the multiplexed signal such as an orthogonal relationship with the carrier video signal. [Operation] At least during the video information period, the vestigial sideband has a double-sideband in the video signal carrier that is amplitude-modulated, and the carrier is limited to a general amplitude-modulated band (DSB), and the carrier is converted to the video signal and the PCM. Since the audio signal is modulated so as to have an orthogonal relationship, the influence of the PCM audio signal on the reproduced video signal can be reduced. By lowering the modulation degree of the PCM audio signal compared to the video signal, the PCM can be applied to the video signal reproduced by envelope detection.
The effect of the audio signal can be reduced. In addition, since the PCM audio signal is synchronously detected and reproduced, the orthogonally modulated video signal is not demodulated, and the influence is reduced. In the current terrestrial television broadcasting, a band having both sidebands of the residual sideband amplitude is about 1.25 MHz and about 1 Mbit / band.
It is possible to transmit two channels of digitally encoded high quality PCM audio signals of seconds (for example, 12 bits × 2 channels × 32K sampling × 1.3 redundancy 冗長 1 Mbps). Also, since the frequency and the modulation method are different from those of the current FM audio signal, they are compatible with each other without affecting each other. Further, since there is no video information in the vertical flyback period, the video signal is not easily affected by the video signal. Therefore, the signal is used as a reference signal (for example, a synchronization signal and a control signal) for highly important data multiplexed in this period. There is little disturbance. [Embodiment] As an embodiment of the present invention, FIG. 1 shows an example of a transmitting apparatus for multiplexing and transmitting a digitally encoded PCM audio signal to a current terrestrial transmission television. 1 is a video signal input terminal, 2 is a carrier oscillator, 3 is an AM modulation circuit, 4
Is a first adder, 5 is a VSB filter for vestigial sideband transmission, 6 is a PCM audio signal input terminal, 7 is an analog / digital conversion circuit (hereinafter abbreviated as ADC), 8 is a digital signal processing circuit, and 9 is a digital signal processing circuit. Memory circuit, 10 is a low-pass filter, 11 is a phase shifter, 12 is a digital conversion circuit, 13 is a synchronization signal input terminal, 14 is a clock generation circuit, 15 is an audio signal input terminal for FM modulation, and 16 is an FM modulation circuit , 17 are second adders, and 18 is a transmitting antenna. The output of the carrier starter 2 is AM-modulated by the AM modulation circuit 6 based on the video signal input from the video signal input terminal 1. This AM-modulated signal is band-limited by the VSB filter 5 to a television broadcast band. On the other hand, the audio signal input from the audio signal input terminal 15 is FM-modulated by the FM modulation circuit 16 and added to the AM-modulated video signal by the second adder 17,
It is transmitted from the antenna 18. The above is the same as the conventional terrestrial transmission television broadcast. Next, multiplexing of high-quality PCM audio signals, which is the gist of the present invention, will be described below. The clock generation circuit 14 generates a clock phase-synchronized with the horizontal synchronization signal in the synchronization signal of the video signal input from the synchronization signal input terminal 13. For example, the NTSC system, since the horizontal repetition frequency f _H 15.734 KHz, when the phase-synchronized with the 66 times the frequency of clock 1.038444MHz is obtained, 3 × of f _H ≒ 47 kHz This was peripheral 1/22 minutes The audio signal input from the PCM audio signal input terminal 6 is sampled by the ADC 7 using the sampling pulse. In this case, even if a 16-bit quantization level, when the transmission rate and 66f _H, 16
Transmission rate for transmitting the bits so 48f _H, (6 bits in i.e. 3f _H reference) remainder 18f _H content becomes possible to allocate the additional data such as header indicating the reference position of the error correction code, scrambling. Therefore, the digital signal processing circuit 8 separates the most significant bit from the other bits, performs processing such as adding an error correction code and scrambling each of them, and stores the result in the memory 9.
According to the vertical synchronization in the synchronizing signal input from the synchronizing signal input terminal 13, it is controlled so that it is read from the memory 9 during the vertical retrace period and the other bits are read from other periods. Further serial-to-parallel conversion, 66
after being a serial data bit rate of f _H, remove unwanted high-frequency components through low-pass filter 10 suitable for this rate. The digitally encoded PCM audio signal is modulated by a digital modulation circuit 12 on a carrier wave that has been shifted by 90 ° through a phase shifter 11. Since this output is added by the first adder, the video transmission signal and the PCM audio signal are modulated in an orthogonal relationship. FIG. 2 shows the signal spectrum to be modulated. FIG. 3A shows a video signal, and the spectrum of the processed video signal in the NTSC transmission format has a 4.25 MHz band.
A picture carrier f _C an AM modulated double sideband amplitude modulation spectrum output is that shown in FIG. (B) (DSB) signal followed. On the other hand, FIG.
4 shows an output spectrum of the digital modulation circuit 12 with an M audio signal. Wherein the spectrum of the PCM audio signal is shown a spectrum in the case of modulating a carrier with the transmission rate 66f _H (about 1 Mbit) / sec rolloff about 0.44 signals of. FIG. 4D shows a spectrum obtained by adding the AM-modulated video transmission signal and the digitally-modulated PCM audio signal. FIG (e) shows the spectrum of an FM modulated audio signal, the sound carrier f _S is at a distance 4.5MHz from the picture carrier f _C. FIG. 7F shows the spectrum of the output signal of the adder 17. The video transmission signal is attenuated by a VSB filter from the -0.75 MHz point of the video carrier. The one indicated by the dotted line is the PCM shifted 90 degrees from the video carrier.
3 is a digital modulation spectrum of an audio signal carrier.
In addition, in the vicinity of 4.5 MHz above the 4.25 MHz video signal band, there is a spectrum in which the audio carrier is FM-modulated. Since both sidebands are transmitted for ± 0.75 MHz with respect to the video carrier, it can be considered as a general amplitude modulation (DSB). FIG. 3 is a vector representation of the relationship between the video carrier and the PCM audio signal. When a signal within ± 0.75 MHz, which is orthogonal to the carrier having both sidebands and is modulated with amplitudes A and −A corresponding to digital codes 1 and 0 as shown in FIG. The vector is equal to the video carrier amplitude Vc.
If the modulated signal Vcp becomes _{Vcp = cosw C t ± Asinw C} t (1). Here, w _C is the angular frequency of the carrier. Expanding equation (1), It is. Also Generally, when modulating a picture carrier Vc cosw _C t in signal Vm cosw _C t, in the DSB region, modulated signal Vc is And a carrier amplitude Vc = 1, a quadrature modulation component by a PCM audio signal is added to this Vc, and the signal Vcp is It is. The vector is shown in FIG. Next, FIG. 5 shows an embodiment of a receiving apparatus for stably receiving and demodulating a multiplex signal. In FIG. 5, 101 is an antenna, 102 is a high frequency amplifier circuit, 103 is a frequency conversion circuit, 104 is an intermediate frequency amplifier circuit, 10
5 is a video signal detection circuit, 106 is a video signal amplification circuit, 107 is a color difference signal demodulation circuit, 108 is a primary color signal demodulation circuit, 109 is a CRT, 110 is an audio intermediate frequency amplification circuit, 111 is an audio FM detection circuit, and 112 is audio Signal output terminal, 113 is a band-pass filter, 114 is a synchronous detection circuit, 115 is a carrier recovery circuit, 116 is a code identification circuit, 117 is a clock recovery circuit, 118 is a digital signal processing circuit, and 119 is a digital / analog conversion circuit (hereinafter referred to as a digital / analog conversion circuit). Reference numeral 120 denotes an output terminal of the multiplexed PCM audio signal, and 121 denotes a memory circuit. A television signal input from an antenna 101 is amplified by a high-frequency amplifier circuit 102, frequency-converted by a frequency conversion circuit 103 to an intermediate frequency for demodulation, and amplified by an intermediate-frequency amplifier circuit 104. Tuning is performed by changing the local start frequency of the frequency conversion circuit 103. From the signal amplified by the intermediate frequency amplification circuit 104 to the video signal band, the video signal detection circuit
The primary color signal demodulation circuit 108 detects three primary colors of R, G, and B from the luminance signal output from the video signal amplification circuit 106 and the color difference signal output from the color difference signal demodulation circuit 107.
Projected on. On the other hand, the audio band is amplified by the audio intermediate frequency amplification circuit 110, detected and demodulated by the audio FM detection circuit 111, and an audio signal is obtained at the audio signal output terminal 112. The above is the same as the conventional television receiver. In addition to the above, in order to demodulate a PCM audio signal which is digitally modulated and coded and transmitted by multi-transmission, the PCM multiplexed and transmitted by the band-pass filter 113 from the output of the frequency conversion circuit 103.
Selects and amplifies the audio signal band, and detects and demodulates a signal modulated by a component orthogonal to the amplitude modulation component of the carrier using a signal synchronized with the carrier reproduced by the carrier regeneration circuit 115 in the synchronous detection circuit 114. . The signal obtained as a result is converted to a digital code at a point with a small error rate using a code identification circuit 116, and an error generated during transmission is detected and corrected by a digital signal processing circuit 118 using an error correction code. The clock recovery circuit 117 is a circuit for extracting a transmission clock from a signal output from the synchronous detection circuit 114.
It is necessary to identify the data at the point where the error rate of the output signal of 4 is small (the so-called maximum opening portion of the eye pattern) to make a digital code. The signal in which the error has been detected and corrected is stored in the memory circuit 121, and time alignment of the most significant bit and other bits is performed. The output of the digital signal processing circuit 118 after signal processing such as error detection and correction is converted to an analog signal by the DAC 119 and converted back to an audio signal, and is obtained as an original audio signal at the output terminal 120 of the multiplexed audio signal. . Here, interference of a PCM audio signal with a video signal in an existing general television receiver will be described. Not a disturbance is reproduced the value of the A coefficients only cosw _o t regardless (formula (1 see)) (i.e. the video signal only) for those co detected by the video signal detection circuit cosw _o t . In the case where the video signal detection circuit performs envelope detection, the interference can be reduced by lowering the value of A from 1. For example, if A is 0.1 Although a signal of 0.005 (approximately -46 dB) is affected as compared with 1, there is no practical problem if the signal level to noise ratio (hereinafter, referred to as the SN ratio) of the video signal is 40 dB or more. Further A
If the value is set lower than 0.1, the influence on the video signal is further reduced. On the other hand, interference of the PCM audio signal from the video signal to the detection circuit can be eliminated by demodulating only the component orthogonal to the carrier with the synchronous detection circuit 114 as shown in FIG. Considering the SN ratio, assuming that the SN ratio of the video signal is a practical level of 40 dB, the bandwidth is about 4 times the transmission bandwidth of the PCM audio signal of 1 MHz, so the SN ratio of the PCM audio is 46 dB, PCM
Assuming that the modulation level A of the audio signal is 0.1, the SN ratio is about 26 dB. On the other hand, when the relationship between the SN ratio of the digital signal and the bit error rate is considered using a general binary signal, the SN ratio is 17.4 dB and the bit error rate is 1 × 10 ⁻⁴ (general theoretical value). If the SN ratio of the video signal is 40 dB, the SN of the PCM audio signal
The ratio is 26 dB, which is practically sufficient for digital signal transmission. Here, the most significant bit is multiplexed in the vertical flyback period, but there is no video information in the vertical flyback period, and only the synchronization signal and the burst signal. Therefore, the modulation degree of the video signal is low, and the spectrum is fc (and fc). From the color subcarrier frequency fsc), the phase of the carrier for synchronous detection can be reproduced very stably, and the S / N ratio of the video signal is 40
Even if the level degrades further than dB, the most significant bit can maintain sufficient performance for practical use, so that there is no significant deterioration in sound quality. As described above, the transmission signal transmitting apparatus of the present invention can be realized by the embodiment shown in FIG. The digitalized PCM audio signal can be multiplex-transmitted without interfering with conventional television video and audio signals. FIG. 6 shows another embodiment of the present invention. This circuit is the first
The same numbers are for the same functions based on the circuit shown in the figure. Newly added, 30 is a crystal oscillator, 31 is an oscillation circuit,
32 is a frequency multiplier, 34 and 41 are high frequency amplifiers, and 35 is a type lexer. The carrier of the video is the crystal oscillator 30 and the oscillation circuit
The original oscillation frequency generated at 31 is obtained by multiplying by the multiplying circuit 32. This carrier is used for AM modulation of the image, and the phase is shifted by π / 2 to be a carrier of digital modulation. Also, a signal obtained by amplifying the FM-modulated voice carrier by the high-frequency amplifier 41 and the VSB
The carrier signal of the video amplified by the high frequency amplifier circuit 34 via the filter is synthesized by the diplexer 35 and emitted by the antenna 18. Also in this embodiment, the transmission signal according to the present invention is obtained as in FIG. 1, and the spectrum of the radio wave emitted from the antenna 15 is the same as that in FIG. 2 (f). FIG. 7 shows another embodiment of the present invention. 24 and 30 are crystal oscillators, 25 and 31 are oscillation circuits, 26 is a video signal input terminal, 27
Is an AM modulation circuit, 28 is a high-frequency amplifier circuit, 29 and 40 are frequency conversion circuits, 32 and 39 are frequency multiplication circuits, 33 is a signal synthesis circuit, 3
4, 41 are high-frequency amplifier circuits, 35 is a diplexer, 36 is a transmitting antenna, 37 is an audio signal input terminal, 38 is an FM modulation circuit, 42 is
ADC, 43 is a digital signal processing circuit, 44 is a low-pass filter, 45 is a phase shifter, and 46 is a digital modulation circuit. The video signal input from the video signal input terminal 26 is
The intermediate frequency obtained by the oscillation circuit 24 and the oscillation circuit 25 is AM-modulated by the AM modulation circuit 27. This signal is combined with the digital modulation wave by the combining circuit 33 and amplified by the high frequency amplifier circuit 28. Further, the signal generated by the crystal oscillator 30 and the oscillation circuit 31 is multiplied by the multiplication circuit 32, and the obtained signal and the output signal of the high frequency amplification circuit 28 are synthesized by the frequency conversion circuit 29. The output of the frequency conversion circuit 29 is the carrier of the video, and the high-frequency amplification circuit 34
, And band-limited by the VSB filter 5, and then input to the diplexer 35. On the other hand, the audio signal is input from the audio signal input terminal 37,
The system branches into two systems: a conventional FM modulation system and a new digital modulation system. The audio signal (analog) input to the FM modulation circuit 38 is subjected to FM modulation of a built-in reference frequency, converted to an audio carrier frequency input from the multiplication circuit 39 in the frequency modulation circuit 40, and passed through the high frequency amplification circuit 41. Diplexer
Enter 35. The audio signal input to the ADC 42 is converted to a digital signal by the ADC 42, and the digital signal processing circuit 43
After the digital signal processing, the digital intermediate modulation circuit 46 digitally modulates the video intermediate frequency obtained by shifting the output (video intermediate frequency) of the oscillation circuit 25 by about 90 degrees by the phase shifter 45 through the low-pass filter 44. . The output of the digital modulation circuit 46 is input to the signal synthesis circuit 33. The carrier wave synthesized by the diplexer 35 is emitted from the antenna 36 as a transmission radio wave. The spectrum of the output radio wave is as shown in FIG. 2 (f). In the embodiment, the PCM voice multiplexing according to the present invention is enabled as in FIG. If the digital modulation method is quadrature modulation that modulates with amplitudes A and -A in correspondence with digital codes 1 and 0, data of about 1 Mbit / sec can be transmitted in the band of the above-described embodiment. The orthogonal amplitude is O, A or O, -A 2
Values are also possible. Further, the transmission capacity can be increased by multi-leveling. In this case, for example, if four values are used, stereo broadcasting can be performed in 16 bits. in this case,
What is necessary is just to transmit the most significant bit relationship between the two channels of R and L during the vertical blanking period. Although the sideband components of digital modulation are described in the region of both sidebands of residual sideband amplitude modulation, transmissions that are partially out of band may be allowed if a slight deterioration of the error rate in digital transmission is allowed. It is possible. Next, another embodiment will be considered. There is no problem even if the PCM audio signal interferes with the video signal during the vertical blanking period of the video signal, and the most significant bit can be transmitted during this period, so the error rate in the video information period slightly increases Even though it has little effect on sound quality. Considering these facts, for example, it is possible to further reduce the interference to the video information by making the PCM audio signal level during the video information period smaller than the vertical blanking period. For example, if the vertical retrace period of A is set to 0.1 as in the previous example, and the video information period is set to a level smaller by about 3 dB, that is, 0.07, it becomes about 1.0024 and about -52.
The effect is dB, which is a further 6 dB improvement over the previous example. On the other hand, the SN ratio of the audio signal during the video information period is 23dB and 3dB
Although degraded, there is still a margin of 6 dB compared to 17 dB, and sufficient performance can be obtained. Another embodiment in this case is shown in FIG. In FIG. 8, reference numeral 50 denotes an attenuator. This attenuator is controlled by a control signal indicating a section for multiplexing the most significant bit generated by the digital signal processing circuit 43, and during the period other than the period for multiplexing the most significant bit relation generated from the video signal synchronization signal, 3 dB Operate to attenuate the signal. Further, for example, A = 0.2 in the vertical retrace period and A = 0.1 in the other periods, so that the level is set to be twice as different,
The vertical retrace period is quaternized, and the higher-order bit and the next two bits are transmitted during the vertical retrace period to further improve the quality. In addition, there is a method such as instantaneous companding as a bit compression technique for reducing a bit rate in a PCM audio signal. In this case, a range bit indicating a dynamic range may be transmitted as an important reference signal. This range bit can be transmitted during the vertical blanking period. For example, when instantaneously companding a 13-bit linear PCM audio signal by 9 bits, three range bits are required, and even in this range bit, a higher-order code error most affects the sound quality. Therefore, when transmitting by stereo 8-channel instantaneous companding, the PCM audio signal level in the vertical retrace period is doubled compared to the other periods, and the four most significant bits of the two left and right range bits are transmitted. You should do it. As described above, in the embodiments of the present invention, the upper bits of the PCM audio signal and the like have been described as the reference signal transmitted in a portion other than the video signal period. However, the synchronization signal and the identification signal of the digitally encoded data are described. Similarly, any signal important for reproducing a multiplexed signal such as a digitally encoded PCM audio signal such as a control signal can be received and demodulated stably. Also, the multiplexed signal to be multiplex-transmitted may be other digital data instead of the digitally encoded PCM audio signal. Further, the clock generation circuit 14 for generating the clock for digital signal processing has been described as being phase-synchronized with the video signal synchronization signal. However, it is not always necessary to synchronize the phase with the video signal synchronization. is there. In this case, after digital processing, the data rate is converted by a clock synchronized with the video signal, and the period during which the multiplexed signal is superimposed is reduced by the lack of the rate, or a reduced field (so-called leap field) is provided. Can be dealt with in a known manner. [Effects of the Invention] According to the present invention, a carrier that is amplitude-modulated by a video signal
It is multiplexed and modulated by a PCM audio signal digitally encoded into the orthogonal component of the carrier wave, a signal having different contents is multiplexed and transmitted in a period other than the video information period and the video information period, and a synchronization signal is generated in a period other than the video information period. Multiple reference signals such as control signals can be multiplexed and transmitted.Because there is little interference from video signals to multiplexed signals during periods other than the video information period, the transmitted reference signals are less susceptible to interference and reliable. Since the degree is high, the multiplexed signal is demodulated on the basis of the signal serving as the reference, which has the effect of enabling stable reception and reproduction of the multiplexed signal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a spectrum diagram of a signal obtained in the embodiment of the present invention, FIG. 3 and FIG.
FIG. 5 is a vector diagram of a signal, FIG. 5 is a configuration diagram of an example of a receiving apparatus for receiving a transmission signal of the present invention, FIG. 6 is a configuration diagram of another embodiment of the present invention, and FIG. FIG. 8 is a block diagram of still another embodiment of the present invention. 2 ... Carrier oscillator, 3,27 ... AM modulation circuit, 11,45 ... 90-degree phase shifter, 8,43 ... Digital signal processing circuit, 9 ... Memory circuit, 12,46 ... Digital modulation circuit , 4,33 Adder, 5 VSB filter, 14 Clock generator circuit, 16,38 FM modulation circuit, 32,39 Multiplier circuit, 35 Diplexer, 18,36 antenna.

Continuation of the front page (72) Inventor Akihide Okuda 292 Yoshida-cho, Totsuka-ku, Yokohama-shi Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) H04J 11/00 H04N 7 / 08

Claims (1)

(57) [Claims] A first carrier is amplitude-modulated in a vestigial sideband with a video signal, and a second carrier having a phase substantially different from that of the first carrier by + or -90 degrees within a band having both sidebands in the vestigial sideband. A multiplexed signal such as a digitized audio signal and a signal serving as a reference for receiving and reproducing the multiplexed signal such as the digitized audio signal are respectively provided so that a basic signal band exists in the video signal. The carrier suppression amplitude modulation is performed on the transmission digital coded signal that is time-division multiplexed between the video information period and the period other than the video information period, and the first carrier and the carrier suppression amplitude modulation that are subjected to the residual sideband amplitude modulation. A second carrier is synthesized, and the first carrier and the third carrier having a frequency different from that of the second carrier, which are frequency-modulated with a voice signal, are synthesized by frequency multiplexing to form a transmission signal. Transmission signal transmission method characterized in that it is produced. 2. 2. The transmission signal transmission method according to claim 1, wherein a period other than the video information period is a vertical blanking period of the video signal. 3. 3. The method according to claim 1, wherein the multiplex signal is a digitized audio signal, and the content of the digitized audio signal and the content of the audio signal for frequency-modulating the third carrier wave. Wherein the transmission signal is generated with the same content as the transmission signal. 4. Claims 1 or 2 or 3
Item, wherein the multiplexed signal is a digitized audio signal, and a transmission signal is generated in a video information period of the video signal by compressing a digital code of the digitized audio signal on a time axis. Transmission signal transmission method to be described. 5. Claims 1 or 2 or 3
The transmission signal transmission method according to claim 4 or 4, wherein a transmission signal is generated at a transmission rate of the multiplexed signal that is an integral multiple of a horizontal synchronization signal frequency of the video signal. 6. Claims 1 or 2 or 3
In the term, the term “4” or the term “5”, the synthesis of the first carrier wave subjected to the vestigial sideband amplitude modulation and the second carrier wave subjected to the carrier suppression amplitude modulation is performed by the vestigial sideband amplitude modulation. The maximum value of the amplitude of the carrier-suppressed amplitude-modulated second carrier is less than or equal to 0.1 with respect to the maximum value of the amplitude of the first carrier, and the video information period of the video signal is other than the video information period. A transmission signal transmission method, wherein the ratio of the maximum value of the amplitude of the carrier-suppressed amplitude-modulated second carrier is different between periods. 7. A first carrier generating means for generating a carrier, a video signal modulating means for modulating the output carrier of the first carrier generating means with a video signal in a residual sideband amplitude, and a multiplexed signal such as a digitized audio signal. Compression means for compressing the time axis during a certain period of the video information period of the video signal; reference signal generation means for generating a signal serving as a reference for receiving and reproducing a multiplexed signal such as the digitized audio signal; Time-division multiplexing means for temporally multiplexing the output signal of the reference signal generation means and the output signal of the compression means during a period other than the video information period of the video signal; and a phase substantially different from the carrier by + or -90 degrees Second carrier generation means for generating an orthogonal carrier, and digital for carrier-suppressing amplitude modulation of an output carrier of the second carrier generation means with an output signal of the time division multiplexing means Adjusting means; mixing means for combining the output signal of the video modulation means and the output signal of the digital modulation means; third carrier generation means having a different frequency from the first carrier wave and the second carrier wave; Frequency modulating means for frequency modulating an output carrier of the third carrier generating means with an audio signal; and signal synthesizing means for synthesizing an output signal of the mixing means and an output signal of the frequency modulating means. Characteristic transmission signal transmitting device. 8. 8. The transmission signal transmitting apparatus according to claim 7, wherein a period other than the video signal period is a vertical blanking period of the video signal. 9. 9. The audio signal according to claim 7, wherein the multiplex signal is a digitized audio signal, and the content of the digitized audio signal and the content of the audio signal for frequency-modulating the third carrier wave. A transmission signal transmitting device having the same contents. 10. 10. The control signal as claimed in claim 7, wherein the video signal is input and a reference is made so that a transmission rate of the multiplex signal is an integer multiple of a horizontal synchronizing signal frequency of the video signal. A transmission signal transmitting apparatus comprising a control timing signal generating means for generating a signal and outputting the signal to the time division multiplexing means. 11. In Claim 7, Claim 8, Claim 9, Claim 9, or Claim 10, the synthesizing ratio of the mixing means is adjusted with respect to the maximum value of the amplitude of the output signal of the video signal modulating means. The maximum value of the amplitude of the output signal is a ratio of 0.1 or less, and the ratio of the maximum value of the amplitude of the output signal of the digital modulation unit is different between the video information period of the video signal modulation unit and a period other than the video information period. A transmission signal transmitting device characterized by the above-mentioned.