JPH10145342A - Transmitter, receiver and transmitter-receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the transmitter, the receiver and the transmitter-receiver by which the effect of a shield estimated in a transmission line is reduced remarkably. SOLUTION: The transmitter is provided with an A/D converter 5 that digitizes a signal transmission signal, a delay circuit 7 that generates a plurality of kinds of transmission signals S2, S3, different from delay times from the digitized transmission signal, an up-converter 10 that sends a plurality of generated signals S2, S3, an output amplifier 11 and a transmission antenna 12. Thus, even at the occurrence of a burst error due to transmission, since the receiver side corrects the burst error simply by using a plurality of the signals whose delay time is different, the correction capability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitting device, a receiving device, and a transmitting / receiving device for performing wireless communication using an artificial satellite for relaying.

[0002]

2. Description of the Related Art As a transmission / reception system using an artificial satellite for relaying, a D-SNG (Digital-Sate) is used.
Lite News Gathering). This system transmits and receives information such as video and audio in the form of digital data. Specifically, this transmission / reception system makes it possible to transmit on-site video and audio to a studio of a broadcasting station via artificial satellites. An example of such a transmission / reception system is described in the specification of Japanese Patent Application No. 8-74593 filed by the same applicant as the present invention. In this case, the site is the transmitting side, and the studio is the receiving side.

FIGS. 4 to 7 show the configurations of a conventional transmitting apparatus, receiving apparatus and transmitting / receiving apparatus. First, the configuration of a conventional transmission device will be described with reference to FIGS. In FIG. 4, the transmitting device includes a video / audio recording device 1 for recording video / audio and converting it into a recording signal, a modulator 4 for frequency-modulating the recording signal, and transmitting the modulated recording signal to a transmission signal. It has an up-converter 10 for converting to a frequency, an output amplifier 11 for amplifying the level of a transmission signal so as to be able to transmit, and a transmission antenna 12 for transmitting a transmission signal to the air.

[0004] Here, a video / audio recording device 1 is provided with a camera 2 for photographing a reporter at the site and its background.
And a microphone 3 for collecting a reporter and on-site audio. Further, the modulator 4 includes, as shown in FIG.
An analog / digital converter that converts analog recording signals to digital
A digital circuit comprising a digital converter 5, a data compression processing circuit 6 for compressing data of the digital signal by bit rate reduction, and an error correction coding circuit 9 for adding an error correction code to the data compressed signal. Is also good.

The data compression processing circuit 6 uses a DCT (D
iscrete Cosine Transform)
It has a conversion circuit, a quantization circuit, and a variable length coding circuit. The DCT conversion circuit converts a time component signal into a frequency component signal by Fourier transform. The quantization circuit compresses information by dropping the high frequency part of the frequency component signal. The variable length coding circuit performs code compression by allocating a small number of bits to a state with a high appearance probability and allocating a large number of bits to a state with a low appearance probability. This variable length coding is called Huffman coding. The data compression processing circuit 6 is, for example, an MPEG2 (Moving Picture).
Data compression is performed by an encoding method determined by e Engineering Group).

[0006] The configuration of a conventional receiving apparatus will be described with reference to FIGS. 6 and 7. 6, the receiving apparatus includes a receiving antenna 20 for receiving a transmission signal, a low-noise amplifier 21 for amplifying the received signal with low noise, and a down-converter 22 for converting the amplified received signal to a signal processing frequency. , An FM demodulator 23 for demodulating the frequency of the converted received signal, and a monitor device 3 for reproducing the demodulated received signal
And 1.

Here, the FM demodulator 23 includes an error correction decoding circuit 24 for performing error correction processing by transmission, a compressed data demodulation circuit 29 for expanding compressed data by inverse bit rate reduction, and a digital reception circuit. Digital / analog converter 30 for converting a signal to analog
And a demodulator constituted by a digital circuit having the following.
The compressed data demodulation circuit 29 has an IDCT (Inverse
DiscreteCosine Transfer
m) It has a conversion circuit, an inverse quantization circuit, and a variable length decoding circuit. The IDCT circuit converts a signal of a frequency component into a time component. The inverse quantization circuit reproduces a high-frequency component dropped when quantized. The variable length decoding circuit is
The signal compressed and encoded by the Huffman encoding is decoded and expanded. Thus, the compressed data demodulation circuit 2
Reference numeral 9 performs a process of decompressing data compressed by the data compression processing circuit 6 on the transmission side. Also, the monitor device 31
Has a speaker 23 for reproducing audio and a monitor 23 for reproducing video.

[0008] The operation of the transmitting device and the receiving device thus configured will be described. The outline of the operation is that the video and audio at the site are transmitted from the transmitting device for broadcasting and received by the receiving device in the studio of the broadcasting station. First,
On the transmitting device side, a video signal of the site photographed by the camera 2 is digitized in the modulator 4 and data compression-coded between frames or within a frame, and an error correction code is added. At the same time, the on-site audio signal collected by the microphone 3 is time-division multiplexed with the video signal in the modulator 4. The multiplexed signal is supplied to the upconverter 10. In the up-converter 10, it is converted into a transmittable frequency band. The converted signal is supplied to the output amplifier 11. In the output amplifier 11, the signal is amplified to a transmittable signal level and supplied to the transmission antenna 12 at a high output. Then, it is output as a radio wave by the transmission antenna 12. This radio wave is received by a receiving antenna on the receiving device side, for example, by relaying an artificial satellite.

In the receiving device, a received signal received by the receiving antenna 20 is supplied to a low noise amplifier 21. In the low-noise amplifier 21, the received signal is amplified to a level with low noise and capable of performing signal processing in a subsequent stage. The amplified reception signal is supplied to the down converter 22. In the down-converter 22, the received signal is converted into a frequency band in which the subsequent signal processing is possible. The converted received signal is supplied to the demodulator 23. In the demodulator 23, the received signal is subjected to error correction processing, data is expanded between frames or within a frame, converted into an analog signal, and reproduced by the monitor device 31.

[0010]

In such a conventional transmitting apparatus and receiving apparatus, as described above, the first method of digitizing a transmission wave and adding an error correction code or analog modulation of a carrier wave is used. Data loss due to transmission is corrected by the second method.
For example, when passing under a grade-crossing road or pedestrian bridge in a marathon relay, a signal concentration loss of 0.1 second to several seconds (hereinafter referred to as a burst error) occurs. In the first method described above, although it depends on the method of the error correction code, the circuit scale is increased in order to perform sufficient correction, and in the second method, an obstacle on the transmission line is directly disturbed in the image. There was an inconvenience of becoming.

The present invention has been made in view of the above points, and has as its object to provide a transmission device, a reception device, and a transmission / reception device capable of greatly reducing the influence of a shield assumed on a transmission line. And

[0012]

A transmitting apparatus according to the present invention comprises:
Conversion means for digitizing a single transmission signal; transmission signal generation means for generating a plurality of types of transmission signals having different delay times from the transmission signal digitized by the conversion means; and transmission signal generation means. Transmitting means for transmitting the plurality of generated transmission signals.

[0013] Also, the receiving apparatus of the present invention includes a receiving means for receiving a digital signal transmitted from a transmitting side, a data missing detecting means for detecting a data missing part from the received signal received by the receiving means, A reception signal generation unit that generates a plurality of types of reception signals having different delay times from the reception signal, and a plurality of types of reception signals from the reception signal generation unit according to a data loss detection result in the data loss detection unit. Switching means for switching.

According to another aspect of the present invention, there is provided a transmission / reception apparatus for generating a plurality of types of transmission signals having different delay times from a single transmission signal, and a plurality of transmission signals generated by the transmission signal generation unit. Transmitting means for transmitting a digital signal transmitted from the transmitting side, and data missing detecting means for detecting a data missing part from the received signal received by the receiving means. Receiving signal generation means for generating a plurality of types of reception signals having different delay times from the reception signal; and a plurality of types of reception signals from the signal generation means according to a data loss detection result in the data loss detection means. And a receiving unit having a switching unit for switching between the two.

According to the transmitting device, the receiving device and the transmitting / receiving device of the present invention, the following operations are performed. First, on the transmitting device side, the image signal of the photographed site is digitized by the conversion means, and data compression encoding is performed between or within frames, and an error correction code is added.

That is, once a signal is digitized, the data amount of the transmission signal is greatly reduced by data compression by bit rate reduction. Further, the transmission signal is separated into two systems by the transmission signal generation means. One signal is output as it is, and the other signal is supplied to the delay circuit. The transmission signal generation means generates two transmission signals from one signal, a signal without delay and a signal with delay. These two transmission signals are multiplexed. The multiplexed signal is subjected to an error correction coding process for correcting a relatively short-time error occurring in the transmission path.

At the same time, the on-site audio signal collected is time-division multiplexed together with the video signal. The multiplexed signal is
It is converted to a transmittable frequency band. The converted signal is amplified to a signal level that can be transmitted, and is output as radio waves at a high output by the transmission means. This radio wave is received by a receiving antenna on the receiving device side, for example, by relaying an artificial satellite.

On the other hand, in the receiving apparatus, the received signal received is amplified by the receiving means to a level that allows low-noise signal processing at the subsequent stage, and is converted into a frequency band at which signal processing at the subsequent stage is possible. The converted received signal is subjected to error correction processing, data is expanded between frames or within a frame, and converted into an analog signal.

That is, a data error for a relatively short time is corrected, and the received signal subjected to the error correction is supplied to the data loss detecting means. The data loss detecting means detects a signal loss for a relatively long time based on the result of the error correction. Further, the received signal subjected to the error correction processing is supplied to the received signal generating means. In the reception signal generation means, a signal with a delay delayed on the transmission side;
Two types of reception signals, that is, signals without delay that are not delayed on the transmission side, are generated. The signal with delay delayed on the transmission side is supplied as it is to one terminal of the switching means, and the signal without delay which is not delayed on the transmission side is delayed by the same delay time as the delay time on the transmission side. It is supplied to the terminal. Further, a control signal output from the data loss detecting means when a relatively long signal loss is detected is supplied to the control terminal of the switching means. Here, the control signal is such that when one of the two signals has a missing signal, the output is switched to the other receiving signal, and conversely, when the other receiving signal has a missing signal. The output terminal of the switching means is controlled so that the output is switched to one of the received signals.

In this manner, even if there is a signal loss within the delay time from the output terminal of the switching means, one of the two systems of the received signal is always reproduced on the receiving side, so that no signal is lost. The received signal without the mark is reproduced.

That is, when a dropout, which is a continuous signal loss, occurs in the transmission path, for example, a dropout occurs in the non-delay signal of one system, and the same occurs in the delay signal of the other system. Dropout occurs.

In the reception signal generating means of the receiving apparatus, the time during which a dropout occurs in the non-delay signal of one system and the time during which the dropout occurs in the delay signal of the other system are different from each other. Then, two systems of received signals are generated.

Therefore, the dropout of the signal with delay is detected by the data loss detecting means, and the output of the switching means is switched to the signal without delay only during the dropout of the signal with delay, and the dropout of the signal without delay is detected. By switching the output of the switching unit to the signal with delay only during the period, a complete output signal without dropout can be output from the switching unit.

As described above, by inserting the normal received signal into the missing part of one of the received signals according to the signal missing detection signal from the data missing detecting means, a complementary received signal can be obtained by complementing each other. Can be.

[0025]

Embodiments of the present invention will be described below. As described above, for example, when transmitting an image captured by an on-board camera in a car race or a marathon race by microwave, for example, only 0.01% of the time passing under an overpass or an arched pedestrian bridge is required. The signal may be interrupted for 0.1 second. In this case, a failure such as noise or an invisible image occurs on the reception screen. The time of occurrence of these noises is not constant depending on the environment of the relay, the type of game, the speed, etc., and it is extremely difficult to correct the noise with a specific error correction circuit. Digitize the transmission signal, generate two types of transmission signals with different delay times,
By simultaneously transmitting these two types of transmission signals, the effect of a shield assumed on the transmission path is greatly reduced.

FIGS. 1 and 2 show the configurations of the transmitting apparatus and the receiving apparatus according to the present embodiment. First, the configuration of the transmitting apparatus according to the present embodiment will be described using FIG. In FIGS. 1 and 2, components corresponding to those shown in FIGS. 4 to 7 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, the transmitting device is a video / audio recording device 1 for recording video / audio and converting it into a recorded signal.
A modulator 4 for frequency-modulating the recording signal, an up-converter 10 for converting the modulated recording signal to the transmission frequency of the transmission signal, an output amplifier 11 for amplifying the level of the transmission signal so that it can be transmitted, and A transmitting antenna 12 for transmitting the signal to the air.

Here, the video / audio recording device 1 includes a reporter at the site and a camera 2 for photographing the background thereof.
And a microphone 3 for collecting a reporter and on-site audio. The modulator 4 includes an analog / digital converter 5 for converting an analog recording signal into a digital signal, a data compression processing circuit 6 for compressing a digital signal by bit rate reduction, as shown by a dotted line in FIG. A delay circuit 7 for delaying the data-compressed signal, a signal multiplexing circuit 8 for multiplexing the data-compressed signal and the delayed signal, and an error-correction coding circuit 9 for adding an error correction code to the data-compressed signal And

The data compression processing circuit 6 has a DCT (D
iscrete Cosine Transform)
It has a conversion circuit, a quantization circuit, and a variable length coding circuit. The DCT conversion circuit converts a time component signal into a frequency component signal by Fourier transform. The quantization circuit compresses information by dropping the high frequency part of the frequency component signal. The variable length coding circuit performs code compression by allocating a small number of bits to a state with a high appearance probability and allocating a large number of bits to a state with a low appearance probability. This variable length coding is called Huffman coding. The data compression processing circuit 6 is, for example, an MPEG2 (Moving Picture).
Data compression is performed according to an encoding method determined by e Engineering Group. Further, the modulator 4 may perform a compression process such as subsampling on the audio signal.

The configuration of the receiving apparatus according to the present embodiment will be described with reference to FIG. In FIG. 2, this receiving apparatus
A receiving antenna 20 for receiving a transmission signal, a low-noise amplifier 21 for amplifying the reception signal with low noise, and a down-converter 22 for converting the amplified reception signal to a frequency for signal processing
And a demodulator 23 for demodulating the converted received signal, and a monitor device 31 for reproducing the demodulated received signal.

Here, the demodulator 23 separates the signal into an error-correction decoding circuit 24 for performing error-correction processing by transmission, and a delayed signal and a non-delayed signal multiplexed on the transmission side. A signal separation circuit 25, a delay circuit 26 that outputs a signal delayed on the transmission side as it is, and delays a signal that is not delayed on the transmission side, and a signal that is output based on the result of the error correction processing in the error correction decoding circuit 24. A signal loss detection circuit 27 for detecting a relatively long loss, a switching circuit 28 for switching between a signal delayed on the transmission side and a signal delayed by the delay circuit 26 based on the detection result of the signal loss detection circuit 27, Compressed data demodulation circuit 29 for decompressing the received data by inverse bit rate reduction, and a digital / analog converter for converting a digital received signal to analog. And a converter 30.

The compressed data demodulation circuit 29 has an IDCT (I
nverse DiscreteCosine Tra
(nsform) conversion circuit, an inverse quantization circuit, and a variable length decoding circuit. The IDCT circuit converts a signal of a frequency component into a time component. The inverse quantization circuit reproduces a high-frequency component dropped when quantized. The variable length decoding circuit decodes and decompresses the signal that has been compression-encoded by Huffman encoding. In this way, the compressed data demodulation circuit 29 performs a process of decompressing the data compressed by the data compression processing circuit 6 on the transmission side. In addition, the monitor device 31 includes a speaker 23 that reproduces audio and a monitor 23 that reproduces video.

Here, the transmitting apparatus of the present embodiment is different from the conventional transmitting apparatus in that a delay circuit 7 and a signal multiplexing circuit 8 are added to generate a signal without delay and a signal with delay. Two transmission signals are generated, multiplexed, and transmitted at the same time.

The receiving apparatus according to the present embodiment is different from the conventional receiving apparatus in that the signal separating circuit 25 and the delay circuit 26
And a signal loss detection circuit 27 and a switching circuit 28, and a signal with a delay is output as it is on the transmission side,
The transmission side delays a signal without delay to generate two systems of reception signals, and when a signal loss is detected, the two systems of reception signals are appropriately switched and reproduced.

The operation of the transmitting device and the receiving device configured as described above will be described. As described above, when an obstacle crosses between antennas in an existing transmission path, a transmission signal is lost, and noise may be generated in a restored signal or a signal may not be reproduced.

On the other hand, the merits of digitizing the transmission path with the progress of digital technology include a wide variety of effects such as uniform signal quality by error correction technology, reduction of transmission power, downsizing of antennas, downsizing and weight reduction of equipment. .
On the other hand, advances in data compression technology have promoted this by enabling subdivision of transmission paths, that is, narrowing of bandwidth. The transmitting apparatus and the receiving apparatus according to the present embodiment are applied to improve the reliability of signal quality, which is an effect of the digitization.

The outline of the operation is as follows. By generating two transmission signals, that is, a signal without delay and a signal with delay from the video and audio at the site from the transmitting device, multiplexing these and transmitting them simultaneously, It is transmitted for broadcasting and received by the receiving device in the studio of the broadcasting station. The transmitting side outputs the signal with delay as it is, and the transmitting side delays the signal without delay. When a signal loss is detected and generated, the two systems of received signals are appropriately switched and reproduced, whereby the signal missing parts are complemented by the two systems of received signals to reproduce a received signal without any loss. .

First, on the transmitting device side, a video signal of the site photographed by the camera 2 is transmitted to the modulator 4 by the modulator 4.
The data is digitized, and data compression encoding is performed between frames or within a frame, and an error correction code is added.

That is, the signal once digitized by the analog / digital converter 5 is supplied to the data compression processing circuit 6. The data amount of the transmission signal can be significantly reduced by the data compression by the bit rate reduction in the data compression processing circuit 6. The output signal of the data compression processing circuit 6 is separated into two systems. One signal is supplied to the signal multiplexing circuit 8 as it is, and the other signal is supplied to the delay circuit 7. As a result, two signals of a signal without delay and a signal with delay are generated from one signal. These two signals are supplied to a signal multiplexing circuit 8.
The signals are multiplexed in the signal multiplexing circuit 8. The multiplexed signal is supplied to an error correction processing circuit 9. The error correction processing circuit 9 performs an error correction encoding process for correcting a relatively short-time error occurring in the transmission path.

Here, in the data compression encoding process, inter-frame encoding and intra-frame encoding are selectively performed. As is well known, the inter-frame encoding is a process of encoding a difference between a current video signal and a video signal one frame past. Intra-frame encoding is a process of encoding the current video signal as it is. And encoding is
For the frame difference signal or the current video signal,
DCT transformation, wavelet transformation, quantization, and variable-length encoding processing such as run-length and Fuffman.

As for voice, simple voice processing,
For example, when processing such as pre-emphasis or the amount of information needs to be reduced, a simple sample rate conversion processing is performed. Here, as the conversion of the sample rate, for example, an audio signal sampled at 48 KHz is
The conversion into an audio signal sampled at 4 KHz or the bit length of digital audio data obtained by sampling may be shortened so that lower bits may be simply thinned out.

At the same time, the on-site audio signal collected by the microphone 3 is time-division multiplexed in the modulator 4 together with the video signal. The multiplexed signal is supplied to the upconverter 10. In the up-converter 10, it is converted into a transmittable frequency band. The converted signal is supplied to the output amplifier 11. In the output amplifier 11,
The signal is amplified to a transmittable signal level and supplied to the transmitting antenna 12 at high output. Then, the transmitting antenna 12
Is output as radio waves. This radio wave is received by a receiving antenna on the receiving device side, for example, by relaying an artificial satellite.

On the other hand, in the receiving apparatus, the receiving antenna 2
0 is supplied to the low noise amplifier 21. In the low-noise amplifier 21, the received signal is amplified to a level with low noise and capable of performing signal processing in a subsequent stage. The amplified reception signal is supplied to the down converter 22. In the down-converter 22, the received signal is converted into a frequency band in which the subsequent signal processing can be performed. The converted received signal is supplied to the demodulator 23. In the demodulator 23, the received signal is subjected to error correction processing, data is expanded between frames or within a frame, and is converted into an analog signal.

That is, the error correction decoding circuit 24 corrects a relatively short-time data error, and the error-corrected received signal is converted to a signal loss detection circuit 27.
Supplied to The signal loss detection circuit 27 detects a signal loss for a relatively long time based on the result of the error correction. The received signal subjected to the error correction processing is supplied to the signal separation circuit 25. In the signal separating circuit 25, two signals of a signal with a delay delayed on the transmission side and a signal without delay not delayed on the transmission side are generated. The signal with the delay delayed on the transmission side is supplied to one terminal of the switching circuit 28 as it is, and the signal without delay which is not delayed on the transmission side is supplied to the delay circuit 26 having the same delay time as the delay circuit 7 on the transmission side. Is done. The signal delayed by the delay time is supplied to the other terminal of the switching circuit 28. The control terminal of the switching circuit 28 is supplied with a control signal output from the signal loss detection circuit 27 when a relatively long signal loss is detected.

Here, the control signal is such that the output is switched to the other signal when one of the two signals is missing, and conversely when the other signal is missing. The output terminal of the switching circuit 28 is controlled so that the output is switched to one signal.

In this way, even if there is a signal loss within the delay time of the delay circuit from the output terminal of the switching circuit 28, one of the two signals is always reproduced on the receiving side. A signal without any loss is reproduced.

Here, the switching circuit 28 performs switching using a switcher, mixing of signals themselves using a video special effect device, and the like. For example, the video of one signal and the video of the other signal are synthesized as one screen, and the audio is also synthesized as one audio.

The signal output from the switching circuit 28 is supplied to a compressed data decoding processing circuit 29. In the compressed data decoding processing circuit 29, the data compressed on the transmission side is expanded in reverse.

That is, in the compressed data decoding processing circuit 29, the reverse processing of the data compression processing circuit 6 shown in FIG. 1 is performed. That is, the coded video signal is decoded (decoding of variable-length coded data), and then the video signal is subjected to inverse quantization and IDCT conversion. As a result, an inter-frame difference signal or a frame video signal is obtained. And then,
The original frame video signal is restored using the inter-frame difference signal, the already decoded video signal, and the motion vector data supplied corresponding to the inter-frame difference signal.

For example, assuming that a B picture is obtained by encoding a difference from an I picture one frame before, the following is performed. That is, at the time of encoding,
The block of the I picture whose level arrangement is closest to the block of interest of the B picture is detected, and x from the block of interest of the B picture to the block of the I picture is detected.
And movement amount data in the y direction, that is, motion vector data. Then, the difference between the block of interest of the B picture and the block of the I picture is encoded, and the encoded data is multiplexed with the motion vector data and transmitted.

Therefore, in the decoding, the difference data is added to the block of the decoded I picture, and the block of interest of the B picture is restored. The motion vector data is used to extract the target block of the restored I picture to which the difference data is to be added.

The expanded signal is supplied to a digital / analog converter 30. The digital signal expanded in the digital / analog converter 30 is converted into an analog signal. The converted analog signal is supplied to the monitor device 31. In the monitor device 31, audio is reproduced by the speaker 32, and video is reproduced by the monitor 33.

FIG. 3 is a time chart illustrating the operation of the transmitting apparatus and the receiving apparatus according to the present embodiment using signals. As shown in FIG. 3, in the transmission device, the signal S1
Is an input signal supplied from the video / audio recording device 1 to the analog / digital converter 5. This signal indicates a video signal and an audio signal. The input signal S1 is
“6” to “21” are continuously supplied. These “6” to “21” may correspond to, for example, a frame of a video signal.

The signal S2 is a signal output from the data compression processing circuit 6. That is, the input signal S1 is subjected to data compression processing, and the data compression signal S2 is output. As the data compression signal S2, for example, data for one frame is compressed with respect to the input signal S1, and "5" to "20" are continuously supplied. The signal S3 is a signal output from the delay circuit 7. That is, the compressed data signal S2 is subjected to delay processing, and the delayed signal S3 is output. The delay signal S3 is
“1” to “17” are continuously supplied. Here, the delay time in the delay circuit 7 corresponds to, for example, four frames.

The signal S4 is a signal output from the signal multiplexing circuit 8. That is, the data compression signal S2 and the delay signal S3 are multiplexed and output so that the multiplexed signal S4 is transmitted simultaneously. Then, when the dropout 34 which is a continuous signal loss occurs in the transmission path, for example, in the multiplexed signal S4, “11” to “13” of the signals “5” to “20” of the system of the data compression signal S2. "
Are continuously lost, and “8” to “17” of the signals “1” to “17” of the system of the delay signal S3 in the multiplexed signal S4
"10" is continuously missing.

In the receiving apparatus, the error correction decoding circuit 24
Is a multiplexed signal S4 having a dropout 34. The signal S6 is a transmission-side delay signal of the system of the delay signal S3 with a delay on the transmission side, which is separated and output from the signal separation circuit 25. The signal S5 is a transmission-side non-delay signal obtained by delaying a signal of the system of the data compression signal S2 having no delay at the transmission side separated and output from the signal separation circuit 25 by the delay circuit 26 having the same delay time as the transmission side. .

The transmission-side delay signal S6 is the multiplexed signal S
4, the signals “1” to “17” of the system of the delay signal S3
Among them, “8” to “10” are continuously missing due to the dropout 36. On the other hand, the transmission side non-delay signal S5 is the data compression signal S5 in the multiplexed signal S4.
Of the signals “1” to “17” delayed by four frames of the signals “5” to “20” of the second system, “11” to “13” are continuously lost due to the dropout 35.

Accordingly, the signal loss detection circuit 27 detects the dropout 36 of the transmission-side delay signal S6, and outputs the output of the switching circuit 28 only during the period of the transmission-side delay signal S6. By switching to the signal S5 and switching the output of the switching circuit 28 to the transmission-side delay signal S6 only during the period of the dropout 36 of the transmission-side non-delay signal S5, the complete output signal S7 without dropout is converted to the switching circuit 28.
Can be output from

As described above, by inserting the other normal signal into the missing portion of one signal based on the signal missing detection signal from the signal missing detecting circuit 27, it is possible to obtain a complete signal by complementing each other. .

Here, it goes without saying that if the delay time between the data compression signal S2 and the delay signal S3 is adjusted, the loss tolerance can be set freely.

The transmitting apparatus according to the present embodiment has an analog / digital converter 5 as a converting means for digitizing a single transmitting signal, and a delay time different from the transmitting signal digitized by the converting means. A delay circuit 7 as transmission signal generation means for generating a plurality of types of transmission signals S2 and S3; an up-converter 10 and an output amplifier 11 as transmission means for transmitting a plurality of signals generated by the transmission signal generation means; With the antenna 12, even if a burst error 34 due to transmission occurs,
Since the burst error 34 can be easily corrected on the receiving side by using a plurality of signals having different delay times, the correction capability can be improved.

Further, in the transmitting apparatus of the present embodiment, the signal multiplexing means as the signal multiplexing means for multiplexing the plurality of transmission signals S2 and S3 generated by the delay circuit 7 as the transmission signal generating means described above. Since the circuit 8 is provided, a plurality of transmission signals S2 and S3 having different delay times are multiplexed and transmitted at the same time.
Occurs, the signal multiplexed on the receiving side is separated,
Since the burst error 34 can be easily corrected by using a plurality of signals having different delay times, the correction capability can be improved.

Further, in the transmitting apparatus of the present embodiment, the data compression processing circuit as the data compression means for compressing the transmitted signal digitized by the analog / digital converter 5 as the conversion means is provided. 6, the burst error 34 due to transmission can be obtained by appropriately changing the degree of data compression and the degree of delay time.
Signal loss tolerance can be freely changed according to the maximum amount of time during which the burst error 34 is occurring, and the receiving side can easily burst using a plurality of signals with different delay times. Since the error 34 can be corrected, the correction capability can be improved.

The receiving apparatus according to the present embodiment has a receiving antenna 20, a low-noise amplifier 21, a down-converter 22 as receiving means for receiving a digital signal transmitted from the transmitting side, and a signal received by the receiving means. A signal loss detection circuit 27 as data loss detection means for detecting a data loss portion from the reception signal, and a delay as reception signal generation means for generating a plurality of types of reception signals S5 and S6 having different delay times from the reception signal. A circuit 26 and a plurality of types of reception signals S from the reception signal generation means in accordance with the data loss detection result in the data loss detection means.
5, a switching circuit 28 as switching means for switching between S6 and S6.
Even if 4 occurs, the burst error 34 can be easily corrected by switching to a signal having no data loss among a plurality of signals having different delay times on the receiving side, so that the correction capability can be improved.

In the receiving apparatus according to the present embodiment, in the above description, the received signal is a plurality of types of signals having different delay times, and the delay circuit 26 as the signal generating means is provided.
Delays the signal without delay by the same delay time as the signal with delay to S5, and outputs the signal with delay as it is to S6. Therefore, even if a burst error 34 due to transmission occurs, Since the transmission side cancels the delay time added to the signal, the reception side can easily switch to a signal having no data loss among a plurality of signals having different delay times and correct the burst error 34 easily.
The correction ability can be improved.

In the receiving apparatus according to the present embodiment, the received signal is a data-compressed signal as described above, and the signal switched by the switching circuit 28 as the switching means is used as data expanding means for expanding data. Is provided, the data rate at the time of error correction can be changed even if a burst error 34 due to transmission occurs, and data loss among a plurality of signals having different delay times on the receiving side. Since it is possible to easily correct the burst error 34 by switching to a signal having no signal, the correction capability can be improved and the total bit rate of transmission can be saved.

The transmitting / receiving apparatus according to the present embodiment comprises an analog / digital converter 5 as a converting means for digitizing a single transmission signal, and a delay time from the transmission signal digitized by the converting means. A delay circuit 7 as transmission signal generation means for generating a plurality of different types of transmission signals S2 and S3, and an up-converter 10 as transmission means for transmitting the plurality of transmission signals S2 and S3 generated by the transmission signal generation means. , An output amplifier 11, a transmitting antenna 12, a receiving antenna 20, a low-noise amplifier 21, and a down-converter 22 as receiving means for receiving a digital signal transmitted from the transmitting side. A signal loss detection circuit as data loss detection means for detecting a data loss portion from the received signal. 27, a delay circuit 26 as reception signal generation means for generating a plurality of types of reception signals S5 and S6 having different delay times from the reception signal, and the signal loss detection means in accordance with the data loss detection result in the data loss detection means. And a switching circuit as switching means for switching the plurality of types of reception signals S5 and S6 from the generating means. Therefore, even if a burst error occurs due to transmission, the receiving side has a delay time. Since the burst error can be easily corrected using a plurality of different signals, the correction capability can be improved.

[0068]

According to the transmission apparatus of the present invention, conversion means for digitizing a single transmission signal and a plurality of types of transmission signals having different delay times are generated from the transmission signal digitized by the conversion means. Since there are provided a transmission signal generation means and a transmission means for transmitting a plurality of transmission signals generated by the transmission signal generation means, even if a burst error due to transmission occurs, a plurality of signals having different delay times on the receiving side. Since the burst error can be easily corrected by using the signal of (1), there is an effect that the correction capability can be improved.

In the transmission apparatus of the present invention, the signal multiplexing means for multiplexing the plurality of transmission signals generated by the transmission signal generation means is provided, so that a plurality of signals having different delay times are provided. Since multiplexing is performed and transmission is performed simultaneously, even if a burst error occurs due to transmission, the multiplexed signal is separated on the receiving side, and the burst error can be easily corrected using a plurality of signals having different delay times. Therefore, there is an effect that the correction ability can be improved.

Further, in the transmission apparatus of the present invention, the data compression means for compressing the transmitted signal digitized by the conversion means is provided, so that the degree of data compression and the degree of delay time can be appropriately adjusted. By changing this, even if a burst error occurs due to transmission, it is possible to freely change the signal drop tolerance according to the maximum amount of time during which the burst error occurs. Since the burst error can be easily corrected using the signal, the effect of improving the correction capability can be obtained.

Also, the receiving apparatus of the present invention comprises: a receiving means for receiving a digital signal transmitted from a transmitting side; a data missing detecting means for detecting a data missing portion from the received signal received by the receiving means; A reception signal generation unit that generates a plurality of types of reception signals having different delay times from the reception signal, and a plurality of types of reception signals from the reception signal generation unit according to a data loss detection result in the data loss detection unit. Switching means, so that even if a burst error due to transmission occurs,
Since the burst error can be easily corrected by switching to a signal having no data loss among a plurality of signals having different delay times on the receiving side, it is possible to improve the correction capability.

In the above-mentioned receiving apparatus, the reception signal may be a plurality of types of signals having different delay times, and the reception signal generating means may convert the signal without delay into the same as the signal with delay. The signal is delayed by the delay time, and the signal with delay is output as it is. Even if a burst error occurs due to transmission, the delay time added to the signal is canceled on the transmission side, so the delay time on the reception side is reduced. Since it is possible to easily correct the burst error by switching to a signal having no data loss among a plurality of different signals, it is possible to improve the correction capability.

Further, in the receiving apparatus of the present invention, in the above, the received signal is a data-compressed signal, and the data expanded means for expanding the signal switched by the switching means is provided. Even if an error occurs, the data rate at the time of error correction can be changed, and the burst error can be easily corrected by switching to a signal without data loss among multiple signals with different delay times on the receiving side. Therefore, there is an effect that the correction capability can be improved and the total bit rate of transmission can be saved.

Further, the transmitting and receiving apparatus of the present invention generates conversion means for digitizing a single transmission signal and a plurality of types of transmission signals having different delay times from the transmission signal digitized by the conversion means. A transmission side having transmission signal generation means; transmission means for transmitting a plurality of transmission signals generated by the transmission signal generation means; reception means for receiving a digital signal transmitted from the transmission side; A data loss detecting means for detecting a data loss portion from the received signal received by the means; a reception signal generating means for generating a plurality of types of reception signals having different delay times from the reception signal; Switching means for switching a plurality of types of reception signals from the reception signal generation means in accordance with the data loss detection result. , So that even if a burst error due to transmission occurs, the receiving side can easily correct the burst error using a plurality of signals with different delay times, thereby improving the correction capability. This has the effect that it can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a transmission device according to the present embodiment.

FIG. 2 is a block diagram illustrating a configuration of a receiving device according to the present embodiment.

FIG. 3 is a timing chart showing the operation of the present embodiment.

FIG. 4 is a block diagram illustrating a configuration of a conventional transmission device.

FIG. 5 is a block diagram showing a configuration of a conventional modulator.

FIG. 6 is a block diagram illustrating a configuration of a conventional receiving apparatus.

FIG. 7 is a block diagram showing a configuration of a conventional FM demodulator.

[Explanation of symbols]

1 video / audio recording device, 2 cameras, 3 microphones, 4
Modulator, 5 analog / digital converter, 6 data compression processing circuit, 7 delay circuit, 8 signal multiplexing circuit, 9
Error correction coding circuit, 10 up converter, 11
Output amplifier, 12 transmitting antenna, 20 receiving antenna, 21 low noise amplifier, 22 down converter, 2
3 demodulator, 24 error correction decoding circuit, 25 signal separation circuit, 26 delay circuit, 27 signal loss detection circuit, 2
8 switching circuit, 29 compressed data decoding circuit, 30
Digital / analog converter, 31 monitor equipment, 32
Speakers, 33 monitors, 34, 35, 36 dropouts

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 7/20 H04N 7/20

Claims (7)

[Claims] 1. A conversion means for digitizing a single transmission signal, transmission signal generation means for generating a plurality of types of transmission signals having different delay times from the transmission signal digitized by the conversion means, A transmission device, comprising: transmission means for transmitting a plurality of transmission signals generated by the transmission signal generation means. 2. The transmitting apparatus according to claim 1, further comprising signal multiplexing means for multiplexing a plurality of transmission signals generated by said transmission signal generating means. 3. The transmission device according to claim 1, further comprising a data compression unit for compressing the transmitted signal digitized by the conversion unit. 4. A receiving means for receiving a digital signal transmitted from a transmitting side, a data missing detecting means for detecting a data missing part from the received signal received by the receiving means, and a delay time from the received signal. A reception signal generation unit that generates a plurality of different types of reception signals; and a switching unit that switches the plurality of types of reception signals from the reception signal generation unit in accordance with a data loss detection result of the data loss detection unit. A receiving device. 5. The receiving apparatus according to claim 4, wherein said received signal is a plurality of types of received signals having different delay times, and said received signal generating means converts a signal without delay into a signal with delay. A receiving apparatus characterized in that the signal is delayed by the same delay time as that described above, and a signal with a delay is output as it is. 6. The receiving apparatus according to claim 4, wherein said received signal is a data-compressed signal, and data expansion means for expanding data of the signal switched by said switching means is provided. Receiving device. 7. Conversion means for digitizing a single transmission signal, transmission signal generation means for generating a plurality of types of transmission signals having different delay times from the transmission signal digitized by the conversion means, A transmitting unit that transmits a plurality of transmission signals generated by the transmission signal generating unit; a receiving unit that receives a digital signal transmitted from the transmitting side; and the receiving that is received by the receiving unit A data loss detecting unit that detects a data loss portion from a signal; a reception signal generation unit that generates a plurality of types of reception signals having different delay times from the reception signal; A switching unit for switching between a plurality of types of reception signals from the reception signal generation unit; Place.