KR100244530B1 - Radio transmission and receiver apparatus of digital image - Google Patents

Abstract

The present invention relates to a wireless transmission of video and audio signals and a reception device for transmitting a signal, and wirelessly transmits a situation occurring in a small area such as a race track or a banquet hall by processing digital video and audio signals of MPEG-II method. In addition, through the reception process of the radio signal through the receiving system located in the limited region of the transmitted frequency to provide a good service.

The present invention provides a high-definition video and audio service by digitally transmitting to a monitor system located in a limited area by using a frequency band for local transmission, such as a race or a golf course, an evening concert, etc. In addition, the transmission system is mounted on a vehicle to provide reliability in use by providing a mobile relay service.

Description

Wireless transmission device for digital video and receiving device for video signal

1 is a block diagram of a conventional analog image and audio signal transmission apparatus.

2 is a graph showing the channel band of the NTSC television reception frequency.

3 is a block diagram showing a wireless transmission apparatus of a digital image according to the present invention.

4 is a graph showing a channel structure of a frequency band in the present invention shown in FIG.

5 is a block diagram showing an apparatus for receiving a digital image according to the present invention.

* Explanation of symbols for main parts of the drawings

1: FM modulator 2: AM modulator

3: carrier synthesizer 4: amplifier

11 interface unit 12 video encoder

13: audio encoder 14: multiplexer

15: FEC processing unit 16: QPSK modulator

17 mixer 18 amplifier

21: Tuner 22: QPSK Demodulator

23: FEC demodulator 24: microprocessor

25 demultiplexer 26 video decoder

27: Audio Decoder 28: NTSC Video Converter

29: analog signal processor 30: memory unit

The present invention relates to a wireless transmission of video and audio signals and a receiving device for transmitting a signal. In particular, a situation occurring in a small area such as a race track or a banquet hall may be wirelessly processed through MPEG-II digital video and audio signal processing. The present invention relates to a wireless transmission device for digital video and a reception device for digital video, which provide a high quality video service through a reception process of a wireless signal through a reception system located in a limited region of a frequency to be transmitted.

In the conventional apparatus for transmitting analog video and audio signals for local broadcasting, as shown in FIG. 1 of the accompanying drawings, frequency-modulated OID signals of left and right for transmission are loaded on a subcarrier. An FM (Frequency Modulation) modulator 1, an AM (Amplitude Modulation) modulator 2 for amplifying and modulating a video signal of each frame for transmission and a modulated audio signal carried on a subcarrier, and each signal being amplified and applied A carrier synthesizer 3 for mixing (1-N) and an amplifier 4 for amplifying a signal applied from the carrier synthesizer 3 to a predetermined level and transmitting it wirelessly through an antenna.

Referring to FIG. 1, a transmission operation of a video and audio signal in a conventional analog video and audio signal transmission device is performed as described above.

When the left and right audio signals for broadcasting in a limited area are applied to the FM modulator 1, the FM modulator 1 is 4.51 MHz away from the image carrier as shown in FIG. After synthesizing the audio signal for transmission in the FM audio subcarrier band, and then modulating the frequency by shifting the phase of the audio signal of the light R by π / 2 so that multiple broadcasting can be supported, the AM modulator 2 side To apply.

In this case, the AM modulator 2 synthesizes a video signal for transmission applied from the image input unit to the image carrier and performs amplification modulation. Therefore, the left and right audio signals synthesized to the FM audio subcarrier are used as the AM modulator 2. Amplified and modulated together with the video baseband signal is applied to the carrier synthesizer 3 side, and the broadcast frequency band of the channel is determined by the image carrier and amplified modulated and applied to the carrier synthesizer 3 side. The channel and the channel are formed in a channel structure of 6 MHz intervals, as can be seen in FIG.

The carrier synthesizer 3 forms a full-band signal for the N broadcast signals for each channel applied from the AM modulator 2 side, and then, through the amplifier 4, a stable signal for a receiver receiver in a region where terrestrial broadcast is limited. Amplified to a predetermined level so that it can be received at a level, and wirelessly transmitted through the antenna.

As described above, the conventional local satellite broadcasting system has a problem that the transmission and reception of unstable multi-broadcasting and the bandwidth occupied by one channel are wide, and there is no protection band from neighboring channels, thereby preventing a good reception due to interference of other channel frequencies. In the case of the analog signal, there is a problem in that it is unable to provide a high resolution reception service because it is sensitive to ambient noise and frequency interference of other channels.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and its object is to transmit a conditional relay occurring in a small or limited area such as a golf course, a racetrack, a park, a small evening club, etc. as a digital wireless signal of MPEG-II method. In order to provide high resolution local area broadcasting through a receiving terminal located in a frequency range region of a transmitted radio signal.

A feature of the present invention for achieving the above object is to perform an interface for processing digital signals from analog video signals and left (L) and light (R) audio signals applied from video input means and audio input means. A video encoder for encoding and modulating a video signal applied through the interface unit into a digital signal format of ISO / IEC-13818-2, which is an international standard, and an audio signal applied through the interface unit. An audio encoder for encoding and modulating a digital signal of ISO / IEC-13818-3 method, which is a standardized standard, and a modulated video signal applied from the video encoder and a modulated audio signal applied from the audio encoder and the interface unit Multiplexing the additional data to be modulated into a data stream The key is a multiplexer, an FEC processor that modulates a predetermined state to prevent a transmission error in advance in order to prevent an error occurring in the process of transmitting data compressed and applied from the multiplexer for digital wireless power station, and externally applied. A QPSK modulator for analogizing the transmitted signal by performing a four-phase shift modulation on the phase of the applied video and audio signal with error compensation according to the channel selection signal being used, and the digital video signal and audio of various channels applied from the QPSK modulator. And a mixer for synthesizing a carrier wave to a signal, and an amplifier for amplifying digital video and audio data mixed with carriers through a mixer to a predetermined level and radiating through an antenna.

The present invention also provides a tuner for tuning a frequency band of a channel selected at a digital high frequency received through an antenna, a QPSK demodulator for performing demodulation through phase shifting on video and audio data to which a channel frequency band is tuned and received, A FEC demodulator which demodulates transmission error prevention data inserted into the data to be extracted, and extracts pure video and audio signals only, and demultiplexes a signal applied from the FEC demodulator to separate and extract a video signal, an audio signal, and additional data. A multiplexer, a video decoder which decodes a modulated video signal of the ISO / IEC-13818-2 scheme state, which is separated and extracted by the demultiplexer, and reconstructs an original signal for realizing a moving image; Modulation of ISO / IEC-13818-3 Method Status, an International Standard An audio decoder which decodes an audio signal and restores it to an original audio signal, an NTSC image converter for performing a predetermined process for reproducing an image of a digital image signal applied from the video decoder, and an applied digital video signal and a digital signal. An analog signal processor converts an audio signal into an analog signal and outputs the same through a display means and an audio output means.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a block diagram showing a wireless transmission apparatus of a digital image according to the present invention, FIG. 4 is a graph showing a channel structure of a frequency band in the present invention shown in FIG. 3, and FIG. 5 is a digital diagram according to the present invention. It is a block diagram which shows the image receiving apparatus.

As can be seen in FIG. 3, the apparatus for wirelessly transmitting digital images according to the present invention includes an interface unit 11, a video encoder 12, an audio encoder 13, a multiplexer 14, and an FEC processor 15. , QPSK modulator 16, mixer 17, and heavy amplifier 18. The interface unit 11 is applied from an analog video signal and an audio input means for transmission from a video input means such as a VCR or a camera. The audio signals of the left L and the light R are subjected to interfacing for processing the digital signals. The video encoder 12 encodes and modulates a video image signal applied through the interface unit 11 using MPEG-II image processing means into a digital signal format of ISO / IEC-13818-2, which is an international standard. The audio encoder 13 is an MPEG-II audio processing means, and the AES / EBU or S / DDIF method for satisfying the method of ISO / IEC-13818-3, which is an international standard, is applied to the audio signal applied through the interface unit 11. Convert digital data for wireless transmission. The multiplexer 14 is a modulated video image signal applied from the video encoder 12 and a modulated audio signal applied from the audio encoder 13 and an ISO / IEC-13818-1 scheme applied from the interface unit 11. The additional data is multiplexed and converted into data streams. The Forward Error Ccrrection (FEC) processing unit 15 modulates a predetermined state in order to prevent an error occurring during the transmission of data that is compressed and applied for digital wireless transmission from the multiplexer 14 to prevent transmission errors in advance. It prevents the image from being broken in the display through the receiving system. The QPSK modulator 16 performs an analog processing of the transmitted signal by shifting the phase of the applied video and audio signal into quadrants by compensating for an error in accordance with a channel selection signal applied from a control unit not shown. The mixer 17 synthesizes a carrier wave to a digital video signal and an audio signal of various channels that are analogized and applied through the QPSK modulator 16, amplifies a predetermined level through the amplifier 18, and radiates it through an antenna.

In addition, as shown in FIG. 5, the tuner 21, the QPSK demodulator 22, the FEC demodulator 23, the microprocessor 24, the demultiplexer 25, and the video decoder ( 26, an audio decoder 27, an NTSC video converter 28, an analog signal processor 29, and a memory unit 30, wherein the tuner 21 is a channel at a high frequency received through an antenna. The predetermined frequency band is tuned in accordance with the signal applied from the selection means. QPSK demodulator 22 performs demodulation via phase shifting on the applied video and audio data that is tuned to the selected channel frequency. The FEC demodulator 23 decodes a video signal that is modulated and received through a radio channel and restores the original video signal. The demultiplexer 25 demultiplexes the received signal by multiplexing to separate and extract the video signal, the cucumber degree signal and the additional data. The video decoder 26 decodes the modulated video signal of the ISO / IEC-13818-2 type state, which is an international standard, which is separated and extracted through the demultiplexer 25, and reconstructs the original video for realizing the moving picture. . The audio decoder 27 decodes the modulated audio signal of the ISO / IEC-13818-3 method state, which is an international standard standard separated and extracted through the demultiplexer 25, and restores the original audio signal to an original audio signal. 29) to the side. The NTSC image converter 28 executes a predetermined process for reproducing the image, and then applies the digital image signal applied from the video decoder 26 to the analog signal processor 29 side. The analog signal processor 29 converts the digital video signal applied from the NTSC video converter 28 and the digital audio signal applied from the audio decoding 27 into analog signals and outputs them through the display means and the audio output means. . The memory unit 30 sets an overall operation program for demodulating and outputting the digital video and audio signals which are compressed and received in a predetermined state.

Referring to the operation of the limited local broadcasting and reception processing of the digital video signal in the present invention having the function as described above is as follows.

When the video signal and the audio signal of the left (L) and the light (R) are applied to the interface unit 11 side through the image input means and the audio input means, the interface unit 11 Converts the applied video signal into a digital signal of MPEG-I or MPEG-II capable of processing video and applies it to the video encoder 12, and the audio signal is a digital signal of MPEG-I or MPEG-II. Converts the signal to the audio encoder 13, and processes the video signal and additional data on the information on which the audio signal is digitally processed into signals of ISO / IEC-13818-1, which is an international standard. Applied to the side. At this time, the digital audio signal applied to the audio encoder 13 side satisfies the communication protocol AES / EBU or S / DDIF for wireless transmission. The video encoder 12 processes the MPEG-I or MPEG-II digital video signal applied from the interface unit 11 into a signal of ISO / IEC-13818-2, which is an international standard, and applies it to the multiplexer 14 side. The audio encoder 13 then processes the digital audio signal of MPEG-I or MPEG-II into a signal of ISO / IEC-13818-3, which is an international standard, and applies it to the multiplexer 14 side. The multiplexer 14 multiplexes the applied video signal, the audio signal and the additional data, compresses and modulates the applied data, and then applies the column type data to the FEC processor 15. The FEC processor 15 codes predetermined data set to prevent transmission loss of data applied from the multiplexer 14 and overcomes the occurrence of an error, thereby bandwidth of a state as shown in FIG. Modulation is applied to the QPSK modulator 16 side. At this time, the data coded through the FEC processing unit 15 generates a large number of bits of data according to the amount of insertion of various prevention data bits compared to the input signal in order to overcome an error of the transmission signal. The QPSK modulator 16 performs a four-phase phase shifting modulation according to a channel selection signal applied from a system control means (not shown) to a data bit string into which predetermined data bits are inserted to prevent transmission errors. The analog signalization process is applied to each channel 17 to the mixer 17 side. The mixer 17 synthesizes a carrier to each channel-specific data signal applied from the QPSK modulator 16 and outputs an analogized digital signal of a frequency spectrum having a bandwidth and a guard band of an image channel as shown in FIG. Amplify to a predetermined level through the amplifier 18 and then radiated into the air through the antenna.

The operation of receiving digitally transmitted video and audio signals through the exaggeration as described above is shown in FIG. 5 as shown in FIG. 5 and the high frequency radio signal (RF) tuner 21 transmitted through the antenna of the transmitter. Tuner 21 tunes the frequency band of the corresponding broadcast according to a channel selection signal for listening from a channel selection means (not shown) and applies the detected data to the QPSK demodulator 22 side. The QPSK demodulator 22 decodes the applied data by shifting the four-phase phase according to the control signal applied from the microprocessor 24 and applies the decoded data to the FEC demodulator 23 side. The FEC demodulator 23 decodes the inserted data to extract multiplexed video and audio signals in order to prevent an error occurring during transmission to the received video and audio data to which the phase is decoded and applied, and then demultiplexer 25. Applied to the side. The demultiplexer 25 demultiplexes the data applied from the FEC demodulator 23 to digital video signals of the international standard ISO / IEC-13818-2 and ISO / IEC-13818-3. And extracting additional data of the ISO / IEC-13818-3 scheme and applying the digital video signal to the video decoder 26, applying the digital audio signal to the audio decoder 27, and transmitting the digital data. The additional data including the information about is applied to the display means. The video decoder 26 performs a predetermined operation for processing the original video on the digital video signal applied from the demultiplexer 25, and then analogizes it through an NTSC video converter 28 to perform analog processing. On the processor 29 side, the audio decoder 27 decodes the digital audio signal applied from the demultiplexer 25 to the analog signal processor 29 side. The analog signal processor 29 processes an applied digital video signal and an audio signal into an analog signal and displays an image having high definition with an audio signal through a TV monitor, which is an image display means.

As described above, the present invention uses a frequency band for local transmission of a race or a golf course, an evening concert, etc., to digitally wirelessly transmit to a monitor system located in a limited area using a frequency band for local transmission. And a voice service, and the transmission system is mounted on a vehicle to provide reliability in use by providing a mobile relay service.

Claims (2)

An interface unit for interfacing the analog video signal applied from the video input means and the audio input means and the audio signals of the left (L) and the light (R) for processing the digital signal, and the video video signal applied through the interface unit. Is a video encoder for encoding and modulating a digital signal of ISO / IEC-13818-2 type, which is an international standard, and an audio signal applied through the interface unit, to a digital signal of ISO / IEC-13818-3, an international standard. An audio encoder for encoding and modulating, a multiplexer for multiplexing and modulating a modulated video image signal applied from the video encoder, a modulated audio signal applied from the audio encoder, and additional data applied from the interface unit, and modulating the modulated video image signal into a data string; No digital from multiplexer In order to prevent an error occurring during the transmission process of data compressed and applied for transmission, an FEC processor for preventing transmission error by modulating to a predetermined state and an error is compensated according to a channel selection signal applied from the outside. A mixer for synthesizing a carrier wave to a digital video signal and an audio signal of various channels applied from the QPSK modulator, and a QPSK modulator for performing analogization of a transmitted signal by performing a four-phase shift modulation of an applied video and audio signal; And amplifying the digital video and audio data mixed with a carrier to a predetermined level through an antenna to radiate through an antenna. A tuner that tunes the frequency band of the selected channel at the digital high frequency received through the antenna, a QPSK demodulator that performs demodulation through phase shifting on the applied video and audio data by tuning the channel frequency band, and inserted into the received data. An FEC demodulator for demodulating transmission error prevention data and extracting only pure video and audio signals, a demultiplexer for demultiplexing a signal applied from the FEC demodulator and separating and extracting a video signal, an audio signal, and additional data; A video decoder which decodes the modulated video signal of the ISO / IEC-13818-2 method state, which is an international standard standard separated and extracted through a multiplexer, and restores it to an original signal for realizing a video, and is separated and extracted through the demultiplexer. Modulated audio signal with ISO / IEC-13818-3 standard, international standard An audio decoder for decoding and restoring an original audio signal, an NTSC video converter for performing a predetermined process for reproducing an image from a digital video signal applied from the video decoder, and an applied digital video signal and a digital audio signal. And an analog signal processor which converts the signal into an analog signal and outputs the same through the display means and the audio output means.