JP2019087895A - Broadcast transmission system - Google Patents

Abstract

To provide a broadcast transmission system that can improve the line efficiency when a broadcast material is sent back to a relay site with low delay and reduce the cost.SOLUTION: A broadcast transmission system includes an FPU multiplex transmitter 21 in which a relay station 2 transmits material A data to a broadcasting station 1, a trike station 3 transmits material B data to the broadcasting station 1, the broadcasting station 1 sends back data to the relay station 2 and the trike station 3, and the relay station 2 modulates the transmission return data received from the broadcasting station 1 and the material A data by different modulation methods, multiplexes respective data streams, and transmits the data streams on the same channel, and an FPU multiplex receiver 32 in which a trike station 3 receives the multiplexed and transmitted signal, separates the signal into two the data streams, and demodulates the transmission return data.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a broadcast transmission system for transmitting a broadcast material, and more particularly to a broadcast transmission system capable of improving the line efficiency at the time of sending back an on-air image to a relay site and reducing costs.

[Description of Prior Art]
When transmitting a program material photographed on the spot to a broadcasting station, an FPU (Field Pick-up Unit; wireless relay device for television broadcasting) is used. Normally, transmission of one material occupies one line.

When the broadcaster transmits the material for the live broadcast program, it is necessary to recognize the video currently on air at the relay site.
When terrestrial digital broadcast waves are directly received at the site, the effect of editing and transmission causes a delay of about 5 seconds to 10 seconds from the actual site conditions.
Therefore, on-air video is sent back from the broadcasting station to the relay site.

  In order to support the exchange between the broadcasting station and the field, etc., the live relay uses FPU for sending back, or uses a general line such as LTE (Long Time Evolution) to send back video with low delay from the broadcasting station to the relay site It is transmitting.

[Example of operation of conventional broadcast transmission system (1): FIG. 8]
An operation example (1) of the conventional broadcast transmission system will be described with reference to FIG. FIG. 8 is a schematic explanatory view showing an operation example (1) of the conventional broadcast transmission system. FIG. 8 shows the case of road race relay.
As shown in FIG. 8, the conventional broadcast transmission system includes a broadcasting station 71, a relay station (mobile station mounted on a relay vehicle) 72, and a trike station (mobile station mounted on a trike) 73, The video and audio data acquired from the camera at the relay station 72 and the trike station 73 are transmitted to the broadcast station 71, subjected to editing processing at the broadcast station 71, and output as a broadcast wave.

  Here, the video and audio data acquired by the relay station 72 is transmitted to the broadcast station 71 using the channel (channel) 1 of the FPU circuit, and the video and audio data acquired by the trike station 73 is the FPU channel. It is transmitted to the broadcast station 71 using the channel 3.

Then, the return video from the broadcasting station 71 is transmitted to the relay station 72 using the channel 2 and is transmitted to the trike station 73 using the channel 4.
That is, the transmission of the material from the site to the broadcasting station 71 and the transmission of the video sent back from the broadcasting station 71 to the relay station 72 and the trike station 73 occupy a total of four circuits.

[Example of operation of conventional broadcast transmission system (2): FIG. 9]
Next, an operation example (2) of a conventional broadcast transmission system will be described with reference to FIG. FIG. 9 is a schematic explanatory view showing an operation example (2) of the conventional broadcast transmission system. FIG. 9 shows the case of golf relay.
In a golf broadcast, a program of one tournament may transmit video material from different transmission points.
Video and audio data sent from a plurality of holes are sent to the broadcast station via the main relay station.

In the example of FIG. 9, the main relay station 74 and the mobile stations 75 and 76 are provided.
For example, the mobile station 75 acquires an image of the hall A and transmits it to the main relay station 74 using channel 1 of the FPU line, and the mobile station 76 acquires an image of the hall B, and uses channel 4 to transmit the main relay Send to station 74.

Then, the main relay station 74 transmits the video back to the mobile station 75 using channel 2, and the mobile station 76 transmits the video back to the mobile station 75 using channel 3.
Also in this case, a total of four lines are occupied.
Instead of the return video, a director or the like at the main relay station 74 may transmit an instruction signal for instructing each hole.

[Related Art]
In addition, as a prior art regarding a broadcast transmission system, there exist Unexamined-Japanese-Patent No. 2017-41781 "receiving apparatus" (patent document 1), and Unexamined-Japanese-Patent No. 2014-64273 "transmitting apparatus" (patent document 2).
Patent Document 1 describes a receiving apparatus that efficiently controls the directions of a plurality of receiving antennas performing multi-reception by tracking the position of a transmitting antenna of a mobile station.
Patent Document 2 describes a transmitter that improves transmission characteristics in a transmission line under adverse conditions by adding the inversion operation of a TMCC carrier.
Further, there is Non-Patent Document 1 as a standard for television broadcast program material transmission.

JP, 2017-41781, A JP, 2014-64273, A

Portable OFDM Digital Radio Transmission System for Television Broadcasting Program Material Transmission (ARIB STD-B33)

  As described above, in the conventional broadcast transmission apparatus, in order to send back the broadcast material to the relay site with low delay, the use of the FPU line increases the number of occupied lines and decreases the line efficiency, and the general network instead of the FPU line There is a problem in that if the line is used, the line usage fee is increased and the cost is increased.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a broadcast transmission system capable of improving the line efficiency when sending back the broadcast material to the relay site with low delay and reducing the cost. Do.

  The present invention for solving the problems of the above-described conventional example is a broadcast transmission system for transmitting material data for broadcasting and transmitting return data for sending back an image being broadcast, which comprises a first channel, a second channel, and a second channel. Using the third channel and the second channel, and using the first channel to overlap the same spectrum in the OFDM spectrum, using the first channel division multiplexing scheme. A first layer stream generated by modulating material data by a first modulation scheme, and a second layer stream modulated by transmission data by a second modulation scheme are multiplexed and transmitted. A broadcast apparatus (relay station) extracts a stream of the second layer from the first channel and sends back the received data while transmitting the second material data in the third channel Characterized by having two broadcasting devices (trike stations), and a third broadcasting device (broadcasting station) that receives the second material data from the third channel and transmits the return data on the second channel I assume.

  The present invention is a broadcast transmission system for transmitting material data for broadcasting and transmitting return data for sending back a video being broadcast, using a first channel, a second channel, and a third channel, Layer division multiplexing in which the first material data is received from one channel, the second material data is received from the third channel, and the same spectrum is superimposed on the OFDM spectrum using the second channel A stream of the first layer in which transmission return data is modulated by the first modulation method and a stream of the second layer modulation of the transmission return data by the second modulation method are generated by the method, multiplexed and transmitted. The first broadcast apparatus (main relay station) extracts the stream of the first layer from the second channel and sends it back to receive data, and the first material data is transmitted to the first channel. And a second broadcast apparatus (first mobile station) for transmitting at, and a stream of the second layer from the second channel to be sent back and receive data, and transmit the second material data on the third channel And a third broadcasting device (second mobile station).

  The present invention is characterized in that, in the above-mentioned broadcast transmission system, instruction data is used instead of return data, and different instruction data is included in the data stream of the first layer and the data stream of the second layer.

  According to the present invention, it is possible to receive the return data from the second channel and use the first channel to perform the first source data in a hierarchical division multiplexing scheme in which the same spectrum is superimposed on the same spectrum. A first broadcasting apparatus (relaying system for generating, multiplexing and transmitting a stream of the first layer modulated by the modulation scheme of 1 and a stream of the second layer modulated the transmission return data by the second modulation scheme A second broadcast apparatus (trike station) which extracts the stream of the second layer from the first channel and sends back the received data, and transmits the second material data in the third channel; Since the second material data is received from the third channel, and the third broadcasting device (broadcasting station) that transmits the return data on the second channel is configured as a broadcast transmission system, Improves the line efficiency, there is an effect of reducing the cost of the general network not to use.

  According to the present invention, the first material data is received from the first channel, the second material data is received from the third channel, and the second channel is used to be identical on the OFDM spectrum. A stream of the first layer in which transmission data is modulated by the first modulation method and a stream of the second layer in which transmission data is modulated by the second modulation method are generated by the layer division multiplexing method in which the spectrum is superimposed. A first broadcast apparatus (main relay station) that multiplexes and transmits, and extracts the stream of the first layer from the second channel and sends back the received data; and the first material data is transmitted to the first channel A second broadcast apparatus (first mobile station) to transmit at the second channel, and extracts a stream of the second layer from the second channel to send back and receive data, and the second material data is transmitted to the third channel In since the broadcast transmission system and a third broadcasting apparatus for transmitting (second mobile station), along with improving line efficiency, there is an effect of reducing the cost of the general network not to use.

It is model explanatory drawing which shows the operation example of this broadcast transmission system. It is a schematic block diagram of this broadcast transmission system. It is a block diagram showing the equipment configuration of the present broadcast transmission system. It is explanatory drawing which shows the structure of the modulation part of LDM-FPU transmitter in a relay station. It is explanatory drawing which shows schematic structure of the demodulation part of the LDM-FPU receiver in a strike station. It is model explanatory drawing which shows the operation example of another broadcast transmission system. It is a schematic block diagram of another broadcast transmission system. It is model explanatory drawing which shows the operation example (1) of the conventional broadcast transmission system. It is model explanatory drawing which shows the operation example (2) of the conventional broadcast transmission system.

Embodiments of the present invention will be described with reference to the drawings.
[Overview of the embodiment]
[Overview of this broadcast transmission system]
In the broadcast transmission system (the present broadcast transmission system) according to the embodiment of the present invention, the relay station transmits the material A data to the broadcast station, the trike station transmits the material B data to the broadcast station, and the broadcast station is the relay station The relay station transmits the on-air image back to the trike station, and the relay station modulates the transmission video data received from the receiving apparatus and the material A data with different modulation schemes, multiplexes each data stream, and transmits it on the same channel. The relay station includes an FPU multiplex transmission apparatus, and the trike station includes an FPU multiplex reception apparatus that receives a multiplexed and transmitted signal, separates the signal into two data streams, and demodulates transmission and return video data. Material A data and video data sent back to the trike station can be multiplexed and transmitted on the same line, improving the line efficiency and Not to use the effect of the cost can be reduced.

[Overview of another broadcast transmission system]
In the broadcast transmission system (another broadcast transmission system) according to another embodiment of the present invention, the first mobile station transmits the material data to the main relay station, and the second mobile station transmits the material data to the main relay station. It is transmitted to the relay station, and the main relay station sends back on-air video to the first mobile station and the second mobile station, and the main relay station modulates the sent-back video data with different modulation schemes, and each data stream is The first mobile station is provided with an FPU multiplex transmitter that multiplexes and transmits on the same channel, and the first mobile station receives the multiplexed and transmitted signal, separates it into two data streams, sends it from the first layer, and sends back video data. An FPU receiving apparatus is provided to demodulate, and a second mobile station receives a multiplexed and transmitted signal, separates it into two data streams, and sends it back from the second layer to demodulate video data. Equipped with equipment In the main relay station, video data sent back to the first mobile station and the second mobile station can be multiplexed and transmitted on the same channel, so that channel efficiency can be improved and a general network can not be used. The cost can be reduced.

[Example of operation of this broadcast transmission system: Fig. 1]
An operation example of the present broadcast transmission system will be described with reference to FIG. FIG. 1 is a schematic explanatory view showing an operation example of the present broadcast transmission system.
As shown in FIG. 1, the present broadcast transmission system includes a broadcast station 1, a relay station 2, and a try station 3.
The broadcasting station 1 receives the video and audio data acquired by the relay station 2 and the trike station 3 and outputs it as a broadcast wave after editing and processing, as in the conventional broadcasting station 71 shown in FIG. is there.
However, as a feature of the present broadcast transmission system, only the relay station 2 receives the return data transmitted by the transmitting station 1.

  The relay station 2 is a characteristic part of the present broadcast transmission system, and transmission of Layered Division Multiplexing (LDM) system in which different streams are superimposed on the same spectrum of OFDM (Orthogonal Frequency Division Multiplexing; orthogonal frequency division multiplexing). A device (LDM-FPU transmitter) is provided to multiplex and transmit different data on the same line.

  The trike station 3 is also a feature of the present broadcast transmission system, and is a receiver (LDM) that separates and demodulates a desired signal (here, return video) from the signal multiplexed and transmitted in the relay station 2. FPU receiver) is provided.

In the present broadcast transmission system, by using the LDM system, two different data are multiplexed and transmitted using one line, and the number of lines used is reduced.
Here, the relay station 2 transmits the video material (video / audio data / material data) acquired by itself using the first layer (Upper Layer; UL) of the channel 1, and the second layer of the channel 1 The return data from the broadcasting station 1 is transmitted to the trike station 3 using Lower Layer (LL).

[Operation of this broadcast transmission system]
The operation of the present broadcast transmission system will be briefly described.
As shown in FIG. 1, the relay station 2 transmits the video material (material data) acquired by the relay station 2 to the broadcast station 1 using the channel 1 UL.
The trike station 3 transmits the video material acquired by itself to the broadcast station 1 using the channel 3.
The broadcast station 1 receives each video material to generate an on-air video, and transmits return data to the relay station 2 using the channel 2.

When the relay station 2 receives the return data on the channel 2, the relay station 2 outputs the data to the monitor and multiplexes the data on the channel 1 LL to transmit.
That is, on channel 1, material data from relay station 2 is transmitted to UL, and return data from broadcast station 1 is transmitted to LL.
The trike station 3 separates the LL data stream from the multiplexed channel 1 received signal, demodulates it, and sends back an image.

  Thus, the broadcast transmission system transmits two types of material data from the relay station 2 and the trike station 3 to the transmitting station 1 with only three circuits, and sends back data to both the relay station 2 and the trike station 3. It can be transmitted.

[Schematic configuration of the present broadcast transmission system: FIG. 2]
Next, a schematic configuration of the present broadcast transmission system will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the present broadcast transmission system.
As shown in FIG. 2, the transmitting station 1 includes FPU receivers 11 and 13 and an FPU transmitter 12. The relay station 2 includes an LDM-FPU transmitter 21 and an FPU receiver 22. The station 3 includes an FPU transmitter 31 and an LDM-FPU receiver 32.

The FPU receivers 11, 13, 22 are broadcast receivers that receive broadcast material data.
The FPU transmitters 12 and 31 are broadcast receivers for transmitting material data for broadcast.
The LDM-FPU transmitter 21 is a transmitter for multiplexing and transmitting material data and return data in accordance with the LDM method in which different streams are superimposed on the same OFDM spectrum.
The LDM-FPU receiving device 32 is a receiving device that separates return data from the signal multiplexed and transmitted according to the LDM method, and demodulates the signal.

The broadcasting station 1 receives the material A data from the relay station 2 using the UL of channel 1 in the FPU receiving apparatus 11 and receives the material B data from the trike station 3 using the channel 3 in the FPU receiving apparatus 13 .
Also, the broadcasting station 1 transmits an on-air video as a return data to the relay station 2 by using the channel 2 in the FPU transmitter 12.

The relay station 2 receives the return data of the channel 2 at the FPU receiver 22 and modulates the material A data by the first modulation scheme by the LDM system using the channel 1 at the LDM-FPU transmitter 21 to UL. , And modulates the received return data according to the second modulation scheme to generate and multiplex a data stream of LL, and transmits a multiplexed signal.
The try station 3 receives the multiplexed signal of the channel 1 by the LDM-FPU receiver 32 from the relay station 2, separates the LL data stream, demodulates it, and sends back the returned data.

The conventional broadcasting station was provided with two FPU transmitters for sending back, but in the present broadcast transmission system, only one line is required, the line efficiency can be improved, the equipment configuration can be simplified, and the cost can be reduced. It is a thing.
Furthermore, the FPU transmitter and FPU receiver used in the broadcast station 1 are similar to the conventional ones, and the configuration of the broadcast station 1 does not have to be changed significantly, and can be realized at low cost.

[Device configuration of this broadcast transmission system: Fig. 3]
Next, the equipment configuration of the present broadcast transmission system will be described with reference to FIG. FIG. 3 is a configuration block diagram showing the equipment configuration of the present broadcast transmission system.
In FIG. 3, the schematic configuration shown in FIG. 2 is made into a more specific configuration block.
The broadcast station 1 includes an FPU receiver 11, an FPU transmitter 12, an FPU receiver 13, a decoder (DECODER) 14, an encoder (ENCODER) 15, and a decoder (DECODER) 16.

The relay station 2 includes an LDM-FPU transmitter 21, an FPU receiver 22, a decoder (DECODER) 23, an encoder (ENCODER) 24, and an encoder (ENCODER) 25.
The trike station 3 includes an FPU transmitter 31, an LDM-FPU receiver 32, an encoder (ENCODER) 33, and a decoder (DECODER) 34.

Here, the FPU transmitters 12 and 31 perform modulation according to, for example, the QPSK modulation method as a first modulation method, and the FPU receivers 11, 13 and 22 perform, for example, a QPSK demodulation method as a first demodulation method. Demodulation is performed.
When hierarchical division multiplexing is performed, the LDM-FPU transmitter 21 performs modulation according to, for example, a QPSK modulation method as a first modulation method, and performs modulation according to, for example, a 16 QAM modulation method as a second modulation method. Do.
When hierarchical separation is performed, the LDM-FPU receiver 32 demodulates using, for example, a QPSK demodulation method as a first demodulation method, and performs demodulation using, for example, a 16 QAM demodulation method as a second demodulation method. Do.

[Configuration of each part and data flow]
The configuration of each part will be described below based on the flow of data.
In the trike station 3, the encoder 33 encodes material B data for broadcast, which is photographed and recorded by a camera or the like, and the FPU transmitter 31 transmits the encoded data to the broadcasting station 1 on the channel 3.
In the broadcasting station 1, the FPU receiving device 11 receives the material B data transmitted from the FPU transmitting device 31 of the trike station 3 on the channel 3 and outputs it to the decoder 14, and the decoder 14 decodes and outputs the material B data. .

Further, in the broadcast station 1, the encoder 15 encodes the return data and the FPU transmitter 12 transmits the encoded return data to the relay station 2 on channel 2.
In the relay station 2, the FPU receiving device 22 receives the return data transmitted from the FPU transmitting device 12 of the broadcasting station 1 on the channel 2 and outputs it to the decoder 23, and the decoder 23 decodes it.

Furthermore, the encoder 24 inputs and encodes the decoded data from the decoder 23 and outputs the data to the LDM-FPU transmitter 21. Also, the decoder 25 inputs and encodes the material A data for broadcasting from the camera, and outputs the data to the LDM-FPU transmitter 21.
Here, the relay station 2 may be configured to input the received data as it is to the LDM-FPU transmitter 21 without performing decoding and encoding.
Then, the LDM-FPU transmitter 21 modulates the material A data by QPSK modulation using channel 1 by LDM to generate a UL data stream, and modulates encoded return data by 16 QAM modulation. Then, generate LL data streams, multiplex and transmit.

At the trike station 3, the LDM-FPU receiver 32 receives the multiplexed signal transmitted from the LDM-FPU transmitter 21 of the relay station 2 on the channel 1, separates the LL data stream, and encodes it. The folded data is output to the decoder 34.
The decoder 34 demodulates the encoded aliasing data from the LDM-FPU receiver 32 and outputs the return data to the monitor.

Further, in the broadcast station 1, the FPU receiver 13 receives the multiplexed signal transmitted from the LDM-FPU transmitter 21 of the relay station 3 on the channel 1, separates the UL data stream, and encodes it. The source A data is output to the decoder 16.
The FPU receiver 13 can extract material A data of a UL data stream from a signal multiplexed by demodulation according to the QPSK demodulation method.
The decoder 16 demodulates and outputs the encoded material A data from the FPU receiver 13.

[Delay time]
Here, a delay time to be sent back from the broadcasting station 1 to the trike station 3 is determined.
The time required for FPU transmission is dominated by time interleaving. Assuming mobile relay, time interleaving is assumed to be 378 msec, and encoder and decoder for video and audio compression are assumed to be 100 msec in pairs.

  In the configuration of FIG. 3, when roughly estimated, when the video data captured by the trike station 3 is used on air, a delay of three lines occurs in the FPU, and a delay of three opposing sides occurs in the encoder / decoder . Therefore, the time interleaving for 3 lines: 1134 msec (= 378 msec × 3) and the delay time of the 3-opposed encoder / decoder: 300 msec (= 100 msec × 3), which is 1.43 sec.

When video data other than the try station 3 or the relay station 2 is on air, a delay corresponding to two lines of the FPU occurs, and a delay of two opposites occurs in the encoder / decoder. Therefore, the time interleaving for two lines: 756 msec (= 378 msec × 2) and the delay time of one opposing encoder / decoder: 200 msec (= 100 msec × 2), 0.95 sec.
In either case, transmission of return data with low delay can be realized.

[Modulator of LDM transmitter: FIG. 4]
Next, the configuration of the modulator of the LDM-FPU transmitter 21 in the relay station 2 will be described using FIG. FIG. 4 is an explanatory view showing a configuration of a modulator of the LDM-FPU transmitter in the relay station.
FIG. 4 shows a configuration in which data for UL (UL data, material A data) and data for LL (LL data, return data) are multiplexed in digital signal processing.

As shown in FIG. 4, the LDM modulation unit (digital multiplexing method) includes FEC (Forward Error Correction) units 83a and 83b, bit interleaving units (Bit-ILV) 84a and 84b, and a mapping unit. (MAPPING) 85a, 85b, a weighting unit 86, an adder 87, an OFDM modulation unit 88, an orthogonal modulation unit 89, and a DAC (Digital Analog Converter) unit 90.
The suffix a is for processing UL data and b is for processing LL data.

Then, in the modulation unit of FIG. 4, UL data is error correction coded by the FEC unit 83 a, subjected to bit interleaving by the bit interleaving unit 84 a, mapped in the mapping unit 85 a, and output to the adder 87.
Here, UL data is, for example, QPSK (Quadrature Phase Shift Keying) modulated.

The LL data is error correction coded by the FEC unit 83b, bit interleaved by the bit interleaving unit 84b, mapped by the mapping unit 85b, multiplied by a predetermined weighting coefficient by the weighting unit 86, and added to the adder 87. Output to
The LL data is modulated, for example, by 16 QAM (Quadrature Amplitude Modulation).

  Then, in the adder 87, UL data and weighted LL data are superimposed, OFDM modulated in the OFDM modulator 88, quadrature modulated in the orthogonal modulator 89, converted to an analog signal by the DAC 90, and shown. The signal is output to an FPU transmission high frequency unit and transmitted by radio.

As described above, when multiplexing is performed at the digital signal processing level, the QPSK modulated first layer (UL) stream and the 16 QAM modulated second layer (LL) stream are multiplexed at the subsequent stage of the multilevel modulation unit (mapping unit) Do. The size (proportion) at which the stream of the second layer is superimposed is adjusted by the weighting factor in the weighting unit 86.
Thus, the LDM-FPU transmitter 21 of the relay station 2 superimposes the material A data and the return data on the same channel (channel 1) and transmits them.

  The broadcast station 1 has the same configuration as the conventional one and does not have an LDM-FPU receiver, but receives the multiplexed data stream and QPSK-demodulates it to extract UL data and obtain material A It is possible to obtain data.

[Demodulation unit of LDM receiver: FIG. 5]
Next, a schematic configuration of the demodulator of the LDM-FPU receiver in the try station 3 will be described with reference to FIG. FIG. 5 is an explanatory view showing a schematic configuration of a demodulation unit of the LDM-FPU receiver in the try station.
As shown in FIG. 5, the demodulator is provided in the LDM-FPU receiver 32, and comprises a UL data demodulator 95, a delay buffer 96, and a subtractor 97, and QPSK modulated UL data. And 16 QAM modulated LL data.

  The received signal input to the demodulation unit of FIG. 5 is separated into two, and one of them is subjected to UL demodulation by the UL data demodulation unit 95, and QPSK-modulated UL data (QPSK modulation) from the multiplexed signal. The modulation signal (UL data stream) is extracted and output to a UL data demapping unit (not shown) and to a subtractor 97.

Also, the other separated received signal is delayed by the time required for demodulation of the first layer (UL) in the delay buffer 96, and is input to the subtractor 97.
The subtractor 97 can extract a 16 QAM modulated signal (16 QAM modulated signal, LL data stream) by subtracting the QPSK modulated signal from the delayed received signal, and this is used as a demapping processor for LL data. Output to

That is, in the LDM-FPU receiver 32 of the try station 3, the QPSK modulation signal of UL is used to separate the 16 QAM modulation signal of LL.
The demapping processor for LL data performs 16 QAM demodulation, and the demodulated return data is output to the monitor.

[Another broadcast transmission system: Figures 6 to 7]
Next, another broadcast transmission system will be described with reference to the drawings. FIG. 6 is a schematic explanatory view showing an operation example of another broadcast transmission system, and FIG. 7 is a schematic configuration diagram of another broadcast transmission system.
As shown in FIG. 6, another broadcast transmission system includes the main relay station 4, the mobile station 5 (first mobile station) provided in the hall A, and the mobile station 6 (second one) provided in the hall B. Mobile stations) and

Similar to the conventional main relay station 74 shown in FIG. 9, the main relay station 4 receives the video / audio data acquired by the mobile station 5 and the mobile station 6 and transmits it to the broadcasting station.
However, as a feature of another broadcast transmission system, the main relay station 4 multiplexes and transmits the return data or instruction data for the mobile stations 5 and 6 on the same channel, and the mobile stations 5 and 6 receive the respective data. .
Here, the instruction data is data different from only the return data, such as the instruction voice and the return data in which the instruction voice is multiplexed.

Specifically, the main relay station 4 is provided with a transmitter (LDM-FPU transmitter) that multiplexes and transmits by the LDM method on the same spectrum of OFDM, and the mobile station using UL of channel 2 for transmission data and the like. At the same time, the transmission data and the like are transmitted to the mobile station 6 using LL of channel 2.
Also, the main relay station 4 is a receiving device (FPU receiving device) that receives the material data from the mobile station 5 on the channel 1 and a receiving device that receives the material data from the mobile station 6 on the channel 3 (FPU receiving device) Is equipped.

  The mobile station 5 separates the UL data stream from the multiplexed channel 2 from the transmitting apparatus (FPU transmitting apparatus) that transmits the acquired material data to the main relay station 4 via channel 1, and demodulates and sends back the returned data etc. A receiver (FPU receiver) for acquiring

  The mobile station 6 separates and demodulates the LL data stream from the multiplexed reception signal of the channel 2 and a transmitting device (FPU transmitting device) for transmitting the acquired material data to the main relay station 4 over the channel 3 A receiver (LDM-FPU receiver) for acquiring transmission return data etc. is provided.

[Operation of another broadcast transmission system]
The operation of another broadcast transmission system will be briefly described.
As shown in FIG. 6, the mobile station 5 transmits the material data acquired by itself at the hall A to the main relay station 4 via the channel 1.
The mobile station 6 also transmits the material data acquired by itself in the hall B to the main relay station 4 on the channel 3.
The main relay station 4 receives the material data from the mobile station 5 on the channel 1 and receives the material data from the mobile station 6 on the channel 3.

The main relay station 4 multiplexes transmission data and the like generated from the received material data into LL and UL of the channel 2 by the LDM method, and transmits the multiplexed data to the mobile stations 5 and 6.
The mobile station 5 separates the UL data stream from the signal multiplexed in channel 2 and demodulates it to obtain return data etc.
The mobile station 5 separates the LL data stream from the signal multiplexed in channel 2, demodulates it, and sends back data etc.

[Schematic configuration of another broadcast transmission system: FIG. 7]
Next, the schematic configuration of another broadcast transmission system will be described using FIG. FIG. 7 is a schematic block diagram of another broadcast transmission system.
As shown in FIG. 7, the main relay station 4 includes FPU receivers (FPU RX) 41 and 43 and an LDM-FPU transmitter (LDM-FPU TX) 42, and the mobile station 5 includes an FPU transmitter ( The mobile station 6 includes an FPU receiver 61 and an LDM-FPU receiver (LDM-FPU RX) 62.

The FPU receivers 41, 43, 52 are broadcast transmitters that receive broadcast material data.
The FPU transmitters 51 and 61 are broadcast receivers that transmit material data for broadcast.
The LDM-FPU transmitter 42 is a transmitter that multiplexes return data and the like in an LDM system in which different streams are superimposed on the same spectrum of OFDM, and transmits the multiplexed data. The modulator of the LDM-FPU transmitter 42 is the same as that described in FIG.
The LDM-FPU receiving device 62 is a receiving device that separates return data and the like from a signal multiplexed and transmitted by the LDM method, and demodulates the separated data. The demodulator of the LDM-FPU receiver 62 is the same as that described with reference to FIG.

Here, the return data and the like include individual instruction data for the mobile stations 5 and 6.
That is, the instruction data A for the mobile station 5 may be multiplexed on the UL of the channel 2 and the instruction data B for the mobile station 6 may be multiplexed on the LL of the channel 2 and transmitted.

The main relay station 4 receives the material data from the mobile station 5 using the channel 1 at the FPU receiver 41 and receives the material data from the mobile station 6 using the channel 3 at the FPU receiver 43.
Further, the main relay station 4 multiplexes transmission return data and the like by using the channel 2 in the LDM-FPU transmitter 42 and transmits it to the mobile stations 5 and 6.

The conventional main relay station has been equipped with two FPU transmitters for sending back, but in another broadcast transmission system, only one line is needed, improving the line efficiency, simplifying the equipment configuration and cost. It can be reduced.
Furthermore, the FPU transmitter and FPU receiver used in the mobile station 5 are similar to the conventional ones, and the configuration of the mobile station 5 does not have to be changed significantly, and can be realized at low cost.

  In FIG. 7, although the mobile stations 5 and 6 are configured differently, the second mobile station is provided with an LDM-FPU receiver and an FPU transmitter as the mobile station, and the second LL When acquiring the data demodulated by the demodulation method and separating the UL data stream of the channel 2, changing the setting according to the mobile station equipment so as to acquire the data demodulated by the first demodulation method , Available to one type of mobile station.

[Effect of the embodiment]
According to the present broadcast transmission system, the relay station 2 transmits the material A data to the broadcast station 1, the trike station 3 transmits the material B data to the broadcast station 1, and the broadcast station 1 transmits to the relay station 2 and the trike station 3. The FPU multiplex transmitter 21 transmits the return data, and the relay station 2 modulates the return data received from the broadcasting station 1 and the material A data according to different modulation schemes, multiplexes each data stream, and transmits it on the same channel. , Relay station 3 receives the multiplexed and transmitted signal, separates it into two data streams, and includes an FPU multiplex receiver 32 that demodulates the return data. The A data and the return data to the try station 3 can be multiplexed and transmitted on the same line, improving the line efficiency and avoiding the use of a general network, and the cost can be increased. There is an effect that can be reduced.

  According to another broadcast transmission system, the mobile station 5 transmits the material data to the main relay station 4, the mobile station 6 transmits the material data to the main relay station 4, and the main relay station 4 transmits the mobile station 5 and the mobile station. 6, the main relay station 4 comprises an FPU multiplexer 42 that modulates the transmission data in different modulation schemes and multiplexes each data stream and transmits the same on the same channel, and the mobile station 5 performs multiplexing. And an FPU receiver 52 for receiving the transmitted signal and separating it into two data streams and demodulating data sent back from the first layer, and the mobile station 6 multiplexes and transmits the transmitted signal. It comprises an FPU multiplex receiver 62 that receives and separates into two data streams, and demodulates data sent back from the second layer, and the main relay station 4 multiplexes the data sent back to the mobile station 5 and the mobile station 6 Become Can be transmitted through the same line, thereby improving the line efficiency, there is an effect that it is possible to reduce the cost of the general network not to use.

  The present invention is suitable for a broadcast transmission system capable of improving the line efficiency at the time of sending back the broadcast material to the relay site with a low delay, and reducing the cost.

  Reference Signs List 1 broadcast station 2 relay station 3 trike station 4 main relay station 5 first mobile station 6 second mobile station 11 FPU receiver 12 FPU transmitter 13 ... FPU receiver, 14 ... decoder, 15 ... encoder, 16 ... decoder, 21 ... LDM-FPU transmitter, 22 ... FPU receiver, 23 ... decoder, 24 ... encoder, 31 ... FPU transmitter, 32 ... LDM-FPU Receivers 33: Encoders 34: Decoders 41: FPU receivers 42: LDM-FPU transmitters 43: FPU receivers 51: FPU transmitters 52: FPU receivers 61: FPU receivers 62 ... LDM-FPU receiver, 71 ... broadcast station, 72 ... relay station, 73 ... trike station, 74 ... main relay station, 75 ... mobile station, 76 Mobile station 83a 83b FEC unit 84a 84b Bit interleaving unit 85a 85b Mapping unit 86 Weighting unit 87 Adder 88 OFDM modulator 89 Orthogonal modulator 90 ... DAC unit, 95 ... UL data demodulation unit, 96 ... delay buffer, 97 ... subtractor

Claims (3)

A broadcast transmission system for transmitting material data for broadcasting and transmitting return data for sending back an image being broadcast,
Using a first channel, a second channel, a third channel,
While receiving the return data from the second channel, using the first channel, the first material data is firstly transmitted by layer division multiplexing in which the same spectrum is superimposed on the OFDM spectrum. A first broadcasting apparatus that generates, multiplexes and transmits a stream of a first layer modulated by a modulation scheme and a stream of a second layer modulated by the second modulation scheme of the transmission return data;
A second broadcasting apparatus which extracts the stream of the second layer from the first channel and receives the return data, and transmits second material data in the third channel;
A broadcast transmission system comprising: a third broadcast apparatus that receives the second material data from the third channel and transmits the return data on the second channel. A broadcast transmission system for transmitting material data for broadcasting and transmitting return data for sending back an image being broadcast,
Using a first channel, a second channel, a third channel,
The first material data is received from the first channel, the second material data is received from the third channel, and the same spectrum is superimposed on the OFDM spectrum using the second channel. The stream of the first layer in which the transmission return data is modulated by the first modulation method and the stream of the second layer from the transmission return data modulated by the second modulation method are generated by the hierarchical division multiplexing method. , A first broadcasting apparatus that multiplexes and transmits;
A second broadcasting device that extracts a stream of the first layer from the second channel and receives the return data, and transmits the first material data on the first channel;
And a third broadcasting apparatus for extracting the stream of the second layer from the second channel and receiving the return data, and transmitting the second material data in the third channel. Broadcast transmission system. 3. The broadcast transmission system according to claim 1, wherein the instruction data is used instead of the return data, and different instruction data are included in the data stream of the first layer and the data stream of the second layer.

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