JP6994359B2 - Broadcast transmission system - Google Patents

Description

The present invention relates to a broadcast transmission system for transmitting broadcast materials, and more particularly to a broadcast transmission system capable of improving line efficiency and reducing costs when sending back on-air video to a relay site.

[Explanation of prior art]
An FPU (Field Pick-up Unit; a wireless relay device for television broadcasting) is used when transmitting a program material shot at a site to a broadcasting station. Normally, one line is occupied for the transmission of one material.

When a broadcaster transmits material for a live broadcast program, it is necessary to recognize the video currently on the air at the relay site.
If the terrestrial digital broadcast wave is directly received at the site, a delay of about 5 to 10 seconds will occur from the actual situation at the site due to the influence of editing and transmission.
Therefore, the broadcasting station sends back the on-air video to the relay site.

In order to deal with the interaction between the broadcasting station and the site, FPU is used for sending back in live broadcasting, or a general line such as LTE (Long Time Evolution) is used to send back video with low delay from the broadcasting station to the relay site. Is transmitting.

[Operation example 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 diagram 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 the relay vehicle) 72, and a trike station (mobile station mounted on the trike) 73. The video / audio data acquired from the camera at the relay station 72 and the trike station 73 is transmitted to the broadcast station 71, edited by the broadcast station 71, and output as a broadcast wave.

Here, the video / audio data acquired by the relay station 72 is transmitted to the broadcasting station 71 using the channel 1 of the FPU line, and the video / audio data acquired by the trike station 73 is the video / audio data of the FPU line. It is transmitted to the broadcasting station 71 using the channel 3.

Then, the sent-back 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 sent back video from the broadcasting station 71 to the relay station 72 and the trike station 73 occupy a total of four lines.

[Operation example of conventional broadcast transmission system (2): Fig. 9]
Next, an operation example (2) of the conventional broadcast transmission system will be described with reference to FIG. FIG. 9 is a schematic explanatory diagram showing an operation example (2) of the conventional broadcast transmission system. FIG. 9 shows the case of golf relay.
In a golf broadcast, video material from different transmission points may be transmitted in one tournament program.
Video / audio data sent from a plurality of halls is transmitted to a broadcasting station via a 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 the video of the hall A and transmits it to the main relay station 74 using the channel 1 of the FPU line, and the mobile station 76 acquires the video of the hall B and relays the main relay using the channel 4. Send to station 74.

Then, the main relay station 74 transmits the send-back video to the mobile station 75 using the channel 2, and the mobile station 76 transmits the send-back video using the channel 3.
In this case as well, a total of 4 lines are occupied.
Instead of the sent-back video, the director or the like in the main relay station 74 may transmit an instruction signal for giving an instruction to each hall.

[Related technology]
As the prior art relating to the broadcast transmission system, there are Japanese Patent Application Laid-Open No. 2017-41781 "Receiving Device" (Patent Document 1) and Japanese Patent Application Laid-Open No. 2014-64273 "Transmitting Device" (Patent Document 2).
Patent Document 1 describes a receiving device that efficiently controls the direction of a plurality of receiving antennas that perform multi-reception by following the position of the transmitting antenna of the mobile station.
Patent Document 2 describes a transmission device that improves transmission characteristics in a transmission line under adverse conditions by adding a TMCC carrier inversion operation.
Further, there is Non-Patent Document 1 as a standard for transmission of television broadcast program material.

Japanese Unexamined Patent Publication No. 2017-41781 Japanese Unexamined Patent Publication No. 2014-64273

Portable OFDM digital radio transmission system for transmission of television broadcast program material (ARIB STD-B33)

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

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

The present invention for solving the problems of the above-mentioned conventional example is a broadcast transmission system for transmitting material data for broadcasting and transmitting back data for sending back the video being broadcast, the first channel, the second. Channel, the third channel is used to receive the send-back data from the second channel, and the first channel is used to superimpose the same spectrum on the OFDM spectrum. A first layer stream in which material data is modulated by a first modulation method and a second layer stream in which feedback data is modulated by a second modulation method are generated, multiplexed and transmitted. A broadcasting device (relay station) and a second broadcasting device (trike station) that extracts a second layer stream from the first channel, receives the send-back data, and transmits the second material data on the third channel. ), And a third broadcasting device (broadcasting station) that receives the second material data from the third channel and also transmits the return data on the second channel.

The present invention is a broadcast transmission system for transmitting material data for broadcasting and transmitting back data for sending back the video being broadcast, using a first channel, a second channel, and 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 second channel is used to superimpose the same spectrum on the OFDM spectrum. Depending on the method, a stream of the first layer in which the send-back data is modulated by the first modulation method and a stream of the second layer in which the send-back data is modulated by the second modulation method are generated, multiplexed and transmitted. A second broadcast that extracts the first layer stream from the first broadcasting device (main relay station) and the second channel, receives the send-back data, and transmits the first material data on the first channel. A device (first mobile station) and a third broadcasting device (third broadcasting device) that extracts the second layer stream from the second channel, receives the send-back data, and transmits the second material data on the third channel. It is characterized by having a second mobile station).

The present invention is characterized in that the instruction data is used instead of the return data in the broadcast transmission system, 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, the first material data is subjected to the first material data by the layered division multiplex method in which the feedback data is received from the second channel and the same spectrum is superimposed on the OFDM spectrum using the first channel. A first broadcasting device (relay) that generates, multiplexes, and transmits a first-layer stream modulated by the first modulation method and a second-layer stream obtained by modulating the sent-back data with the second modulation method. The station), the second broadcasting device (trike station) that extracts the second layer stream from the first channel, receives the send-back data, and transmits the second material data on the third channel, and the second. Since the broadcast transmission system has 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, the line efficiency is improved and the line efficiency is improved. It has the effect of reducing costs by not using a general network.

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 the same on the OFDM spectrum. By the layered division multiplexing method that superimposes on the spectrum, a stream of the first layer in which the send-back data is modulated by the first modulation method and a stream of the second layer in which the send-back data is modulated by the second modulation method are generated. The first broadcasting device (main relay station) for multiplexing and transmitting, and the first layer stream are extracted from the second channel to receive the send-back data, and the first material data is transmitted to the first channel. The second broadcasting device (first mobile station) to be transmitted by, and the second layer stream are extracted from the second channel to receive the send-back data, and the second material data is transmitted by the third channel. Since the broadcast transmission system has a third broadcasting device (second mobile station), there is an effect that the line efficiency can be improved and the cost can be reduced by not using the general network.

It is a schematic explanatory diagram 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 which shows the equipment structure of this broadcast transmission system. It is explanatory drawing which shows the structure of the modulation part of the LDM-FPU transmission apparatus in a relay station. It is explanatory drawing which shows the schematic structure of the demodulation part of the LDM-FPU receiving apparatus in a trike station. It is a schematic explanatory diagram which shows the operation example of another broadcast transmission system. It is a schematic block diagram of another broadcast transmission system. It is a schematic explanatory diagram which shows the operation example (1) of the conventional broadcast transmission system. It is a schematic explanatory diagram which shows the operation example (2) of the conventional broadcast transmission system.

An embodiment of the present invention will be described with reference to the drawings.
[Outline of 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 on-air video is sent back to the trike station, and the relay station modulates the sent back video data received from the receiving device and the material A data by different modulation methods, and multiplexes each data stream and transmits them on the same line. It is equipped with an FPU multiplex transmitter, and the trike station is equipped with an FPU multiplex receiver that receives the multiplexed and transmitted signals, separates them into two data streams, and demolishes the sent-back video data. The material A data and the video data sent back to the trike station can be multiplexed and transmitted on the same line, which has the effect of improving the line efficiency and reducing the cost by not using the general network.

[Overview of another broadcast transmission system]
Further, 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 mainly uses the material data. It is transmitted to the relay station, and the main relay station sends back the on-air video to the first mobile station and the second mobile station. The main relay station modulates the sent back video data by a different modulation method, and each data stream is transmitted. Equipped with an FPU multiplex transmission device that multiplexes and transmits on the same line, the first mobile station receives the multiplexed and transmitted signal, separates it into two data streams, and sends back video data from the first layer. It is equipped with an FPU receiver for demodulating, and a second mobile station receives the multiplexed and transmitted signal, separates it into two data streams, and sends back video data from the second layer. FPU multiplex reception. Equipped with a device, the main relay station can multiplex the video data sent back to the first mobile station and the second mobile station and transmit them on the same line, improving line efficiency and providing a general network. There is an effect that the cost can be reduced by not using it.

[Operation example of this broadcast transmission system: Fig. 1]
An operation example of this broadcast transmission system will be described with reference to FIG. FIG. 1 is a schematic explanatory diagram showing an operation example of this broadcast transmission system.
As shown in FIG. 1, the broadcast transmission system includes a broadcast station 1, a relay station 2, and a trike station 3.
Similar to the conventional broadcasting station 71 shown in FIG. 8, the broadcasting station 1 receives the video / audio data acquired by the relay station 2 and the trike station 3, edits and processes the data, and outputs the data as a broadcast wave. be.
However, as a feature of this broadcast transmission system, only the relay station 2 receives the return data transmitted by the transmission station 1.

The relay station 2 is a characteristic part of this broadcast transmission system, and is a layered division multiplexing (LDM) transmission in which different streams are superimposed on the same spectrum of OFDM (Orthogonal Frequency Division Multiplexing). It is equipped with a device (LDM-FPU transmission device) and multiplexes and transmits different data on the same line.

The trike station 3 is also a characteristic part of the main broadcast transmission system, and is a receiving device (LDM) that separates a desired signal (here, a return video) from the signal multiplexed and transmitted by the relay station 2 and demodulates it. -FPU receiver) is provided.

In this broadcast transmission system, by using the LDM method, 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 (video / audio data / material data). Lower Layer; LL) is used to transmit the send-back data from the broadcasting station 1 to the trike station 3.

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

When the relay station 2 receives the send-back data on the channel 2, it outputs the data to the monitor and multiplexes the data to the LL of the channel 1 for transmission.
That is, the material data from the relay station 2 is multiplexed and transmitted to the channel 1 and the feedback data from the broadcasting station 1 is multiplexed and transmitted to the LL.
The trike station 3 separates the LL data stream from the multiplexed received signal of the channel 1, demodulates it, and obtains a sent-back video.

As a result, this broadcast transmission system transmits two types of material data from the relay station 2 and the trike station 3 to the transmission station 1 with only three lines, and sends back the data to both the relay station 2 and the trike station 3. It can be transmitted.

[Summary configuration of this broadcast transmission system: Fig. 2]
Next, the schematic configuration of this broadcast transmission system will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the main broadcast transmission system.
As shown in FIG. 2, the transmitting station 1 includes FPU receiving devices 11 and 13 and an FPU transmitting device 12, and the relay station 2 includes an LDM-FPU transmitting device 21 and an FPU receiving device 22 and is a trike. The station 3 includes an FPU transmitting device 31 and an LDM-FPU receiving device 32.

The FPU receiving devices 11, 13 and 22 are broadcasting receiving devices for receiving material data for broadcasting.
The FPU transmitting devices 12 and 31 are broadcasting receiving devices that transmit material data for broadcasting.
The LDM-FPU transmission device 21 is a transmission device that multiplexes and transmits material data and return data by an LDM method in which different streams are superimposed on the same spectrum of OFDM.
The LDM-FPU receiving device 32 is a receiving device that separates the sent back data from the signal multiplexed and transmitted by the LDM method and demodulates it.

The broadcasting station 1 receives the material A data from the relay station 2 using the UL of the channel 1 in the FPU receiving device 11, and receives the material B data from the trike station 3 using the channel 3 in the FPU receiving device 13. ..
Further, the broadcasting station 1 uses the channel 2 in the FPU transmission device 12 to transmit the on-air video to the relay station 2 as return data.

The relay station 2 receives the send-back data of the channel 2 by the FPU receiving device 22, and modulates the material A data by the LDM method using the channel 1 by the LDM-FPU transmitting device 21 by the first modulation method, and UL. The data stream of LL is generated, the received send-back data is modulated by the second modulation method, the data stream of LL is generated and multiplexed, and the multiplexed signal is transmitted.
The trike station 3 receives the multiplexed signal of the channel 1 from the relay station 2 by the LDM-FPU receiving device 32, separates the LL data stream, demodulates it, and acquires the sent back data.

Conventional broadcasting stations have two FPU transmission devices for sending back, but this broadcasting transmission system requires only one line, improving line efficiency, simplifying the device configuration, and reducing costs. It is a thing.
Further, the FPU transmitting device and the FPU receiving device used in the broadcasting station 1 are the same as those in the conventional one, and it is not necessary to significantly change the configuration of the broadcasting station 1, and it can be realized at low cost.

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

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

Here, the FPU transmitting devices 12 and 31 perform modulation by, for example, the QPSK modulation method as the first modulation method, and the FPU receiving devices 11, 13 and 22 use, for example, the QPSK demodulation method as the first demodulation method. Demodulate with.
Further, the LDM-FPU transmission device 21 performs modulation by, for example, a QPSK modulation method as a first modulation method, and modulation by, for example, a 16QAM modulation method as a second modulation method when performing layer division multiplexing. conduct.
Further, when the LDM-FPU receiving device 32 performs layer separation, the demodulation is performed by, for example, the QPSK demodulation method as the first demodulation method, and the demodulation is performed by, for example, the 16QAM demodulation method as the second demodulation method. conduct.

[Structure of each part and data flow]
The configuration of each part will be described below based on the data flow.
In the trike station 3, the encoder 33 encodes the material B data for broadcasting taken and recorded by a camera or the like, and the FPU transmission device 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 the material B data to the decoder 14, and the decoder 14 decodes and outputs the material B data. ..

Further, in the broadcasting station 1, the encoder 15 encodes the send-back data, and the FPU transmission device 12 transmits the encoded return data to the relay station 2 via the 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, outputs the data to the decoder 23, and the decoder 23 decodes the data.

Further, the encoder 24 inputs the decoded data from the decoder 23, encodes it, and outputs it to the LDM-FPU transmission device 21. Further, the decoder 25 inputs and encodes the material A data for broadcasting from the camera, encodes it, and outputs it to the LDM-FPU transmission device 21.
Here, the relay station 2 may be configured to input the received data as it is to the LDM-FPU transmission device 21 without decoding and encoding.
Then, the LDM-FPU transmission device 21 modulates the material A data by the QPSK modulation method using the channel 1 by the LDM method to generate a UL data stream, and modulates the encoded feedback data by the 16QAM modulation method. LL data stream is generated, multiplexed and transmitted.

In the trike station 3, the LDM-FPU receiving device 32 receives the multiplexed signal transmitted from the LDM-FPU transmitting device 21 of the relay station 2 on channel 1, separates and encodes the LL data stream. The folded data is output to the decoder 34.
The decoder 34 demodulates the encoded return data from the LDM-FPU receiving device 32 and outputs the sent back data to the monitor.

Further, in the broadcasting station 1, the FPU receiving device 13 receives the multiplexed signal transmitted from the LDM-FPU transmitting device 21 of the relay station 3 on the channel 1, separates and encodes the UL data stream. The material A data is output to the decoder 16.
The FPU receiving device 13 can extract the material A data of the UL data stream from the multiplexed signal by demodulating by the QPSK demodulation method.
The decoder 16 demodulates and outputs the coded material A data from the FPU receiving device 13.

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

Approximately with the configuration of FIG. 3, when the video data taken by the trike station 3 is used on the air, a delay of 3 lines occurs in the FPU, and a delay of 3 opposites occurs in the encoder / decoder. .. Therefore, the time interleaving for 3 lines: 1134 msec (= 378 msec × 3) and the delay time of the encoder / decoder of 3 opposites: 300 msec (= 100 msec × 3) are 1.43 sec.

When video data other than the trike station 3 or the relay station 2 is on the air, a delay of two lines occurs in the FPU, 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 facing encoder / decoder: 200 msec (= 100 msec × 2) are 0.95 sec.
In either case, transmission of the sent back data with low delay can be realized.

[Modulation section of LDM transmission device: FIG. 4]
Next, the configuration of the modulation unit of the LDM-FPU transmission device 21 in the relay station 2 will be described with reference to FIG. FIG. 4 is an explanatory diagram showing a configuration of a modulation unit of the LDM-FPU transmission device in the relay station.
FIG. 4 shows a configuration in which UL data (UL data, material A data) and LL data (LL data, return data) are multiplexed in digital signal processing.

As shown in FIG. 4, the LDM system 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 and 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 are provided.
The subscript a is for processing UL data, and b is for processing LL data.

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

Further, the LL data is error-corrected 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 addeder 87. Is output to.
The LL data is modulated, for example, by 16QAM (Quadrature Amplitude Modulation).

Then, in the adder 87, the UL data and the weighted LL data are superposed, OFDM-modulated by the OFDM modulation unit 88, quadrature-modulated by the quadrature modulation unit 89, converted into an analog signal by the DAC unit 90, and illustrated. No FPU transmission Output to the high frequency section and transmitted wirelessly.

In this way, when multiplexing at the digital signal processing level, the QPSK-modulated first layer (UL) stream and the 16QAM-modulated second layer (LL) stream are multiplexed in the subsequent stage of the multi-level modulation section (mapping section). do. The size (ratio) of superimposing the streams of the second layer is adjusted by the weighting coefficient in the weighting unit 86.
In this way, the LDM-FPU transmission device 21 of the relay station 2 superimposes and transmits the material A data and the return data on the same line (channel 1).

The broadcasting station 1 has the same configuration as the conventional one and does not have an LDM-FPU receiving device. However, by receiving the multiplexed data stream and demodulating it by QPSK, the UL data is taken out and the material A is taken out. Data can be obtained.

[Demodulation unit of LDM type receiver: FIG. 5]
Next, the schematic configuration of the demodulation unit of the LDM-FPU receiving device in the trike station 3 will be described with reference to FIG. FIG. 5 is an explanatory diagram showing a schematic configuration of a demodulation unit of the LDM-FPU receiving device in the trike station.
As shown in FIG. 5, the demodulation unit is provided in the LDM-FPU receiver 32, includes a UL data demodulation unit 95, a delay buffer 96, and a subtractor 97, and is QPSK-modulated UL data. It operates as a separator that separates 16QAM-modulated LL data.

The received signal input to the demodulation unit of FIG. 5 is separated into two, one of which is demodulated for UL by the UL data demodulation unit 95 and QPSK-modulated UL data (QPSK) from the multiplexed signal. The modulation signal (UL data stream) is taken out, output to the demapping processing unit (not shown) for UL data, and input to the subtractor 97.

Further, the other received signal separated 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.
In the subtractor 97, by subtracting the QPSK modulated signal from the delayed received signal, a signal modulated by 16QAM (16QAM modulated signal, LL data stream) can be taken out, and this is a demapping processing unit for LL data. Output to.

That is, in the LDM-FPU receiving device 32 of the trike station 3, the UL QPSK modulation signal is used to separate the LL 16QAM modulation signal.
In the demapping processing unit for LL data, 16QAM demodulation is performed, and the demodulated send-back data is output to the monitor.

[Another broadcast transmission system: Figures 6-7]
Next, another broadcast transmission system will be described with reference to the drawings. FIG. 6 is a schematic explanatory diagram 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 a main relay station 4, a mobile station 5 (first mobile station) provided in the hall A, and a mobile station 6 (second mobile station) provided in the hall B. It is equipped with a mobile station).

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 the video / audio data 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 to 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 includes a transmission device (LDM-FPU transmission device) that is multiplexed and transmitted by the LDM method on the same spectrum of OFDM, and is a mobile station that transmits back data and the like using UL of channel 2. In addition to transmitting to 5, the send-back data and the like are transmitted to mobile station 6 using the LL of channel 2.
Further, the main relay station 4 has a receiving device (FPU receiving device) that receives the material data from the mobile station 5 on the channel 1 and a receiving device (FPU receiving device) that receives the material data from the mobile station 6 on the channel 3. It is equipped with.

The mobile station 5 separates the UL data stream from the multiplexed channel 2 and the transmission device (FPU transmission device) that transmits the acquired material data to the main relay station 4 on the channel 1, demodulates the data stream, and sends back the data. It is equipped with a receiving device (FPU receiving device) for acquiring the data.

The mobile station 6 separates and demodulates the LL data stream from the transmission device (FPU transmission device) that transmits the acquired material data to the main relay station 4 on the channel 3 and the received signal of the multiplexed channel 2. It is equipped with a receiving device (LDM-FPU receiving device) for acquiring return data and the like.

[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 in the hall A to the main relay station 4 on 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 the send-back data and the like generated from the received material data into the LL and UL of the channel 2 by the LDM method and transmits them to the mobile stations 5 and 6.
The mobile station 5 separates the UL data stream from the signal multiplexed on the channel 2 and demodulates the data stream to obtain back data and the like.
The mobile station 5 separates the LL data stream from the signal multiplexed on the channel 2, demodulates it, and obtains the send-back data and the like.

[Summary configuration of another broadcast transmission system: Fig. 7]
Next, a schematic configuration of another broadcast transmission system will be described with reference to FIG. 7. FIG. 7 is a schematic configuration diagram of another broadcast transmission system.
As shown in FIG. 7, the main relay station 4 includes an FPU receiving device (FPU RX) 41, 43 and an LDM-FPU transmitting device (LDM-FPU TX) 42, and the mobile station 5 is an FPU transmitting device (FPU transmitting device). The FPU TX) 51 and the FPU receiving device 52 are provided, and the mobile station 6 includes an FPU receiving device 61 and an LDM-FPU receiving device (LDM-FPU RX) 62.

The FPU receiving devices 41, 43, and 52 are broadcasting transmitting devices that receive material data for broadcasting.
The FPU transmitting devices 51 and 61 are broadcasting receiving devices that transmit material data for broadcasting.
The LDM-FPU transmission device 42 is a transmission device that multiplexes and transmits back data and the like by the LDM method in which different streams are superimposed on the same spectrum of OFDM. The modulation section of the LDM-FPU transmission device 42 is the same as that described with reference to FIG.
The LDM-FPU receiving device 62 is a receiving device that separates and demodulates the send-back data and the like from the signals multiplexed and transmitted by the LDM method. The demodulation unit of the LDM-FPU receiving device 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 and transmitted to the UL of the channel 2, and the instruction data B for the mobile station 6 may be transmitted to the LL of the channel 2.

The main relay station 4 receives the material data from the mobile station 5 using the channel 1 in the FPU receiving device 41, and receives the material data from the mobile station 6 using the channel 3 in the FPU receiving device 43.
Further, the main relay station 4 uses the channel 2 in the LDM-FPU transmission device 42 to multiplex the send-back data and the like and transmit the data to the mobile stations 5 and 6.

The conventional main relay station is equipped with two FPU transmission devices for sending back, but another broadcast transmission system requires only one line, improving line efficiency, simplifying the device configuration and reducing costs. It can be reduced.
Further, the FPU transmitting device and the FPU receiving device used in the mobile station 5 are the same as those in the conventional one, and it is not necessary to significantly change the configuration of the mobile station 5, and it can be realized at low cost.

In FIG. 7, the mobile stations 5 and 6 have different configurations, but when the mobile station is provided with an LDM-FPU receiving device and an FPU transmitting device and the data stream of the LL of the channel 2 is separated, the second is used. When acquiring the data demodulated by the demodulation method and separating the UL data stream of channel 2, the setting may be changed according to the device of the mobile station so as to acquire the data demodulated by the first demodulation method. , Can be used with one type of mobile station.

[Effect of embodiment]
According to this 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 sends the material B data to the relay station 2 and the trike station 3. FPU multiplex transmission device 21 that transmits the send-back data, the relay station 2 modulates the send-back data received from the broadcasting station 1 and the material A data by a different modulation method, and multiplexes each data stream and transmits them on the same line. The trike station 3 is provided with an FPU multiplex receiver 32 that receives the multiplexed and transmitted signals, separates them into two data streams, and demolishes the sent-back data. The A data and the data sent back to the trike station 3 can be multiplexed and transmitted on the same line, which has the effect of improving the line efficiency and reducing the cost by not using the general network.

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. The main relay station 4 is provided with an FPU multiplex transmission device 42 that transmits the send-back data to the 6th, the send-back data is modulated by a different modulation method, and each data stream is multiplexed and transmitted on the same line, and the mobile station 5 is multiplexed. It is provided with an FPU receiving device 52 that receives the transmitted signal, separates it into two data streams, and demolishes the data sent back from the first layer, and the mobile station 6 transmits the multiplexed and transmitted signal. It is provided with an FPU multiplex receiving device 62 that receives, separates into two data streams, and demolishes the sent back data from the second layer, and the main relay station 4 multiplexes the sent back data to the mobile station 5 and the mobile station 6. It can be converted and transmitted on the same line, which has the effect of improving the line efficiency and reducing the cost by not using the general network.

The present invention is suitable for a broadcast transmission system capable of improving line efficiency and reducing costs when sending back broadcast materials to a relay site with low delay.

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 Receiver, 33 ... Encoder, 34 ... Decoder, 41 ... FPU receiver, 42 ... LDM-FPU transmitter, 43 ... FPU receiver, 51 ... FPU transmitter, 52 ... FPU receiver, 61 ... FPU receiver, 62 ... LDM-FPU receiver, 71 ... Broadcasting station, 72 ... Relay station, 73 ... Trike station, 74 ... Main relay station, 75 ... Mobile station, 76 ... Mobile station, 83a, 83b ... FEC section, 84a, 84b ... Bit Interleave section, 85a, 85b ... Mapping section, 86 ... Weight section, 87 ... Adder, 88 ... OFDM modulation section, 89 ... Orthogonal modulation section, 90 ... DAC section, 95 ... UL data demodulation section, 96 ... Delay buffer, 97 … Subtractor

Claims (3)

It is a broadcast transmission system that transmits material data for broadcasting and also transmits back data that sends back the video being broadcast.
Using the first channel, the second channel, and the third channel,
The first material data is first modulated by a layered division multiplexing method in which the sent back data is received from the second channel and the same spectrum is superimposed on the OFDM spectrum using the first channel. A first broadcasting device that generates, multiplexes, and transmits a first-layer stream modulated by a method and a second-layer stream obtained by modulating the sent-back data by a second modulation method.
A second broadcasting device that extracts the stream of the second layer from the first channel, receives the return data, and transmits the second material data on the third channel.
A broadcast transmission system comprising a third broadcasting device that receives the second material data from the third channel and transmits the return data on the second channel. It is a broadcast transmission system that transmits material data for broadcasting and also transmits back data that sends back the video being broadcast.
Using the first channel, the second channel, and the third channel,
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 superimpose the same spectrum on the OFDM spectrum. By the layered division multiplex method, a stream of the first layer in which the feedback data is modulated by the first modulation method and a stream of the second layer in which the sendback data is modulated by the second modulation method are generated. , The first broadcasting device to multiplex and transmit,
A second broadcasting device that extracts a stream of the first layer from the second channel, receives the return data, and transmits the first material data on the first channel.
It is characterized by having a third broadcasting device that extracts a second layer stream from the second channel, receives the return data, and transmits the second material data on the third channel. Broadcast transmission system. The broadcast transmission system according to claim 1 or 2, wherein the instruction data is used instead of the return data, and different instruction data is included in the data stream of the first layer and the data stream of the second layer.

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