JP7144138B2 - Broadcast transmission equipment - Google Patents

Description

The present invention relates to a broadcast transmission apparatus for transmitting video/audio data as a material for broadcasting, and in particular, it is possible to stably transmit and receive additional data without interfering with the transmission of video/audio data. It relates to a broadcast transmission device.

[Description of prior art]
2. Description of the Related Art Conventionally, an FPU (Field Pickup Unit) transmission system has been used to transmit broadcast materials (video, audio). The FPU system is used as a broadcasting transmission device for relaying programs and transmitting captured images to broadcasting stations.

By the way, depending on the program, there are cases where it is desired to superimpose and transmit data (digital data) other than video and audio, such as road race odometer data.
In such a case, conventionally, digital data is transmitted using empty data such as the NULL portion of a TS (Transport Stream) packet.

However, depending on the type of video data and the transmission rate, NULL packets may not occur. Therefore, in order to transmit digital data, it is necessary to operate the transmission rate with a sufficient margin.

In addition, digital data other than conventional video and audio broadcast materials, such as news manuscripts, text files containing information obtained from field interviews, image files taken with a digital camera, and audio files obtained with a voice recorder, are available. , there is also a case where you want to send from the relay site to the broadcasting station.

In such a case, conventionally, an e-mail is sent using a mobile phone line, but it cannot be used outside the communication area of the mobile phone.
There is also a file transmission system that converts digital data into TS packets and transmits them using a dedicated line of the FPU, but in that case, one line is occupied for data transmission.

[Conventional transmission system: FIG. 12]
Here, the configuration of a conventional broadcast transmission apparatus will be described with reference to FIG. FIG. 12 is an explanatory diagram showing a schematic configuration of a conventional broadcast transmission apparatus.
As shown in FIG. 12, the conventional broadcast transmission apparatus includes a camera 71, an encoder 72, a PC 73, a file transmission adapter 74, an FPU transmission control section 75, and an FPU transmission high frequency section 76 on the transmission side. , an FPU reception high-frequency unit 77, an FPU reception control unit 78, a decoder 79, a file transmission adapter 80, a monitor 81, and a PC 82 on the receiving side.

The operation of a conventional broadcast transmission device will be described.
On the transmission side, the video/audio data (SDI data) input from the camera 71 is encoded by the encoder 72, converted into TS packets, and sent to the FPU transmission control unit 75 using the line for TS1 (TS1 line). transmitted.
Digital data input from the PC 73 is converted into TS packets by the file transmission adapter 74 and transmitted to the FPU transmission control unit 75 through the line for TS2 (TS2 line).

The FPU transmission control unit 75 performs signal processing for wireless transmission such as combining the signals from the TS1 line and the TS2 line, and outputs an IF (Intermediate Frequency) signal to the FPU transmission high frequency unit 76. , converted into a high-frequency signal by the FPU transmission high-frequency unit 76, and transmitted by radio.

On the receiving side, the radio signal received by the FPU reception high-frequency unit 77 is converted into an IF signal and signal-processed by the FPU reception control unit 78, resulting in TS packets of video/audio data and TS packets of digital data. separated into

The TS packets of video/audio data are transmitted to the decoder 79 through the line for TS1 (TS1 line), decoded by the decoder 79 and transmitted to the monitor 81 as an SDI signal, and the monitor 81 outputs video and audio. .
The TS packet of digital data is transmitted to the file transmission adapter 80 through the line for TS2 (TS2 line), converted into digital data, and output to the PC 82 .

[Hierarchical demultiplexing method]
Next, in OFDM (Orthogonal Frequency Division Multiplexing), a layered division multiplexing (LDM) system in which different streams are superimposed on the same spectrum will be briefly described.
Here, it is assumed that the main data is video/audio data, and the sub data is digital data as additional data.

[Digital multiplexing: Fig. 13]
First, the configuration of a modulation section that performs digital multiplexing will be described with reference to FIG. FIG. 13 is an explanatory diagram showing a schematic configuration of an LDM modulation unit (digital multiplexing method). The modulation section corresponds to the FPU transmission control section 75 shown in FIG.
FIG. 13 shows a configuration for multiplexing main data and sub-data in digital signal processing.

As shown in FIG. 13, 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 section 86, an adder 87, an OFDM modulation section 88, a quadrature modulation section 89, and a DAC (Digital Analog Converter) section 90 are provided.
The suffix a is for main data, and the suffix b is for sub data.

13, the main data is error-correction coded by the FEC section 83a, bit interleaved by the bit interleaving section 84a, mapped by the mapping section 85a, and output to the adder 87. FIG.
Here, the main data is QPSK (Quadrature Phase Shift Keying) modulated, for example.

The sub-data is error-correction coded by the FEC unit 83b, bit-interleaved by the bit interleaver 84b, mapped by the mapping unit 85b, given weighting by the weighting unit 86, and output to the adder 87. be done.
The sub-data is 16QAM (Quadrature Amplitude Modulation) modulated, for example.

Then, in the adder 87, the main data and the weighted sub-data are superimposed, OFDM-modulated by the OFDM modulation section 88, quadrature-modulated by the quadrature modulation section 89, and converted to an analog signal by the DAC section 90. 12 is output to the FPU transmission high-frequency unit 76 and wirelessly transmitted.

In this way, when multiplexing at the digital signal processing level, the QPSK-modulated first layer stream and the 16QAM-modulated second layer stream are multiplexed after the multilevel modulation unit (mapping unit). The size (ratio) of superimposing the stream of the second layer is adjusted by the weighting coefficient in the weighting unit 86 .

[Analog multiplex system: Fig. 14]
Next, the configuration of the modulation section based on analog multiplexing will be described with reference to FIG. FIG. 14 is an explanatory diagram showing a schematic configuration of an LDM modulation unit (analog multiplexing method).
As shown in FIG. 14, in the case of analog multiplexing, OFDM modulation sections 91a and 91b, quadrature modulation sections 92a and 92b, DAC sections 93a and 93b, and an adder 94 are provided.
The suffix a is for main data and b is for sub data, and the processing of each section is the same as in the case of the digital multiplexing method.

In the analog multiplexing method, the adder 94 multiplexes the analog signals after the DAC sections 93a and 93b.
In the configuration of the analog multiplexing method, two systems of digital circuit portions before multiplexing are required, so that the circuit scale and power consumption become large.

[LDM demodulator: FIG. 15]
Next, the LDM demodulator will be described with reference to FIG. FIG. 15 is an explanatory diagram showing a schematic configuration of an LDM demodulator.
As shown in FIG. 15, the demodulation section is provided in the FPU reception control section 78 shown in FIG. 16QAM-modulated main data and 16QAM-modulated sub-data.

The received signal input to the demodulator in FIG. 15 is separated into two, one of which is demodulated in the first layer by the main data demodulator 95, and the QPSK-modulated main data ( QPSK modulated signal) is extracted and output to a demapping processor (not shown) for main data and input to a subtractor 97 .

The other separated received signal is delayed by the time required for demodulation of the first layer in the delay buffer 96 and is input to the subtractor 97 .
The subtractor 97 can extract a 16QAM-modulated signal (16QAM-modulated signal) by subtracting the QPSK-modulated signal from the delayed received signal, and outputs it to the sub-data demapping processor.

The main data demapping processor performs QPSK demodulation, and the demodulated main data is output to the decoder 79 via the line TS1.
The sub-data demapping processor performs 16QAM demodulation, and the demodulated sub-data is output to the file transmission adapter 80 via the line TS2.

[Related technology]
Incidentally, as conventional technologies related to broadcast transmission devices, there are Japanese Unexamined Patent Application Publication No. 2017-41781 “Receiving Apparatus” (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2014-64273 “Transmitting Apparatus” (Patent Document 2).
Patent Literature 1 describes a receiving apparatus that efficiently controls the orientation of a plurality of receiving antennas for multi-receiving by following the position of a transmitting antenna of a mobile station.
Patent Literature 2 describes a transmission device that improves transmission characteristics in a transmission line under bad conditions by adding a TMCC carrier inversion operation.
Also, there is Non-Patent Document 1 as a standard for transmission of television broadcast program material.

JP 2017-41781 A JP 2014-64273 A

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

However, in a conventional broadcast transmission device, when digital data (additional data) is superimposed on the NULL portion of a TS packet, the amount of data in the NULL packet varies depending on the type of video/audio data, so the transmission rate of the digital data is low. was not stable.

Also, with conventional broadcast transmission equipment, when digital data is converted into TS packets and transmitted, one line is occupied for the transmission of digital data. had the problem that the transmission of digital data had to be temporarily stopped.

In addition, in the conventional transmission system, when sending digital data using mail of a mobile phone, there was a problem that it could not be sent from outside the service area.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a broadcast transmission apparatus capable of stably transmitting digital data without interfering with the transmission of video/audio data.

In order to solve the above-described problems of the prior art, the present invention uses data including either video/audio data for broadcasting or digital data as first data, and video/audio data for broadcasting different from the first data. Broadcast transmission equipment for multiplexing and transmitting data including either audio data or digital data as second data, wherein the multiplexing method is a hierarchical division multiplexing method in which the same spectrum is superimposed on the spectrum of OFDM. on the transmitting side to generate a first layer stream obtained by modulating the first data with the first modulation method and a second layer stream obtained by modulating the second data with the second modulation method. and a modulation unit for weighting and multiplexing with the weighting coefficients of the first layer and the weighting coefficients of the second layer. and based on the weighting factor of the second hierarchy, perform demodulation corresponding to the first modulation scheme to demodulate and output the first data, and perform demodulation corresponding to the second modulation scheme to output the second data. and a demodulator for demodulating and outputting the data of the first data and the second data. Regarding video/audio data and digital data, when there is no input of video/audio data for broadcasting and there is input of digital data, when there is input of both video/audio data for broadcasting and digital data, and when there is input of video/audio data for broadcasting and digital data A weighting selection table is provided in which weighting coefficients in the first hierarchy and weighting coefficients in the second hierarchy are defined corresponding to cases where video/audio data is input and digital data is not input, and a video/audio data for broadcasting is provided. The presence or absence of input of audio data and digital data is detected, based on the weighting selection table, the weighting factor of the first hierarchy and the weighting factor of the second hierarchy are selected according to the detection result, and the video/audio data for broadcasting and When all the digital data are input, a plurality of combinations of the weighting coefficients of the first hierarchy and the weighting coefficients of the second hierarchy are stored according to the type of video/audio data for broadcasting and the degree of importance of the digital data. The weighting factor of the first layer and the weighting factor of the second layer specified from the weighting setting table are set in the weighting selection table .

Further, in the broadcast transmission apparatus of the present invention, the demodulation section demodulates the multiplexed and transmitted signal corresponding to the first modulation scheme, demodulates the first data, and outputs the demodulated data. modulates the demodulated first data again with the first modulation method, multiplies the modulated first data by the reciprocal of the weighting factor of the first layer, and delays the multiplexed and transmitted signal. and subtracting the first data modulated again and multiplied by the reciprocal of the weighting factor of the first layer from the signal obtained by multiplying the reciprocal of the weighting factor of the second layer to separate the stream of the second layer, It is characterized by demodulating digital data from the stream of the second layer.

Further, according to the present invention, in the broadcast transmission apparatus described above, the weighting factors of the first hierarchy and the weighting factors of the second hierarchy are included in the transmission multiplex control signal.

Further, in the above broadcast transmission apparatus, when changing the setting information including the information of the modulation method for the first data or the second data, the transmission multiplex control of the setting information after the change is performed on the transmission side. After being included in a signal frame and transmitted, the first data or second data modulated based on the changed setting information is transmitted from the next frame, and the receiving side transmits the setting information of the transmission multiplex control signal is monitored, and when the difference is detected, the first data or the second data received in the next frame is demodulated based on the setting information from which the difference is detected.

According to the present invention, data including either video/audio data for broadcasting or digital data is set as the first data, and either video/audio data for broadcasting or digital data different from the first data is used. A broadcast transmission apparatus for multiplexing and transmitting data including data as second data, wherein the multiplexing method uses a hierarchical division multiplexing method in which the same spectrum is superimposed on the spectrum of OFDM, and on the transmitting side, the first A first layer stream obtained by modulating the data of the first layer with a first modulation method and a second layer stream obtained by modulating the second data with a second modulation method are generated, and the first layer of the stream is generated. Equipped with a modulation unit that weights and multiplexes with the weighting factor and the weighting factor of the second layer, and on the receiving side, for the multiplexed and transmitted signal, the weighting factor of the first layer and the weighting factor of the second layer demodulation corresponding to the first modulation scheme to demodulate and output the first data, and demodulation corresponding to the second modulation scheme to demodulate and output the second data. section, and when the modulation section sets one of the first data and the second data to video/audio data for broadcasting and the other to digital data, for the video/audio data for broadcasting and the digital data, When there is no input of video/audio data for broadcasting and there is input of digital data, when there is input of both video/audio data for broadcasting and digital data, and when there is input of video/audio data for broadcasting and digital data Presence or absence of input of video/audio data and digital data for broadcasting, provided with a weighting selection table that defines the weighting coefficients of the first hierarchy and the weighting coefficients of the second hierarchy corresponding to each case of no data input. is detected, and based on the weighting selection table, the weighting factor of the first hierarchy and the weighting factor of the second hierarchy are selected according to the detection result. If there is also an input, from a weighting setting table that stores a plurality of combinations of weighting coefficients of the first hierarchy and weighting coefficients of the second hierarchy according to the type of video/audio data for broadcasting and the importance of digital data , the specified weighting factors of the first hierarchy and the weighting factors of the second hierarchy are set in the weighting selection table, so that the weighting factors of the first hierarchy and the weighting factors of the second hierarchy are appropriately adjusted. As a result, the transmission of one of the first data and the second data can be stably transmitted without hindering the transmission of the other data. When there is no input of audio data, by setting the weighting factor of one corresponding layer to 0 and the weighting factor of the other layer to 1, a large amount of digital data can be transmitted, and video/audio data can be transmitted. If there is an input, one of the corresponding weighting coefficients is set to 1, and the other weighting coefficient is set to be smaller than that, so that digital data can continue to be transmitted without interfering with the transmission of video/audio data. , it enables stable transmission, and has the effect of being able to change the weighting coefficient according to the type of video/audio data, the importance of digital data, and the like.

Further, according to the present invention, the demodulator demodulates the multiplexed and transmitted signal in accordance with the first modulation scheme, demodulates and outputs the first data, and outputs the demodulated data. The first data is again modulated by the first modulation method, the modulated first data is multiplied by the reciprocal of the weighting factor of the first layer, and the multiplexed and transmitted signal is delayed to obtain the second modulation method. The first data modulated again and multiplied by the reciprocal of the weighting factor of the first layer is subtracted from the signal multiplied by the reciprocal of the weighting factor of the layer to separate the stream of the second layer. Since the above broadcast transmission apparatus demodulates digital data from a stream, by appropriately adjusting the weighting coefficients of the first hierarchy and the weighting coefficients of the second hierarchy, one of the first data and the second data is The other data can be stably transmitted without disturbing the transmission of the other data, and the demodulation can be performed with high accuracy.

Further, according to the present invention, when changing the setting information including the modulation scheme information for the first data or the second data, the transmitting side stores the changed setting information in the frame of the transmission multiplex control signal. After transmitting the first data or second data modulated based on the changed setting information from the next frame, the receiving side monitors the difference of the setting information of the transmission multiplex control signal. Then, when the difference is detected, the first data or the second data received in the next frame is demodulated based on the setting information from which the difference is detected, so that the setting information is changed. In this case, the transmitting side can transmit the new setting information one frame earlier to notify the receiving side of the new setting information, and the receiving side can reliably perform demodulation using the new setting information. This has the effect of making it possible to smoothly change the setting information.

FIG. 3 is a configuration block diagram of an FPU transmission control section of the transmission device; 2 is a configuration block diagram of a TS1 transmission processing unit 13 shown in FIG. 1; FIG. FIG. 4 is an explanatory diagram showing input and output in a weighting setting unit; FIG. 4 is a schematic explanatory diagram of a weighting selection table; FIG. 4 is a schematic explanatory diagram of a weighting setting table; FIG. 3 is a schematic explanatory diagram showing a transmission image in this transmitting device; FIG. 4 is an explanatory diagram showing TMCC data in the present broadcast transmission device; 3 is a configuration block diagram of an FPU reception control section of this reception apparatus; FIG. FIG. 10 is an explanatory diagram showing the flow of TMCC and second layer data when changing the second layer parameters; FIG. 10 is an explanatory diagram showing the flow of TMCC and first layer data when changing a first layer parameter; 1 is a schematic configuration diagram of a transmission system to which a broadcast transmission device according to an embodiment is applied; FIG. 1 is an explanatory diagram showing a schematic configuration of a conventional broadcast transmission device; FIG. FIG. 4 is an explanatory diagram showing a schematic configuration of an LDM modulation unit (digital multiplexing method); FIG. 3 is an explanatory diagram showing a schematic configuration of an LDM modulation unit (analog multiplexing method); FIG. 4 is an explanatory diagram showing a schematic configuration of an LDM demodulator;

An embodiment of the present invention will be described with reference to the drawings.
[Outline of Embodiment]
A broadcast transmission apparatus according to an embodiment of the present invention multiplexes and transmits video/audio data as main data and digital data as sub-data using the LDM method. , a first layer stream obtained by modulating main data with a first modulation method and a second layer stream obtained by modulating sub data with a second modulation method, depending on the presence or absence of input of main data and sub data. , are multiplied by respective weighting coefficients, multiplexed and transmitted, and on the receiving side, the FPU reception control unit demodulates the multiplexed received signals corresponding to the first modulation scheme to extract main data, and A signal obtained by modulating the main data again with the first modulation method and multiplying it by the reciprocal of the weighting factor of the first layer is converted from a signal obtained by delaying the multiplexed received signal and multiplying the reciprocal of the weighting factor of the second layer. Subtraction is performed, and the result of subtraction is demodulated in accordance with the second modulation method to extract digital data. Therefore, main data can be mainly transmitted, and sub-data can also be transmitted. When there is no data, the weight of the digital data is increased, and when there is video/audio data, the weight of the digital data is decreased and multiplexed. It is possible to stably continue the transmission of digital data.

Here, video/audio data is used as main data as the first data, and digital data is used as sub data as the second data. and the second data may be both video/audio data or digital data.

In addition, here, more effective modulation schemes and demodulation schemes will be mainly described, but other modulation schemes may be used. A direct demodulation method may be used.

[Configuration of transmission device according to embodiment: FIG. 1]
A configuration of a transmission device (this transmission device) used on the transmission side of a broadcast transmission device (this broadcast transmission device) according to an embodiment of the present invention will be described.
The basic configuration of this transmission device is the same as that of the transmission side of the conventional broadcast transmission device shown in FIG.

FIG. 1 is a configuration block diagram of the FPU transmission control section of this transmission device.
The FPU transmission control unit of this transmission device generates transmission data by multiplexing main data (video/audio data) and sub-data (digital data) according to the LDM method. , DVB-ASI (Digital Video Broadcasting-Asynchronous Serial Interface) interfaces 11 and 12, a TS1 transmission processing unit 13, a TS2 transmission processing unit 14, a weight setting unit 15, multipliers 16 and 17, and an adder 18 , OFDM frame configuration unit 19, AC (Auxiliary Channel) generation unit 21, CP (Continual Pilot) generation unit 22, TMCC (Transmission and Multiplexing Configuration Control; transmission multiplexing control signal) generation unit 23, IFFT (Inverse Fast Fourie Transform) section 24 , GI (Guard Interval) addition section 25 , and digital quadrature modulation section 26 .

Each section of the FPU transmission control section will be described.
The DVB-ASI interface 11 inputs video/audio data from the encoder 72 shown in FIG.
The DVB-ASI interface 12 inputs digital data from the file transmission adapter shown in FIG.

The TS1 transmission processing unit 13 performs signal processing associated with wireless transmission, such as error correction coding and modulation, on the data of the first layer (TS1 data: video/audio data). The TS1 transmission processing unit 13 QPSK-modulates the TS1 data. QPSK modulation is the first modulation scheme recited in the claims.
The configuration of the TS1 transmission processing unit 13 will be described later.
The TS2 transmission processing unit 14 performs signal processing accompanying wireless transmission on the data of the second layer (TS2 data: digital data). The TS2 transmission processing unit 14 modulates the TS2 data with 16QAM. 16QAM is a second modulation scheme.

The weighting setting unit 15 is a characteristic part of this transmitting apparatus, and sets the weighting coefficient g1 to be multiplied by the TS1 data in the multiplication unit 16, and sets the weighting coefficient g2 by which the TS2 data is multiplied in the multiplication unit 17.
Here, as a feature of this transmitting apparatus, the weighting setting section 15 changes and sets the weighting coefficients g1 and g2 in accordance with an instruction from the control section (to be described later) and whether TS1 data and TS2 data are input.
The operation of the weight setting unit 15 will be described later.

The multiplier 16 multiplies the TS1 data output from the TS1 transmission processor 13 by the weighting coefficient g1.
The multiplier 17 multiplies the TS2 data output from the TS2 transmission processor 14 by the weighting coefficient g2.
The adder 18 multiplexes the g1-weighted TS1 data and the g2-weighted TS2 data to generate transmission data.

The AC generator 21, CP generator 22, and TMCC generator 23 generate subcarriers containing various control information associated with transmission and reception.
The AC generator 21 generates an additional information signal regarding transmission control of modulated waves.
CP generator 22 generates a pilot signal.
The TMCC generator 23 generates control information such as parameters for error correction and multilevel modulation.

The OFDM frame construction unit 19 arranges the multiplexed transmission data, AC signal, pilot signal, and TMCC at predetermined positions to generate an OFDM frame.
The IFFT unit 24 transforms the input signal onto the frequency axis.
A GI adding unit 25 adds a guard interval signal.
The digital quadrature modulation section 26 quadrature-modulates the input signal and outputs it to the FPU transmission high-frequency section 76 shown in FIG.

The operation of the FPU transmission control unit of this transmission device will be briefly described.
In the FPU transmission control section of this transmission device, the TS1 data (video/audio data) input from the DVB-ASI interface 11 is subjected to error correction coding and modulation in the TS1 transmission processing section 13, and weighting coefficients in the multiplication section 16. It is multiplied by g1 and output to the adder 18 .

Similarly, the TS2 data (digital data) input from the DVB-ASI interface 12 is subjected to error correction coding and modulation in the TS2 transmission processing section 14, multiplied by the weighting coefficient g2 in the multiplication section 17, and added by the adder 18. output to

The adder 18 multiplexes the TS1 data and the TS2 data weighted by a predetermined weight, and inputs them together with the AC, CP, and TMCC information to the OFDM frame construction unit 19 to generate an OFDM frame, and the IFFT unit 24 performs inverse Fourier transform, GI addition section 25 adds a guard interval, digital quadrature modulation is performed in digital quadrature modulation section 26, and output to FPU transmission high frequency section 76 shown in FIG.
The modulated signal is up-converted in the FPU transmission high-frequency unit 76 and sent out as a radio signal.

[Configuration of TS1 transmission processing unit: FIG. 2]
Next, the configuration of the TS1 transmission processing section 13 shown in FIG. 1 will be specifically described using FIG. FIG. 2 is a configuration block diagram of the TS1 transmission processing section 13 shown in FIG.
As shown in FIG. 2, the TS1 transmission processing unit 13 includes a data frame synchronization unit 31, an energy spreading unit 32, an outer coding unit 33, a byte interleaving unit 34, an inner coding unit 35, and a frequency interleaving unit. 36 , a time interleaver 37 and a mapping unit 38 .

Since each part of the TS1 transmission processing part 13 is described in JP-A-2014-64273, a detailed description thereof will be omitted.
Also, the configuration and operation of the TS2 transmission processing unit 14 are the same as those of the TS1 transmission processing unit 13 .
However, the encoding processing in the inner coding unit 35 and the multilevel modulation processing in the mapping unit 38 are performed differently for each transmission system so that the intra-symbol distance between the two transmission systems is increased.

[Input/output in the weighting setting part: Fig. 1, Fig. 3]
Next, input/output in the weighting setting unit 15 shown in FIG. 1 will be described with reference to FIGS. 1 and 3. FIG. FIG. 3 is an explanatory diagram showing input and output in the weighting setting section.
As shown in FIGS. 1 and 3, the weighting setting unit 15 includes a DVB-ASI interface 11 for inputting first layer data, a DVB-ASI interface 12 for inputting second layer data, and a control panel information processing unit. An instruction from the unit 30 is input, and weighting coefficients g1 and g2 are selected according to the input and output to the multipliers 16 and 17. FIG.
The weighting setting unit 15 has a weighting selection table that specifies weighting coefficients g1 and g2 corresponding to the presence or absence of data input from the DVB-ASI interfaces 11 and 12. FIG.
The weighting selection table will be described later.

First layer data (TS1 data; video/audio data) is input from the DVB-ASI interface 11, and the weighting setting unit 15 monitors whether TS1 data is input or not.
Second layer data (TS2 data; digital data) is input from the DVB-ASI interface 12, and the weight setting unit 15 monitors whether or not TS2 data is input.

The control panel information processing section 30 is a control section of a control panel operated by an operator, and stores in advance a plurality of combinations of weighting coefficients g1 and g2 (p and q to be described later). Then, it selects an appropriate combination from the stored combinations and outputs an instruction to the weighting setting unit 15 according to the operator's operation or the like.

[Weighting selection table: Fig. 4]
A weighting selection table stored in the weighting setting unit 15 will be described with reference to FIG. FIG. 4 is a schematic explanatory diagram of a weighting selection table.
As shown in FIG. 4, the weighting selection table stores the presence/absence of TS1 data and TS2 data in association with combinations of weighting coefficients g1 and g2.

Specifically, as shown in FIG. 4, when TS1 data is "absent" and TS2 data is "present", only TS2 data can be transmitted. there is
In such a case, the micro circuit can be used only for transmission of TS-packetized digital data.
Conversely, when TS1 data is "present" and TS2 data is "absent," the weighting coefficients are g1=1 and g2=0.

As a feature of this apparatus, g1=p and g2=q are set when both TS1 data and TS2 data are "present". That is, when both TS1 data and TS2 data are input, they are weighted and multiplexed with weighting coefficients g1=p and g2=q, respectively.

p and q are variable values set by instructions from the control panel information processing section 30 .
Here, the TS1 data is video/audio data and should be preferentially transmitted, so basically p>q, and the values of p and q do not hinder the transmission of the video/audio data. However, it can be changed according to the type of video/audio data and the degree of importance of digital data.

Furthermore, in this transmitting device, p and q are set to values other than zero. In other words, when both TS1 data and TS2 data are input, both are transmitted although the degree of weighting is changed.
As a result, even if there is video/audio data to be transmitted, this transmission device can superimpose and transmit the digital data to the extent that the transmission is not hindered, and the digital data can be stably and continuously transmitted. It is possible.

[Weighting setting table: FIG. 5]
Next, the weighting setting table provided in the control panel information processing section 30 will be explained using FIG. FIG. 5 is a schematic explanatory diagram of a weighting setting table.
As shown in FIG. 5, the weighting setting table stores combinations of values of p and q in the weighting selection table described above in association with combination numbers.
Specifically, in the example of FIG. 5, the combination number k is "p=1, q=0.1", the combination number m is "p=1, q=0.2", and the combination number n is "p= 1, q=0.3” are stored.

When receiving an input from the control panel, the control panel information processing section 30 identifies a predetermined combination number according to the type of video/audio data or digital data, and refers to the weighting setting table. , the values of p and q corresponding to the combination number are read, and the weighting setting unit 15 is instructed with the values of p and q.
In other words, the control panel information processing unit 30 stores in advance combination numbers that are optimal p and q according to the types of video/audio data and digital data.
When the instruction is input, the weighting setting unit 15 updates p and q in the weighting selection table with the instructed values, and performs weighting setting according to the presence or absence of input data.

For example, in the middle of a file transmission in which only TS2 data is being transmitted, if relaying is started or something that requires sudden on-air occurs, TS1 data and TS2 data are input, and TS1 data is transmitted. With the data weighting factor g1(p)=1 and the TS2 data weighting factor g2(q)=0.2, both TS packets are superimposed and transmitted.

When video/audio data is not input for a long time, such as at night, the control panel information processing section 30 instructs the weighting setting section 15 to forcibly transmit TS2 data preferentially ( TS2 priority instruction) may be transmitted.

When the TS2 priority instruction is input, weighting setting unit 15 sets g1=0 and g2=1 in multipliers 16 and 17 without referring to the weighting selection table.
When an instruction to cancel the TS2 priority instruction is input from the control panel information processing section 30, the weighting setting section 15 selects a weighting factor according to the presence or absence of data input from the DVB-ASI interfaces 11 and 12. return.
Similarly, the control panel information processing section 30 may transmit an instruction (TS1 priority instruction) to forcibly prioritize transmission of TS1 data.

[Transmission image in this transmitter: Fig. 6]
Next, a transmission image in this transmitting device will be described with reference to FIG. FIG. 6 is a schematic explanatory diagram showing a transmission image in this transmitting device.
In FIG. 6, the horizontal axis represents time and the vertical axis represents transmission power. In period T1, video/audio data is ON (data is input). A large amount of transmission power is allocated to transmission of the layer stream, and the stream of the second layer is also transmitted at the same time.
As described above, the second layer stream is weighted so as not to interfere with the first layer data transmission.

During the period T2, since the video/audio data is OFF (no data input), only the second layer stream is transmitted with the first layer weighting coefficient g1=0 and the second layer weighting coefficient g2=1. .
In the period T3, since the video/audio data is turned ON again, the data of the first layer and the data of the second layer are multiplexed and transmitted with predetermined weighting based on the weighting selection table.

As described above, the present transmission device can continuously and stably transmit the digital data of the second layer regardless of whether the data of the first layer is ON/OFF. During a period in which there is no data, the data of the second layer can be preferentially transmitted.

[TMCC data in this broadcasting transmission device: FIG. 7]
Next, TMCC data in this broadcast transmission apparatus will be explained using FIG. FIG. 7 is an explanatory diagram showing TMCC data in this broadcast transmission apparatus.
As shown in FIG. 7, the TMCC data includes various setting information such as error correction and multilevel modulation parameters for the TS packet of the first layer following the synchronization signal (SYNC). Setting information about the TS packets of the second layer to be superimposed and LDM weighting information are loaded.

The setting information of the second layer includes parameters for error correction and multilevel modulation.
The LDM weighting information is the values of the weighting coefficient g1 of the first layer and the weighting coefficient g2 of the second layer described above.
These pieces of information are used for demodulation on the receiving side.

[Configuration of Receiving Apparatus According to Embodiment: FIG. 8]
Next, the configuration of a receiving device (this receiving device) used on the receiving side of this broadcast transmission device will be described.
This receiving apparatus has the same basic configuration as the receiving side of the conventional broadcast transmission apparatus shown in FIG. 12, but differs from the conventional one in the configuration and operation of the FPU reception control section.

FIG. 8 is a configuration block diagram of the FPU reception control section of this reception apparatus.
The FPU reception control section of this receiver receives the data multiplexed and transmitted by the LDM system from the transmitter shown in FIG. 1, separates it into main data and sub-data, and demodulates the data. , an OFDM demodulation unit 41, a first layer demapping unit 42, a first layer error correction decoding unit 43, a remapping unit 44, a delay unit 45, multipliers 46 and 47, a subtractor 48, and a A second layer demapping section 49 and a second layer error correction decoding section 50 are provided.

Each section of the FPU reception control section will be described.
The OFDM demodulator 41 FFT-converts the multiplexed data after the orthogonal demodulation and OFDM-demodulates it.
The first layer demapping unit 42 performs demapping (here, QPSK demodulation) on the multiplexed signal corresponding to the multilevel modulation applied by the mapping unit of the TS1 transmission processing unit of the transmission device, Extract the data of the first layer.

The first layer error correction decoding unit 43 performs error correction decoding corresponding to the error correction encoding performed by the TS1 transmission processing unit of the transmission device, and outputs demodulated first layer data.
The remapping unit 44 remaps the demodulated first layer data by QPSK modulation. The remapped data is used for layer 2 demodulation.

The delay unit 45 delays the OFDM-demodulated multiplexed data by the time required for demodulation and remapping of the first layer.
The multiplier 46 multiplies the remapped first layer data by the reciprocal of the first layer weighting coefficient g1.
The multiplier 47 multiplies the delayed multiple data by the reciprocal of the weighting coefficient g2 of the second layer.

A subtractor 48 subtracts the weight-removed first layer remapping data from the weight-removed multiplexed data to extract the second layer data modulated by 16QAM.
A second layer demapping unit 49 demodulates the output of the subtractor 48 with 16QAM and outputs second layer data.
The second layer error correction decoding unit 50 performs error correction decoding corresponding to the error correction encoding performed by the TS2 transmission processing unit of the transmitting apparatus, and outputs demodulated second layer data.

The operation of the FPU reception control section of this reception apparatus will be briefly described.
In the FPU reception control section, the OFDM demodulation section 41 performs OFDM demodulation to demodulate the TMCC carrier shown in FIG. 7 to obtain transmission parameters and weighting coefficients for the first and second layers.
Then, the OFDM-demodulated multiplexed data is divided into two, one of which is subjected to demapping processing by the first layer demapping unit 42, error correction processing by the error correction decoding unit 43, and remapping unit 44. re-mapped. However, if the weighting coefficient of the 11th layer is "0", the remapping signal is "0".

The remapped data is multiplied by the reciprocal of the weighting coefficient g 1 of the first hierarchy in the multiplier 46 and input to the subtractor 48 .
The other divided multiplexed data is delayed by the delay unit 45 , multiplied by the reciprocal of the weighting g 2 of the second layer by the multiplier 47 , and input to the subtractor 48 .
The subtractor 48 subtracts the output of the multiplier 46 from the output of the multiplier 47, and outputs second layer mapping data (second layer stream).

Then, the output of the subtractor 48 is demapped by the second layer demapping unit 49 to obtain 16QAM-demodulated second layer data, which is subjected to error correction decoding and demodulated second layer data. Data is output.
In this manner, the operation of the FPU reception control section of the present receiving apparatus is performed.

[Effects of Embodiment]
According to this broadcast transmission device, the FPU transmission control unit on the transmission side generates a first layer stream obtained by modulating video/audio data as main data with QPSK, and a second layer stream obtained by modulating digital data as sub data with 16QAM. The hierarchical streams are multiplied by weighting coefficients g1 and g2, respectively, according to the presence or absence of input of main data and sub-data, and then multiplexed and transmitted. is QPSK-demodulated to extract video/audio data, and the demodulated video/audio data is QPSK-modulated again and multiplied by the reciprocal of the weighting coefficient g1 of the first layer, and the multiplexed received signal is It is delayed and subtracted from the signal multiplied by the reciprocal of the second layer weighting coefficient g2, and the subtraction result is subjected to 16QAM demodulation to extract digital data. By increasing the weighting of the digital data and multiplexing the digital data with a lower weighting when there is video/audio data, the transmission of the video/audio data is not hindered and the digital data can be continuously stably transmitted. has the effect of transmitting

[Broadcast transmission device according to another embodiment]
Next, a broadcast transmission device (another broadcast transmission device) according to another embodiment will be described with reference to FIGS. 9 and 10. FIG.
Another broadcast transmission device has the same basic configuration and operation as the present broadcast transmission device described above, but furthermore, parameters (error correction, multi-level modulation parameters) for the data of the first layer and the second layer can be changed smoothly.

In the broadcast transmission apparatus described above, when the setting information is changed, it may be difficult to demodulate the data of the frame with the new setting information.
Therefore, in another broadcast transmission device, when changing the setting information of the first layer and the second layer to be mounted on the TMCC in the FPU transmission control unit, in order to notify the switching to the receiving side, The new setting information is put in the frame and transmitted.

In addition, the FPU reception control unit is provided with a difference detector that compares TMCC setting information for each frame and detects a difference.
Then, when the difference is detected by the difference detector, the FPU reception control unit uses the setting information included in the detected frame to switch the data of the next frame to new setting information for demodulation.

[When changing the parameters of the second layer: Fig. 9]
First, the case of changing the parameters of the data of the second layer will be described with reference to FIG. FIG. 9 is an explanatory diagram showing the flow of TMCC and second layer data when changing the second layer parameters.
As shown in FIG. 9, as described above, the setting information of the second layer is loaded in the surplus portion of the TMCC. It should be noted that FIG. 9 omits illustration of the weighting information included in the surplus portion.
In frame i at the left end, setting A information is written as setting information on the second layer, and data (setting A data) that has undergone error correction coding and modulation based on setting A information is written as data on the second layer. is installed.

Here, when the setting information of the second layer is changed to the setting B information, the FPU transmission control unit, in frame i+1, leaves the data part as it is (for example, the same data as in frame i), and inserts a new second layer into the TMCC. Transmit with the layer setting B information.

Then, in the next frame (frame i+2), new second layer setting B information is put in the TMCC, and data (setting B data) subjected to error correction coding and modulation by the second layer setting B information is put as data. Send.

In the FPU reception control unit, the difference detector monitors the difference between the received TMCC setting information between the previous frame and the current frame.
If the difference detector does not detect the difference, demodulation is performed based on the already received configuration information.
When the difference detector detects a difference, the FPU reception control unit stores new setting information included in the detected frame, switches to the new setting information from the next frame, and performs demodulation.

In the example of FIG. 9, when the difference detector detects a difference in the second layer setting data at frame i+1, the second layer setting B information is stored, and the second layer setting is performed from the received data of the next frame (frame i+2). Demodulation is performed based on the B information.

[When changing the data of the first layer: Fig. 10]
Next, the case of changing the data of the first layer will be described with reference to FIG. FIG. 10 is an explanatory diagram showing the flow of TMCC and first layer data when changing the first layer parameters.
Changing the setting information of the first layer is similar to changing the setting data of the second layer.
As shown in FIG. 10, the setting information of the first layer is mounted in the "setting information" of TMCC, the setting A information is mounted as the first layer setting information in the frame k, and the setting A information is mounted as the first layer data. Loaded with error correction encoded and modulated configuration A data based on information.

Then, when changing the first layer setting information to the setting B information, the FPU transmission control unit writes the setting B information to the "setting information" of the TMCC in the next frame k+1, and writes the setting B information to the "setting information" of the TMCC in the next frame k+2. Write and transmit configuration B data encoded and modulated with B information.

In the FPU reception control unit, when the difference detector detects a difference in setting information between frames (frame k+1), using the setting information included in the detected frame, the following frame (frame k+2) is based on the setting B information. to demodulate the examination data.
In this way, when the setting information is changed, the new setting information is transmitted one frame before the data, and the received data can be demodulated without delay.

[Effect of another broadcast transmission device]
According to another broadcast transmission apparatus, when the setting information of the first layer or the second layer is changed, the transmitting side sets the new setting to the frame one before transmitting the data processed with the new setting information. Information is inserted and transmitted, and the receiving side is equipped with a difference detector for detecting the difference in the setting information for each frame. Since demodulation is performed based on the above, there is an effect that setting information can be switched smoothly.

[Example of application of broadcast transmission device according to embodiment: Fig. 11]
Next, a transmission system to which the broadcast transmission apparatus according to the embodiment is applied will be explained using FIG. FIG. 11 is a schematic configuration diagram of a transmission system to which the broadcast transmission device according to the embodiment is applied.
The transmission system of the application example is a system using the above-described broadcast transmission device or another broadcast transmission device, and is a system for transmitting image/audio data and digital data from a relay site to a broadcasting station via a base station. .

As shown in FIG. 11, the transmission system of the application includes a camera 51, an encoder 52, a PC 53, a file transmission adapter 54, an FPU transmitter (FPU-TX) 55, and a base station. An FPU receiving device (FPU-RX) 56, a TSL (Transmitter to Studio Link) transmitting device 57, a file transmission adapter 58, a server (referred to as a server in the figure) 60, and a broadcasting station provided in the station. A TSL receiver 59 and a server (described as a server in the figure) 61 are provided.

The FPU transmission device 55 has the function of combining the FPU transmission control section and the FPU transmission high-frequency section of the above-described broadcast transmission device or another broadcast transmission device, and the FPU reception device 56 performs the FPU reception high-frequency section and the FPU reception control. , and performs the same operation as the above-described main broadcast transmission device or another broadcast transmission device.

In the transmission system of the application example, as shown in FIG. 11, the FPU receiver 56 transmits the received video/audio data from the relay site to the TSL transmitter (TSL-TX) 57 using the TS1 line. Then, it is transmitted from the TSL transmitter 57 using the TSL line and received by the TSL receiver 59 provided at the broadcasting station.

Also, the FPU receiver 56 transmits the received digital data to the file transmission adapter 58 using the TS2 line, accumulates it in the server 60, and transmits it to the server 61 on the broadcasting station side using a general line such as an optical line. do.
In this way, existing equipment can be used to stably transmit video/audio data and digital data from the relay site to the broadcasting station.

INDUSTRIAL APPLICABILITY The present invention is suitable for a broadcast transmission apparatus capable of stably transmitting and receiving additional data without interfering with the transmission of video/audio data.

11, 12... DVB-ASI interface 13... TS1 transmission processing unit 14... TS2 transmission processing unit 15... Weight setting unit 16, 17, 46, 47... Multiplier 18... Adder 19... OFDM frame configuration Section 21 AC generation section 22 CP generation section 23 TMCC generation section 24 IFFT section 25 GI addition section 26 Digital quadrature modulation section 30 Control panel information processing section 31 Data frame Synchronization section 32 Energy spreading section 33 Outer encoding section 34 Byte interleaving section 35 Inner encoding section 36 Frequency interleaving section 37 Time interleaving section 38, 85 Mapping section 41 OFDM demodulator 42 First layer demapping unit 43 First layer error correction decoding unit 44 Remapping unit 45 Delay unit 48, 97 Subtractor 49 Second layer demapping unit 50 Second layer error correction decoder 51, 71 Camera 52, 72 Encoder 53, 73, 82 PC 54, 58, 74, 80 File transmission adapter 55 FPU transmitter 56 FPU receiver 57 TSL transmitter 59 TSL receiver 60, 61 Server 75 FPU transmission control unit 76 FPU transmission high frequency unit 77 FPU reception high frequency unit 78 FPU reception control unit 79 Decoder 81 Monitor 83 FEC unit 84 Bit interleaving unit 86 Weighting unit 87, 94 Adder 88, 91 OFDM modulation unit 89, 92 Quadrature modulation unit 90, 93 ... DAC section, 95 ... main data demodulation section, 96 ... delay buffer

Claims (4)

Data containing either video/audio data for broadcasting or digital data is defined as first data, and data containing either video/audio data for broadcasting or digital data different from the first data is defined as second data. A broadcast transmission device that multiplexes and transmits as data of
As a multiplexing method, using a hierarchical division multiplexing method in which the same spectrum is superimposed on the OFDM spectrum,
A transmitting side generates a first hierarchical stream obtained by modulating the first data with a first modulation scheme and a second hierarchical stream obtained by modulating the second data with a second modulation scheme. each comprising a modulation unit that weights and multiplexes with the weighting factor of the first layer and the weighting factor of the second layer,
On the receiving side, the multiplexed and transmitted signal is demodulated corresponding to the first modulation scheme based on the weighting factor of the first hierarchy and the weighting factor of the second hierarchy, and the first a demodulation unit that demodulates and outputs the data of and demodulates according to the second modulation scheme to demodulate and output the second data,
When the modulation unit uses one of the first data and the second data as video/audio data for broadcasting and the other as digital data,
Regarding the video/audio data for broadcasting and the digital data, if the video/audio data for broadcasting is not input and the digital data is input, both the video/audio data for broadcasting and the digital data are The weighting factor of the first layer and the weighting factor of the second layer are defined corresponding to the case of input and the case of input of the video/audio data for broadcasting and no input of the digital data. and detecting whether or not the video/audio data for broadcasting and the digital data are input, and based on the weighting selection table, the weighting coefficients of the first layer according to the detection results and selecting a weighting factor of the second hierarchy ;
When both the video/audio data for broadcasting and the digital data are input, the weighting coefficients and A broadcasting characterized in that, from a weighting setting table storing a plurality of combinations of weighting factors of the second hierarchy, the specified weighting factors of the first hierarchy and the weighting factors of the second hierarchy are set in the weighting selection table. transmission equipment. A demodulation section demodulates the multiplexed and transmitted signal in accordance with a first modulation scheme, demodulates and outputs first data, and regenerates the demodulated first data to the first data. 1, the modulated first data is multiplied by the reciprocal of the weighting factor of the first layer, and the multiplexed and transmitted signal is delayed to obtain the reciprocal of the weighting factor of the second layer. is subtracted from the signal multiplied by the first data that has been re-modulated and multiplied by the reciprocal of the weighting factor of the first layer to separate the stream of the second layer, digital from the stream of the second layer 2. The broadcast transmission apparatus according to claim 1 , wherein the data is demodulated. 3. A broadcast transmission apparatus according to claim 1, wherein the weighting factor of the first hierarchy and the weighting factor of the second hierarchy are included in the transmission multiplex control signal. When changing setting information including modulation scheme information for the first data or the second data,
On the transmitting side, the changed setting information is included in a frame of the transmission multiplexing control signal and transmitted, and then the first data or the second data modulated based on the changed setting information from the next frame. and send
On the receiving side, the difference in the setting information of the transmission multiplex control signal is monitored, and when the difference is detected, the first data or the second data received in the next frame is replaced with the difference. 4. The broadcast transmission apparatus according to any one of claims 1 to 3 , wherein demodulation is performed based on setting information.

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