JP7375124B2 - Transmission device and transmission method - Google Patents

Description

The present invention relates to a transmitting device that transmits video/audio data as broadcast material, and in particular, to a transmitting device that can stably transmit and receive additional data without interfering with the transmission of video/audio data. The present invention relates to a device, a transmitting method, and a receiving device .

[Description of prior art]
Conventionally, FPU (Field Pickup Unit) type transmission systems have been used to transmit broadcast materials (video, audio). The FPU system is used as a broadcast transmission device that relays programs and sends collected video to broadcast stations.

Incidentally, depending on the program, there may be cases where it is desired to superimpose data (digital data) other than video and audio, such as road race odometer data, on top of the data and transmit the data.
In such a case, conventionally, digital data is transmitted using a data vacant area such as a 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, so in order to transmit digital data, it is necessary to operate with a sufficient margin in the transmission rate.

In addition, digital data that is different from conventional video and audio broadcast materials, such as news manuscripts, text files containing information obtained from on-site interviews, image files taken with digital cameras, and audio files acquired with voice recorders, is also available. In some cases, it may be necessary to send information from the relay site to the broadcasting station.

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

[Conventional transmission system: Figure 12]
Here, the configuration of a conventional broadcast transmission device will be explained using FIG. 12. FIG. 12 is an explanatory diagram showing a schematic configuration of a conventional broadcast transmission device.
As shown in FIG. 12, the conventional broadcast transmission device 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. The receiving side includes an FPU reception high frequency section 77, an FPU reception control section 78, a decoder 79, a file transmission adapter 80, a monitor 81, and a PC 82.

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

The FPU transmission control section 75 performs signal processing for wireless transmission, such as combining signals from the TS1 line and the TS2 line, and the IF (Intermediate Frequency) signal is sent to the FPU transmission high frequency section 76. The signal is input to the FPU transmission high frequency section 76, where it is converted into a high frequency signal, and then wirelessly transmitted.

On the receiving side, the wireless signal received by the FPU reception high-frequency section 77 is converted into an IF signal, and the signal processing is performed by the FPU reception control section 78, which converts it into TS packets of video/audio data and TS packets of digital data. separated into

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

[Layered separation multiplexing method]
Next, a layered division multiplexing (LDM) method for superimposing different streams on the same spectrum in OFDM (Orthogonal Frequency Division Multiplexing) will be briefly described.
Here, main data will be explained as video/audio data, and sub data will be explained as digital data serving as additional data.

[Digital multiplexing method: Figure 13]
First, the configuration of a modulation section that performs digital multiplexing will be explained using FIG. 13. FIG. 13 is an explanatory diagram showing a schematic configuration of an LDM modulation section (digital multiplexing method). Note that the modulation section corresponds to the FPU transmission control section 75 shown in FIG.
FIG. 13 shows a configuration in which main data and sub data are multiplexed in digital signal processing.

As shown in FIG. 13, the LDM modulation unit (digital multiplexing system) 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, an orthogonal modulation section 89, and a DAC (Digital Analog Converter) section 90.
Note that the subscript a indicates that processing is performed on main data, and the subscript b indicates that processing is performed on subdata.

In the modulation section of FIG. 13, the main data is subjected to error correction encoding in an FEC section 83a, subjected to bit interleaving in a bit interleaving section 84a, mapped in a mapping section 85a, and output to an adder 87.
Here, the main data is modulated using, for example, QPSK (Quadrature Phase Shift Keying).

Further, the sub data is subjected to error correction encoding in the FEC section 83b, subjected to bit interleaving in the bit interleaving section 84b, mapped in the mapping section 85b, given predetermined weighting in the weighting section 86, and output to the adder 87. be done.
The sub-data is modulated using, for example, 16QAM (Quadrature Amplitude Modulation).

Then, the main data and the weighted sub-data are superimposed in the adder 87, OFDM modulated in the OFDM modulation section 88, orthogonally modulated in the orthogonal modulation section 89, and converted into an analog signal in the DAC section 90. The signal is outputted to the FPU transmission high frequency section 76 shown at 12 and transmitted wirelessly.

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

[Analog multiplexing method: Figure 14]
Next, the configuration of the modulation section using the analog multiplexing method will be explained using FIG. 14. FIG. 14 is an explanatory diagram showing a schematic configuration of an LDM modulation section (analog multiplexing method).
As shown in FIG. 14, in the case of the analog multiplex system, OFDM modulation sections 91a and 91b, orthogonal modulation sections 92a and 92b, DAC sections 93a and 93b, and an adder 94 are provided.
The suffix a indicates processing of main data, and subscript b indicates processing of sub-data, and the processing of each part is the same as in the case of the digital multiplexing method.

In the analog multiplexing method, the analog signals after the DAC sections 93a and 93b are multiplexed in an adder 94.
In the configuration of the analog multiplex system, two systems of digital circuit parts are required before multiplexing, resulting in an increase in circuit scale and power consumption.

[LDM demodulator: Figure 15]
Next, the LDM demodulator will be explained using FIG. 15. FIG. 15 is an explanatory diagram showing a schematic configuration of an LDM demodulation section.
As shown in FIG. 15, the demodulation section is provided in the FPU reception control section 78 shown in FIG. 12, and includes a main data demodulation section 95, a delay buffer 96, and a subtracter 97. It operates as a separation unit that separates the main data that has been modulated and the sub-data that has been modulated using 16QAM.

The received signal input to the demodulator in FIG. 15 is separated into two parts, one of which is demodulated at the first layer in the main data demodulator 95, and the main data (QPSK modulated) is obtained from the multiplexed signal. QPSK modulated signal) is output to a demapping processing section (not shown) for main data, and is also input to a subtracter 97.

Further, the other separated received signal is delayed by the time required for demodulation of the first layer in the delay buffer 96 and input to the subtracter 97 .
The subtracter 97 can extract a 16QAM modulated signal (16QAM modulated signal) by subtracting the QPSK modulated signal from the delayed received signal, and outputs this to the subdata demapping processing section.

In the main data demapping processing section, QPSK demodulation is performed, and the demodulated main data is output to the decoder 79 via the line TS1.
The subdata demapping processing unit performs 16QAM demodulation, and the demodulated subdata is output to the file transmission adapter 80 via the line TS2.

[Related technology]
In addition, as conventional technologies related to broadcast transmission devices, there are JP-A No. 2017-41781 “Receiving device” (Patent Document 1) and JP-A No. 2014-64273 “Transmitting device” (Patent Document 2).
Patent Document 1 describes a receiving device that follows the position of a transmitting antenna of a mobile station and efficiently controls the orientation of a plurality of receiving antennas that perform multi-reception.
Patent Document 2 describes a transmitting device that improves transmission characteristics on a transmission path under poor conditions by adding a TMCC carrier inversion operation.
In addition, there is a non-patent document 1 as a standard regarding the transmission of television broadcast program materials.

Japanese Patent Application Publication No. 2017-41781 JP2014-64273A

Portable OFDM digital wireless transmission system for transmitting television broadcast program materials (ARIB STD-B33)

However, in conventional broadcast transmission equipment, when digital data (additional data) is superimposed on the NULL part of a TS packet, the amount of data in the NULL packet changes depending on the type of video/audio data, so the transmission rate of the digital data is The problem was that it was not stable.

In addition, with conventional broadcast transmission equipment, when converting digital data into TS packets and transmitting them, one line is occupied for transmitting the digital data, and when it becomes necessary to transmit other video/audio data. However, there was a problem in that the transmission of digital data had to be temporarily stopped.

Furthermore, in conventional transmission systems, when transmitting digital data using e-mail from a mobile phone, there was a problem in that the data could not be transmitted from outside the service area.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a transmitting device, a transmitting method, and a receiving device that can stably transmit digital data without interfering with the transmission of video/audio data. purpose.

The present invention for solving the problems of the above-mentioned conventional example uses data including either video/audio data for broadcasting or digital data as first data, and video/audio data for broadcasting that is different from the first data. A transmitting device that multiplexes and transmits data including either audio data or digital data as second data on an OFDM spectrum using a layer division multiplexing method in which the same spectrum is superimposed, the first data being A first layer stream modulated with a first modulation method and a second layer stream where second data is modulated with a second modulation method are generated, and the first layer weighting coefficient and the second layer stream are respectively generated. A case where the modulation unit includes a modulation unit that weights and multiplexes with a weighting coefficient of the second layer, and the modulation unit has no input of the first data and input of the second data regarding the first data and the second data. , the weight coefficient of the first layer and the case where both the first data and the second data are input, and the case where the first data is input and the second data is not input, A weighting selection table is provided in which weighting coefficients for the second layer are defined, and the presence or absence of input of the first data and the second data is detected, and based on the weighting selection table, the weighting of the first layer is determined according to the detection result. When a coefficient and a weighting coefficient of the second layer are selected, and both the first data and the second data are input, a plurality of combinations of the weighting coefficient of the first layer and the weighting factor of the second layer are stored. The method is characterized in that the identified first layer weighting coefficient and second layer weighting coefficient are set in the weighting selection table from the weighting setting table determined by the user.

Further, in the transmitting device, the present invention provides that one of the first data and the second data is video/audio data for broadcasting and the other is digital data, and that the video/audio data for broadcasting and the digital data are If there is also an input, the weighting setting table stores multiple combinations of first-layer weighting coefficients and second-layer weighting coefficients according to the type of video/audio data for broadcasting and the importance of digital data. , the identified first layer weighting coefficient and second layer weighting factor are set in a weighting selection table.

Furthermore, the present invention is characterized in that, in the transmitting apparatus, a first layer weighting coefficient and a second layer weighting coefficient are included in the transmission multiplexing control signal .

Furthermore, in the transmitting device, when changing the setting information including modulation method information for the first data or the second data, the present invention includes the changed setting information in the frame of the transmission multiplex control signal. It is characterized in that the first data or the second data modulated based on the changed setting information is transmitted from the next frame.

Further, in the present invention, data including either video/audio data for broadcasting or digital data is used as the first data, and either video/audio data for broadcasting or digital data different from the first data is used as the first data. A transmission method in which the data contained in the data is multiplexed and transmitted as second data on an OFDM spectrum using a layer division multiplexing method in which the same spectrum is superimposed, and the modulation unit combines the first data and the second data. The presence or absence of input is detected, and if both the first data and the second data are input, the first layer stream in which the first data is modulated with the first modulation method and the second layer stream are A second layer stream in which data is modulated using a second modulation method is generated, and the first data is selected from among the plurality of stored combinations of first layer weighting coefficients and second layer weighting coefficients. and specify a first layer weighting coefficient and a second layer weighting coefficient according to the second data, and assign the first layer stream and the second layer stream to the specified first layer weight, respectively. It is characterized in that it is weighted with a second layer weighting coefficient specified as a coefficient, multiplexed, and transmitted .

According to the present invention, data including either video/audio data for broadcasting or digital data is the first data, and either video/audio data for broadcasting or digital data that is different from the first data is set as the first data. A transmitting device that multiplexes and transmits data included as second data on an OFDM spectrum using a layer division multiplexing method in which the same spectrum is superimposed , the first data being modulated with a first modulation method. A first layer stream and a second layer stream in which second data is modulated using a second modulation method are generated, and each is weighted with a first layer weighting coefficient and a second layer weighting coefficient. and a modulation unit that multiplexes the first data and the second data, when the first data is not input and the second data is input, the modulation unit multiplexes the first data and the second data. The weighting coefficient of the first layer and the weighting factor of the second layer are defined corresponding to the case where both data have input, and the case where the first data has input and the second data has no input. It detects the presence or absence of input of the first data and the second data, and, based on the weighting selection table, determines the weighting coefficient of the first layer and the weighting coefficient of the second layer according to the detection result. If selected, and both the first data and the second data are input, the specified weighting setting table stores a plurality of combinations of first layer weighting coefficients and second layer weighting coefficients. Since the transmitting device sets the weighting coefficients of the first layer and the weighting coefficients of the second layer in the weighting selection table , by adjusting the weighting factors of the first layer and the weighting factors of the second layer as appropriate, and the second data, there is an effect that the other data can be stably transmitted without interfering with the transmission of one data.

Further, according to the present invention, one of the first data and the second data is video/audio data for broadcasting, and the other is digital data, and both the video/audio data for broadcasting and the digital data are In the case of input, from a weighting setting table storing a plurality of combinations of first layer weighting coefficients and second layer weighting coefficients according to the type of video/audio data for broadcasting and the importance of digital data, Since the transmitting device sets the identified first layer weighting coefficient and second layer weighting coefficient in the weighting selection table, when there is input of video/audio data, the corresponding one of the weighting coefficients is set in the weighting selection table. By setting one weighting coefficient to 1 and setting the other weighting coefficient to a smaller value, it is possible to continue transmitting digital data without interfering with the transmission of video/audio data, which has the effect of making stable transmission possible.

Further, according to the present invention, when changing the setting information including the modulation method information for the first data or the second data, the changed setting information is included in the frame of the transmission multiplex control signal and transmitted. In the above, the transmitting device transmits the first data or the second data modulated based on the changed configuration information from the next frame, so when the configuration information is changed, the transmitting side transmits the new data. By transmitting the setting information one frame earlier, new setting information can be notified to the receiving side, which has the effect of making it possible to smoothly change the setting information.

Further, according to the present invention, data including either video/audio data for broadcasting or digital data is the first data, and any video/audio data for broadcasting or digital data different from the first data is set as the first data. A transmission method that multiplexes and transmits data including the first data and the second data on the OFDM spectrum using a layer division multiplexing method in which the same spectrum is superimposed on the OFDM spectrum. The presence or absence of data input is detected, and if both the first data and the second data are input, the first layer stream in which the first data is modulated using the first modulation method, and the A second layer stream is generated by modulating the data of No. 2 with a second modulation method, and the first layer stream is generated from among the plurality of stored combinations of the first layer weighting coefficient and the second layer weighting coefficient. A first layer weighting coefficient and a second layer weighting coefficient are specified according to the data and the second data, and the first layer stream and the second layer stream are respectively converted into Since the transmission method is to weight the weighting coefficient using the weighting coefficient of the second layer and the weighting coefficient of the specified second layer, and to transmit the multiplexed data, by appropriately adjusting the weighting coefficient of the first layer and the weighting coefficient of the second layer. Regarding the first data and the second data, there is an effect that the other data can be stably transmitted without interfering with the transmission of one data.

FIG. 2 is a configuration block diagram of an FPU transmission control section of the present transmitting device. 2 is a configuration block diagram of a TS1 transmission processing section 13 shown in FIG. 1. FIG. FIG. 2 is an explanatory diagram showing input and output in a weighting setting section. FIG. 3 is a schematic explanatory diagram of a weighting selection table. FIG. 2 is a schematic explanatory diagram of a weighting setting table. FIG. 2 is a schematic explanatory diagram showing a transmission image in the present transmitting device. It is an explanatory diagram showing TMCC data in this broadcast transmission device. FIG. 2 is a configuration block diagram of an FPU reception control section of the receiver. FIG. 7 is an explanatory diagram showing the flow of data in the TMCC and the second layer when changing parameters in the second layer. It is an explanatory diagram showing the flow of data of TMCC and the first layer when changing the parameters of the first layer. 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. 2 is an explanatory diagram showing a schematic configuration of a modulation section (digital multiplexing method) of an LDM method. FIG. 2 is an explanatory diagram showing a schematic configuration of an LDM modulation section (analog multiplexing method). FIG. 2 is an explanatory diagram showing a schematic configuration of a demodulation section of an LDM system.

Embodiments of the present invention will be described with reference to the drawings.
[Overview of embodiment]
The broadcast transmission device according to the embodiment of the present invention multiplexes and transmits video/audio data as main data and digital data as sub data using the LDM method, and on the transmitting side, an FPU transmission control unit , a first layer stream in which main data is modulated by a first modulation method and a second layer stream in which sub data is modulated by a second modulation method, depending on whether or not main data and sub data are input. , are multiplied by weighting coefficients, multiplexed, and transmitted, and on the receiving side, the FPU reception control unit performs demodulation corresponding to the first modulation method from the multiplexed received signal to extract the main data, and The main data is modulated again using the first modulation method and multiplied by the reciprocal of the weighting coefficient of the first layer, and the multiplexed received signal is delayed and multiplied by the reciprocal of the weighting coefficient of the second layer. Since the subtraction result is demodulated in accordance with the second modulation method and the digital data is extracted, it is possible to mainly transmit the main data and also transmit the sub data. When there is no data, the weighting of the digital data is increased, and when there is video/audio data, the weighting of the digital data is decreased and multiplexed, without interfering with the transmission of the video/audio data. It is possible to continue the stable transmission of digital data.

Note that 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, but each data may be reversed, and the first Both the data and the second data may be video/audio data or both digital data.

In addition, although more effective modulation and demodulation methods will be mainly explained here, other modulation methods may be used, and the first data and second data may correspond to each modulation method. A method of direct demodulation using a demodulation method may also be used.

[Configuration of transmitting device according to embodiment: FIG. 1]
The configuration of a transmitting device (present transmitting device) used on the transmitting side of a broadcast transmitting device (present broadcast transmitting device) according to an embodiment of the present invention will be described.
The basic configuration of this transmitting device is the same as that of the transmitting side of the conventional broadcast transmission device shown in FIG. 12, but the configuration and operation of the FPU transmission control section are different from the conventional one.

FIG. 1 is a block diagram of the configuration of the FPU transmission control section of the present transmitter.
The FPU transmission control unit of this transmitter generates transmission data by multiplexing main data (video/audio data) and sub data (digital data) using the LDM method, as shown in Figure 1. , DVB-ASI (Digital Video Broadcasting - Asynchronous Serial Interface) interfaces 11 and 12, a TS1 transmission processing section 13, a TS2 transmission processing section 14, a weighting setting section 15, multipliers 16 and 17, and an adder 18. , an OFDM frame configuration unit 19, an AC (Auxiliary Channel) generation unit 21, a CP (Continual Pilot) generation unit 22, a TMCC (Transmission and Multiplexing Configuration Control) generation unit 23, and an IFFT (Inverse Fast The fourie transform section 24, a GI (Guard Interval) adding section 25, and a digital orthogonal modulation section 26 are provided.

Each part of the FPU transmission control unit will be explained.
The DVB-ASI interface 11 inputs video/audio data from the encoder 72 shown in FIG. 12 via the TS1 line as first layer (denoted as first layer in the figure) data.
The DVB-ASI interface 12 receives digital data from the file transmission adapter shown in FIG. 12 via the TS2 line as second layer (denoted as second layer in the figure) data.

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

The weighting setting unit 15 is a characteristic part of this transmitting device, and sets a weighting coefficient g1 to be multiplied by the TS1 data in the multiplication unit 16, and sets a weighting coefficient g2 to be multiplied by the TS2 data in the multiplication unit 17.
Here, as a feature of the present transmitting device, the weighting setting section 15 changes and sets the weighting coefficients g1 and g2 according to an instruction from a control section, which will be described later, and whether or not TS1 data and TS2 data are input.
The operation of the weighting setting section 15 will be described later.

The multiplication unit 16 multiplies the TS1 data output from the TS1 transmission processing unit 13 by a weighting coefficient g1.
The multiplication unit 17 multiplies the TS2 data output from the TS2 transmission processing unit 14 by a weighting coefficient g2.
The adder 18 multiplexes the TS1 data weighted by g1 and the TS2 data weighted by g2 to generate transmission data.

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

The OFDM frame configuration unit 19 arranges the multiplexed transmission data, AC signal, pilot signal, and TMCC at predetermined positions to generate an OFDM frame.
The IFFT section 24 converts the input signal into a frequency axis.
The GI adding section 25 adds a guard interval signal.
The digital orthogonal modulation section 26 orthogonally 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 section of this transmitter will be briefly described.
In the FPU transmission control section of this transmitter, TS1 data (video/audio data) input from the DVB-ASI interface 11 is subjected to error correction encoding and modulation in the TS1 transmission processing section 13, and weighted coefficients are applied to it in the multiplication section 16. It is multiplied by g1 and output to the adder 18.

Similarly, 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 a weighting coefficient g2 in the multiplication section 17, and then added to the adder 18. is output to.

The adder 18 multiplexes the predetermined weighted TS1 data and TS2 data, and inputs the multiplexed data together with AC, CP, and TMCC information to the OFDM frame configuration section 19 to generate an OFDM frame. 24, the signal is inverse Fourier transformed, a GI adding section 25 adds a guard interval, a digital orthogonal modulation section 26 performs digital orthogonal modulation, and the signal is output to the FPU transmission high frequency section 76 shown in FIG.
In the FPU transmission high frequency section 76, the modulated signal is up-converted and sent out as a radio signal.

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

Each part of the TS1 transmission processing unit 13 is described in Japanese Patent Application Laid-open No. 2014-64273, so a detailed description thereof will be omitted.
Furthermore, the configuration and operation of the TS2 transmission processing section 14 are similar to those of the TS1 transmission processing section 13.
However, the encoding processing in the inner encoding section 35 and the multilevel modulation processing in the mapping section 38 are performed differently for each transmission system so that the intra-symbol distance between the two transmission systems becomes large.

[Input/output in weight setting section: Figures 1 and 3]
Next, the input/output in the weighting setting section 15 shown in FIG. 1 will be explained using FIGS. 1 and 3. 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 that inputs first layer data, a DVB-ASI interface 12 that inputs second layer data, and a control panel information processing An instruction from unit 30 is input, and weighting coefficients g1 and g2 are selected according to the input and output to multipliers 16 and 17.
The weighting setting unit 15 includes a weighting selection table that specifies weighting coefficients g1 and g2 in accordance with the presence or absence of data input from the DVB-ASI interfaces 11 and 12.
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 or not TS1 data is input.
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, an appropriate combination is selected from among the stored combinations according to the operator's operation, and an instruction is output to the weighting setting section 15.

[Weighting selection table: Figure 4]
The weighting selection table stored in the weighting setting section 15 will be explained using FIG. 4. FIG. 4 is a schematic explanatory diagram of the weighting selection table.
As shown in FIG. 4, the weighting selection table stores the presence or 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, so the weighting coefficients are set as g1=0, g2=1. There is.
In such a case, the micro line can be used only for transmitting TS packetized digital data.
Conversely, when the TS1 data is "present" and the TS2 data is "absent", the weighting coefficients are set to g1=1 and g2=0.

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

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

Furthermore, in this transmitter, p and q are values other than 0. That is, when both TS1 data and TS2 data are input, both are transmitted, although the degree of weighting changes.
As a result, even if there is video/audio data to be transmitted, this transmitter can superimpose digital data to the extent that does not interfere with the transmission, and can transmit digital data stably and continuously. It is something that can be done.

[Weighting setting table: Figure 5]
Next, the weighting setting table provided in the control panel information processing section 30 will be explained using FIG. 5. FIG. 5 is a schematic explanatory diagram of the weighting setting table.
As shown in FIG. 5, the weighting setting table stores combinations of values p and q of the weighting selection table described above in correspondence 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'' is stored.

When the control panel information processing section 30 receives an input from the control panel, it identifies a combination number predetermined 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 out, and the values of p and q are instructed to the weighting setting section 15.
That is, the control panel information processing section 30 stores in advance combination numbers that provide the optimum p and q depending on the type of video/audio data or digital data.
When the instruction is input, the weighting setting unit 15 updates p and q of 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 file transmission where only TS2 data is being transmitted, if relaying starts or something that requires sudden on-airing occurs, the TS1 Both TS packets are superimposed and transmitted with the data weighting coefficient g1(p)=1 and the TS2 data weighting coefficient g2(q)=0.2.

In addition, 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 send TS2 data with priority ( TS2 priority instruction) may also be transmitted.

When the TS2 priority instruction is input, the weighting setting unit 15 sets g1=0 and g2=1 in the multipliers 16 and 17 without referring to the weighting selection table.
Then, when the instruction to cancel the TS2 priority instruction is input from the control panel information processing section 30, the weighting setting section 15 performs a process of selecting a weighting coefficient depending on the presence or absence of data input from the DVB-ASI interfaces 11 and 12. return.
Similarly, the control panel information processing unit 30 may send an instruction to forcibly send TS1 data with priority (TS1 priority instruction).

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

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

In this way, this transmitting device can continuously and stably transmit the digital data of the second layer regardless of whether the data of the first layer is on or off. During periods when there is no data, second layer data can be transmitted preferentially.

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

The second layer setting information includes error correction and multilevel modulation parameters.
Further, the LDM weighting information is the value of the above-mentioned first layer weighting coefficient g1 and second layer weighting coefficient g2.
This information is used for demodulation on the receiving side.

[Configuration of receiving device according to embodiment: FIG. 8]
Next, the configuration of a receiving device (this receiving device) used on the receiving side of this broadcasting transmission device will be explained.
The basic configuration of this receiving device is the same as that of the receiving side of the conventional broadcast transmission device shown in FIG. 12, but the configuration and operation of the FPU reception control section are different from the conventional one.

FIG. 8 is a block diagram of the configuration of the FPU reception control section of the receiver.
The FPU reception control unit of this receiver receives data multiplexed and transmitted using the LDM method from the transmitter shown in FIG. 1, separates the data into main data and sub data, and demodulates the data. , OFDM demodulation section 41, first layer demapping section 42, first layer error correction decoding section 43, remapping section 44, delay section 45, multipliers 46 and 47, subtracter 48, It includes a second layer demapping section 49 and a second layer error correction decoding section 50.

Each part of the FPU reception control unit will be explained.
The OFDM demodulation section 41 performs FFT transform on the multiplexed data after orthogonal demodulation and performs OFDM demodulation.
The first layer demapping unit 42 performs demapping (here, QPSK demodulation) corresponding to the multilevel modulation performed by the mapping unit of the TS1 transmission processing unit of the transmitting device on the multiplexed signal, and Extract the first layer data.

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

The delay unit 45 delays the OFDM demodulated multiplexed data by the time required for first layer demodulation and remapping.
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 multiplexed data by the reciprocal of the second layer weighting coefficient g2.

The subtracter 48 subtracts the first layer remapping data from which the weighting has been removed from the multiplexed data from which the weighting has been removed, and extracts the second layer data modulated by 16QAM.
The second layer demapping section 49 performs 16QAM demodulation on the output of the subtracter 48 and outputs second layer data.
The second layer error correction decoding section 50 performs error correction decoding corresponding to the error correction encoding performed by the TS2 transmission processing section of the transmitting device, and outputs demodulated second layer data.

The operation of the FPU reception control section of this reception device will be briefly explained.
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.
The OFDM demodulated multiplexed data is then divided into two parts, one of which is subjected to demapping processing in the first layer demapper 42, error correction processing is performed in the error correction decoding section 43, and one is subjected to the error correction processing in the remapping section 44. Re-mapped. However, if the weighting coefficient of the 11th layer is "0", the remapping signal will be "0".

The remapped data is multiplied by the reciprocal of the first layer weighting coefficient g1 in the multiplier 46, and is input to the subtraction unit 48.
The other divided multiplexed data is delayed by the delay unit 45, multiplied by the reciprocal of the second layer weighting g2 by the multiplication unit 47, and input to the subtracter 48.
The subtracter 48 subtracts the output of the multiplier 46 from the output of the multiplier 47, and outputs second layer mapping data (second layer stream).

The output of the subtracter 48 is then demapped by a second layer demapper 49 to obtain 16QAM demodulated second layer data, which is then subjected to error correction decoding to obtain demodulated second layer data. Data is output.
In this way, the operation of the FPU reception control section of the present receiver is performed.

[Effects of embodiment]
According to this broadcast transmission device, the FPU transmission control unit on the transmitting side generates a first layer stream in which video/audio data as main data is modulated with QPSK, and a second layer stream in which digital data as sub data is modulated in 16QAM. layer streams are multiplied by weighting coefficients g1 and g2, respectively, depending on the presence or absence of input of main data and sub data, multiplexed and transmitted, and the FPU reception control unit on the receiving side receives the multiplexed received signal. QPSK demodulation is performed on the video/audio data to extract the video/audio data, and the demodulated video/audio data is QPSK-modulated again and a signal multiplied by the reciprocal of the weighting coefficient g1 of the first layer is used as the multiplexed received signal. Since the signal is delayed and subtracted from the signal multiplied by the reciprocal of the weighting coefficient g2 of the second layer, and the subtraction result is subjected to 16QAM demodulation to extract digital data, if there is no video/audio data, By increasing the weighting of digital data and, if there is video/audio data, lowering the weighting of the digital data and multiplexing it, the digital data can be continuously and stably transmitted without interfering with the transmission of the video/audio data. It has the effect of being able to transmit.

[Broadcast transmission device according to another embodiment]
Next, a broadcast transmission device (another broadcast transmission device) according to another embodiment will be described using FIGS. 9 and 10.
Another broadcast transmission device has the same basic configuration and operation as the present broadcast transmission device described above, but it also has parameters (error correction, multi-level modulation parameters) for data in the first layer and second layer. This allows for smooth changes.

In the above-described broadcast transmission apparatus, when the setting information is changed, it may be difficult to demodulate the data of the frame using the new setting information.
Therefore, in another broadcast transmission device, when changing the setting information of the first layer and the second layer installed in 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 sent.

Furthermore, the FPU reception control unit is equipped with a difference detector that compares the TMCC setting information for each frame and detects a difference.
When the difference detector detects a difference, the FPU reception control unit uses the setting information included in the detected frame to switch to new setting information from the data of the next frame and perform demodulation.

[When changing the parameters of the second layer: Figure 9]
First, a case in which parameters of data in the second layer are changed will be described using FIG. 9. FIG. 9 is an explanatory diagram showing the flow of data in the TMCC and the second layer when changing parameters in the second layer.
As shown in FIG. 9, as described above, the second layer configuration information is installed in the surplus portion of the TMCC. In addition, in FIG. 9, illustration of the weighting information carried in the surplus portion is omitted.
In the leftmost frame i, setting A information is written as second layer setting information, and data (setting A data) that has been subjected to error correction encoding and modulation based on the setting A information is written as second layer data. It is installed.

Here, when the second layer configuration information is changed to configuration B information, the FPU transmission control unit leaves the data part unchanged (for example, the same data as frame i) in frame i+1, and adds a new second layer to the TMCC. Enter layer setting B information and send.

Then, in the next frame (frame i+2), new second layer setting B information is input into the TMCC, and data (setting B data) that has been subjected to error correction encoding and modulation with the second layer setting B information is input as data. Send.

In the FPU reception control unit, a difference detector monitors the difference between the previous frame and the current frame regarding the received TMCC setting information.
If the difference detector does not detect a difference, demodulation is performed based on the already received setting information.
When the difference detector detects a difference, the FPU reception control unit stores new setting information included in the detected frame, and 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 in frame i+1, it stores the second layer setting B information and uses the received data of the next frame (frame i+2) to set the second layer setting. Demodulation is performed based on the B information.

[When changing data in the first layer: Figure 10]
Next, a case in which data in the first layer is changed will be described using FIG. 10. FIG. 10 is an explanatory diagram showing the flow of data in the TMCC and the first layer when changing the parameters of the first layer.
The case of changing the setting information of the first layer is the same as the case of changing the setting data of the second layer.
As shown in FIG. 10, the setting information of the first layer is loaded in the "setting information" of TMCC, and in frame k, the setting A information is loaded as the first layer setting information, and the setting A is loaded as the first layer data. Setting A data that has been error correction encoded and modulated based on the information is loaded.

Then, when changing the first layer setting information to 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 in the next frame k+2, the FPU transmission control unit writes the setting B information to the "setting information" of the TMCC. Setting B data encoded and modulated with B information is written and transmitted.

In the FPU reception control unit, when the difference detector detects a difference in setting information between frames (frame k+1), the setting information included in the detected frame is used to change the settings from the next frame (frame k+2) based on the setting B information. demodulates the received 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 any problem.

[Effects of another broadcast transmission device]
According to another broadcast transmission device, when the setting information of the first layer or the second layer is changed, on the transmitting side, the new setting is added to the frame immediately 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 that detects the difference in setting information for each frame. When the difference detector detects a difference in setting information, new setting information is inserted from the data of the next frame. Since the demodulation is performed based on the , the setting information can be switched smoothly.

[Application example of broadcast transmission device according to embodiment: FIG. 11]
Next, a transmission system to which the broadcast transmission device according to the embodiment is applied will be described using FIG. 11. 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 that uses the above-mentioned broadcast transmission device or another broadcast transmission device, and is a system that transmits image/audio data and digital data from a relay site to a broadcast station via a base station. .

As shown in FIG. 11, the transmission system of the application example 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 (described as server in the figure) 60, and a server (denoted as server in the figure) 60 installed in the broadcasting station. A TSL receiving device 59 and a server (denoted as server in the figure) 61 are provided.

The FPU transmitting device 55 has a function that combines the FPU transmitting control section and the FPU transmitting high frequency section of the above-mentioned main broadcast transmitting device or another broadcast transmitting device, and the FPU receiving device 56 has the functions of the FPU receiving high frequency section and the FPU receiving control section. This broadcast transmission device operates in the same way as the above-mentioned main broadcast transmission device or another broadcast transmission device.

In the transmission system of the application example, as shown in FIG. 11, the FPU receiving device 56 transmits the received video and audio data from the relay site to the TSL transmitting device (TSL-TX) 57 using the TS1 line. The information is transmitted from a TSL transmitting device 57 using a TSL line, and is received by a TSL receiving device 59 provided at the broadcasting station.

Further, the FPU receiving device 56 transmits the received digital data to the file transmission adapter 58 using the TS2 line, stores it in the server 60, and transmits it to the broadcast station side server 61 using a general line such as an optical line. do.
In this way, video/audio data and digital data can be stably transmitted from the relay site to the broadcast station using existing equipment.

INDUSTRIAL APPLICABILITY The present invention is suitable for a transmitting device, a transmitting method, and a receiving device that can stably transmit and receive additional data without interfering with the transmission of video/audio data.

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

Claims (5)

Data including either video/audio data for broadcasting or digital data is defined as first data, and data including any of video/audio data for broadcasting or digital data different from the first data is defined as second data. A transmitting device that multiplexes and transmits data using a layer division multiplexing method in which data is superimposed on an OFDM spectrum using the same spectrum,
generating a first layer stream in which the first data is modulated with a first modulation method and a second layer stream in which the second data is modulated in a second modulation method, respectively; a modulation unit that weights and multiplexes the first layer weighting coefficient and the second layer weighting coefficient,
Regarding the first data and the second data, if the first data is not input and the second data is input, the modulation unit is configured such that the first data and the second data are The weighting coefficient of the first layer and the weighting factor of the second layer correspond to the case where both have input and the case where the first data has input and the second data has no input. A prescribed weighting selection table is provided, detecting the presence or absence of input of the first data and the second data, and determining, based on the weighting selection table, the weighting coefficient of the first layer according to the detection result. selecting a weighting coefficient for the second layer;
When both the first data and the second data are input, the combinations of the first layer weighting coefficient and the second layer weighting coefficient are specified from a weighting setting table storing a plurality of combinations. A transmitting apparatus characterized in that a first layer weighting coefficient and a second layer weighting coefficient are set in the weighting selection table. If one of the first data and the second data is broadcast video/audio data and the other is digital data, and both the broadcast video/audio data and the digital data are input, , identified from a weighting setting table storing a plurality of combinations of weighting coefficients of the first layer and weighting coefficients of the second layer according to the type of the video/audio data for broadcasting and the importance of the digital data. 2. The transmitting device according to claim 1, wherein a first layer weighting coefficient and a second layer weighting coefficient are set in the weighting selection table. 3. The transmitting apparatus according to claim 1, wherein a first layer weighting coefficient and a second layer weighting coefficient are included in the transmission multiplex control signal. When changing the setting information including modulation method information for the first data or the second data,
Transmitting the changed setting information in a frame of a transmission multiplex control signal, and then transmitting the first data or the second data modulated based on the changed setting information from the next frame. A transmitting device according to any one of claims 1 to 3, characterized in that: Data including either video/audio data for broadcasting or digital data is defined as first data, and data including any of video/audio data for broadcasting or digital data different from the first data is defined as second data. A transmission method in which the data is multiplexed and transmitted using a layer division multiplexing method in which the same spectrum is superimposed on the OFDM spectrum,
A modulation unit detects the presence or absence of input of the first data and the second data, and when both the first data and the second data are input, the modulation unit modulates the first data. generating a first layer stream modulated using a first modulation method and a second layer stream modulating the second data using a second modulation method;
From among a plurality of stored combinations of the first layer weighting coefficients and the second layer weighting coefficients, the first layer weighting coefficients and the second layer weighting coefficients are determined according to the first data and the second data. Identify the weighting factors for the hierarchy,
The first layer stream and the second layer stream are weighted and multiplexed using the identified first layer weighting coefficient and the identified second layer weighting coefficient, respectively, and then transmitted. A transmission method characterized by:

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