JP7796564B2 - Transmitting device, receiving device and control device - Google Patents

Description

The present invention relates to a transmitting device, a receiving device, and a control device.

Development of the Advanced Terrestrial Broadcasting Standard (hereinafter referred to as the "Advanced Standard") is underway as a transmission standard for next-generation terrestrial digital television broadcasting. Channel bonding (hereinafter referred to as "CB") transmission is an optional feature of the Advanced Standard. CB transmission expands transmission capacity by combining N physical channels (N, where N is an integer greater than or equal to 2). For example, when N=2, CB transmission can be performed in two modes: Plain mode, which splits the data stream into two streams at the transport layer before error correction coding, and MIMO (Multiple-Input and Multiple-Output)-like mode, which splits the data stream into two streams at the physical layer after error correction coding. When the C/N (Carrier-to-Noise Ratio) of the two physical channels differs, MIMO-like mode provides a diversity effect compared to Plain mode, thereby improving transmission characteristics. Hereinafter, the two physical channels that make up N=2 CB transmission are referred to as the primary channel and secondary channel.

Examples of use cases for CB transmission include high-capacity transmission channels that transmit large amounts of content, such as 120 Hz-UHD (Ultra-high Definition) content; transition channels in which three or more operators share two channels to provide services equivalent to the current ISDB-T (Integrated Services Digital Broadcasting-Terrestrial); and transition channels in which multiple broadcasters share a physical channel that becomes available after the transition to an advanced system as additional transmission bandwidth (hereinafter referred to as "post-transition channels"). A prior example is the specification of CB transmission as an optional feature in ATSC (Advanced Television Systems Committee) 3.0, the next-generation terrestrial broadcasting system in the United States (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2020-022118

In the after-transition channel, in addition to the physical channel (primary channel) that carries the regular broadcast service, an additional channel (part of the secondary channel) that serves as an additional transmission band is assigned later. Therefore, while continuing the regular broadcast service, it is conceivable to use the additional channel to transmit auxiliary information, for example, to improve the quality of the video, thereby improving the quality of the broadcast service on the receiver. For example, a conceivable operation would be to transmit 60 Hz-UHD video on the primary channel and transmit auxiliary information on the additional channel, allowing the receiver to view 120 Hz-UHD video. Because the auxiliary information transmitted on the additional channel is not required for demodulating the data signal transmitted on the primary channel, the receiver can demodulate the video and audio without using the auxiliary information. This type of operation is intended to accommodate the sale of receivers with only one tuner (those that do not support CB transmission), since CB transmission is an optional feature.

On the other hand, the high-capacity transmission channels and transition channels mentioned above use two physical channels from the start of the broadcasting service, so data signals transmitted on two physical channels (primary channel and secondary channel) are required for video and audio demodulation.

Whether or not CB transmission is taking place can be notified to the receiver by superimposing a CB flag, which indicates whether CB transmission is taking place, on the TMCC information. The receiver can determine whether CB transmission is taking place by referencing the CB flag. However, simply referencing the CB flag does not allow the receiver to determine whether the data transmitted on the secondary channel is essential for demodulating the data signal transmitted on the primary channel, or whether it is auxiliary information that does not affect the normal broadcast service. As a result, it becomes impossible to continue receiving the broadcast service. Therefore, there is a need for technology that enables appropriate processing of data signals transmitted via CB transmission according to the broadcast service.

As mentioned above, ATSC 3.0 specifies CB transmission as an optional feature. However, because ATSC 3.0 does not anticipate use cases such as the after-transition channel mentioned above, sufficient consideration has not been given to the configuration for appropriately processing data signals transmitted via CB transmission depending on the broadcast service.

The object of the present invention is to solve the above-mentioned problems and provide a transmitting device, a receiving device, and a control device that can appropriately process data signals transmitted by CB transmission according to the broadcast service.

To solve the above problem, the transmitting device of the present invention is a transmitting device capable of channel bonding transmission in which a data signal is transmitted by combining a first physical channel and a second physical channel, and includes a scheduler unit that allocates and outputs a first data signal to systems corresponding to the first physical channel and the second physical channel, or outputs the first data signal to the system corresponding to the first physical channel and outputs auxiliary information for the first data signal to the system corresponding to the second physical channel, and a generator that generates type information indicating the type of data transmitted on the second physical channel and superimposes the generated type information on at least one of the first data signal and a second data signal transmitted on the first physical channel and the second physical channel with less delay than the first data signal.

Furthermore, in the transmitting device according to the present invention, it is preferable that the type information is information indicating whether the data transmitted on the second physical channel is the auxiliary information.

Furthermore, a receiving device according to the present invention is a receiving device that receives a data signal transmitted by channel bonding transmission combining a first physical channel and a second physical channel, wherein the first data signal is divided and transmitted to each of the first physical channel and the second physical channel, or the first data signal is transmitted on the first physical channel, auxiliary information of the first data signal is transmitted on the second physical channel, and type information indicating the type of data transmitted on the second physical channel is superimposed on the first data signal and/or a second data signal transmitted on the first physical channel and the second physical channel with less delay than the first data signal, and the receiving device includes a first tuner that receives the signal transmitted via the first physical channel, a second tuner that receives the signal transmitted via the second physical channel, and a demodulation processing unit that demodulates the received signals of the first tuner and the second tuner in accordance with the type information superimposed on at least one of the first data signal and the second data signal received by the first tuner.

Furthermore, in the receiving device according to the present invention, it is preferable that the demodulation processing unit, when the type information indicates that the data transmitted on the second physical channel is the first data signal, combines and demodulates the first data signal received by the first tuner and the first data signal received by the second tuner, and, when the type information indicates that the data transmitted on the second physical channel is the auxiliary information, demodulates the first data signal received by the first tuner using the auxiliary information received by the second tuner.

Furthermore, a receiving device according to the present invention is a receiving device that receives a data signal transmitted by channel bonding transmission combining a first physical channel and a second physical channel, and includes a tuner that receives a signal transmitted via the first physical channel, where the first data signal is distributed to each of the first physical channel and the second physical channel and transmitted, or the first data signal is transmitted on the first physical channel, auxiliary information of the first data signal is transmitted on the second physical channel, and type information indicating the type of data transmitted on the second physical channel is superimposed on the first data signal and/or a second data signal transmitted on the first physical channel and the second physical channel with less delay than the first data signal, and a demodulation processing unit that demodulates the signal received by the tuner in accordance with the type information superimposed on at least one of the first data signal and the second data signal received by the tuner.

Furthermore, in the receiving device according to the present invention, the demodulation processing unit does not demodulate the first data signal received by the tuner when the type information indicates that the data transmitted on the second physical channel is the first data signal, and demodulates the first data signal received by the tuner when the type information indicates that the data transmitted on the second physical channel is the auxiliary information.

Furthermore, a control device according to the present invention controls the transmission of data signals via channel bonding transmission combining a first physical channel and a second physical channel, and includes a dividing unit that distributes and outputs a first data signal to a first remultiplexing device that multiplexes data signals transmitted on the first physical channel and a second remultiplexing device that multiplexes data signals transmitted on the second physical channel, or that outputs the first data signal to the first remultiplexing device and outputs auxiliary information of the first data signal to the second remultiplexing device, and a control unit that generates type information indicating the type of data transmitted on the second physical channel, outputs the generated type information to the first remultiplexing device and the second remultiplexing device, and multiplexes it onto the data signals transmitted on the first physical channel and the second physical channel.

The transmitting device and receiving device according to the present invention make it possible to appropriately process data signals transmitted via CB transmission according to the broadcast service.

FIG. 10 is a diagram illustrating an example of the configuration of a transmission/reception system in which plain mode CB transmission is performed when N=2. FIG. 10 is a diagram illustrating an example of the configuration of a transmission/reception system in which CB transmission in MIMO-like mode is performed when N=2. FIG. 1 is a diagram illustrating an example of the configuration of a conventional remultiplexing device. 1 is a diagram illustrating an example of the configuration of a remultiplexing device according to a first embodiment of the present invention. 4 is a diagram illustrating an example of the configuration of an XMI packet transmission scheduler unit illustrated in FIG. 3. FIG. 5 is a diagram illustrating an example of the configuration of an A-layer XMI packet distribution unit shown in FIG. 4. 5 is a diagram illustrating an example of the configuration of an L0 symbol distribution unit illustrated in FIG. 4. 1 is a diagram illustrating an example of the configuration of a demodulation device according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating another example of the configuration of a demodulation device according to the first embodiment of the present invention. FIG. 10 is a diagram illustrating an example of the configuration of a transmission/reception system according to a second embodiment of the present invention. FIG. 10 is a diagram illustrating an example of the configuration of a division unit illustrated in FIG. 9 .

The following describes an embodiment of the present invention with reference to the drawings.

(First embodiment)
First, referring to Figures 1A and 1B, the configurations of transmission/reception systems 1 and 1A that perform channel bonding transmission (CB transmission) will be described. Figure 1A is a diagram illustrating an example of the configuration of a transmission/reception system 1 that performs CB transmission in plain mode when N = 2. Figure 1B is a diagram illustrating an example of the configuration of a transmission/reception system 1A that performs CB transmission in MIMO-like mode when N = 2. Current ISDB-T employs hierarchical transmission, in which data signals of multiple layers with different transmission tolerances and transmission capacities are simultaneously transmitted within the same channel. Furthermore, in advanced systems, consideration is being given to transmitting emergency earthquake alerts and the like with lower latency than the data signals of each layer using the same physical channel as the data signals of each layer. The transmission path through which such low-latency data signals are transmitted is referred to as an LLch. The following description will be given assuming that three-layer (A, B, and C) hierarchical transmission and transmission via an LLch are performed.

First, referring to Figure 1A, we will explain the configuration of a transmission/reception system 1 in which plain mode CB transmission is performed.

As shown in Figure 1A, the transmission/reception system 1 includes a remultiplexing device 2, two modulation devices 3 (modulation devices 3p and 3s), two transmitters 4 (transmitters 4p and 4s), two receivers 5 (receivers 5p and 5s), and a demodulation device 6. The modulation device 3p, transmitter 4p, and receiver 5p are provided corresponding to the primary channel, and the modulation device 3s, transmitter 4s, and receiver 5s are provided corresponding to the secondary channel.

The remultiplexer 2 remultiplexes the data signals (video and audio data) for each layer of hierarchical transmission with the data signal for the LL channel. When performing CB transmission, the remultiplexer 2 outputs a multiplexed frame (XMI packet) in which the data signals for each layer and the data signal for the LL channel are remultiplexed to two systems corresponding to the primary channel and the secondary channel, respectively. In other words, the remultiplexer 2 outputs the multiplexed frame in which the data signals for each layer and the data signal for the LL channel are remultiplexed to the modulation device 3p corresponding to the primary channel and the modulation device 3s corresponding to the secondary channel.

The modulator 3p performs predetermined processing such as error correction coding and carrier modulation on the output of the remultiplexer 2 to construct an Orthogonal Frequency Division Multiplexing (OFDM) frame. The modulator 3p then performs Inverse Fast Fourier Transform (IFFT) processing and adds a guard interval (GI) to the constructed OFDM frame, and outputs it to the transmitter 4p. The transmitter 4p transmits the OFDM frame output from the modulator 3p via the primary channel.

The modulator 3s performs predetermined processing, such as error correction coding and modulation, on the output of the remultiplexer 2 to construct an OFDM frame. The modulator 3s performs IFFT and adds a GI to the constructed OFDM frame, and outputs it to the transmitter 4s. The transmitter 4s transmits the OFDM frame output from the modulator 3s via a secondary channel. The transmitters 4p and 4s are synchronized, and emit broadcast waves at the same time.

Receiver 5p receives broadcast waves transmitted from transmitter 4p via the primary channel and outputs the received signal to demodulator 6. Receiver 5s receives broadcast waves transmitted from transmitter 4s via the secondary channel and outputs the received signal to demodulator 6.

When CB transmission is taking place, demodulation device 6 demodulates the received signals of receiver 5p and receiver 5s, and acquires and outputs the data signals of each layer and the LL channel transmitted via the primary channel and secondary channel.

Next, with reference to Figure 1B, we will explain the configuration of a transmission/reception system 1A in which CB transmission in MIMO-like mode is performed. In Figure 1B, components similar to those in Figure 1A are assigned the same reference numerals, and their explanation will be omitted.

As shown in Figure 1B, the transmission/reception system 1A includes a remultiplexing device 2A, a modulation device 3A, two transmitters 4 (transmitters 4p and 4s), two receivers 5 (receivers 5p and 5s), and a demodulation device 6A. The transmission/reception system 1A shown in Figure 1B differs from the transmission/reception system 1 shown in Figure 1A in that the remultiplexing device 2, modulation device 3, and demodulation device 6 have been replaced with a remultiplexing device 2A, modulation device 3A, and demodulation device 6A, respectively.

The remultiplexer 2A multiplexes the data signals of each layer of the hierarchical transmission and the LL channel data signal into a single system, creating a multiplexed frame (XMI packet), which it outputs to the modulator 3A.

The modulation device 3A divides the multiplexed frame output from the remultiplexing device 2A into two systems corresponding to the primary and secondary channels, constructs an OFDM frame in which the data signals for each layer of the hierarchical transmission, the LL channel data signal, and the TMCC signal are placed on predetermined carriers, and outputs this to the transmitters 4p and 4s.

When CB transmission is being performed, demodulation device 6A demodulates the received signals from receiver 5p and receiver 5s, and outputs the data signals for each layer and the LL channel transmitted via the primary channel and secondary channel, respectively.

In the transmission/reception system 1 shown in FIG. 1A, which performs plain-mode CB transmission, different data signals can be transmitted on the primary channel and the secondary channel, so the data signal transmitted on the secondary channel is not required to demodulate the data signal transmitted on the primary channel. On the other hand, in the transmission/reception system 1A shown in FIG. 1B, which performs MIMO-like mode CB transmission, the data signal transmitted on the secondary channel is required to demodulate the data signal transmitted on the primary channel. As described above, in the after-transition channel, for example, normal broadcast services (main line) are transmitted on the primary channel, and auxiliary information is transmitted on the secondary channel. Therefore, in the after-transition channel, the data signal transmitted on the secondary channel is not required to demodulate the data signal transmitted on the primary channel. The transmitting device and receiving device according to the present invention are compatible with CB transmission using after-transition channels. Therefore, the transmitting device and receiving device according to the present invention are applicable to the transmission/reception system 1 shown in FIG. 1A, which performs N=2 plain-mode CB transmission (CB transmission consisting of a primary channel (first physical channel) and a secondary channel (second physical channel)).

Next, we will explain the configuration of the remultiplexing device 10 as a transmitting device according to the present invention, and the configuration of the demodulation device 20 as a receiving device according to the present invention. The configurations of the modulation device 3, transmitter 4, and receiver 5 are not directly related to the present invention, so their explanation will be omitted.

First, before explaining the configuration of the remultiplexing device 10 according to this embodiment, for comparison purposes, we will explain the configuration of a conventional remultiplexing device 10a, which does not support CB transmission, with reference to Figure 2.

When hierarchical transmission (layers A, B, and C) and transmission via LL channels are performed, a multiplexing device is provided for each layer and LL channel. The multiplexing device for each layer multiplexes the video and audio data transmitted at the corresponding layer and packetizes it into packets (MMT packets) in MMT (MPEG Media Transport) format, for example. The multiplexing device for each layer generates IP packets (hereinafter referred to as "MMT/IP packets") that store the generated MMT packets and outputs them to remultiplexing device 10a. The multiplexing device for the LL channel multiplexes the data transmitted on the LL channel to generate MMT packets and outputs the MMT/IP packets that store the MMT packets to remultiplexing device 10a.

The remultiplexing device 10a remultiplexes the MMT/IP packets output from the multiplexing devices corresponding to each layer and LLch into one system. As shown in FIG. 2, the remultiplexing device 10a includes a packet filter 101, an IP header compression unit 102, a TLV (Type Length Value) packetization unit 103, a FIFO (First In First Out) buffer 104, an FEC (Forward Error Correction) block configuration unit 105, a layer-specific frame configuration unit 106, an XMI (eXtensible Modulation Interface) packetization unit 107, a packet filter 108, IP header compression units 109 and 110, TLV packetization units 111 and 112, FIFO buffers 113 and 114, an L0 symbol configuration unit 115, an L1 symbol configuration unit 116, a GPS reference signal generator 117, a synchronization control XMI packet configuration unit 118a, a stuff XMI packet configuration unit 119, and an XMI packet transmission scheduler unit 120a. The packet filter 101, IP header compression unit 102, TLV packetization unit 103, FIFO buffer 104, FEC block construction unit 105, layer-specific frame construction unit 106, and XMI packetization unit 107 are provided to correspond to layers A, B, and C, respectively, but to simplify the illustration, Figure 2 only shows the configuration corresponding to layer A. The configuration corresponding to layer A will be explained below, but the same applies to layers B and C.

Packet filter 101 receives layer A data (MMT/IP packets) from a multiplexing device (not shown) corresponding to layer A. Packet filter 101 selects packets to transmit (packet filtering) based on the source IP address, destination IP address, protocol type, source port number and destination port number in the UDP (User Datagram Protocol) header of the input MMT/IP packets, and outputs the selected MMT/IP packets to IP header compression unit 102.

The IP header compression unit 102 compresses the IP header of the MMT/IP packet output from the packet filter 101 as necessary and outputs it to the TLV packetization unit 103.

The TLV packetizer 103 receives signaling information (SI) in TLV format (TLV-SI). The SI defines, for example, a terrestrial distribution system descriptor, which indicates the physical conditions of the terrestrial transmission path. The TLV packetizer 103 encapsulates the input TLV-SI and the MMT/IP packet output from the IP header compressor 102 into a TLV packet to generate a TLV packet. The TLV packet includes a reserved area, a packet type area, a data length area, and a data area. The packet type area indicates the type of TLV packet, and the data length area indicates the size of the data stored in the data area. The TLV packetizer 103 stores the TLV-SI and MMT/IP packet in the data area. Details regarding TLVs are described, for example, in "Video coding, audio coding, and multiplexing specifications for digital broadcasting," ARIB-STD B32, and therefore will not be described here.

The TLV packetization unit 103 outputs the generated TLV packets to the FIFO buffer 104.

The FIFO buffer 104 stores the TLV packets output from the TLV packetization unit 103 and outputs the stored TLV packets to the FEC block construction unit 105 in the order in which they were stored.

The multiplexing device corresponding to each layer may output the multiplexed data as TLV packets (TLV/IP packets) rather than as MMT/IP packets. In this case, the TLV packets output from the multiplexing device are stored in the FIFO buffer 104. When TLV packets are input from the multiplexing device, the remultiplexing device 10a does not need to include the packet filter 101, IP header compression unit 102, and TLV packetization unit 103.

The FEC block construction unit 105 constructs FEC blocks at regular intervals from the TLV packets output from the FIFO buffer 104. An FEC block is a block (processing block) that serves as the unit of error correction coding processing.

The FEC block includes an FEC block header area, a main signal area, a BCH parity area, a stuff bit area, and an LDPC parity area. The main signal area stores TLV packets output from the FIFO buffer 104. The FEC block header area is a field (first TLV indication field) that stores information indicating the position of the first byte of the first TLV packet stored in the main signal area of the FEC block, expressed as the number of bytes from the beginning of the FEC block excluding the FEC block header. The BCH parity area, stuff bit area, and LDPC area store the bit "1".

The FEC block construction unit 105 concatenates the TVL packets output from the FIFO buffer 104 in the order they were output and stores them in the main signal area, and sets the value of the first TLV indication field for each FEC block. The FEC block construction unit 105 outputs the constructed FEC blocks to the hierarchical frame construction unit 106.

The layer-specific frame construction unit 106 constructs layer-specific frames from the FEC blocks output from the FEC block construction unit 105.

A layer-specific frame includes a frame header area and an FEC block area. The FEC block area stores multiple concatenated FEC blocks and FEC block fragments. The size of a layer-specific frame is determined by factors such as the modulation method, FFT (Fast Fourier Transform) size, GI ratio, pilot signal ratio, and number of segments (the number of segments into which the frequency band of one physical channel (physical ch) is divided).

The frame header area contains an FEC block pointer with a predetermined number of bits, and the remaining area contains the bit "1". The FEC block pointer indicates the position, in bits or bytes, of the first bit of the first FEC block, including the beginning of the FEC blocks to be stored in the hierarchical frame, from the start of the FEC block area.

The layer-specific frame constructor 106 concatenates the FEC blocks output from the FEC block constructor 105 in the order they were output and stores them in the FEC block area. The layer-specific frame constructor 106 calculates an FEC block pointer from the position of the FEC block stored in the FEC block area and stores it in the frame header. The layer-specific frame constructor 106 outputs the constructed layer-specific frame to the XMI packetizer 107.

The XMI packetizer 107 composes XMI packets (layer A XMI packets) from the layer-specific frames output from the layer-specific frame composer 106. Specifically, the XMI packetizer 107 divides the layer-specific frames into pieces of a predetermined size (e.g., 10,448 bits) to compose data units. The XMI packet includes a header and a data unit area. The XMI packetizer 107 stores the data units in the data unit area. Note that there are cases where the last data unit is smaller than the predetermined size. In this case, the XMI packetizer 107 adds predetermined bits (stuff bits) to the data units that are smaller than the predetermined size to make them the predetermined size, and stores them in the data unit area.

The XMI packetizer 107 outputs the generated XMI packets to the XMI packet transmission scheduler 120a. XMI is a protocol designed as an interface for outputting layer-specific OFDM frames to the modulator 3.

The packet filter 108 receives LL channel data (MMT/IP packets) from a multiplexer (not shown) corresponding to the LL channel. The packet filter 108 selects packets to transmit (packet filtering) based on the source IP address, destination IP address, protocol type, source port number and destination port number in the UDP header of the input MMT/IP packets, and outputs the selected MMT/IP packets to the IP header compression unit 109 or the IP header compression unit 110.

The IP header compression unit 109 compresses the IP header of the MMT/IP packet output from the packet filter 108 as necessary, and outputs the result to the TLV packetization unit 111. The IP header compression unit 110 compresses the IP header of the MMT/IP packet output from the packet filter 108 as necessary, and outputs the result to the TLV packetization unit 112.

The TLV packetizer 111 encapsulates the MMT/IP packets output from the IP header compressor 109 into TLV packets to generate TLV packets, and outputs them to the FIFO buffer 113. The TLV packetizer 112 encapsulates the MMT/IP packets output from the IP header compressor 110 into TLV packets to generate TLV packets, and outputs them to the FIFO buffer 114.

FIFO buffer 113 stores the TLV packets output from TLV packetization unit 111 and outputs the stored TLV packets to L0 symbol construction unit 115 in the order they were stored. FIFO buffer 114 stores the TLV packets output from TLV packetization unit 112 and outputs the stored TLV packets to L1 symbol construction unit 116 in the order they were stored.

The multiplexing device corresponding to the LL channel may output the multiplexed data as TLV packets (TLV/IP packets) instead of MMT/IP packets. In this case, the TLV packets output from the multiplexing device are stored in FIFO buffers 113 and 114. When TLV packets are input from the multiplexing device, the remultiplexing device 10a may be equipped with packet filter 121 instead of packet filter 108.

The packet filter 121 selects (packet filters) packets to transmit based on the source IP address, destination IP address, protocol type, source port number and destination port number in the UDP header of the TLV packets (TLV/IP packets) input from a multiplexing device (not shown) corresponding to the LL channel, and outputs the selected TLV packets to the FIFO buffer 113 or FIFO buffer 114. Therefore, when TLV packets are input from a multiplexing device corresponding to the LL channel, the remultiplexing device 10a does not need to include the packet filter 108, IP header compression units 109 and 110, and TLV packetization units 111 and 112.

The L0 symbol constructor 115 constructs a symbol (L0 symbol) from the TLV packet output from the FIFO buffer 113 and outputs it to the XMI packet transmission scheduler 120a. The L1 symbol constructor 116 constructs a symbol (L1 symbol) from the TLV packet output from the FIFO buffer 114 and outputs it to the XMI packet transmission scheduler 120a.

The L0 symbol is transmitted, for example, in a segment for partial reception among multiple segments into which the frequency band of one physical channel is divided, and the L1 symbol is transmitted in the remaining segment. Therefore, packet filtering by packet filter 108 (or packet filter 121) is also performed according to this allocation.

The GPS reference signal generator 117 outputs a constant-period reference signal generated from the GPS received signal.

The synchronization control XMI packet configuration unit 118a generates synchronization control information including transmission parameters for configuring OFDM frames, the timing for transmitting the OFDM frames, and TMCC (Transmission and Multiplexing Configuration Control) information, which is control information related to the transmission of data signals at each layer. TMCC information includes, for example, the carrier modulation method and coding rate for the data signals at each layer. The synchronization control XMI packet configuration unit 118a generates an XMI packet (hereinafter referred to as a "synchronization control XMI packet") that stores the generated synchronization control information in the data unit area, and outputs this to the XMI packet transmission scheduler unit 120a.

The stuff XMI packet construction unit 119 constructs an XMI packet (hereinafter referred to as a "stuff XMI packet") in which only stuff bits of the same size as the data unit are stored in the data unit area, and outputs it to the XMI packet transmission scheduler unit 120a. Stuff XMI packets are used to keep the number of XMI packets output per second by the remultiplexing device 10a constant, even when the modulation method or coding rate is different.

The XMI packet transmission scheduler unit 120a multiplexes the XMI packets for each layer (layer A XMI packets, layer B XMI packets, and layer C XMI packets) output from the XMI packetization units 107 corresponding to layers A, B, and C, respectively, the L0 symbols output from the L0 symbol configuration unit 115, the L1 symbols output from the L1 symbol configuration unit 116, the synchronization control XMI packets output from the synchronization control XMI packet configuration unit 118a, and the stuff XMI packets output from the stuff XMI packet configuration unit 119 into one system and outputs it to the modulation devices 3p and 3s.

Current ISDB-T uses a Single Frequency Network (SFN), which transmits the same broadcast content from multiple transmission stations at the same frequency. Therefore, the XMI packet transmission scheduler unit 120a outputs XMI packets in multiple streams (two streams in Figure 2). However, the data in each stream is the same.

Next, the configuration of a remultiplexing device 10 as a transmitting device according to the present invention will be described with reference to Figure 3. The remultiplexing device 10 according to this embodiment performs CB transmission (normal CB transmission) using the primary and secondary channels of the video and audio data signals (main line signals) of broadcast content, or performs CB transmission using an after-transition channel that transmits auxiliary information for improving the quality of the main line signal on the secondary channel. That is, when normal CB transmission is performed, the video and audio data signals are input to the remultiplexing device 10. When CB transmission using an after-transition channel is performed, the video and audio data signals and auxiliary information for those data signals are input. In Figure 3, components similar to those in Figure 2 are assigned the same reference numerals, and their description will be omitted. Figure 3 will be described using an example where N=2 CB transmission is performed.

The remultiplexing device 10 shown in Figure 3 comprises a packet filter 101, an IP header compression unit 102, a TLV packetization unit 103, a FIFO buffer 104, an FEC block construction unit 105, a hierarchical frame construction unit 106, an XMI packetization unit 107, a packet filter 108, IP header compression units 109, 110, TLV packetization units 111, 112, FIFO buffers 113, 114, an L0 symbol construction unit 115, an L1 symbol construction unit 116, a GPS reference signal generator 117, a synchronization control XMI packet construction unit 118, a stuff XMI packet construction unit 119, an XMI packet transmission scheduler unit 120, and a CB TLV-SI generation unit 122. The remultiplexing device 10 shown in Figure 3 differs from the remultiplexing device 10a shown in Figure 2 in that it adds a CB TLV-SI generation unit 122, and that the synchronization control XMI packet construction unit 118a and XMI packet transmission scheduler unit 120a have been changed to a synchronization control XMI packet construction unit 118 and XMI packet transmission scheduler unit 120, respectively. The CB TLV-SI generation unit 122 is an example of a generation unit.

Similar to synchronization control XMI packet constructor 118a, synchronization control XMI packet constructor 118 generates synchronization control information including TMCC information related to the transmission of data signals for each layer, and generates a synchronization control XMI packet that stores the generated synchronization control information in the data unit area. Synchronization control XMI packet constructor 118 also superimposes a CB flag (flag information) indicating whether CB transmission is to be performed on the physical channel that transmits data signals for each layer, on the TMCC information. Synchronization control XMI packet constructor 118 outputs the synchronization control XMI packet, in which synchronization control information including TMCC information with the superimposed CB flag is stored in the data unit area, to XMI packet transmission scheduler 120.

The CB TLV-SI generation unit 122 generates channel bonding control information (hereinafter referred to as "CB control information"), which is control information required to receive CB transmission. Specifically, the CB TLV-SI generation unit 122 generates a TLV-format packet (hereinafter referred to as "CB TLV-SI packet") containing CB control information. The CB control information includes frequency information of the physical channels that make up the CB transmission used within the area. For example, if N = 2, it includes frequency information of the paired primary and secondary channels. When a multi-frequency network (MFN) is adopted, which uses different frequencies for each area, the CB control information includes at least frequency information of the physical channels that make up the CB transmission in all areas. For example, if N = 2, it includes frequency information of the primary and secondary channels.

The CB control information also includes a CB mode indicating the CB transmission mode (Plain mode or MIMO-like mode). Furthermore, the CB control information also includes type information indicating the type of data transmitted on the secondary ch. The type information may be information that can determine whether the data transmitted on the secondary ch is a type of data essential for demodulating the data signal transmitted on the primary ch, i.e., whether the data transmitted on the secondary ch is a data signal or auxiliary information. Therefore, the type information may be, for example, one-bit flag information (hereinafter referred to as an "auxiliary information flag") indicating whether the data transmitted on the secondary ch is auxiliary information. In the following description, the CB TLV-SI generation unit 122 generates an auxiliary information flag and includes it in the CB control information.

In this case, when CB transmission is performed via the after-transition channel, the CB TLV-SI generation unit 122 turns on the auxiliary information flag because auxiliary information is transmitted on the secondary channel. On the other hand, when normal CB transmission is performed, the CB TLV-SI generation unit 122 turns off the auxiliary information flag because video and audio data signals (main line signals) are transmitted on the secondary channel.

The CB TLV-SI generation unit 122 outputs the generated CB TLV-SI packets to the TLV packetization unit 112 and the XMI packet transmission scheduler unit 120 at regular intervals (e.g., every 1 second).

The TLV packetizer 112 outputs to the FIFO buffer 114 TLV packets in which the MMT/IP packets output from the IP header compressor 110 are stored in the data area, and CB TLV-SI packets output from the CB TLV-SI generator 122. The TLV packets and CB TLV-SI packets stored in the FIFO buffer 114 are output to the L1 symbol constructor 116, which constructs L1 symbols. The L1 channel on which the L1 symbols are transmitted may also be used for purposes such as reducing PAPR (Peak to Average Power Ratio). The CB TLV-SI generator 122 outputs CB TLV-SI packets so that the CB TLV-SI packets are transmitted at a transmission rate that does not affect the use of the L1 channel.

The XMI packet transmission scheduler unit 120, described in detail below, multiplexes CB TLV-SI packets onto the XMI packets of each layer. The XMI packet transmission scheduler unit 120 multiplexes the XMI packets of each layer onto which the CB TLV-SI packets have been multiplexed, the L0 symbol, the L1 symbol, the synchronization control XMI packets, and the stuff XMI packets into one system, then separates them into two systems corresponding to the primary and secondary channels, and outputs them to the modulation devices 3p and 3s.

In this embodiment, the CB TLV-SI generation unit 122 outputs a CB TLV-SI packet including type information (auxiliary information flag) indicating the type of data transmitted on the secondary channel to the TLV packetization unit 112 and the XMI packet transmission scheduler unit 120. In this way, the CB TLV-SI generation unit 122 can multiplex the auxiliary information flag onto the data signals of each layer (first data signal), which are video and audio data, and the LL channel data signal (second data signal), which is transmitted with less delay than the data signals of each layer.

Figure 4 shows an example configuration of the XMI packet transmission scheduler unit 120.

As shown in FIG. 4, the XMI packet transmission scheduler unit 120 includes an A-layer XMI packet distribution unit 1201, a B-layer XMI packet distribution unit 1202, a C-layer XMI packet distribution unit 1203, an L0 symbol distribution unit 1204, an L1 symbol distribution unit 1205, a CB TLV-SI packet distribution unit 1206, a primary ch XMI transmission scheduler unit 1207, and a secondary ch XMI transmission scheduler unit 1208.

The layer A XMI packet distribution unit 1201 receives layer A XMI packets and control information related to layer transmission (e.g., number of layers, number of segments, etc.). The layer A XMI packets include XMI packets containing the main line signals transmitted on layer A and XMI packets containing auxiliary information for the main line signals transmitted on layer A. As shown in FIG. 5, the layer A XMI packet distribution unit 1201 switches the connection destination of the switch between the primary ch XMI scheduler unit 1207 and the secondary ch XMI transmission scheduler unit 1208 based on the control information, and distributes and outputs the input layer A XMI packets to the primary ch XMI scheduler unit 1207 and the secondary ch XMI transmission scheduler unit 1208.

Specifically, when CB transmission is performed using an after-transition channel, the layer A XMI packet distribution unit 1201 outputs a layer A XMI packet containing the main line signal transmitted on layer A to the primary ch XMI transmission scheduler unit 1207, and outputs a layer A XMI packet containing auxiliary information of the main line signal transmitted on layer A to the secondary ch XMI transmission scheduler unit 1208. The main line signal and auxiliary information can be distinguished using a TLV header or a UDP port number, etc. Furthermore, when normal CB transmission is performed, the layer A XMI packet distribution unit 1201 distributes and transmits layer A XMI packets containing the main line signal transmitted on layer A to the primary ch XMI transmission scheduler unit 1207 and the secondary ch XMI transmission scheduler unit 1208.

Referring again to FIG. 4, the B-layer XMI packet distribution unit 1202 distributes the B-layer XMI packets to the primary ch XMI scheduler unit 1207 and the secondary ch XMI transmission scheduler unit 1208 in the same manner as the A-layer XMI packet distribution unit 1201. Furthermore, the C-layer XMI packet distribution unit 1203 distributes the C-layer XMI packets to the primary ch XMI scheduler unit 1207 and the secondary ch XMI transmission scheduler unit 1208 in the same manner as the A-layer XMI packet distribution unit 1201.

The configurations of the B-layer XMI packet distribution unit 1202 and the C-layer XMI packet distribution unit 1203 are the same as the configuration of the A-layer XMI packet distribution unit 1201, so explanations will be omitted.

The layer A XMI packet distribution unit 1201, layer B XMI packet distribution unit 1202, and layer C XMI packet distribution unit 1203 distribute the XMI packets of each layer to the primary ch XMI transmission scheduler unit 1207 and secondary ch XMI transmission scheduler unit 1208, for example, in FEC block units (units of multiple XMI packets that make up an FEC block), which are processing block units for error correction coding. This makes it possible to synchronize the start of the FEC block with the start of the OFDM frame.

The L0 symbol is input to the L0 symbol distribution unit 1204. As shown in FIG. 6, the L0 symbol distribution unit 1204 is connected to the primary ch XMI transmission scheduler unit 1207 and the secondary ch XMI transmission scheduler unit 1208, and outputs the input L0 symbol to each of the primary ch XMI transmission scheduler unit 1207 and the secondary ch XMI transmission scheduler unit 1208.

Referring again to FIG. 4, the L1 symbol distributor 1205, like the L0 symbol distributor 1204, outputs L1 symbols to the primary ch XMI transmission scheduler 1207 and the secondary ch XMI transmission scheduler 1208. The CB TLV-SI packet distributor 1206, like the L0 symbol distributor 1204, outputs CB TLV-SI packets to the primary ch XMI transmission scheduler 1207 and the secondary ch XMI transmission scheduler 1208. The configurations of the L1 symbol distributor 1205 and the CB TLV-SI packet distributor 1206 are the same as those of the L0 symbol distributor 1204, so a description thereof will be omitted.

The primary ch XMI transmission scheduler unit 1207 receives synchronization control XMI packets, stuff XMI packets, XMI packets for each layer, L0 symbols, L1 symbols, and CB TLV-SI packets. The primary ch XMI transmission scheduler unit 1207 multiplexes the received synchronization control XMI packets, stuff XMI packets, XMI packets for each layer, L0 symbols, L1 symbols, and CB TLV-SI packets into a single system and outputs the multiplexed system to the modulation device 3p.

Specifically, the primary ch XMI transmission scheduler unit 1207 outputs one synchronization control XMI packet at the beginning of the OFDM frame. Subsequently, the primary ch XMI transmission scheduler unit 1207 outputs the XMI packets and CB TLV-SI packets for each layer. As described above, the CB TLV-SI packets are output at regular intervals. Therefore, the primary ch XMI transmission scheduler unit 1207 outputs the CB TLV-SI packets at regular intervals between the XMI packets for each layer. In this way, the CB TLV-SI packets are multiplexed with the XMI packets for each layer into a single system and output to the modulation device 3p. After outputting all the XMI packets for each layer, the primary ch XMI transmission scheduler unit 1207 outputs stuff XMI packets so that the number of XMI packets constituting the OFDM frame remains constant. The data unit area of the XMI packet for each layer is allocated an area for storing the L0 symbol and the L1 symbol (L0 symbol storage area, L1 symbol storage area). When an L0 symbol is input, the primary ch XMI transmission scheduler unit 1207 quickly (with low delay) allocates the L0 symbol to the L0 symbol storage area of the XMI packet for each layer, and when an L1 symbol is input, it quickly (with low delay) allocates the L1 symbol to the L1 symbol storage area of the XMI packet for each layer. In this way, the primary ch XMI transmission scheduler unit 1207 can output LLch data to the modulation device 3 with low delay.

The secondary ch XMI transmission scheduler unit 1208, like the primary ch XMI transmission scheduler unit 1207, multiplexes the input synchronization control XMI packets, stuff XMI packets, XMI packets for each layer, L0 symbols, L1 symbols, and CB TLV-SI packets into one system and outputs it to the modulation device 3s.

The XMI packets output from the primary ch XMI transmission scheduler unit 1207 and secondary ch XMI scheduler unit 1208 are input to the modulation device 3 via a wired line or a wireless line (STL (Studio to Transmitter Link), TTL (Transmitter to Transmitter Link)).

In this way, when normal CB transmission is performed, the XMI packet transmission scheduler unit 120 distributes and outputs the main line signal (first data signal) to the systems corresponding to the primary ch (first physical ch) and the secondary ch (second physical ch). Furthermore, when CB transmission is performed on an after-transition ch, the XMI packet transmission scheduler unit 120 transmits the main line signal to the system corresponding to the primary ch and transmits the auxiliary information of the main line signal to the system corresponding to the secondary ch.

In this embodiment, an example has been described in which CB control information (auxiliary information flags) is superimposed on the data signals (XMI packets) of each layer and the data signal (L1 symbol) of the LL channel, but the present invention is not limited to this. When CB transmission is performed in plain mode, CB control information may be superimposed on only either the data signals of each layer or the data signal of the LL channel. Therefore, the configuration of the remultiplexing device 10 may be modified as appropriate depending on whether CB control information is superimposed on only the data signals of each layer, only the data signal of the LL channel, or both.

Next, the configuration of a demodulator 20 serving as a receiving device according to the present invention will be described. The demodulator 20 according to this embodiment receives, via a receiver 5, broadcast waves transmitted over CB from a remultiplexer 10 serving as a transmitting device according to the present invention via modulators 3p, 3s and transmitters 4p, 4s, and acquires data signals of each layer from the received signals. Figure 7 is a diagram showing an example configuration of a demodulator 20 according to this embodiment. Figure 7 shows an example configuration in which the demodulator 20 is compatible with CB transmission.

As shown in FIG. 7, the demodulation device 20 according to this embodiment includes two tuners 201 and 202, GI removal and FFT units 203 and 204, OFDM frame synchronization units 205 and 206, TMCC demodulation units 207 and 208, pilot extraction units 209 and 210, channel estimation units 211 and 212, waveform equalization units 213 and 214, deinterleaving and LLR (Log Likelihood Ratio) calculation and error correction decoding units 215 and 216, LLch demodulation and error correction decoding units 217 and 218, a CB transmission determination unit 219, a side information flag determination unit 220, a P/S synchronization unit 221, a CB combining and output unit 222, and a demodulation unit 223. The CB combining and output unit 222 and the demodulation unit 223 form a demodulation processing unit 224.

Tuner 201, acting as the first tuner, receives broadcast waves transmitted via the primary channel via receiver 5p. Tuner 201 selects and acquires the signal of the specified physical channel from the received signal. Tuner 201 performs A/D conversion on the acquired signal and outputs the A/D converted signal to GI removal/FFT unit 203.

The GI removal/FFT unit 203 performs GI removal and FFT on the output signal of the tuner 201, and outputs the resulting OFDM frame to the OFDM frame synchronization unit 205.

The OFDM frame synchronization unit 205 outputs the OFDM frame output from the GI removal/FFT unit 203 to the TMCC demodulation unit 207, pilot extraction unit 209, and LLch demodulation/error correction decoding unit 217.

The TMCC demodulation unit 207 demodulates the TMCC signal placed on the TMCC carrier from the OFDM frame output from the OFDM frame synchronization unit 205, and obtains the TMCC information contained in the TMCC signal. In this way, the TMCC demodulation unit 207 extracts TMCC information from the signal received by the tuner 201. The TMCC demodulation unit 207 outputs the extracted TMCC information to the CB transmission determination unit 219. Furthermore, based on the extracted TMCC information, the TMCC demodulation unit 207 instructs the pilot extraction unit 209 on the position of the pilot carrier on which the pilot signal is placed.

The pilot extraction unit 209 extracts pilot signals allocated to pilot carriers specified by the TMCC demodulation unit 207 from the OFDM frame output from the OFDM frame synchronization unit 205. The pilot extraction unit 209 outputs the extracted pilot signals to the channel estimation unit 211. The pilot extraction unit 209 also outputs the OFDM frame input from the OFDM frame synchronization unit 205 to the waveform equalization unit 213.

The channel estimation unit 211 performs channel estimation using the pilot signal output from the pilot extraction unit 209 and outputs the estimated value to the waveform equalization unit 213.

Based on the estimated value output from the channel estimation unit 211, the waveform equalization unit 213 corrects (equalizes) the signal distortion that occurs in the transmission path for the OFDM frame output from the channel estimation unit 211, and outputs the equalized signal to the deinterleaving/LLR calculation/error correction decoding unit 215.

The deinterleaving/LLR calculation/error correction decoding unit 215 performs deinterleaving on the output signal of the waveform equalization unit 213, which is the reverse of the interleaving performed by the modulation device 3, and calculates the LLR (Log Likelihood Ratio) for each bit. The deinterleaving/LLR calculation/error correction decoding unit 215 uses the calculated LLR to perform error correction decoding on the deinterleaved signal and obtain the data signal for each layer. As described with reference to Figure 3, when CB transmission is performed, CB TLV-SI packets may be multiplexed onto the XMI packets of each layer. The deinterleaving/LLR calculation/error correction decoding unit 215 obtains the XMI packets (main line signals) of each layer and the CB TLV-SI packets (CB control information) multiplexed onto the XMI packets of each layer. The deinterleaving/LLR calculation/error correction decoding unit 215 outputs the acquired data signals (main line signals) of each layer to the CB synthesis output unit 222, and outputs the acquired CB control information to the auxiliary information flag determination unit 220.

The LLch demodulation and error correction decoding unit 217 extracts the carrier on which the LLch data is assigned from the OFDM frame output from the OFDM frame synchronization unit 205 and demodulates the LLch data. The LLch demodulation and error correction decoding unit 217 performs error correction decoding on the demodulated signal to obtain the LLch data signal. As described with reference to FIG. 3, when CB transmission is performed, a CB TLV-SI packet may be multiplexed onto the LLch data. The LLch demodulation and error correction decoding unit 217 obtains the LLch data signal and the CB control information multiplexed onto the LLch data signal. The LLch demodulation and error correction decoding unit 217 outputs the obtained LLch data signal to the CB synthesis and output unit 222 and outputs the obtained CB control information to the auxiliary information flag determination unit 220.

The operations of the tuner 202, GI removal/FFT unit 204, OFDM frame synchronization unit 206, TMCC demodulation unit 208, pilot extraction unit 210, channel estimation unit 212, waveform equalization unit 214, deinterleaving/LLR calculation/error correction decoding unit 216 and LLch demodulation/error correction decoding unit 218 are similar to the operations of the tuner 201, GI removal/FFT unit 203, OFDM frame synchronization unit 205, TMCC demodulation unit 207, pilot extraction unit 209, channel estimation unit 211, waveform equalization unit 213, deinterleaving/LLR calculation/error correction decoding unit 215 and LLch demodulation/error correction decoding unit 518, except that the processing target is the received signal via receiver 5s, and therefore will not be described here. However, when a data signal (main line signal) of each layer is transmitted via a secondary channel by normal CB transmission, the deinterleaving/LLR calculation/error correction decoding unit 216 acquires the data signal of each layer and outputs it to the CB combining/output unit 222. Furthermore, when auxiliary information is transmitted via a secondary channel by CB transmission of an after-transition channel, the deinterleaving/LLR calculation/error correction decoding unit 216 acquires the auxiliary information and outputs it to the CB combining/output unit 222. The TMCC demodulation unit 208 outputs the extracted TMCC information only to the pilot extraction unit 210, and does not output it to the CB transmission determination unit 219. Furthermore, the deinterleaving/LLR calculation/error correction decoding unit 216 and the LLch demodulation/error correction decoding unit 218 do not output CB control information to the auxiliary information flag determination unit 220.

The CB transmission determination unit 219 references the CB flag superimposed on the TMCC information output from the TMCC demodulation unit 207, determines whether CB transmission is occurring on the physical channel received via the tuner 501, and outputs the determination result to the auxiliary information flag determination unit 220. The CB transmission determination unit 219, for example, scans across the frequency bands of all physical channels and, during an initial scan to detect receivable channels, references the CB flag superimposed on the TMCC information and determines whether CB transmission is occurring on each physical channel. In this way, by superimposing the CB flag indicating whether CB transmission is occurring on the TMCC information, the CB transmission determination unit 219 can determine whether CB transmission is occurring without demodulating the data signal of each layer or the data signal of the LL channel.

When the CB transmission determination unit 219 determines that CB transmission is occurring, after the initial scan is completed, the auxiliary information flag determination unit 220 acquires frequency information, etc. of the physical channel received by the tuner 201 and the physical channels that make up the CB transmission. Specifically, the auxiliary information flag determination unit 220 references the CB control information output from at least one of the deinterleaving/LLR calculation/error correction decoding unit 215 and the LL channel demodulation/error correction decoding unit 217, and acquires frequency information, etc. of the two physical channels that make up a pair that make up the CB transmission.

When CB transmission is performed on the physical channel on which tuner 201 receives broadcast waves, auxiliary information flag determination unit 220 activates tuner 202, which is a second tuner, and tunes the receiving frequency of tuner 202 to the frequency of the physical channel paired with the physical channel received by tuner 201. This makes it possible to receive broadcast waves transmitted on both the primary channel and the secondary channel.

When CB transmission is performed on a physical channel receiving broadcast waves via the tuner 201, the auxiliary information flag discrimination unit 220 causes the P/S synchronization unit 221 to synchronize the OFDM frame synchronization unit 205 and the OFDM frame synchronization unit 206. As described above, broadcast waves are emitted at the same timing for the primary channel and secondary channel. By synchronizing the OFDM frame synchronization unit 205 and the OFDM frame synchronization unit 206, the demodulation timing for the primary channel and secondary channel can be matched.

The auxiliary information flag discrimination unit 220 also references the auxiliary information flag included in the CB control information to determine the type of data received by the tuner 202 (data received on the secondary channel). For example, if the auxiliary information flag is on, the auxiliary information flag discrimination unit 220 determines that the data received on the secondary channel is auxiliary information that is not essential for demodulating the data signal received on the primary channel. If the auxiliary information flag is off, the auxiliary information flag discrimination unit 220 determines that the data received on the secondary channel is a video/audio data signal (main line signal) that is essential for demodulating the data signal received on the primary channel. The auxiliary information flag discrimination unit 220 outputs the discrimination result to the demodulation unit 223.

When normal CB transmission is performed, main line signals are output from the deinterleaving/LLR calculation/error correction decoding unit 215 and the deinterleaving/LLR calculation/error correction decoding unit 216. The CB combining output unit 222 combines the main line signal output from the deinterleaving/LLR calculation/error correction decoding unit 215 with the main line signal output from the deinterleaving/LLR calculation/error correction decoding unit 216, and outputs the combined signal to the demodulation unit 223. Specifically, the CB combining output unit 222 reconstructs the main line signal output from the deinterleaving/LLR calculation/error correction decoding unit 215 and the main line signal output from the deinterleaving/LLR calculation/error correction decoding unit 216 into the original single data stream, and outputs the combined signal to the demodulation unit 223.

Furthermore, when auxiliary information is transmitted on the secondary channel via the after-transition channel, the main signal is output from the deinterleaving/LLR calculation/error correction decoding unit 215, and the auxiliary information is output from the deinterleaving/LLR calculation/error correction decoding unit 216. The CB combining output unit 222 outputs the main signal output from the deinterleaving/LLR calculation/error correction decoding unit 215 and the auxiliary information output from the deinterleaving/LLR calculation/error correction decoding unit 216 to the demodulation unit 223. The CB combining output unit 222 may output the main signal and auxiliary information separately to the demodulation unit 223, or may multiplex the main signal and auxiliary information into a single data stream and output it to the demodulation unit 223. In addition, the CB synthesis output unit 222 synthesizes the LLch data signal output from the LLch demodulation and error correction decoding unit 217 and the LLch data signal output from the LLch demodulation and error correction decoding unit 218, and outputs the result to the demodulation unit 223.

When the auxiliary information flag discrimination unit 220 determines that the data received on the secondary channel is a main line data signal essential for demodulating the data signal received on the primary channel, the demodulation unit 223 demodulates the data signal combined by the CB combination output unit 222. Furthermore, when the auxiliary information flag discrimination unit 220 determines that the data received on the secondary channel is auxiliary information not essential for demodulating the data signal received on the primary channel, the demodulation unit 223 demodulates the data signal received on the primary channel using the auxiliary information received on the secondary channel. When CB transmission is performed via the after-transition channel, scalable coding, for example, is used to encode video and audio. Scalable coding is a technique for hierarchically encoding video from coarse information to fine information. The demodulation unit 223 can obtain higher-definition video by, for example, demodulating the data signal transmitted on the primary channel using auxiliary information.

As described above, the CB synthesis output unit 222 and the demodulation unit 223 constitute the demodulation processing unit 224. The demodulation processing unit 224 demodulates the received signal of tuner 201 and the received signal of tuner 202 according to type information superimposed on at least one of the video/audio data signal received by tuner 201 and the LL channel data signal. Specifically, when the type information (auxiliary information flag) indicates that the data transmitted on the secondary channel is a main line signal (first data signal) (in the case of normal CB transmission), the demodulation processing unit 224 synthesizes and demodulates the data signal (main line signal) received by tuner 201 and the data signal (main line signal) received by tuner 202. Furthermore, when the auxiliary information flag indicates that the data transmitted on the secondary channel is auxiliary information (in the case of CB transmission of an after-transition channel), the demodulation processing unit 224 demodulates the data signal (main line signal) received by tuner 201 using the auxiliary information received by tuner 202. Therefore, with the demodulation device 20 shown in FIG. 7, by referencing the type information (auxiliary information flag), it is possible to appropriately process the data signal transmitted by CB transmission depending on the broadcast service (whether it is a broadcast service via normal CB transmission or a broadcast service via CB transmission of an after-transition channel).

In Figure 7, an example was described in which the demodulation device 20 has two tuners 201, 202 and is capable of supporting CB transmission. However, as mentioned above, CB transmission is an optional function. Below, an example configuration in which the demodulation device 20 has only one tuner 201 will be described with reference to Figure 8. In Figure 8, components similar to those in Figure 7 are designated by the same reference numerals, and their description will be omitted.

The demodulation device 20 shown in Figure 8 comprises a tuner 201, a GI removal/FFT unit 203, an OFDM frame synchronization unit 205, a TMCC demodulation unit 207, a pilot extraction unit 209, a channel estimation unit 211, a waveform equalization unit 213, a deinterleaving/LLR calculation/error correction decoding unit 215, an LLch demodulation/error correction decoding unit 217, an auxiliary information flag discrimination unit 220, a demodulation unit 223A, and an output unit 225. The demodulation device 20 shown in FIG. 8 differs from the demodulation device 20 shown in FIG. 7 in that the tuner 202, GI removal/FFT unit 204, OFDM frame synchronization unit 206, TMCC demodulation unit 208, pilot extraction unit 210, channel estimation unit 212, waveform equalization unit 214, deinterleaving/LLR calculation/error correction decoding unit 216, LLch demodulation/error correction decoding unit 218, and CB synthesis output unit 222 have been removed, an output unit 225 has been added, and the demodulation unit 223 has been changed to demodulation unit 223A.

The output unit 225 receives the data signals (main line signals) for each layer from the deinterleaving/LLR calculation/error correction decoding unit 216, and receives the LLch data signal from the LLch demodulation/error correction decoding unit 217. The output unit 225 outputs the received data signals for each layer and the LLch data signal to the demodulation unit 223A.

The demodulation unit 223A, which serves as a demodulation processing unit, receives the data signals of each layer and the LL channel data signal from the output unit 225, and receives the result of the determination of the type of data received on the secondary channel based on the auxiliary information flag from the auxiliary information flag determination unit 220. The demodulation unit 223A demodulates the signal received by the tuner 202 (the data signal of each layer) according to the determination result by the auxiliary information flag determination unit 220. In other words, the demodulation unit 223A demodulates the signal received by the tuner 201 according to the auxiliary information flag superimposed on at least one of the data signals of each layer and the LL channel data signal received by the tuner 201.

Specifically, when the auxiliary information flag indicates that the data transmitted on the secondary ch is a main line signal, the demodulation unit 223A does not demodulate the received data signal because it cannot demodulate the data signal (main line signal) received by the tuner 201 alone. On the other hand, when the auxiliary information flag indicates that the data transmitted on the secondary ch is auxiliary information, the demodulation unit 223 can demodulate the data signal of each layer received by the tuner 201 because it can demodulate the data signal transmitted on the primary ch alone. Here, the demodulation device 20 cannot receive auxiliary information transmitted on the secondary ch, so it demodulates only the data signal of each layer transmitted on the primary ch.

As described above, the remultiplexing device 10 serving as a transmitting device according to this embodiment includes an XMI packet transmission scheduler unit 120 serving as a scheduler unit and a CB TLV-SI generator unit 122 serving as a generator. The XMI packet transmission scheduler unit 120 distributes and outputs data signals (first data signals) of each layer to systems corresponding to the primary ch (first physical ch) and secondary ch (second physical ch), respectively, or outputs data signals of each layer to systems corresponding to the primary ch and outputs auxiliary information for the data signals of each layer to systems corresponding to the secondary ch. The CB TLV-SI generator unit 122 generates type information indicating the type of data transmitted on the second physical channel and superimposes the generated type information on the data signals of each layer and/or on the LL ch data signals transmitted on the primary and secondary ch with shorter delay than the data signals of each layer.

In addition, demodulation device 20, which serves as a receiving device according to this embodiment, includes tuner 201 (first tuner) that receives signals transmitted via the primary channel, tuner 202 (second tuner) that receives signals transmitted via the secondary channel, and demodulation processing unit 224. Demodulation processing unit 224 demodulates the signals received by tuner 201 and tuner 202 according to type information superimposed on at least one of the data signals of each layer and the data signal of the LL channel.

In addition, the demodulation device 20 serving as a receiving device according to this embodiment includes a tuner 201 that receives a signal transmitted via the primary channel, and a demodulation unit 223A serving as a demodulation unit process that demodulates the signal received by the tuner 201 in accordance with type information superimposed on at least one of the data signal of each layer and the data signal of the LL channel received by the tuner 201.

By superimposing type information indicating the type of data transmitted on the secondary channel onto the data signal of each layer or the data signal of the LL channel, the demodulation device 20 can determine whether the data transmitted on the secondary channel is essential for demodulating the data transmitted on the primary channel. Therefore, data signals transmitted via CB transmission can be appropriately processed depending on the broadcast service, such as whether it is normal CB transmission or CB transmission via an after-transition channel.

Second Embodiment
In the first embodiment, an example has been described in which the remultiplexing device 10 distributes data signals and auxiliary information for each layer, generates type information (auxiliary information flag) indicating the type of data transmitted on the secondary channel, and multiplexes the type information onto a data signal (main line signal or LL channel data signal), but the present invention is not limited to this.

Figure 9 is a diagram showing an example configuration of a transmission/reception system 1' according to a second embodiment of the present invention. In Figure 9, components similar to those in Figures 1A and 1B are designated by the same reference numerals, and descriptions thereof will be omitted.

As shown in FIG. 9, the transmission/reception system 1' according to this embodiment includes a remultiplexing device 2s as a first remultiplexing device, a remultiplexing device 2p as a second remultiplexing device, modulation devices 3p and 3s, transmitters 4p and 4s, receivers 5p and 5s, demodulation devices 6p and 6s, a combiner 7, and a control device 30. The remultiplexing device 2p, modulation device 3p, transmitter 4p, receiver 5p, and demodulation device 6p are provided corresponding to the primary channel. The remultiplexing device 2s, modulation device 3s, transmitter 4s, receiver 5s, and demodulation device 6s are provided corresponding to the secondary channel.

The remultiplexers 2p and 2s have the same configuration as the conventional remultiplexer 10a, which does not support CB transmission. However, the remultiplexers 2p and 2s multiplex the XMI packets, L0 symbols, L1 symbols, synchronization control XMI packets, and stuff XMI packets of each layer into a single system and output them to the corresponding modulation devices 3p and 3s. In other words, unlike the remultiplexer 10a shown in Figure 2, the remultiplexers 2p and 2s have a single output destination.

The control device 30 controls the transmission of data signals via CB transmission that combines primary and secondary channels. As shown in FIG. 9, the control device 30 includes a division unit 31 and a control unit 32.

The splitter 31 distributes transmission packets between the primary channel and the secondary channel. Figure 10 shows an example configuration of the splitter 31.

As shown in FIG. 10, when normal CB transmission is performed, the splitter 31 distributes and outputs the video and audio data signals (first data signals) transmitted at each layer to the re-multiplexer 2p and re-multiplexer 2s. When CB transmission is performed using an after-transition channel, the splitter 31 outputs the video and audio data signals to the re-multiplexer 2p and outputs auxiliary information for the video and audio data signals to the re-multiplexer 2s. The splitter 31 receives control information indicating the upper limit setting value for the bit rate for each channel from the control unit 32, which will be described later, and distributes the data signals to each channel so as not to exceed that upper limit setting value.

Note that while Figure 10 shows an example of physically dividing the data signal, this is not limiting. The dividing unit 31 may also divide the data signal logically, for example, by changing the UDP port numbers associated with each divided channel.

The control unit 32 outputs control information to the division unit 31. The control unit 32 also generates type information (auxiliary information flag) indicating the type of data transmitted on the secondary channel. The control unit 32 then outputs the generated type information to the remultiplexing unit 2p and the remultiplexing unit 2s. The type information output to the remultiplexing unit 2p and the remultiplexing unit 2s is multiplexed onto at least one of the data signals of each layer and the data signal of the LL channel, similar to the remultiplexing unit 10 described with reference to FIG. 3, and transmitted. Therefore, in this embodiment, the type information is transmitted on both the primary channel and the secondary channel. In this way, the control unit 32 outputs the type information to the remultiplexing unit 2p and the remultiplexing unit 2s, and multiplexes it onto the data signals transmitted on the primary channel and the secondary channel (at least one of the data signals of each layer and the data signal of the LL channel).

The combiner 7 combines the data signal demodulated by the demodulator 6p and the data signal demodulated by the demodulator 6s and outputs the combined signal. The operation of the combiner 7 is similar to that of the CB combiner output unit 222 shown in Figure 7, for example.

In this embodiment, by providing a control device 30 that distributes data signals and auxiliary information for each layer, generates type information, and multiplexes the type information onto data signals (main line signals or LL channel data signals), it is possible to use existing equipment that does not support CB transmission as remultiplexing devices 2s and 2p.

Although not specifically mentioned in the embodiments, a program may be provided that causes a computer to function as the remultiplexing device 10, demodulation device 20, or control device 30. The program may also be recorded on a computer-readable medium. Using a computer-readable medium makes it possible to install the program on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, but may be, for example, a CD-ROM, DVD-ROM, or other recording medium.

Alternatively, a chip may be provided that is configured with a memory that stores programs for executing the processes performed by the remultiplexing device 10, demodulation device 20, or control device 30, and a processor that executes the programs stored in the memory, and is mounted on the remultiplexing device 10, demodulation device 20, or control device 30.

The above-described embodiments have been described as representative examples, but it will be apparent to those skilled in the art that numerous modifications and substitutions are possible within the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the above-described embodiments, and various modifications and alterations are possible without departing from the scope of the claims. For example, it is possible to combine multiple component blocks shown in the configuration diagrams of the embodiments into one, or to divide one component block.

1, 1A Transmission/reception system 2, 2p, 2s, 2A Remultiplexing device 3, 3p, 3s, 3A Modulation device 4, 4p, 4s Transmitter 5, 5p, 5s Receiver 6, 6p, 6s, 6A Demodulation device 7 Combining unit 10 Remultiplexing device (transmission device)
101, 108, 121 Packet filter 102, 109, 110 IP header compression unit 103, 111, 112 TLV packetization unit 104, 113, 114 FIFO buffer 105 FEC block construction unit 106 Layer-specific frame construction unit 107 XMI packetization unit 115 L0 symbol construction unit 116 L1 symbol construction unit 117 GPS reference signal generator 118, 118a Synchronization control XMI packet construction unit 119 Stuff XMI packet construction unit 120, 120a XMI packet transmission scheduler unit (scheduler unit)
122 TLV-SI generation unit for CB (generation unit)
20 Demodulation device (receiving device)
201, 202 Tuner 203, 204 GI removal/FFT unit 205, 206 OFDM frame synchronization unit 207, 208 TMCC demodulation unit 209, 210 Pilot extraction unit 211, 212 Channel estimation unit 213, 214 Waveform equalization unit 215, 216 Deinterleaving/LLR calculation/error correction decoding unit 217, 218 LLch demodulation/error correction decoding unit 219 CB transmission determination unit 220 Side information flag determination unit 221 P/S synchronization unit 222 CB synthesis output unit 223, 223A Demodulation unit 224 Demodulation processing unit 30 Control device 31 Synthesis unit 32 Control unit

Claims (7)

A transmitting device capable of channel bonding transmission for transmitting a data signal by combining a first physical channel and a second physical channel, comprising:
a scheduler unit that allocates a first data signal to a system corresponding to the first physical channel and a second physical channel and outputs the allocated first data signal, or that outputs the first data signal to a system corresponding to the first physical channel and auxiliary information of the first data signal to a system corresponding to the second physical channel;
a generating unit that generates type information indicating a type of data transmitted on the second physical channel, and superimposes the generated type information on the first data signal and/or on a second data signal transmitted on the first physical channel and the second physical channel with a shorter delay than the first data signal. 2. The transmitting device according to claim 1,
A transmitting device, wherein the type information is information indicating whether the data transmitted on the second physical channel is the auxiliary information. A receiving device for receiving a data signal transmitted by channel bonding transmission combining a first physical channel and a second physical channel, comprising:
a first data signal is transmitted by being allocated to the first physical channel and the second physical channel, or the first data signal is transmitted on the first physical channel, and auxiliary information of the first data signal is transmitted on the second physical channel;
type information indicating a type of data transmitted on the second physical channel is superimposed on the first data signal and/or a second data signal transmitted on the first physical channel and the second physical channel with a shorter delay than the first data signal;
a first tuner for receiving a signal transmitted over the first physical channel;
a second tuner for receiving a signal transmitted over the second physical channel;
A receiving device comprising: a demodulation processing unit that demodulates the received signals of the first tuner and the second tuner in accordance with the type information superimposed on at least one of the first data signal and the second data signal received by the first tuner. 4. The receiving device according to claim 3,
The demodulation processing unit
When the type information indicates that the data transmitted on the second physical channel is the first data signal, the first data signal received by the first tuner and the first data signal received by the second tuner are combined and demodulated;
A receiving device that, when the type information indicates that the data transmitted on the second physical channel is the auxiliary information, demodulates the first data signal received by the first tuner using the auxiliary information received by the second tuner. A receiving device for receiving a data signal transmitted by channel bonding transmission combining a first physical channel and a second physical channel, comprising:
a first data signal is transmitted by being allocated to the first physical channel and the second physical channel, or the first data signal is transmitted on the first physical channel, and auxiliary information of the first data signal is transmitted on the second physical channel;
type information indicating a type of data transmitted on the second physical channel is superimposed on the first data signal and/or a second data signal transmitted on the first physical channel and the second physical channel with a shorter delay than the first data signal;
a tuner for receiving a signal transmitted over the first physical channel;
a demodulation processing unit that demodulates the received signal of the tuner in accordance with the type information superimposed on at least one of the first data signal and the second data signal received by the tuner. 6. The receiving device according to claim 5,
The demodulation processing unit
If the type information indicates that the data transmitted on the second physical channel is the first data signal, the first data signal received by the tuner is not demodulated;
a receiving device that demodulates a first data signal received by the tuner when the type information indicates that the data transmitted on the second physical channel is the auxiliary information; A control device for controlling transmission of a data signal by channel bonding transmission combining a first physical channel and a second physical channel,
a division unit that distributes and outputs a first data signal to a first remultiplexing device that multiplexes data signals transmitted on the first physical channel and a second remultiplexing device that multiplexes data signals transmitted on the second physical channel, or that outputs the first data signal to the first remultiplexing device and outputs auxiliary information of the first data signal to the second remultiplexing device;
a control unit that generates type information indicating the type of data transmitted on the second physical channel, outputs the generated type information to the first remultiplexing device and the second remultiplexing device, and multiplexes the type information onto the data signals transmitted on the first physical channel and the second physical channel.