Transmission device, transmission method, reception device, and reception method

Abstract

The present invention relates to a transmission device, a transmission method, a reception device, and a reception method capable of appropriately allocating data to a plurality of channels used for channel bonding. Divided data obtained by dividing target data to be transmitted by channel bonding using a plurality of channels is allocated to one of the plurality of channels on the basis of a CB transmission capacity that is a transmission capacity used for channel bonding of each of the plurality of channels, and the divided data is transmitted on the channel to which the divided data is allocated. The present invention can be applied, for example, to a transmission system that performs transmission by channel bonding.

Description

Transmitting device, transmitting method, receiving device, and receiving method

[0001] The present technology relates to a transmitting device, a transmitting method, a receiving device, and a receiving method, and in particular to a transmitting device, a transmitting method, a receiving device, and a receiving method that enable appropriate allocation of data to multiple channels used in channel bonding, for example.

[0002] Various technologies are being investigated to enhance the next generation of terrestrial digital television broadcasting, including Channel Bonding (CB), a technology that uses multiple channels for data transmission.

[0003] As a CB technique, for example, there is a technique of multiplexing control information related to a plurality of (physical) channels used for CB into a Transmission Multiplexing Configuration Control (TMCC) (see, for example, Patent Document 1).

[0004] Japanese Patent Application Publication No. 2023-143848

[0005] CB requires that data be allocated appropriately to multiple channels, but no technology has yet been proposed for appropriately allocating data to multiple channels.

[0006] The present technology has been made in view of such circumstances, and makes it possible to appropriately allocate data to a plurality of channels used for CB.

[0007] The transmitting device of the present technology is a transmitting device that includes an allocation unit that allocates split data, which is obtained by dividing target data to be transmitted by channel bonding using multiple channels, to one of the multiple channels based on the CB transmission capacity, which is the transmission capacity used for the channel bonding, of each of the multiple channels, and a transmitting unit that transmits the split data on the channel to which the split data is allocated.

[0008] The transmission method of the present technology is a transmission method that includes dividing target data to be transmitted by channel bonding using a plurality of channels, and allocating divided data to one of the plurality of channels based on the CB transmission capacity, which is the transmission capacity used for the channel bonding, of each of the plurality of channels, and transmitting the divided data on the channel to which the divided data is allocated.

[0009] The receiving device of the present technology is a receiving device that includes: a receiving unit that receives signals of multiple channels transmitted by a transmission method that includes dividing target data to be transmitted by channel bonding using multiple channels, assigning the divided data to one of the multiple channels based on a CB transmission capacity, which is the transmission capacity used for the channel bonding for each of the multiple channels, and transmitting the divided data on the channel to which the divided data is assigned; and a reconstructing unit that reconstructs the divided data included in the signals of the multiple channels into their original order, wherein physical layer frames transmitted on each of the multiple channels include channel bonding control information related to the channel bonding as physical layer data, and the reconstructing unit is a receiving device that identifies the allocation of the divided data to each of the multiple channels based on the channel bonding control information.

[0010] A receiving method of the present technology includes receiving signals of multiple channels transmitted by a transmission method including: dividing target data to be transmitted by channel bonding using multiple channels, assigning the divided data to one of the multiple channels based on a CB transmission capacity, which is the transmission capacity used for the channel bonding for each of the multiple channels, and transmitting the divided data on the channel to which the divided data is assigned; and reconstructing the divided data included in the signals of the multiple channels into their original order, wherein physical layer frames transmitted on each of the multiple channels include channel bonding control information related to the channel bonding as physical layer data, and in reconstructing the divided data, the method specifies the allocation of the divided data to each of the multiple channels based on the channel bonding control information.

[0011] In the transmitting device and transmitting method of the present technology, target data to be transmitted by channel bonding using a plurality of channels is divided into divided data, and the divided data is assigned to one of the plurality of channels based on the CB transmission capacity, which is the transmission capacity used for the channel bonding, of each of the plurality of channels. Then, the divided data is transmitted on the channel to which the divided data is assigned.

[0012] In the receiving device and receiving method of the present technology, signals of multiple channels transmitted by a transmission method including: allocating divided data, obtained by dividing target data to be transmitted by channel bonding using multiple channels, to one of the multiple channels based on CB transmission capacity, which is the transmission capacity of each of the multiple channels used for the channel bonding, and transmitting the divided data on the channel to which the divided data is assigned. Then, the divided data included in the signals of the multiple channels are reconstructed into their original order. A physical layer frame transmitted on each of the multiple channels includes channel bonding control information related to the channel bonding as physical layer data, and in the reconstruction of the divided data, the allocation of the divided data to each of the multiple channels is specified based on the channel bonding control information.

[0013] The transmitting device and the receiving device may be independent devices or may be internal blocks constituting a single device.

[0014] The transmitting device and receiving device can be realized by causing a computer to execute a program. The program for causing a computer to function as a transmitting device or a receiving device can be provided by transmitting it via a transmission medium or by recording it on a recording medium.

[0015] 1 is a block diagram illustrating an example configuration of an embodiment of a transmission system to which the present technology is applied. FIG. 1 is a diagram illustrating an overview of CB. FIG. 2 is a diagram illustrating an example of the number of segments and the number of data carriers in a subsegment. FIG. 2 is a block diagram illustrating an example configuration of a transmitting device 10. FIG. 3 is a block diagram illustrating a first example configuration of a dividing unit 32 and a modulating unit 41 of the transmitting device 10. FIG. 4 is a diagram illustrating data transmission using CB. FIG. 5 is a diagram illustrating an example of setting a transmission band (transmission capacity) used for CB for each of channels CH0 and CH1. FIG. 6 is a diagram illustrating an example of allocation of FEC target blocks to each of channels CH0 and CH1 used for CB. FIG. 7 is a flowchart illustrating a process of generating an allocation table as an allocation rule. FIG. 8 is a diagram illustrating a specific example of generating an allocation table as an allocation rule. FIG. 9 is a diagram illustrating the relationship between an FEC block index idx, a count value of a CH0 counter, a count value of a CH1 counter, and a channel to which an FEC target block idx is allocated. FIG. 10 is a diagram illustrating the relationship between an FEC block index idx, a count value of a CH0 counter, a count value of a CH1 counter, and a channel to which an FEC target block idx is allocated (allocated channel). 1 is a diagram showing the relationship between an FEC block index idx, the count value of a CH0 counter, the count value of a CH1 counter, and the channel (allocated channel) to which an FEC target block idx is assigned. FIG. 2 is a diagram showing the relationship between an FEC block index idx, the count value of a CH0 counter, the count value of a CH1 counter, and the channel (allocated channel) to which an FEC target block idx is assigned. FIG. 3 is a diagram showing an example of an arrangement of FEC target blocks at each time point in the transmitting device 10 when FEC target blocks are assigned to channels so as to minimize the difference between the cumulative transmission time of channel CH0 and the cumulative transmission time of channel CH1. FIG. 4 is a block diagram showing a second example configuration of the dividing unit 32 and the modulating unit 41 of the transmitting device 10. FIG. 5 is a diagram showing an example of an arrangement of FEC target blocks at each time point in the transmitting device 10 when FEC target blocks are uniformly assigned and the FEC target blocks are delayed by the delay unit 71. FIG. 6 is a block diagram showing an example configuration of a receiving device 20. FIG. 7 is a block diagram showing examples of the configuration of a combining unit 102 and a demodulating unit 111 of the receiving device 20.1 is a diagram illustrating an example of the processing of the synthesis unit 102 and the demodulation unit 111. FIG. 1 is a diagram illustrating an example of the syntax of transmission control auxiliary information. FIG. 2 is a diagram illustrating the syntax of CB control information aux_cb_configuration(). FIG. 3 is a diagram illustrating a sub-hierarchy. FIG. 4 is a diagram illustrating FEC_Block_index included in the CB control information aux_cb_configuration(). FIG. 5 is a flowchart illustrating an example of the processing of the transmitting device 10 and the receiving device 20. FIG. 6 is a diagram illustrating an example of an FEC block planned for use in advanced terrestrial digital broadcasting. FIG. 7 is a diagram illustrating the configuration of a normal code. FIG. 8 is a diagram illustrating an example of the configuration of an FEC target block when CB is performed. FIG. 9 is a diagram illustrating an example of the processing of the synthesis unit 102 and the demodulation unit 111 when an FEC block index idx is included in (the payload of) the FEC target block instead of CB control information. FIG. 10 is a block diagram illustrating an example of the configuration of an embodiment of a computer to which the present technology is applied.

[0016] <One embodiment of a transmission system to which the present technology is applied>

[0017] FIG. 1 is a block diagram showing an example of the configuration of an embodiment of a transmission system to which the present technology is applied.

[0018] 1, the transmission system is composed of a transmitting device 10 and a receiving device 20. In the transmission system, transmission conforming to a predetermined broadcasting method is performed, and transmission is performed via a transmission path such as terrestrial waves (terrestrial broadcasting).

[0019] The transmitting device 10 performs necessary processing such as encoding and modulation on the data of the content of the broadcast program, and transmits the resulting transmission signal. The receiving device 20 receives the transmission signal transmitted from the transmitting device 10, performs necessary processing such as demodulation and decoding, and outputs, for example, the video and audio of the content of the broadcast program.

[0020] In the transmission system of Figure 1, a broadcasting system based on a broadcasting system such as ISDB-T (Integrated Services Digital Broadcasting - Terrestrial) can be used as the broadcasting system for terrestrial digital television broadcasting. In Japan, ISDB-T is used, but next-generation systems for terrestrial digital television broadcasting are under consideration. In the transmission system of Figure 1, a next-generation system of the current ISDB-T system (hereinafter also referred to as advanced terrestrial digital broadcasting) (a system based on it) can be used as the broadcasting system.

[0021] The transmission system in Figure 1 can transmit using multiple channels via CB (Channel Bonding), which uses part or all of the frequency bands of multiple channels as if they were a single transmission path (channel), enabling greater transmission capacity and improved transmission efficiency.

[0022] In the transmission system of FIG. 1, the number of each of the transmitting device 10 and the receiving device 20 may be more than one, and may be more than one.

[0023] FIG. 2 is a diagram for explaining an overview of CB.

[0024] 2, a transmitting device 10 transmits transmission signals on two channels CH0 and CH1 from a transmitting antenna installed at a transmitting station using CB. The transmission signals transmitted for each channel by CB are received by a receiving device 20 such as a television set via an antenna.

[0025] Channel CH0 has a frequency band (Freq) of F1 and a network ID (network_id) of f1, and channel CH1 has a frequency band of F2 and a network ID of f2. The multiple channels used for CB have different frequency bands (Freq) and network IDs (network_id). The network ID is an ID (identifier) ​​that identifies a network related to broadcasting. The transmitting device 10 transmits a list of network IDs of the multiple channels used for CB to the receiving device 20, thereby enabling the receiving device 20 to tune in to a transmission signal transmitted on a channel used for CB.

[0026] FIG. 3 is a diagram showing an example of the number of segments and the number of data carriers in a sub-segment.

[0027] In advanced terrestrial digital broadcasting, for example, a segment structure in which one channel is divided into 35 segments allows for hierarchical transmission with up to eight layers. For example, transmission on layer B for fixed reception and transmission on layer A for mobile reception can be performed.

[0028] Furthermore, in advanced terrestrial digital broadcasting, a sub-segment structure in which a segment is divided into three sub-segments allows sub-hierarchical transmission with up to two sub-hierarchical layers. Sub-hierarchical transmission can provide, for example, a service that transmits only audio with high robustness for mobile reception.

[0029] One sub-segment is made up of 1 / 3 of the segments and has 130 data carriers (sub-carriers). Two sub-segments are made up of 2 / 3 of the segments and have 259 data carriers. Three sub-segments are made up of 1 segment and have 388 data carriers. Four sub-segments are made up of 4 / 3 of the segments and have 518 data carriers.

[0030] <Configuration example of transmission device 10>

[0031] FIG. 4 is a block diagram showing an example of the configuration of the transmitting device 10.

[0032] In FIG. 4, the transmitting device 10 includes an encoding unit 31, a dividing unit 32, a transmitting unit 33, and a control information generating unit .

[0033] The encoding unit 31 is composed of an encoder conforming to a predetermined encoding method. The encoding unit 31 encodes data input thereto, such as the content of a broadcast program, according to the predetermined encoding method. The encoding unit 31 outputs a TLV stream, which is a series of TLV (type length value) packets including data obtained as a result of the encoding, to the dividing unit 32 as target data to be transmitted via CB.

[0034] The dividing unit 32 divides the target data from the encoding unit 31 into multiple pieces of divided data. The dividing unit 32 assigns each piece of divided data to one of multiple channels used for CB, for example, two channels CH0 and CH1, and outputs the data to the transmitting unit 33. Here, for example, the transmitting unit 33 has modulation units 41-1 and 41-2 corresponding to the two channels CH0 and CH1 used for CB, respectively. The dividing unit 32 outputs the divided data assigned to channel CH0 to the modulation unit 41-1 corresponding to channel CH0, and outputs the divided data assigned to channel CH1 to the modulation unit 41-2 corresponding to channel CH1.

[0035] In the transmitting unit 33, the modulating unit 41-1 performs modulation processing on the divided data from the dividing unit 32 in accordance with a predetermined modulation method, and transmits the resulting transmission signal on channel CH0. The modulating unit 41-2 performs modulation processing on the divided data from the dividing unit 32 in accordance with a predetermined modulation method, and transmits the resulting transmission signal on channel CH1. The transmission signals transmitted on channels CH0 and CH1 each include physical layer control information from the control information generating unit 34.

[0036] The control information generator 34 generates physical layer control information to be transmitted as physical layer data based on the information input thereto, and outputs the physical layer control information to the transmitter 33. The physical layer control information includes transmission control information such as TMCC.

[0037] 4, for the sake of simplicity, the transmitting device 10 is shown as having the components of the encoding unit 31, the dividing unit 32, the transmitting unit 33, and the control information generating unit 34. However, these components may be provided in separate devices (such as broadcast servers) and do not need to be installed in the same location. For example, the transmitting device 10 may be configured as a transmission system (sending system) in which a device (such as a first broadcast server) having the encoding unit 31 and a device (such as a second broadcast server) having the dividing unit 32, the transmitting unit 33, and the control information generating unit 34 are connected via a communication line or the like.

[0038] Furthermore, three or more channels can be used as the multiple channels used for CB. The transmitter 33 is provided with a modulation unit corresponding to each of the multiple channels used for CB.

[0039] <First Configuration Example of the Dividing Unit 32 and the Modulating Unit 41>

[0040] FIG. 5 is a block diagram showing a first example of the configuration of the dividing unit 32 and the modulation unit 41 of the transmitting device 10.

[0041] The dividing unit 32 includes a converting unit 51 and an allocating unit 52 .

[0042] The converter 51 receives a TLV stream as target data from the encoder 31 (FIG. 4). The converter 51 divides the TLV stream and converts it into FEC target blocks, which are units of divided data to be allocated to channels used for CB. That is, the converter 51 divides the TLV stream and places the data obtained by the division as payloads after FEC block headers, thereby forming FEC target blocks that are targets (units) of FEC processing (error correction coding). The converter 51 supplies the FEC target blocks, each consisting of an FEC block header and a payload, to the allocation unit 52 as divided data obtained by dividing the TLV stream as target data.

[0043] The allocation unit 52 allocates each FEC target block as each divided data from the conversion unit 51 to either channel CH0 or CH1 based on the CB transmission capacity, which is the transmission capacity used for CB, of each of channels CH0 and CH1 as multiple channels used for CB. The allocation unit 52 outputs the FEC target block allocated to channel CH0 to the modulation unit 41-1 corresponding to channel CH0, and outputs the FEC target block allocated to channel CH1 to the modulation unit 41-2 corresponding to channel CH1.

[0044] The modulation unit 41-1 includes a bit interleaved coded modulation (BICM) unit 61-1, an orthogonal frequency division multiplexing (OFDM) frame generation unit 62-1, and an RF (radio frequency) conversion unit 63-1.

[0045] The BICM unit 61-1 is supplied with FEC target blocks allocated to channel CH0 from the allocation unit 52. The BICM unit 61-1 performs BICM processing on the FEC target blocks from the allocation unit 52, and supplies the resulting transmission symbols (data symbols) (information indicating positions on the IQ constellation) to the OFDM frame generation unit 62-1. The BICM processing includes FEC processing (error correction coding) on ​​the FEC target blocks, bit interleaving on the FEC blocks obtained by the FEC processing, and mapping of the FEC blocks (data constituting the FEC blocks) after bit interleaving to the IQ constellation.

[0046] The OFDM frame generation unit 62-1 performs time interleaving and frequency interleaving on the transmission symbols from the BICM unit 61-1. Furthermore, the OFDM frame generation unit 62-1 adds (inserts) transmission symbols as pilot signals and transmission symbols as physical layer control information from the control information generation unit 34 (FIG. 4) to the transmission symbols from the BICM unit 61-1 to generate an OFDM frame, which is a physical layer frame, and supplies the frame to the RF conversion unit 63-1.

[0047] The RF conversion unit 63-1 converts the OFDM frame from the OFDM frame generation unit 62-1 into a frequency domain signal by performing an IFFT (inverse fast Fourier transform) of the OFDM frame at a predetermined FFT size to convert it into a time domain OFDM frame. Furthermore, the RF conversion unit 63-1 adds a GI (guard interval) having a length that is a predetermined proportion of the symbol length of the OFDM symbol to each OFDM symbol constituting the OFDM frame to generate an OFDM signal as a transmission signal. The RF conversion unit 63-1 then performs frequency conversion on the OFDM signal as the transmission signal, and transmits the OFDM signal as the frequency-converted transmission signal on channel CH0. The OFDM symbols constituting the OFDM frame are a sequence of transmission symbols equal to the FFT size for which IFFT is performed.

[0048] The modulation unit 41-2 has a BICM unit 61-2, an OFDM frame generation unit 62-2, and an RF conversion unit 63-2. The BICM unit 61-2 to the RF conversion unit 63-2 perform the same processing as the BICM unit 61-1 to the RF conversion unit 63-1, respectively, on the FEC target block assigned to channel CH1, and transmit the OFDM signal as the transmission signal for the FEC target block assigned to channel CH1 over channel CH1.

[0049] Hereinafter, unless there is a particular need to distinguish between them, the modulation units 41-1 and 41-2 will also be referred to as modulation unit 41. Similarly, the BICM units 61-1 and 61-2 will also be referred to as BICM unit 61, the OFDM frame generation units 62-1 and 62-2 will also be referred to as OFDM frame generation unit 62, and the RF conversion units 63-1 and 63-2 will also be referred to as RF conversion unit 63.

[0050] <Data transmission via CB>

[0051] FIG. 6 is a diagram for explaining data transmission using CB.

[0052] Figure 6 shows data transmission by CB using two channels (RF Channels) CH0 and CH1 described in Figure 2. In Figure 6, TLV streams identified by the same stream ID (TLV_stream_id) = xx are transmitted by CB using two channels CH0 and CH1 as multiple channels with different network IDs.

[0053] In CB of FIG. 6, two channels CH0 and CH1 are used as if they were one (virtual) channel to transmit a TLV stream with stream ID=xx.

[0054] It should be noted that CB can use three or more channels instead of two.

[0055] In advanced terrestrial digital broadcasting, for each channel used for CB, the transmission band (transmission capacity) used for CB can be set, for example, in sub-segment units.

[0056] FIG. 7 is a diagram showing an example of setting the transmission band (transmission capacity) used for CB for each of channels CH0 and CH1.

[0057] Fig. 7 shows an OFDM frame, which is a physical layer frame transmitted on channels CH0 and CH1, in which the horizontal axis represents time and the vertical axis represents frequency.

[0058] The OFDM frame is configured by arranging, in time order from the beginning, a frame synchronization signal (transmission symbol), a TMCC (transmission symbol), and a data symbol (transmission symbol of the FEC target block).

[0059] Here, the transmission capacity and transmission band used for CB are also referred to as CB transmission capacity and CB transmission band, respectively.

[0060] 7, the entire bandwidth of channel CH0 is set as the CB transmission bandwidth. Therefore, the CB transmission capacity of channel CH0 is equivalent to 105 subsegments (=35 segments×3 subsegments).

[0061] 7, a total of 31 subsegments, including some subsegments on the low frequency side and some subsegments on the high frequency side of channel CH1, are set in the CB transmission band. Therefore, the CB transmission capacity of channel CH1 is equivalent to 31 subsegments.

[0062] For simplicity, unless otherwise specified, the BICM processing and OFDM parameters for the CB transmission band are assumed to be the same in the CB transmission band of each channel used for CB. In this case, the CB transmission capacity (or the corresponding value) of each channel used for CB can be expressed by the number of subsegments. BICM processing parameters include, for example, the coding rate of the LDPC code used for FEC (forward error correction) and the modulation method used for mapping. OFDM parameters include, for example, the allocation pattern of transmission symbols as pilot signals.

[0063] In this technology, the CB transmission capacity of each channel used for CB does not need to have an absolute value, but only needs to be a relative value. In the CB transmission band of each channel used for CB, if the BICM processing and OFDM parameters of the CB transmission band are the same, the CB transmission capacity of each channel can be expressed as a relative value, for example, by the number of subsegments that make up the CB transmission band. Therefore, the CB transmission capacity of channel CH0 can be expressed as 105, and the CB transmission capacity of channel CH1 can be expressed as 31.

[0064] <Allocation of FEC target blocks to channels>

[0065] FIG. 8 is a diagram showing an example of allocation of FEC target blocks to each of channels CH0 and CH1 used for CB.

[0066] In FIG. 8, three patterns 1, 2, and 3 are shown as patterns for allocating FEC target blocks to channels CH0 and CH1, respectively.

[0067] Pattern 1 is a pattern in which 105 FEC target blocks 0 to 104, which is the CB transmission capacity of channel CH0, are assigned to channel CH0, and then 31 FEC target blocks 105 to 135, which is the CB transmission capacity of channel CH1, are assigned to channel CH1, and this pattern is repeated. FEC target block i represents the (i+1)th FEC target block in the sorting order (chronological order) of the FEC target blocks.

[0068] Pattern 2 is a pattern in which one FEC target block is alternately assigned to each of channels CH0 and CH1, and after 31 FEC target blocks (FEC target blocks 1, 3, 5, ..., 57, 59, 61), which is the CB transmission capacity of channel CH1, are assigned to channel CH1, which has a small CB transmission capacity, 74 (=105-31) FEC target blocks (FEC target blocks 62, 63, ..., 135), which is the remaining CB transmission capacity of channel CH0, are assigned to channel CH0.

[0069] Pattern 3 is a pattern in which one FEC target block is assigned to each of channels CH0 and CH1, and then three or four FEC target blocks are assigned to channel CH0, and one FEC target block is assigned to channel CH1, which are repeated alternately.

[0070] The CB transmission capacities of channels CH0 and CH1 are 105 and 31, respectively, and the CB transmission capacity of channel CH1 is smaller than that of channel CH0. Therefore, the transmission time of one FEC target block on channel CH1 (the time from transmission from transmitting device 10 to reception by receiving device 20) is longer than the transmission time of one FEC target block on channel CH0. In other words, the transmission rate of FEC target blocks on channel CH1 is slower than the transmission rate of FEC target blocks on channel CH0.

[0071] Therefore, if many FEC target blocks are assigned to channel CH1, the receiving device 20 (receiving side) must wait for the FEC target blocks that are transmitted later on channel CH1 and that are earlier in the sequence. In order to wait for the FEC target blocks that are transmitted later on channel CH1, the receiving device 20 needs a buffer to store the FEC target blocks that are transmitted earlier on channel CH0. The longer the wait time for the FEC target blocks transmitted on channel CH1, the larger the capacity of the buffer that stores the FEC target blocks transmitted on channel CH0 must be. Therefore, the buffer capacity is largest in pattern 1, and next largest in pattern 2. Pattern 3 requires the smallest buffer capacity.

[0072] The allocation unit 52 (FIG. 5) allocates FEC target blocks to either channel CH0 or CH1 based on the CB transmission capacities of channels CH0 and CH1 used for CB. The CB transmission capacities of channels CH0 and CH1 are 105 and 31, respectively. Based on the CB transmission capacities of channels CH0 and CH1, the allocation unit 52 allocates one FEC target block to channel CH1, while allocating approximately 3.4 (≈105 / 31) FEC target blocks to channel CH0. Since it is not possible to allocate a decimal number of FEC target blocks in the actual allocation of FEC target blocks, an integer number of FEC target blocks are allocated in the actual allocation of FEC target blocks. In other words, one FEC target block is allocated to channel CH1, while three or four FEC target blocks are allocated to channel CH0.

[0073] This allows the FEC target blocks to be appropriately allocated to channels CH0 and CH1. For example, the FEC target blocks can be allocated so as to reduce the waiting time for the FEC target blocks in the receiving device 20, and thus reduce the buffer capacity required in the receiving device 20.

[0074] The allocation unit 52 generates an allocation table as an allocation rule for allocating FEC target blocks to channel CH0 or CH1 based on the CB transmission capacities of channels CH0 and CH1 used for CB. The allocation unit 52 then allocates FEC target blocks to channel CH0 or CH1 according to the allocation table as the allocation rule. If the smaller of the CB transmission capacities of channels CH0 and CH1 is denoted by xL and the larger of the CB transmission capacities is denoted by xH, an allocation rule based on the CB transmission capacities xL and xH ideally allocates one FEC target block to a channel with CB transmission capacity xL, while allocating xH / xL FEC target blocks to a channel with CB transmission capacity xH. However, with such an ideal allocation rule, xH / xL is not necessarily an integer. Therefore, the present technology employs a rule for allocating FEC target blocks to channels CH0 and CH1 so as to minimize the difference between the cumulative values ​​of the transmission times (accumulated transmission times) of the FEC target blocks for channels CH0 and CH1. According to this allocation rule, when viewed over a relatively long-term span, one FEC target block is allocated to a channel with CB transmission capacity xL, while an average of xH / xL FEC target blocks are allocated to a channel with CB transmission capacity xH.

[0075] FIG. 9 is a flowchart illustrating the process of generating an allocation table as an allocation rule.

[0076] The allocation table as the allocation rules can be generated by each of the transmitting device 10 and the receiving device 20, or can be generated by the transmitting device 10 and provided (transmitted) to the receiving device 20. Alternatively, the allocation table can be generated by a server (not shown) and provided to the transmitting device 10 and the receiving device 20. Here, for example, the allocation unit 52 of the transmitting device 10 generates the allocation table as the allocation rules, and the process of generating the allocation table will be described.

[0077] In step S11, the allocation unit 52 sets a unit transmission time required to transmit one FEC target block for each of channels CH0 and CH1, and the process proceeds to step S12.

[0078] The unit transmission time of a channel used for CB corresponds to the CB transmission capacity of that channel and is inversely proportional to the CB transmission capacity. As with the CB transmission capacity, the unit transmission time of each channel used for CB does not need to have an absolute value; it is sufficient to know a relative value. Therefore, if the CB transmission capacities of channels CH0 and CH1 are 105 and 31, respectively, the unit transmission times required to transmit one FEC target block on channels CH0 and CH1 can be expressed as, for example, 31 and 105, respectively, obtained by multiplying 1 / 105 and 1 / 31 by 105 × 31 to obtain integers. For example, in step S11, the allocation unit 52 sets 31 as the unit transmission time of channel CH0 and 105 as the unit transmission time of channel CH1.

[0079] In step S12, the allocation unit 52 resets the count value (variable) of the cumulative transmission time counter, which counts the cumulative value (cumulative transmission time) of the FEC target block for each of channels CH0 and CH1, to 0, and the process proceeds to step S13. The cumulative transmission time counters for channels CH0 and CH1 are also referred to as a CH0 counter and a CH1 counter.

[0080] In step S13, the allocation unit 52 initializes an FEC block index idx, which is a variable indicating the arrangement order of FEC target blocks (and therefore FEC blocks), to an initial value, for example, 0, and the process proceeds to step S14. The FEC target block of the FEC block index idx will also be referred to as the FEC target block idx.

[0081] In step S14, the allocation unit 52 allocates the FEC target block idx (=0) to the channel CH0 having the shortest unit transmission time out of the channels CH0 and CH1 used for CB, and the process proceeds to step S15.

[0082] In step S15, the allocation unit 52 increments the count value of the CH0 counter of the channel CH0 to which the FEC target block idx was previously allocated by the unit transmission time of channel CH0 (a value corresponding to the CB transmission capacity), and the process proceeds to step S16.

[0083] In step S16, the allocation unit 52 increments the FEC block index idx by 1, and the process proceeds to step S17.

[0084] In step S17, the allocation unit 52 allocates the FEC target block idx to one of the channels CH0 and CH1 used for CB, which has the smaller count value of the cumulative transmission time counter, and the process proceeds to step S18.

[0085] In step S18, the allocation unit 52 increments the count value of the cumulative transmission time counter of the channel to which the FEC target block idx was most recently allocated, out of the channels CH0 and CH1 used for CB, by the unit transmission time of that channel (a value corresponding to the CB transmission capacity).Then, the process proceeds from step S18 to step S19.

[0086] In step S19, the allocation unit 52 determines whether the count value of the CH0 counter is equal to the count value of the CH1 counter.

[0087] If it is determined in step S19 that the count value of the CH0 counter and the count value of the CH1 counter are not equal, the process returns to step S16, and the processes of steps S16 to S19 are repeated.

[0088] On the other hand, if it is determined in step S19 that the count value of the CH0 counter and the count value of the CH1 counter are equal, the process proceeds to step S20. In step S20, the allocation unit 52 generates, as an allocation rule, an allocation table describing the allocation of FEC blocks 0 to idx-1, which are allocation unit FEC block groups, to channel CH0 or CH1 in steps S14 and S17, and then the process ends.

[0089] The allocation table generated as described above describes the allocation of each of the idx FEC target blocks 0 to idx-1, which are the allocation unit FEC target block group, to channel CH0 or CH1. The allocation unit 52 allocates each of the idx FEC target blocks 0 to idx-1, which are the allocation unit FEC target block group, to channel CH0 or CH1 in units of the allocation unit FEC target block group, in accordance with this allocation table.

[0090] When the count value (cumulative transmission time) of the CH0 counter and the count value of the CH1 counter become equal, that count value becomes the least common multiple LCM of the unit transmission times T0 and T1 of channels CH0 and CH1. Here, the unit transmission times T0 and T1 of channels CH0 and CH1 are 31 and 105, respectively, so the count value of the CH0 counter and the count value of the CH1 counter become equal when the least common multiple LCM = T0 × T1 = 31 × 105 = 3255. The number idx of FEC target blocks 0 to idx-1 in the allocation unit FEC target block group is 136, which is the sum of the multiplier 105 used to convert the unit transmission time T0 = 31 to the least common multiple LCM = 3255 and the multiplier 31 used to convert the unit transmission time T1 = 105 to the least common multiple LCM = 3255. In this case, the allocation unit 52 repeatedly allocates each of the 136 FEC blocks 0 to 135 to channel CH0 or CH1 in units of 136 FEC blocks 0 to 135, which are the allocation unit FEC block group.

[0091] Here, if channel CH0 requires 31 unit transmission times to transmit one FEC target block, channel CH1 requires 105 unit transmission times to transmit one FEC target block. If FEC target blocks are allocated to channels CH0 and CH1 so that there is as little difference as possible between the cumulative transmission time required to transmit FEC target blocks on channel CH0 and the cumulative transmission time required to transmit FEC target blocks on channel CH1, the waiting time for the FEC target blocks in receiving device 20, and ultimately the capacity of the buffer that stores the FEC target blocks, can be reduced.

[0092] In Figure 9, we have explained the generation of an allocation table as an allocation rule when there are two channels used for CB, but when there are N channels, three or more, used for CB, the allocation rule is generated as follows.

[0093] The CB transmission capacities of N channels are represented as c1, c2, ..., cN, in descending order. Normalizing CB transmission capacities c1 to cN by the largest CB transmission capacity c1 gives 1, c2 / c1, ..., cN / c1. The inverse of 1, c2 / c1, ..., cN / c1, 1, c1 / c2, ..., c1 / cN, is the unit transmission time required to transmit one FEC target block on each of the N channels. Expressing the unit transmission time for each of the N channels as an integer, for example, multiplying 1, c1 / c2, ..., c1 / cN by c2×c3×...×cN gives c2×c3×...×cN, c1×c3×...×cN, ..., c1×c2×...×c(N-1). Of these unit transmission times c2×c3×...×cN, c1×c3×...×cN, ..., c1×c2×...×c(N-1), the unit transmission times of the channels to which the FEC target blocks are assigned are accumulated into the cumulative transmission time of the channels, and an allocation table is generated as allocation rules so that the FEC target blocks are assigned to each channel so that there is no difference in the cumulative transmission time of each channel.

[0094] In allocating FEC blocks to N channels (three or more), one FEC block is allocated to each of the N channels for the first N FEC blocks, and the (N+1)th and subsequent FEC blocks are allocated to each channel so that there is no difference in the cumulative transmission time of each channel, as described above. If the allocation of the first N FEC blocks to N channels is referred to as initial allocation, the order in which the FEC blocks are allocated to each of the N channels in the initial allocation of FEC blocks (hereinafter also referred to as allocation order) needs to be set in advance.

[0095] In Figure 9, for two channels CH0 and CH1, the channel CH0 with the larger CB transmission capacity (shorter unit transmission time) is assigned the first priority for allocation, and the other channel CH1 is assigned the second priority for allocation, so that initial allocation of FEC target blocks is performed.

[0096] FIG. 10 is a diagram for explaining a specific example of generating an allocation table as an allocation rule.

[0097] FIG. 10 shows the FEC block index idx, the count value of the CH0 counter indicating the cumulative transmission time (of the FEC target block) of channel CH0, the count value of the CH1 counter indicating the cumulative transmission time (of the FEC target block) of channel CH1, and some of the assigned channels to which the FEC target block idx is assigned, when the channels used for CB are channel CH0 with a unit transmission time of 31 and channel CH1 with a unit transmission time of 105.

[0098] In generating an allocation table as allocation rules, first, the count value of the CH0 counter, which indicates the cumulative transmission time of channel CH0, and the count value of the CH1 counter, which indicates the cumulative transmission time of channel CH1, are reset to zero.

[0099] Then, the FEC block index idx is initialized to the initial value 0, and the FEC target block idx=0 is assigned to a channel. The FEC target block idx=0 is assigned to, for example, channel CH0, which has a smaller unit transmission time, of channels CH0 and CH1.

[0100] The count value of the CH0 counter, which indicates the cumulative transmission time of the channel CH0 to which the FEC target block idx=0 is assigned, is incremented by the unit transmission time 31 of that channel CH0, and becomes 31=0+31.

[0101] Thereafter, the FEC block index idx is incremented by 1, so that 1 = 0 + 1, and the FEC target block idx = 1 is assigned to a channel. The FEC target block idx = 1 is assigned to either channel CH0 or CH1, whichever channel has the smaller count value of its cumulative transmission time counter (CH0 counter or CH1 counter). For the FEC target block idx = 1, the count values ​​of the CH0 counter and CH1 counter are 31 and 0, respectively, so the FEC target block idx = 1 is assigned to either channel CH0 or CH1, which channel has the smaller count value of its cumulative transmission time counter, 0.

[0102] The count value of the CH1 counter, which indicates the cumulative transmission time of the channel CH1 to which the FEC target block idx=1 is assigned, is incremented by the unit transmission time 105 of that channel CH1, to become 105=0+105.

[0103] Thereafter, the FEC block index idx is incremented by 1, so that 2 = 1 + 1, and the FEC target block idx = 2 is assigned to a channel. The FEC target block idx = 2 is assigned to either channel CH0 or CH1, whichever has the smaller count value of the cumulative transmission time counter. For the FEC target block idx = 2, the count values ​​of the CH0 counter and the CH1 counter are 31 and 105, respectively, so the FEC target block idx = 2 is assigned to channel CH0, which has the smaller count value of 31 of the cumulative transmission time counter, of channels CH0 and CH1.

[0104] The count value of the CH0 counter, which indicates the cumulative transmission time of the channel CH0 to which the FEC target block idx=2 is assigned, is incremented by the unit transmission time of that channel CH0, 31, to become 62=31+31.

[0105] Similarly, the process of incrementing the FEC block index idx, allocating the FEC target block idx to either channel CH0 or CH1, whichever has the smaller count value of its cumulative transmission time counter, and incrementing the count value of the cumulative transmission time counter of the channel to which the FEC target block idx is allocated by the unit transmission time is repeated until the count values ​​of the CH0 counter and the CH1 counter become equal. In this way, 136 (=105+31) FEC target blocks 0 to 135, which are the allocation unit FEC target block group, are allocated to either channel CH0 or CH1, and an allocation table describing these allocations is generated.

[0106] 11, 12, 13, and 14 are diagrams showing the relationship between the FEC block index idx, the count value of the CH0 counter, the count value of the CH1 counter, and the channel to which the FEC target block idx is assigned (allocated channel). Fig. 12 is a continuation of Fig. 11, and Fig. 13 is a continuation of Fig. 12. Fig. 14 is a continuation of Fig. 13.

[0107] 11 to 14, when the FEC block index idx is 136 (=105+31), the count value of the CH0 counter and the count value of the CH1 counter are equal, 3255 (=105×31). Then, 136 FEC target blocks 0 to 135 are treated as an allocation unit FEC target block group, and an allocation table is generated that describes the allocation of each of the 136 FEC target blocks 0 to 135, which make up the allocation unit FEC target block group, to channel CH0 or CH1. The allocation unit 52 allocates FEC target blocks to channels for each of the 136 FEC target blocks 0 to 135, which make up the allocation unit FEC target block group, in accordance with the allocation table.

[0108] FIG. 15 shows an example of the arrangement of FEC target blocks at each point in time in the transmitting device 10 when FEC target blocks are assigned to channels so that the difference between the cumulative transmission time of channel CH0 and the cumulative transmission time of channel CH1 is as small as possible.

[0109] The allocation of FEC blocks to channels so as to minimize the difference between the cumulative transmission time of channel CH0 and the cumulative transmission time of channel CH1 is also called uniform allocation of FEC blocks. Uniform allocation of FEC blocks can be performed by allocating FEC blocks to channel CH0 or CH1 according to an allocation table as an allocation rule. In uniform allocation of FEC blocks, FEC blocks 0, 2, 3, 4, 6, 7, 8, 10, 11, 12, 13, ... are assigned to channel CH0, and FEC blocks 1, 5, 9, 14, ... are assigned to channel CH1.

[0110] Fig. 15A shows the arrangement of FEC target blocks assigned to channels CH0 and CH1 at time P1 (Fig. 5) when the FEC target blocks are output from the allocation unit 52 when uniform allocation of FEC target blocks is performed. Fig. 15B shows the arrangement of FEC target blocks assigned to channels CH0 and CH1 at time P2 (Fig. 5) when the FEC target blocks are input to the BICM unit 61 when uniform allocation of FEC target blocks is performed. Fig. 15C shows the arrangement of FEC target blocks assigned to channels CH0 and CH1 at time P3 (Fig. 5) when the OFDM frame generation unit 62 is output when uniform allocation of FEC target blocks is performed.

[0111] For simplicity's sake, if we assume that there is no delay between the allocation unit 52 and the BICM unit 61, the sequence of FEC target blocks at time P1 when output from the allocation unit 52 (A in Figure 15) will be the same as the sequence of FEC target blocks at time P2 when input to the BICM unit 61 (B in Figure 15).

[0112] In an OFDM frame, as shown in C of FIG. 15 , FEC target blocks (and corresponding transmission symbols) assigned to channel CH1, which has a small CB transmission capacity of 31, are arranged in a manner that is stretched out in the time direction compared to FEC target blocks (and corresponding transmission symbols) assigned to channel CH0, which has a large CB transmission capacity of 105.

[0113] The number of FEC target blocks allocated to each of channels CH0 and CH1 arranged in one OFDM frame corresponds to the CB transmission capacity of each of channels CH0 and CH1. That is, the ratio of the number of FEC target blocks allocated to each of channels CH0 and CH1 arranged in one OFDM frame matches the ratio of the CB transmission capacities of each of channels CH0 and CH1. In this embodiment, the number of FEC target blocks allocated to channel CH0, which has a CB transmission capacity of 105, arranged in one OFDM frame is, for example, approximately 2.94. The number of FEC target blocks allocated to channel CH0, which has a CB transmission capacity of 31, arranged in one OFDM frame is, for example, approximately 0.87.

[0114] For this reason, all of FEC target block 0, all of FEC target block 2, and part of FEC target block 3 are placed in the OFDM frame with frame number 1 transmitted on channel CH0 (hereinafter referred to as the first OFDM frame). In contrast, part of FEC target block 1 is placed in the first OFDM frame transmitted on channel CH1.

[0115] The second OFDM frame transmitted on channel CH0 contains the remainder of FEC target block 3, all of FEC target block 4, all of FEC target block 6, and part of FEC target block 7. In contrast, the second OFDM frame transmitted on channel CH1 contains the remainder of FEC target block 1 and part of FEC target block 5.

[0116] As shown in C of Figure 15, after the transmission of FEC target blocks 0, 2, and 3 on channel CH0 is completed, the transmission of FEC target block 1 on channel CH1 is completed. Therefore, in the receiving device 20, after the reception of FEC target blocks 0, 2, and 3 on channel CH0 is completed, the reception of FEC target block 1 on channel CH1 is completed. Therefore, the receiving device 20 needs to store FEC target blocks 2 and 3 in a buffer and wait for the output of FEC target blocks 2 and 3 at least from the time of receiving FEC target blocks 2 and 3 until the reception of FEC target block 1 is completed. As described above, before the reception of the earlier FEC target block transmitted on channel CH1 is completed, the later FEC target block that is received on channel CH0 needs to be stored in a buffer and wait for its output. In the receiving device 20, the longer the wait time for output (reading) of the FEC target block from the buffer is, the larger the buffer capacity may become.

[0117] Therefore, by configuring the transmitting device 10 as follows, it is possible to reduce the buffer capacity of the receiving device 20.

[0118] <Second Configuration Example of the Dividing Unit 32 and the Modulating Unit 41>

[0119] FIG. 16 is a block diagram showing a second example of the configuration of the dividing unit 32 and the modulation unit 41 of the transmitting device 10.

[0120] In the figure, parts corresponding to those in FIG. 5 are given the same reference numerals, and the description thereof will be omitted below as appropriate.

[0121] The transmitting device 10 (of the dividing unit 32 and the modulating unit 41) in Figure 16 differs from the case in Figure 5 in that a delay unit 71 is newly provided in the input stage of the modulating unit 41-1 corresponding to channel CH0, which has a large CB transmission capacity out of the channels CH0 and CH1 used for CB.

[0122] The delay unit 71 is supplied with FEC target blocks allocated to channel CH0 from the allocation unit 52. The delay unit 71 delays the input of the FEC target blocks allocated to channel CH0 from the allocation unit 52 to the BICM unit 61-1 by a predetermined number of FEC target blocks, thereby delaying the transmission of the FEC target blocks by the predetermined number of FEC target blocks. For example, the delay unit 71 delays the transmission by an integer number of FEC target blocks based on a transmission capacity division value obtained by dividing the larger of the CB transmission capacities of channels CH0 and CH1 by the smaller CB transmission capacity.

[0123] The integer value based on the transmission capacity division value can be, for example, the integer value -1 obtained by rounding up the decimal point of the transmission capacity division value, or the integer value -1 obtained by rounding up the decimal point of the transmission capacity division value. Here, for example, the integer value -1 obtained by rounding up the decimal point of the transmission capacity division value is used as the integer value based on the transmission capacity division value. In this case, the integer value based on the transmission capacity division value is ceil(105 / 31)-1=3, and the delay unit 71 delays the FEC target block assigned to channel CH0 by the amount of three FEC target blocks. The function ceil(x) represents the smallest integer equal to or greater than x.

[0124] FIG. 17 is a diagram showing an example of an arrangement of FEC target blocks at each time point in the transmitting device 10 when the FEC target blocks are uniformly allocated and delayed by the delay unit 71. In FIG.

[0125] As described with reference to FIG. 15, in uniform allocation of FEC blocks, FEC blocks 0, 2, 3, 4, 6, 7, 8, 10, 11, 12, 13, . . . are allocated to channel CH0, and FEC blocks 1, 5, 9, 14, .

[0126] 17A shows the arrangement of FEC blocks assigned to channels CH0 and CH1 at time P11 (FIG. 16) of the output of the assignment unit 52. FIG. 17B shows the arrangement of FEC blocks assigned to channels CH0 and CH1 at time P12 (FIG. 16) of the input of the BICM unit 61 (output of the delay unit 71). FIG. 17C shows the arrangement of FEC blocks assigned to channels CH0 and CH1 at time P13 (FIG. 16) of the output of the OFDM frame generation unit 62.

[0127] 17, the shaded FEC target blocks are FEC target blocks in the FEC target block group of the allocation unit immediately preceding the current allocation unit FEC target block group. In this embodiment, the allocation unit FEC target block group is made up of FEC target blocks 0 to 135, so the last FEC target block in the previous allocation unit FEC target block group is the shaded FEC target block 135, and the next FEC target block is the first FEC target block 0 in the current allocation unit FEC target block group. The same applies to similar figures described later.

[0128] 17, between the allocation unit 52 and the BICM unit 61-1 (in the modulation unit 41-1) corresponding to channel CH0, the FEC target blocks allocated to channel CH0 are delayed by a delay caused by the delay unit 71. As a result, the sequence of FEC target blocks allocated to channel CH0 at time P12 of input to the BICM unit 61 (B in FIG. 17) is delayed by three FEC target blocks from the sequence of FEC target blocks allocated to channel CH0 at time P11 of output from the allocation unit 52 (A in FIG. 17).

[0129] On the other hand, there is no delay between the allocation unit 52 and the BICM unit 61-2 (in the modulation unit 41-2) corresponding to channel CH1, as in the case of Fig. 15. Therefore, the sequence of FEC target blocks allocated to channel CH1 at time P11 when output from the allocation unit 52 (A in Fig. 17) is the same as the sequence of FEC target blocks allocated to channel CH1 at time P2 when input to the BICM unit 61 (B in Fig. 17).

[0130] As a result, in the OFDM frame, the FEC target blocks assigned to channel CH0 are arranged in an array delayed by three FEC target blocks compared to the case of Fig. 15, as shown in Fig. 17C. On the other hand, the FEC target blocks assigned to channel CH1 are arranged in the same array as in Fig. 15, as shown in Fig. 17C.

[0131] That is, the first OFDM frame transmitted on channel CH0 contains all of FEC target block 133, all of FEC target block 134, and part of FEC target block 135 in the previous allocation unit FEC target block group. In contrast, the first OFDM frame transmitted on channel CH1 contains part of FEC target block 1 in the allocation unit FEC target block group of interest.

[0132] The second OFDM frame transmitted on channel CH0 contains the remainder of FEC target block 135 of the previous allocation unit FEC target block group, as well as all of FEC target block 0, all of FEC target block 2, and part of FEC target block 3 of the allocation unit FEC target block group of interest. In contrast, the second OFDM frame transmitted on channel CH1 contains the remainder of FEC target block 1 and part of FEC target block 5 of the allocation unit FEC target block group of interest.

[0133] The third OFDM frame transmitted on channel CH0 contains the remainder of FEC target block 3, all of FEC target block 4, all of FEC target block 6, and part of FEC target block 7 of the allocation unit FEC target block group under consideration. In contrast, the third OFDM frame transmitted on channel CH1 contains the remainder of FEC target block 5 and part of FEC target block 9 of the allocation unit FEC target block group under consideration.

[0134] As a result of arranging the FEC target blocks in the OFDM frame as described above, as shown in C of Fig. 17 , shortly after the completion of the transmission of FEC target block 1 of the FEC target block group of allocation units of interest on channel CH1, the transmission of FEC target blocks 0, 2, and 3 on channel CH0 is completed. Therefore, the receiving device 20 must store FEC target block 1 in a buffer and wait for the output of FEC target block 1, at least from the time of receiving FEC target block 1 until the reception of FEC target block 0 is completed. However, after the reception of FEC target block 0 is completed and FEC target block 0 is output, FEC target block 1 can be output. Furthermore, as for FEC target blocks 2 and 3 transmitted thereafter on channel CH0, they can be output immediately after the reception of FEC target blocks 2 and 3, without having to wait for output.

[0135] Therefore, in the receiving device 20, the waiting time for the output of the FEC target block from the buffer can be shortened, and the buffer capacity can be reduced.

[0136] <Configuration example of receiving device 20>

[0137] FIG. 18 is a block diagram showing an example of the configuration of the receiving device 20.

[0138] 18, the receiving device 20 includes a receiving unit 101 , a combining unit 102 , a decoding unit 103 , and a control unit 104 .

[0139] The receiving unit 101 receives a transmission signal transmitted from the transmitting device 10 via CB using two channels CH0 and CH1 via an antenna (not shown). The receiving unit 101 is composed of a tuner, a demodulator, etc. The receiving unit 101 has demodulation units 111-1 and 111-2 corresponding to the two channels CH0 and CH1 used for CB. The demodulation units 111-1 and 111-2 can be made to correspond to channels CH0 and CH1, respectively, or conversely, can be made to correspond to channels CH1 and CH0, respectively. Here, for convenience, the demodulation units 111-1 and 111-2 are assumed to correspond to channels CH0 and CH1, respectively. The demodulation unit 111-1 performs demodulation processing on the transmission signal of the corresponding channel CH0 in accordance with a predetermined demodulation method. The demodulation unit 111-2 performs demodulation processing on the transmission signal of the corresponding channel CH1 in accordance with a predetermined demodulation method.

[0140] In the demodulation process, physical layer control information is acquired from the OFDM frame included in the transmission signal, and is output from each of the demodulation units 111-1 and 111-2 to the control unit 104. Furthermore, in the demodulation process, FEC target blocks assigned to channel CH0 or CH1 are acquired as divided data obtained by dividing the TLV stream as target data from the OFDM frame included in the transmission signal, and are output from each of the demodulation units 111-1 and 111-2 to the combining unit 102.

[0141] The combiner 102 combines the FEC target blocks as divided data from the demodulator 111-1 with the FEC target blocks as divided data from the demodulator 111-2 to restore the TLV stream as the original target data. That is, the combiner 102 reconstructs the FEC target blocks assigned to channel CH0 from the demodulator 111-1 and the FEC target blocks assigned to channel CH1 from the demodulator 111-2 into a sequence of FEC target blocks in the original order. Furthermore, the combiner 102 converts the sequence of FEC target blocks in the original order into a TLV stream as target data and outputs it to the decoder 103.

[0142] The decoding unit 103 is composed of a decoder and the like that conforms to a predetermined decoding method corresponding to the predetermined encoding method of the encoding unit 31 (FIG. 4). The decoding unit 103 performs decoding processing on the TLV stream input from the synthesis unit 102 according to a predetermined decoding method, and outputs the resulting decoded data, such as data of broadcast program content, to a subsequent stage. A display and a speaker are provided subsequent to the decoding unit 103, and the video signal and audio signal included in the content data are processed. As a result, in the receiving device 20, the video of the content is displayed on the display, and audio synchronized with the video is output from the speaker.

[0143] The control unit 104 is composed of a processor or the like, and controls the operation of each unit. For example, the control unit 104 controls the selection of a channel (transmission signal) used for CB based on physical layer control information from the demodulation units 111-1 and 111-2. Also, for example, the control unit 104 controls the reconfiguration of FEC target blocks assigned to each channel used for CB into a sequence of FEC target blocks in the original order based on the physical layer control information.

[0144] When three or more channels are used as the multiple channels used for CB, the receiving unit 101 is provided with a demodulation unit corresponding to each of the three or more channels used for CB.

[0145] <Configuration example of the combining unit 102 and the demodulating unit 111>

[0146] FIG. 19 is a block diagram showing an example of the configuration of the combining unit 102 and the demodulating unit 111 of the receiving device 20.

[0147] The combiner 102 includes buffers 131-1 and 131-2, a reconstruction unit 132, and a conversion unit 133. The demodulator 111-1 includes an OFDM demodulator 121-1 and an inverse BICM unit 122-1, and the demodulator 111-2 includes an OFDM demodulator 121-2 and an inverse BICM unit 122-2.

[0148] The OFDM demodulation unit 121-1 demodulates the OFDM signal as the transmission signal of the corresponding channel CH0 among the channels used for CB in accordance with the control of the control unit 104 (Figure 18), and supplies the series of transmission symbols arranged in the OFDM frame obtained by the demodulation to the inverse BICM unit 122-1.

[0149] The inverse BICM unit 122-1 performs inverse BICM processing, which is the inverse conversion of BICM processing, on the sequence of transmission symbols from the OFDM demodulation unit 121-1, and outputs the resulting FEC target blocks as divided data assigned to channel CH0 to a buffer 131-1 in the combiner 102. The inverse BICM processing includes demapping, bit deinterleaving, FEC processing (decoding of error correction codes), etc. Hereinafter, the divided data or FEC target blocks assigned to channel CH0 will also be referred to as divided data or FEC target blocks of channel CH0.

[0150] The OFDM demodulation unit 121-2 and the inverse BICM unit 122-2 perform the same processing as the OFDM demodulation unit 121-1 and the inverse BICM unit 122-1, respectively, on the OFDM signal as the transmission signal of the corresponding channel CH1 among the channels used for CB. As a result, the FEC target block as the divided data assigned to channel CH1 is output from the inverse BICM unit 122-2 to the buffer 131-2 of the combiner 102.

[0151] The buffer 131-1 is a buffer for channel CH0 that temporarily stores FEC target blocks for channel CH0, and stores the FEC target blocks for channel CH0 from the inverse BICM unit 122-1. The buffer 131-2 is a buffer for channel CH1 that temporarily stores FEC target blocks for channel CH1, and stores the FEC target blocks for channel CH1 from the inverse BICM unit 122-2. Hereinafter, the buffer 131-1 for channel CH0 will also be referred to as the CH0 buffer, and the buffer 131-2 for channel CH1 will also be referred to as the CH1 buffer.

[0152] The reconstructing unit 132 specifies the allocation of FEC target blocks to each of channels CH0 and CH1 used for CB, based on the allocation table serving as the allocation rules generated as described in Fig. 9. Based on the result of specifying the allocation of FEC target blocks to each of channels CH0 and CH1, the reconstructing unit 132 reads out the FEC target blocks of channel CH0 stored in buffer 131-1 and the FEC target blocks of channel CH1 stored in buffer 131-2 in the original order of the FEC target blocks, thereby reconstructing the sequence of FEC target blocks in the original order, and outputs the sequence to the converting unit 133.

[0153] The conversion unit 133 converts the sequence of FEC target blocks in the original order from the reconstruction unit 132 into a TLV stream as target data (restores the TLV stream) and outputs it to the decoding unit 103 (FIG. 18).

[0154] Hereinafter, unless there is a particular need to distinguish between them, the demodulation units 111-1 and 111-2 will also be referred to as demodulation units 111. Similarly, the OFDM demodulation units 121-1 and 121-2 will also be referred to as OFDM demodulation units 121, the inverse BICM units 122-1 and 122-2 will also be referred to as inverse BICM units 122, and the buffers 131-1 and 131-2 will also be referred to as buffers 131.

[0155] FIG. 20 is a diagram illustrating an example of the processing performed by the combining unit 102 and the demodulating unit 111 in FIG.

[0156] For example, it is assumed that the OFDM frame generator 62 (FIG. 16) of the transmitting device 10 generates an OFDM frame in which FEC target blocks for channels CH0 and CH1 shown in FIG. 17C are arranged.

[0157] In this case, the OFDM frames included in the transmission signals of channels CH0 and CH1 demodulated by the OFDM demodulation unit 121 (FIG. 19) include FEC target blocks similar to those described in FIG. 17C.

[0158] 20, all of FEC target block 133, all of FEC target block 134, and part of FEC target block 135 of the previous allocation unit FEC target block group are arranged in the first OFDM frame (included in the transmission signal) of channel CH0. On the other hand, part of FEC target block 1 of the allocation unit FEC target block group of interest is arranged in the first OFDM frame (included in the transmission signal) of channel CH1.

[0159] The second OFDM frame of channel CH0 contains the remainder of FEC target block 135 of the previous allocation unit FEC target block group, as well as all of FEC target block 0, all of FEC target block 2, and part of FEC target block 3 of the allocation unit FEC target block group of interest. On the other hand, the second OFDM frame of channel CH1 contains the remainder of FEC target block 1 and part of FEC target block 5 of the allocation unit FEC target block group of interest.

[0160] The third OFDM frame of channel CH0 contains the remainder of FEC target block 3, all of FEC target block 4, all of FEC target block 6, and part of FEC target block 7 of the allocation unit FEC target block group under consideration. On the other hand, the third OFDM frame of channel CH1 contains the remainder of FEC target block 5 and part of FEC target block 9 of the allocation unit FEC target block group under consideration.

[0161] The inverse BICM unit 122 (FIG. 19) performs inverse BICM processing on the transmission symbols of the OFDM frame described above, and each time an FEC target block is obtained, outputs the FEC target block to the buffer 131 (FIG. 19).

[0162] For example, in the inverse BICM unit 122-1, FEC blocks 133, 134, and 135 of channel CH0 are sequentially obtained for the previous allocation unit FEC block group, and the FEC blocks 133, 134, and 135 of channel CH0 are sequentially output.

[0163] For the previous allocation unit FEC block group, shortly after FEC block 135 for channel CH0 is obtained, the inverse BICM unit 122-2 obtains FEC block 1 for channel CH1 for the allocation unit FEC block group of interest. The inverse BICM unit 122-2 outputs FEC block 1 for channel CH1. Shortly after FEC block 1 for channel CH1 is obtained, the inverse BICM unit 122-1 obtains FEC block 0 for channel CH0 and outputs FEC block 0 for channel CH0. The inverse BICM unit 122-1 then sequentially obtains and outputs FEC blocks 2 and 3 for channel CH0. Shortly after FEC block 3 for channel CH0 is obtained, the inverse BICM unit 122-2 obtains and outputs FEC block 5 for channel CH1.

[0164] The FEC blocks 133 to 135 of the FEC block group in the previous allocation unit for the channel CH1 output by the inverse BICM unit 122-2 are written (stored) in the CH1 buffer (buffer 131-2 (FIG. 19)). The FEC blocks 133 to 135 written in the CH1 buffer are read out by the reconstruction unit 132 (FIG. 19) without any waiting time.

[0165] FEC target blocks 0, 2, and 3 of channel CH0 output by the inverse BICM unit 122-1 are written to the CH0 buffer (buffer 131-1 (FIG. 19)). FEC target blocks 1 and 5 of channel CH1 output by the inverse BICM unit 122-2 are written to the CH1 buffer.

[0166] The FEC target blocks 0, 2, and 3 of channel CH0 written in the CH0 buffer are read out by the reconstruction unit 132 without any particular waiting time.

[0167] On the other hand, the reconstruction unit 132 waits for the FEC blocks 1 and 5 of channel CH1 written to the CH1 buffer to be read out after the FEC block immediately preceding those FEC blocks 1 and 5 has been read out from the CH0 buffer before reading them. That is, the FEC block 1 written to the CH1 buffer is read out after the FEC block 0 immediately preceding that FEC block 1 has been read out from the CH0 buffer before reading them. The FEC block 5 written to the CH1 buffer is read out after the FEC block 4 immediately preceding that FEC block 5 has been read out from the CH0 buffer before reading them.

[0168] As described above, ideally, there is no need to provide a CH0 buffer because the FEC target block of channel CH0 written in the CH0 buffer is read without any particular waiting time by the reconstruction unit 132. Even if a CH0 buffer is provided, a buffer with a capacity for one FEC target block is sufficient.

[0169] On the other hand, the FEC target block of channel CH1 written in the CH1 buffer is read after the previous FEC target block has been read from the CH0 buffer. In the transmitting device 10, when the above-described uniform allocation of FEC target blocks and the delay unit 71 delays the FEC target blocks, the inverse BICM unit 122-2 obtains FEC target block 1 of channel CH1 after the previous FEC target block of channel CH1 written in the CH1 buffer has been read. Furthermore, the inverse BICM unit 122-2 obtains FEC target block 5 of channel CH1 after the previous FEC target block 1 of channel CH1 written in the CH1 buffer has been read. The same applies to subsequent FEC target blocks of channel CH1. Therefore, a buffer with a capacity for one FEC target block is sufficient for the CH1 buffer.

[0170] As described above, by uniformly allocating FEC target blocks and delaying the FEC target blocks in the delay unit 71 in the transmitting device 10, the capacity of the buffer 131 provided in the receiving device 20 can be reduced.

[0171] <Syntax of transmission control auxiliary information>

[0172] FIG. 21 is a diagram illustrating an example of the syntax of the transmission control auxiliary information.

[0173] In the current ISDB-T, TMCC is specified as transmission control information. TMCC includes information such as transmission parameters, such as the modulation method and error correction coding rate of each layer. In advanced terrestrial digital broadcasting, TMCC is expected to be used, as in the current ISDB-T. TMCC includes transmission control auxiliary information. In this technology, CB control information aux_cb_configuration() indicating the CB configuration can be transmitted by being included in transmission control auxiliary information Auxiliary_data(); in other words, CB control information aux_cb_configuration() can be transmitted by being included in physical layer control information.

[0174] In the following description, among signals (hereinafter also referred to as CB signals) corresponding to FEC target blocks as divided data of each channel used for CB, the CB signal of a channel of interest is also referred to as its own signal. Among the CB signals of each channel used for CB, the CB signals of channels other than the channel of interest are also referred to as other signals.

[0175] The auxiliary transmission control information Auxiliary_data() has an 8-bit number_of_aux_data, which indicates the number of auxiliary transmission control information (information to be used as auxiliary transmission control information).

[0176] After the number_of_aux_data, an 8-bit aux_data_type and 8-bit aux_data_size set is placed, the number of which corresponds to the number_of_aux_data. The aux_data_type indicates the type that identifies the auxiliary transmission control information. The CB control information aux_cb_configuration() is assigned aux_data_type = 2. The aux_data_size indicates the size of the auxiliary transmission control information.

[0177] If aux_data_type = 2, CB control information aux_cb_configuration() is placed after aux_data_type.

[0178] FIG. 22 is a diagram showing the syntax of the CB control information aux_cb_configuration().

[0179] The CB control information aux_cb_configuration() has a 16-bit network_id, a 3-bit subframe, a 3-bit layer, a 1-bit sublayer, a 3-bit num_rf, and a 10-bit FEC_Block_index.

[0180] network_id indicates the network ID of the own signal (channel).

[0181] "subframe" represents the subframe number of the signal itself. That is, an OFDM frame, in which transmission symbols as a payload are arranged, can be configured with one or more subframes, and "subframe" represents the subframe number that identifies the subframe in which the transmission symbols as the signal itself are arranged.

[0182] The layer is information about the layer used for CB of the channel (channel of the own signal) on which the OFDM frame including this layer is transmitted, and represents, for example, the layer number of the own signal. That is, the layer represents the layer number that identifies the layer on which the own signal is placed out of a maximum of eight layers configured in units of segments.

[0183] The sublayer is information about the sublayer used for CB of the channel (channel of the own signal) on which the OFDM frame including this sublayer is transmitted, and represents, for example, the sublayer number of the own signal. That is, the sublayer represents the layer number that identifies the sublayer in which the own signal is arranged, out of a maximum of two sublayers configured in units of subsegments.

[0184] The subframe, layer, and sublayer can be used to identify the subframe, layer, and sublayer as the CB transmission band of the channel of the own signal. Furthermore, the subframe, layer, and sublayer can be used to identify the CB transmission capacity of the channel of the own signal, for example, in units of the number of segments or the number of subsegments. Note that the CB control information aux_cb_configuration() can include information on the CB transmission capacity of the channel of the own signal, in addition to the subframe, layer, and sublayer.

[0185] num_rf represents the number of CB signals (signals constituting CB) (the number of channels used for CB). Since the number of channels used for CB is, for example, up to eight, num_rf is 3 bits.

[0186] The FEC_Block_index is an FEC block index idx representing the order of the FEC blocks included in the OFDM frame containing this FEC_Block_index within the allocation unit FEC block group. For example, the FEC_Block_index is the FEC block index idx of the first FEC block (including the FEC block) whose beginning is included in the OFDM frame containing this FEC_Block_index. If the CB transmission capacity can be expressed as the number of subsegments, a case in which CB is performed using the maximum CB transmission capacity of 105 on each of the maximum eight channels that can be used for CB is a case in which the number of FEC blocks constituting the allocation unit FEC block group is the maximum, 8 × 105. The FEC_Block_index is 10 bits long because it represents the FEC block index idx representing the order of the 8 × 105 FEC blocks.

[0187] In addition, an FEC block pointer is separately defined to indicate the position of the beginning of the first FEC target block (including FEC block) whose beginning is included in the OFDM frame, and this FEC block pointer can be used to identify the position of the first FEC target block (including FEC block) whose beginning is included in the OFDM frame, and further the positions of subsequent FEC target blocks in the OFDM frame.

[0188] In the CB control information aux_cb_configuration(), 4 reserved bits are placed after the FEC_Block_index for byte alignment.

[0189] After the 4-bit reserve, other signal information for each channel used for CB other than the channel of the own signal is placed. The other signal information consists of a set of 16-bit cb_network_id, 3-bit cb_subframe, 3-bit cb_layer, 1-bit cb_sublayer, 7-bit cb_num_layer, and 10-bit cb_FEC_Block_index. The number of other signal information bits is the same as the number of other signals, i.e., the number of CB signals represented by num_rf minus 1.

[0190] cb_network_id corresponds to the network_id of the own signal and represents the network ID of the other signal (channel). cb_subframe corresponds to the subframe of the own signal and represents the subframe number of the other signal. cb_layer corresponds to the layer of the own signal and represents the layer number of the other signal. cb_sublayer corresponds to the sublayer of the own signal and represents the sublayer number of the other signal. cb_num_layer represents the CB transmission capacity of the channel of the other signal in terms of the number of subsegments. The CB transmission capacity of the channel of the other signal can also be specified by the subframe, layer, and sublayer. cb_FEC_Block_index corresponds to the FEC_Block_index of the own signal and represents the FEC block index idx of the first FEC target block (including the FEC block) whose head is included in the OFDM frame including the other signal that is transmitted on another channel simultaneously with the OFDM frame including this cb_FEC_Block_index.

[0191] The channel of the other signal can be identified by cb_network_id. By acquiring the CB control information aux_cb_configuration() included in the OFDM frame of the channel of the other signal, it is possible to identify the subframe number, layer number, sub-layer number, CB transmission capacity of the other signal, and the FEC block index idx of the first FEC target block (including the FEC block) whose head is included in the OFDM frame including the other signal.

[0192] Therefore, the CB control information aux_cb_configuration() can be configured without including cb_subframe, cb_layer, cb_sublayer, cb_num_layer, and cb_FEC_Block_index. However, if the CB control information aux_cb_configuration() includes cb_subframe, cb_layer, cb_sublayer, cb_num_layer, and cb_FEC_Block_index, it is possible to identify the subframe number, layer number, sub-layer number, CB transmission capacity, and FEC block index idx of the first FEC target block whose head is included in the OFDM frame including the other signal before acquiring the CB control information aux_cb_configuration() included in the OFDM frame of the channel of the other signal.

[0193] By acquiring the CB control information aux_cb_configuration() configured as described above, the receiving device 20 can identify each channel used for CB (each channel of the CB signal). Then, the receiving device 20 can tune to each channel of the CB signal. Furthermore, by acquiring the CB control information aux_cb_configuration(), the receiving device 20 can identify the allocation of FEC target blocks to each channel of the CB signal. Then, based on the allocation of FEC target blocks to each channel of the CB signal, the receiving device 20 can reconstruct the FEC target blocks of each channel into a sequence of FEC target blocks in the original order.

[0194] <Sub-level>

[0195] FIG. 23 is a diagram illustrating the sub-hierarchy.

[0196] FIG. 23 shows an OFDM frame including two subframes 1 and 2, where subframe 1 has layer A (1A) and layer B (1B), and subframe 2 has only layer A (2A).

[0197] A layer can be divided into a maximum of two sub-layers. In Figure 23, layer A (1A) of subframe 1 is divided into sub-layer a (1Aa) and sub-layer b (1Ab). Sub-layering can be performed in units of subsegments.

[0198] <FEC_Block_index>

[0199] FIG. 24 is a diagram illustrating the FEC_Block_index included in the CB control information aux_cb_configuration().

[0200] For example, it is assumed that the OFDM frame generator 62 (FIG. 16) of the transmitting device 10 generates an OFDM frame in which FEC target blocks for channels CH0 and CH1 shown in FIG. 17C are arranged.

[0201] In this case, the OFDM frames included in the transmission signals of channels CH0 and CH1 demodulated by the OFDM demodulator 121 (FIG. 19) include FEC target blocks similar to those described in FIG. 17C.

[0202] 24, all of FEC target block 133, all of FEC target block 134, and part of FEC target block 135 of the previous allocation unit FEC target block group are arranged in the first OFDM frame of channel CH0. On the other hand, part of FEC target block 1 of the allocation unit FEC target block group of interest is arranged in the first OFDM frame of channel CH1.

[0203] The FEC_Block_index included in the first OFDM frame of channel CH0 is set to 133, which is the FEC block index idx of FEC target block 133 in the previous allocation unit FEC target block group, which is the first FEC target block whose beginning is included in that OFDM frame.

[0204] The FEC_Block_index included in the first OFDM frame of channel CH1 is set to 1, which is the FEC block index idx of FEC target block 1 in the allocation unit FEC target block group under consideration, which is the first FEC target block whose beginning is included in that OFDM frame.

[0205] The second OFDM frame of channel CH0 contains the remainder of FEC target block 135 of the previous allocation unit FEC target block group, as well as all of FEC target block 0, all of FEC target block 2, and part of FEC target block 3 of the allocation unit FEC target block group of interest. On the other hand, the second OFDM frame of channel CH1 contains the remainder of FEC target block 1 and part of FEC target block 5 of the allocation unit FEC target block group of interest.

[0206] The FEC_Block_index included in the second OFDM frame of channel CH0 is set to 0, which is the FEC block index idx of FEC target block 0 in the allocation unit FEC target block group under consideration, which is the first FEC target block whose beginning is included in that OFDM frame.

[0207] The FEC_Block_index included in the second OFDM frame of channel CH1 is set to 5, which is the FEC block index idx of FEC target block 5 in the allocation unit FEC target block group under consideration, which is the first FEC target block whose beginning is included in that OFDM frame.

[0208] Similarly, FEC_Block_index is set for the following blocks.

[0209] The receiving device 20 can identify the CB transmission capacity of each channel used for CB based on the CB control information aux_cb_configuration(). Furthermore, the receiving device 20 can generate an allocation table as an allocation rule for FEC blocks to each channel, as described with reference to FIG. 9 , based on the CB transmission capacity of each channel used for CB, and identify the allocation of FEC blocks to each channel. That is, for example, it can be identified that FEC blocks 0, 2, 3, 4, 6, 7, 8, 10, ... are allocated to channel CH0, and FEC blocks 1, 5, 9, 14, ... are allocated to channel CH1. Then, by referring to the FEC_Block_index based on the allocation of FEC blocks to each channel, the receiving device 20 can identify the FEC block (the FEC block index idx) included in the OFDM frame that includes that FEC_Block_index. For example, by referencing the FEC_Block_index of 0 included in the second OFDM frame of channel CH0, it is possible to identify that the FEC target blocks that can be included in that OFDM frame from the beginning are FEC target blocks 0, 2, 3, .... Furthermore, by referencing the FEC_Block_index of 5 included in the second OFDM frame of channel CH1, it is possible to identify that the FEC target blocks that can be included in that OFDM frame from the beginning are FEC target blocks 5, 9, 14, .... By identifying the FEC target blocks (their FEC block indexes idx) included in the OFDM from the beginning, it is possible to reconstruct the FEC target blocks of each channel into a sequence of FEC target blocks in the original order.

[0210] <Processing of the transmitting device 10 and the receiving device 20>

[0211] FIG. 25 is a flowchart illustrating an example of processing by the transmitting device 10 and the receiving device 20.

[0212] The processes of steps S31 to S33 are executed by the transmitting device 10, and the processes of steps S41 to S44 are executed by the receiving device 20.

[0213] In step S31, the division unit 32 (FIG. 3) divides the TLV stream as target data and converts it into FEC target blocks as divided data units to be allocated to channels CH0 and CH1 used for CB. The division unit 32 allocates each FEC target block to channel CH0 or CH1 in accordance with an allocation table as an allocation rule generated based on the CB transmission capacity of each of channels CH0 and CH1 used for CB, and outputs the allocated blocks to the transmission unit 33. The process then proceeds from step S31 to step S32.

[0214] In step S32, the control information generator 34 (FIG. 3) generates CB control information, and the process proceeds to step S33. The CB control information is included in physical layer control information such as transmission control auxiliary information.

[0215] In step S33, the transmitter 33 (FIG. 3) transmits a transmission signal via CB using two channels CH0 and CH1. That is, the transmitter 33 generates OFDM frames including FEC target blocks as divided data assigned to channels CH0 and CH1 using the modulators 41-1 and 41-2, respectively. The OFDM frames include physical layer control information including CB control information generated by the control information generator 34. The transmitter 33 transmits transmission signals of the OFDM frames including the FEC target blocks assigned to channels CH0 and CH1 (transmission signals including CB signals (signals constituting CB)) via channels CH0 and CH1, respectively.

[0216] In step S41, the receiving unit 101 (FIG. 18) receives the transmission signals of channels CH0 and CH1 transmitted from the transmitting device 10 by the demodulating units 111-1 and 111-2, respectively, and the process proceeds to step S42.

[0217] In step S42, the receiving unit 101 processes the transmission signals of channels CH0 and CH1 using demodulation units 111-1 and 111-2 to obtain the CB control information contained in the physical layer control information, outputs it to the control unit 104, and the processing proceeds to step S43.

[0218] In step S43, the control unit 104 identifies the CB signals of channels CH0 and CH1 based on the CB control information from the receiving unit 101. The control unit 104 acquires the identified CB signals and controls the receiving unit 101 to demodulate (reconstruct) the corresponding FEC target blocks.

[0219] Furthermore, in step S43, the control unit 104 specifies allocation of FEC blocks as divided data to each of channels CH0 and CH1, based on the CB control information from the receiving unit 101. Based on the specified allocation of FEC blocks, the control unit 104 controls the combining unit 102 to reconstruct the FEC blocks of each of channels CH0 and CH1 into a sequence of FEC blocks in the original order, and the process proceeds from step S43 to step S44.

[0220] In step S44, the receiving unit 101, under the control of the control unit 104, demodulates the FEC target blocks of channels CH0 and CH1 from the CB signals of channels CH0 and CH1, respectively, and outputs the demodulated blocks to the combining unit 102. Under the control of the control unit 104, the combining unit 102 reconstructs the FEC target blocks of channels CH0 and CH1 from the receiving unit 101 into a sequence of FEC target blocks in their original order. Furthermore, the combining unit 102 converts the sequence of FEC target blocks in their original order into a TLV stream as target data, and outputs the converted data to the decoding unit 103. The decoding unit 103 decodes the TLV stream into content data.

[0221] In the above description, it has been assumed that the BICM processing and OFDM parameters are the same in the CB transmission band of each channel used for CB. However, the present technology can also be applied to cases where the BICM processing and OFDM parameters are not the same in the CB transmission band of each channel. However, if the BICM processing and OFDM parameters are not the same in the CB transmission band of each channel, the CB transmission capacity of each channel may not be expressed as an integer number of subsegments. For example, it may be necessary to express the CB transmission capacity of each channel as the number of transmission symbols (an integer). When the CB transmission capacity of each channel is expressed as the number of transmission symbols, the least common multiple LCM of the unit transmission times (integers) of each channel becomes a large value. When the least common multiple LCM is large, the number of FEC blocks constituting the allocation unit FEC block group also increases. The FEC_Block_index and cb_FEC_Block_index of the CB control information (FIG. 22) must have a number of bits sufficient to represent the order of the FEC target blocks that make up the allocation unit FEC target block group. In the above, the CB control information aux_cb_configuration() includes the FEC_Block_index (and cb_FEC_Block_index), but the FEC_Block_index can be included in the FEC target block instead of the CB control information aux_cb_configuration(). The following describes the case where the FEC_Block_index is included in the FEC target block.

[0222] <FEC block configuration>

[0223] FIG. 26 is a diagram showing an example of an FEC block that is planned to be used in advanced terrestrial digital broadcasting.

[0224] The FEC target block is composed of an FEC block header and a main signal as a payload. For example, the main signal is data obtained by dividing a TLV stream.

[0225] In FEC processing (error correction coding), BCH coding is performed on the FEC target block (information bits). The BCH code obtained by BCH coding is composed of the FEC target block as information bits and parity bits of the BCH code. In FEC processing, LDPC coding is also performed on the BCH code. The LDPC code obtained by LDPC coding is the FEC block, and is composed of the BCH code as information bits and parity bits of the LDPC code. It can also be said that the FEC block is composed of the FEC target block as information bits, the parity bits of the BCH code, and the parity bits of the LDPC code.

[0226] In advanced terrestrial digital broadcasting, LDPC codes are defined as LDPC codes with a code length of 69,120 bits and LDPC codes with a code length of 17,280 bits. Fig. 26A shows an FEC block encoded with an LDPC code with a code length of 69,120 bits. Fig. 26B shows an FEC block encoded with an LDPC code with a code length of 17,280 bits. The LDPC code with a code length of 69,120 bits is also called a normal code, and the LDPC code with a code length of 17,280 bits is also called a short code.

[0227] FIG. 27 is a diagram showing the structure of a normal code.

[0228] In FIG. 27, normal codes with coding rates of 2 / 16 to 14 / 16 are shown.

[0229] The FEC target block, i.e., the FEC block header and the main signal, are used as information bits of the BCH code to perform BCH coding, and parity bits of the BCH code are generated. LDPC coding is performed using the information bits and parity bits of the BCH code as information bits of the LDPC code to generate parity bits of the LDPC code.

[0230] As shown in FIG. 27, the FEC block header is fixed to 16 bits regardless of the coding rate of the normal code.

[0231] FIG. 28 is a diagram showing an example of the configuration of an FEC target block when CB is performed.

[0232] When CB is not performed, the FEC target block is made up of an FEC block header fixed to 16 bits and the main signal as the payload, as described with reference to FIGS.

[0233] When CB is performed, the FEC target block can be composed of an FEC block header fixed to 16 bits, a 10-bit FEC block index idx (index) of the FEC target block as a payload, and the main signal. That is, when CB is performed, the FEC target block can be composed of an FEC block header, an FEC block index idx arranged at the beginning of the payload, and the main signal arranged in the subsequent payload.

[0234] As described above, when the FEC block index idx of the FEC target block is included in the FEC target block, the arrangement order of the FEC target block in the allocation unit FEC target block group can be identified from the FEC target block. Therefore, the CB control information aux_cb_configuration() (FIG. 22) can be configured without providing the FEC_Block_index and cb_FEC_Block_index.

[0235] FIG. 29 is a diagram illustrating an example of the processing of the combining unit 102 and the demodulation unit 111 in FIG. 19 when the FEC block index idx is included in the FEC target block (the payload) instead of the CB control information.

[0236] In Figure 29, as in the case of Figure 20, the OFDM frame generation unit 62 (Figure 16) of the transmitting device 10 generates an OFDM frame in which FEC target blocks for each of channels CH0 and CH1 shown in C of Figure 17 are arranged.

[0237] In this case, the OFDM frames included in the transmission signals of channels CH0 and CH1 demodulated by the OFDM demodulation unit 121 (FIG. 19) include FEC target blocks similar to those described with reference to C in FIG. 17 and FIG. 20.

[0238] Therefore, the FEC target block is output from the inverse BICM unit 122 (FIG. 19) to the buffer 131, and written into the buffer 131 (CH0 buffer, CH1 buffer), in the same manner as described with reference to FIG.

[0239] That is, FEC target blocks 133, 134, 135 of the previous allocation unit FEC target block group of channel CH0 are written in sequence into the CH0 buffer, and FEC target blocks 0, 2, 3, ... of the allocation unit FEC target block group of interest are written in sequence into the CH0 buffer.On the other hand, FEC target blocks 1, 5, ... of the allocation unit FEC target block group of interest of channel CH1 are written in the CH1 buffer.

[0240] The reconstruction unit 132 does not read (discards) the FEC target blocks written to the CH0 buffer while it has not acquired the FEC target blocks of the FEC target block group of the allocation unit being focused on in channel CH1, that is, until the inverse BICM unit 122 starts outputting the FEC target blocks of the FEC target block group of the allocation unit being focused on in channel CH1 (step S61).

[0241] Therefore, by the time FEC target block 1 of the FEC target block group of the allocation unit of interest for channel CH1 is acquired, FEC target blocks 133 and 134 of the previous allocation unit FEC target block group that were written to the CH0 buffer are not read out and are consequently discarded.

[0242] When FEC target block 1 of the FEC target block group of allocation units of interest for channel CH1 is acquired, the reconstructor 132 starts reading out FEC target blocks from the buffer 131 (step S62). That is, when one or more FEC target blocks for each of channels CH0 and CH1 are acquired, the reconstructor 132 starts reading out FEC target blocks from the buffer 131.

[0243] The reconstruction unit 132 reads out the FEC target block of channel CH0 and the FEC target block of channel CH1 written in the CH0 buffer and the CH1 buffer, respectively, whichever FEC target block has the smaller FEC block index idx located immediately after the FEC block header (step S63).

[0244] In Figure 29, at the start of reading the FEC target blocks, FEC target block 135 of the previous allocation unit FEC target block group of channel CH0 is written in the CH0 buffer, and FEC target block 1 of the allocation unit FEC target block group of interest of channel CH1 is written in the CH1 buffer.

[0245] Between the FEC target block of the previous allocation unit FEC target block group and the FEC target block of the current allocation unit FEC target block group, the FEC block index of the FEC target block of the previous allocation unit FEC target block group is treated as being smaller than the FEC block index of the FEC target block of the current allocation unit FEC target block group. Therefore, between the FEC target block 135 of the previous allocation unit FEC target block group of channel CH0 written to the CH0 buffer and the FEC target block 1 of the current allocation unit FEC target block group of channel CH1 written to the CH1 buffer, the FEC target block 135 of the previous allocation unit FEC target block group of channel CH0 has a smaller FEC block index, so that FEC target block 135 is read.

[0246] Thereafter, the reconstruction unit 132 repeatedly reads out the FEC target block of channel CH0 and the FEC target block of channel CH1 written in the CH0 buffer and the CH1 buffer, respectively, whose FEC block index idx located immediately after the FEC block header is the next value after the FEC block index of the FEC target block read immediately before (step S64).

[0247] Therefore, after the FEC block 135 of the FEC block group of the previous allocation unit of channel CH0 is read, FEC blocks 0, 1, 2, 3, . . . of the FEC block group of the current allocation unit are read in order.

[0248] The timing of writing and reading the FEC target blocks of the FEC target block group of allocation units of interest to the CH0 buffer and CH1 buffer is the same as in the case of Fig. 20. Therefore, in the case of Fig. 29, as in the case of Fig. 20, the capacity of the buffer 131 (CH0 buffer and CH1 buffer) provided in the receiving device 20 can be reduced.

[0249] <Modification>

[0250] Although the present technology has been described above assuming a broadcasting system based on ISDB-T as a broadcasting system for terrestrial digital television broadcasting, the present technology can also be applied to cases where other broadcasting systems are assumed. For example, the present technology can be applied to other broadcasting systems such as ATSC (Advanced Television Systems Committee). Furthermore, the present technology is not limited to terrestrial broadcasting (terrestrial broadcasting), but can also be applied to broadcasting systems such as broadcasting satellites (BS), communications satellites, and cable broadcasting (CATV: Common Antenna Television).

[0251] In the above description, the receiving device 20 has been described as a fixed receiver such as a television set, but the fixed receiver may also be an electronic device such as a set-top box (STB), a recorder, a game console, a personal computer (PC), etc. Furthermore, the receiving device 20 is not limited to a fixed receiver, and may also be an electronic device such as a mobile receiver such as a smartphone, a mobile phone, or a tablet computer, an in-vehicle device mounted in a vehicle such as an in-vehicle television, or a wearable computer such as a head-mounted display (HMD).

[0252] In addition, in a transmission system to which the present technology is applied, a communication server having various functions connected to a communication line such as the Internet may be provided, so that a receiving device 20 having communication functions can access the communication server via the communication line to perform two-way communication, and receive and process various data such as content and applications.

[0253] <Description of a computer to which this technology is applied>

[0254] Next, the above-described series of processes can be performed by hardware or software. When the series of processes is performed by software, the programs that make up the software are installed on a general-purpose computer or the like.

[0255] FIG. 30 is a block diagram showing an example of the configuration of an embodiment of a computer in which a program for executing the above-described series of processes is installed.

[0256] The program can be recorded in advance on the hard disk 905 or ROM 903 as a recording medium built into the computer.

[0257] Alternatively, the program can be stored (recorded) on a removable recording medium 911 driven by the drive 909. Such a removable recording medium 911 can be provided as a so-called package software. Here, examples of the removable recording medium 911 include a flexible disk, a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto Optical) disk, a DVD (Digital Versatile Disc), a magnetic disk, and a semiconductor memory.

[0258] The program can be installed into the computer from the removable recording medium 911 as described above, or can be downloaded to the computer via a communication network or a broadcasting network and installed on the built-in hard disk 905. That is, the program can be transferred to the computer wirelessly from a download site via an artificial satellite for digital satellite broadcasting, or transferred to the computer via a wired network such as a LAN (Local Area Network) or the Internet.

[0259] The computer includes a CPU (Central Processing Unit) 902 , to which an input / output interface 910 is connected via a bus 901 .

[0260] When a user inputs a command via an input / output interface 910 by operating an input unit 907, the CPU 902 executes a program stored in a read-only memory (ROM) 903 in accordance with the command. Alternatively, the CPU 902 loads a program stored on a hard disk 905 into a random access memory (RAM) 904 and executes the program.

[0261] As a result, the CPU 902 performs processing according to the flowchart described above or processing performed by the configuration of the block diagram described above. Then, the CPU 902 outputs the processing results from the output unit 906 via the input / output interface 910, or transmits them from the communication unit 908, or further records them on the hard disk 905, as necessary.

[0262] The input unit 907 is made up of a keyboard, a mouse, a microphone, etc. The output unit 906 is made up of an LCD (Liquid Crystal Display), a speaker, etc.

[0263] In this specification, the processing performed by a computer according to a program does not necessarily have to be performed in chronological order according to the order described in the flowchart. In other words, the processing performed by a computer according to a program also includes processing that is executed in parallel or individually (for example, parallel processing or object-based processing).

[0264] The program may be processed by a single computer (processor), or may be distributed among multiple computers. Furthermore, the program may be transferred to a remote computer for execution.

[0265] Furthermore, in this specification, a system refers to a collection of multiple components (devices, modules (components), etc.), regardless of whether all of the components are contained in the same housing. Therefore, multiple devices housed in separate housings and connected via a network, and a single device housed in a single housing with multiple modules, are both systems.

[0266] It should be noted that the embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible within the scope of the present technology.

[0267] For example, the present technology can be configured as a cloud computing system in which a single function is shared and processed collaboratively by a plurality of devices via a network.

[0268] Furthermore, each step described in the above flowchart can be executed by one device, or can be shared and executed by a plurality of devices.

[0269] Furthermore, when one step includes multiple processes, the multiple processes included in that one step can be executed by one device or can be shared and executed by multiple devices.

[0270] Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0271] The present technology can have the following configurations.

[0272] <1> A transmitting device comprising: an allocating unit that allocates divided data, obtained by dividing target data to be transmitted via channel bonding using a plurality of channels, to one of the plurality of channels based on a CB transmission capacity, which is the transmission capacity of each of the plurality of channels used for the channel bonding; and a transmitting unit that transmits the divided data on the channel to which the divided data is allocated. <2> The transmitting device described in <1>, wherein the allocating unit allocates the divided data to channels so that there is no difference in cumulative transmission time required for transmitting the divided data on each of the plurality of channels. <3> The transmitting device described in <2>, wherein the allocating unit allocates the divided data to one of two channels having a smaller count value of the cumulative transmission time, and adds a value corresponding to the CB transmission capacity of the other channel to the count value of the channel to which the divided data is allocated, thereby allocating the divided data to each of the two channels. <4> The transmitting device described in any one of <1> to <3>, further comprising a delay unit that delays transmission of the divided data allocated to a predetermined channel of the plurality of channels by a predetermined number of the divided data. <5> The transmitting device according to <4>, wherein the delay unit delays transmission of the divided data assigned to one of two channels having the larger CB transmission capacity by an integer value of the divided data based on a value obtained by dividing the larger of the CB transmission capacities of the two channels by the smaller of the CB transmission capacities of the two channels. <6> The transmitting device according to any one of <1> to <5>, wherein the physical layer frame transmitted on each of the multiple channels includes, as physical layer data, channel bonding control information related to the channel bonding, and the channel bonding control information includes an index indicating an order of the divided data included in the physical layer frame including the channel bonding control information. <7> The transmitting device according to <6>, wherein the channel bonding control information includes an index indicating an order of the first of the divided data whose head is included in the physical layer frame including the channel bonding control information.<8> The transmitting device according to <6> or <7>, wherein the channel bonding control information includes information on a hierarchical layer used for the channel bonding of a channel on which the physical layer frame including the channel bonding control information is transmitted. <9> The transmitting device according to any of <6> to <8>, wherein the channel bonding control information includes information on a sub-hierarchical layer used for the channel bonding of a channel on which the physical layer frame including the channel bonding control information is transmitted. <10> The transmitting device according to any of <1> to <9>, wherein the divided data is an FEC target block that is a target of FEC processing. <11> A transmitting method comprising: allocating divided data obtained by dividing target data to be transmitted by channel bonding using a plurality of channels to one of the plurality of channels based on CB transmission capacity, which is the transmission capacity of each of the plurality of channels used for the channel bonding; and transmitting the divided data on the channel to which the divided data is allocated. <12> A receiving device comprising: a receiving unit that receives signals of multiple channels transmitted by a transmission method including: allocating divided data, obtained by dividing target data to be transmitted by channel bonding using multiple channels, to one of the multiple channels based on a CB transmission capacity of each of the multiple channels, the divided data being the transmission capacity used for the channel bonding, and transmitting the divided data on the channel to which the divided data is assigned; and a reconstructing unit that reconstructs the divided data included in the signals of the multiple channels into their original order, wherein a physical layer frame transmitted on each of the multiple channels includes, as physical layer data, channel bonding control information related to the channel bonding, and the reconstructing unit specifies the allocation of the divided data to each of the multiple channels based on the channel bonding control information. <13> The receiving device described in <12>, in which the divided data is assigned to channels such that there is no difference in cumulative transmission time required for transmitting the divided data on each of the multiple channels (FIG. 9).<14> The receiving device according to <12> or <13>, further comprising a buffer that stores the divided data, wherein the reconstruction unit reads out the divided data stored in the buffer in their original order. <15> The receiving device according to any one of <12> to <14>, wherein the channel bonding control information includes an index indicating an order of the divided data included in the physical layer frame including the channel bonding control information. <16> The receiving device according to <15>, wherein the channel bonding control information includes an index indicating an order of the first divided data whose head is included in the physical layer frame including the channel bonding control information. <17> The receiving device according to any one of <12> to <16>, wherein the channel bonding control information includes information of a layer used for the channel bonding of a channel through which the physical layer frame including the channel bonding control information is transmitted. <18> The receiving device according to any one of <12> to <17>, wherein the channel bonding control information includes information of a sub-layer used for the channel bonding of a channel through which the physical layer frame including the channel bonding control information is transmitted. <19> The receiving device according to any one of <12> to <18>, wherein the divided data is a forward error correction (FEC) target block that is a target of FEC processing.<20> A receiving method comprising: receiving signals of the plurality of channels transmitted by a transmitting method including: dividing target data to be transmitted by channel bonding using a plurality of channels, the divided data being obtained by dividing the target data to be transmitted by channel bonding using a plurality of channels, and assigning the divided data to one of the plurality of channels based on a CB transmission capacity of each of the plurality of channels, which is the transmission capacity used for the channel bonding for the channel bonding; and transmitting the divided data on the channel to which the divided data is assigned; and reconstructing the divided data included in the signals of the plurality of channels into their original order, wherein a physical layer frame transmitted on each of the plurality of channels includes, as physical layer data, channel bonding control information related to the channel bonding, and in the reconstruction of the divided data, assignment of the divided data to each of the plurality of channels is specified based on the channel bonding control information.

[0273] 10 transmitting device, 20 receiving device, 31 encoding unit, 32 division unit, 33 transmitting unit, 34 control information generating unit, 41-1, 41-2 modulation unit, 51 conversion unit, 52 allocation unit, 61-1, 61-2 BICM unit, 62-1, 62-2 OFDM frame generating unit, 63-1, 63-2 RF conversion unit, 71 delay unit, 101 receiving unit, 102 synthesis unit, 103 decoding unit, 104 control unit, 111-1, 111-2 demodulation unit, 121-1, 121-2 OFDM demodulation unit, 122-1, 122-2 inverse BICM unit, 131-1, 131-2 buffer, 132 reconstruction unit, 133 conversion unit, 901 bus, 902 CPU, 903 ROM, 904 RAM, 905 hard disk, 906 output unit, 907 input unit, 908 communication unit, 909 drive, 910 input / output interface, 911 removable recording medium

Claims

1. A transmitting device comprising: an allocation unit that allocates divided data obtained by dividing target data to be transmitted using channel bonding using multiple channels to one of the multiple channels based on the CB transmission capacity, which is the transmission capacity used for the channel bonding of each of the multiple channels; and a transmitting unit that transmits the divided data on the channel to which the divided data is allocated.

2. The transmitting device according to claim 1, wherein said allocating section allocates said divided data to said channels so that there is no difference in cumulative transmission time required for transmitting said divided data among said plurality of channels.

3. The transmitting device according to claim 2, wherein the allocation unit allocates the divided data to one of the two channels having a smaller count value of the cumulative transmission time, and adds a value corresponding to the CB transmission capacity of the other channel to the count value of the channel to which the divided data is allocated, thereby allocating the divided data to each of the two channels.

4. The transmitting device according to claim 1, further comprising a delay unit that delays transmission of the divided data assigned to a predetermined channel among the plurality of channels by an amount equivalent to a predetermined number of the divided data.

5. The transmitting device according to claim 4, wherein the delay unit delays transmission of the divided data assigned to one of the two channels having the larger CB transmission capacity by an integer value of the divided data based on a quotient obtained by dividing the larger of the CB transmission capacities of the two channels by the smaller of the CB transmission capacities of the two channels.

6. The transmitting device according to claim 1, wherein the physical layer frame transmitted on each of the plurality of channels includes, as physical layer data, channel bonding control information relating to the channel bonding, and the channel bonding control information includes an index indicating the order of the divided data included in the physical layer frame that includes the channel bonding control information.

7. The transmitting device according to claim 6, wherein the channel bonding control information includes an index indicating the order of the first divided data whose head is included in the physical layer frame including the channel bonding control information.

8. The transmitting device according to claim 6, wherein the channel bonding control information includes information on a layer used for the channel bonding of a channel on which the physical layer frame including the channel bonding control information is transmitted.

9. The transmitting device according to claim 6, wherein the channel bonding control information includes information on a sub-layer used for the channel bonding of a channel on which the physical layer frame including the channel bonding control information is transmitted.

10. The transmitting device according to claim 1, wherein the divided data is a forward error correction (FEC) target block that is to be subjected to FEC processing.

11. A transmission method comprising: allocating divided data obtained by dividing target data to be transmitted using channel bonding using multiple channels to one of the multiple channels based on the CB transmission capacity, which is the transmission capacity used for the channel bonding, of each of the multiple channels; and transmitting the divided data on the channel to which the divided data is allocated.

12. A receiving device comprising: a receiving unit that receives signals of multiple channels transmitted by a transmission method including: dividing target data to be transmitted by channel bonding using multiple channels, and allocating the divided data to one of the multiple channels based on CB transmission capacity, which is the transmission capacity of each of the multiple channels used for the channel bonding; and transmitting the divided data on the channel to which the divided data is assigned; and a reconstructing unit that reconstructs the divided data included in the signals of the multiple channels into their original order, wherein physical layer frames transmitted on each of the multiple channels include channel bonding control information related to the channel bonding as physical layer data, and the reconstructing unit identifies the allocation of the divided data to each of the multiple channels based on the channel bonding control information.

13. The receiving device according to claim 12, wherein the divided data are assigned to the channels so that there is no difference in cumulative transmission time required for transmitting the divided data on each of the plurality of channels (FIG. 9).

14. The receiving device according to claim 12, further comprising a buffer for storing the divided data, wherein the reconstruction unit reads out the divided data stored in the buffer in the original order.

15. The receiving device according to claim 12, wherein the channel bonding control information includes an index indicating the order of the divided data included in the physical layer frame that includes the channel bonding control information.

16. The receiving device according to claim 12, wherein the channel bonding control information includes an index indicating the order of the first divided data whose head is included in the physical layer frame including the channel bonding control information.

17. The receiving device according to claim 12, wherein the channel bonding control information includes information on a layer used for the channel bonding of a channel on which the physical layer frame including the channel bonding control information is transmitted.

18. The receiving device according to claim 12, wherein the channel bonding control information includes information on a sub-layer used for the channel bonding of a channel on which the physical layer frame including the channel bonding control information is transmitted.

19. The receiving device according to claim 12, wherein the divided data is a forward error correction (FEC) target block that is to be subjected to FEC processing.

20. A receiving method comprising: receiving signals of multiple channels transmitted by a transmitting method comprising: dividing target data to be transmitted by channel bonding using multiple channels, assigning the divided data to one of the multiple channels based on the CB transmission capacity of each of the multiple channels, which is the transmission capacity used for the channel bonding, and transmitting the divided data on the channel to which the divided data is assigned; and reconstructing the divided data included in the signals of the multiple channels into their original order, wherein physical layer frames transmitted on each of the multiple channels include channel bonding control information related to the channel bonding as physical layer data, and in reconstructing the divided data, the allocation of the divided data to each of the multiple channels is specified based on the channel bonding control information.

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