Transmitter, receiver, and program

Abstract

To improve frequency utilization efficiency in transmitting a frame having a TMCC section in addition to a subframe section.SOLUTION: A transmitter is used in a broadcast transmission system which transmits an OFDM frame in which a TMCC section and a subframe section following the TMCC section are arranged in a time-division manner. The transmitter includes time interleaving means which performs time interleaving to disperse modulation symbols to be transmitted by data carriers in a time direction. The time interleaving means has a symbol buffer for buffering the modulation symbols, for each data carrier. In the case where residual carriers having no TMCC signal assigned thereto in the TMCC section are used as data carriers for allocating data in the subframe section, the time interleaving means determines a length of the symbol buffer on the basis of the number of data carrier symbols in the subframe.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present invention relates to a transmitting device, a receiving device, and a program for use in a broadcast transmission system. [Background technology]

[0002] In order to improve the quality and functionality of terrestrial digital broadcasting, studies are underway on a next-generation terrestrial broadcasting transmission method (hereinafter also referred to as the "terrestrial broadcasting advanced method") that inherits the features of the current ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) method defined in Non-Patent Document 1.

[0003] ISDB-T provides mobile reception and fixed reception services simultaneously on one channel through hierarchical transmission. It is expected that the advanced terrestrial broadcasting system will also transmit multiple services and contents on one channel through hierarchical transmission.

[0004] Here, ISDB-T allows for hierarchical transmission based on frequency division multiplexing. Specifically, hierarchical transmission is achieved by dividing the transmission band of one channel into 13 segments and allocating each segment for mobile reception and fixed reception. By setting the mobile reception hierarchical layer to the central segment, narrowband reception is possible, which has the advantage of allowing receiving devices to receive with less power consumption.

[0005] On the other hand, European and American broadcasting standards DVB-T2 and ATSC (Advanced Television Systems Committee) 3.0 allow hierarchical transmission based on time division multiplexing. Specifically, a hierarchy can be divided into OFDM (Orthogonal Frequency Division Multiplexing) symbol units to provide a plurality of subframes, for example, subframes for mobile reception and subframes for fixed reception (see, for example, Non-Patent Document 2). In the case of time division multiplexing, the FFT (Fast Fourier Transform) size can be changed for each subframe, making it possible to set an optimal FFT size according to the service.

[0006] Furthermore, in broadcast transmission systems, in addition to main line signals such as content, control information such as transmission parameters must also be multiplexed and transmitted. In ISDB-T, which is based on frequency division multiplexing, specific OFDM subcarriers are assigned for transmitting control information, and control information is transmitted in units of frames (also called "OFDM frames"). In the case of ISDB-T, this corresponds to the TMCC (Transmission and Multiplexing Configuration Control) signal. Meanwhile, in DVB-T2 and ATSC3.0, which are based on time division multiplexing, control information is transmitted in the first few symbols of the frame. In ATSC3.0, this corresponds to the bootstrap and preamble signals.

[0007] Conventional broadcasting systems are based on either frequency division multiplexing or time division multiplexing as a multiplexing method, but frequency division multiplexing and time division multiplexing each have different advantages. Also, the optimal multiplexing method differs depending on the service requirements. However, in existing broadcast transmission systems, it is necessary to select either frequency division multiplexing or time division multiplexing, and there is a problem that the optimal multiplexing method cannot be applied depending on the service requirements.

[0008] In view of such problems, Patent Document 1 describes a technology that can apply an optimal multiplexing method according to the required conditions of a service in an advanced terrestrial broadcasting system. Specifically, the technology described in Patent Document 1 is compatible with both hierarchical transmission of frequency division multiplexing and time division multiplexing, and transmits a synchronization signal (preamble signal) and TMCC (transmission control information) at the beginning of a frame.

[0009] In addition, in the technology described in Patent Document 1, the transmitting device has a time interleaving means that performs time interleaving on data to be transmitted in a subframe section following a TMCC section. Note that time interleaving is a process of dispersing carrier symbols in the time direction in order to ensure resistance to time fluctuations in the propagation path. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2022-181709 A [Non-patent literature]

[0011] [Non-Patent Document 1] ARIB STD-B31 Association of Radio Industries and Businesses [Non-Patent Document 2] ATSC 3.0 Standard:Physical Layer Protocol A / 322:2020 P245-249, https: / / www.atsc.org / wp-content / uploads / 2020 / 01 / A322-2020-Physical-Layer-Protocol.pdf Summary of the Invention [Problem to be solved by the invention]

[0012] In the advanced terrestrial broadcasting system described in Patent Document 1, when there are remaining carriers (remaining subcarriers) to which TMCC signals are not assigned in a TMCC section, there is a problem that the remaining carriers are not used for transmission, and frequency utilization efficiency may decrease.

[0013] Therefore, an object of the present invention is to provide a transmitting device, a receiving device, and a program capable of improving frequency utilization efficiency when transmitting a frame having a TMCC section in addition to a subframe section. [Means for solving the problem]

[0014] A transmitting device according to a first aspect is a transmitting device used in a broadcast transmission system that transmits an OFDM frame in which a TMCC section and a subframe section following the TMCC section are arranged in a time-division manner, and includes a time interleaving means that performs time interleaving to distribute modulation symbols transmitted by data carriers in the time direction. The time interleaving means has a symbol buffer for buffering the modulation symbols for each of the data carriers. When remaining carriers in the TMCC section to which a TMCC signal is not assigned are used as data carriers to which data of the subframe section is assigned, the time interleaving means determines the length of the symbol buffer based on the number of data carrier symbols in the subframe.

[0015] A receiving device according to a second aspect is a receiving device used in a broadcast transmission system that transmits OFDM frames in which TMCC sections and subframe sections following the TMCC sections are arranged in a time-division manner, and includes a time deinterleaving means that performs time deinterleaving, which is the inverse process of time interleaving that distributes modulation symbols transmitted by data carriers in the time direction. The time deinterleaving means has a symbol buffer for buffering the modulation symbols for each of the data carriers. When remaining carriers in the TMCC section to which no TMCC signal is assigned are used as data carriers to which data of the subframe section is assigned, the time deinterleaving means determines the length of the symbol buffer based on the number of data carrier symbols in the subframe.

[0016] A program according to the third aspect causes a computer to function as the transmitting device according to the first aspect or the receiving device according to the second aspect. Effect of the Invention

[0017] According to the present invention, it is possible to provide a transmitting device, a receiving device, and a program capable of improving frequency utilization efficiency when transmitting a frame having a TMCC section in addition to a subframe section. [Brief description of the drawings]

[0018] [Figure 1] 1 is a diagram showing a broadcast transmission system according to an embodiment. [Diagram 2] 2 is a diagram showing an example of a frame configuration used in the broadcast transmission system according to the embodiment. FIG. [Diagram 3] 1 is a diagram for explaining interleaving between subframes that can be applied in a broadcast transmission system according to an embodiment. FIG. [Figure 4] FIG. 10 is a diagram for explaining a TMCC section according to the embodiment, showing a case where there is no partial reception band. [Diagram 5]FIG. 10 is a diagram for explaining a TMCC section according to the embodiment, showing a case where a partial reception band is present; [Figure 6] FIG. 11 is a diagram illustrating an example of transmission parameters of a subframe section according to the embodiment. [Figure 7] FIG. 2 is a diagram showing an example of an OFDM segment configuration in a subframe period according to the embodiment. [Figure 8] FIG. 2 is a diagram illustrating a frame configuration unit in a transmission device according to an embodiment. [Figure 9] FIG. 2 is a diagram illustrating an OFDM modulation unit in each subframe configuration unit according to the embodiment. [Figure 10] 10A to 10C are diagrams for explaining a time IL part and a frequency IL part according to an embodiment. [Figure 11] FIG. 2 is a diagram illustrating a configuration of a time interleaving unit according to the embodiment. [Figure 12] 11 is a diagram showing the configuration of a time IL portion within a data segment according to the embodiment; FIG. [Figure 13] 11 is a diagram for explaining the operation of a time IL section within a data segment according to the embodiment. FIG. [Figure 14] FIG. 1 is a diagram illustrating an example of a receiving device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] (1) Overview of the embodiment In the embodiment, in the advanced terrestrial broadcasting system as described in Patent Document 1, when the remaining carrier (remaining subcarrier) to which the TMCC signal is not assigned is in the TMCC section, the data of the subframe section is assigned to the remaining carrier and transmitted. That is, the remaining carrier is used as a data carrier to transmit data in the TMCC section in addition to the subframe section. This allows the resources of the TMCC section to be effectively utilized, thereby improving frequency utilization efficiency.

[0020] Here, when transmitting data in the TMCC section in addition to the subframe section, the technology on how to apply time interleaving to the data has not yet been established.

[0021] A transmitting device according to a first feature is a transmitting device used in a broadcast transmission system that transmits an OFDM frame in which a TMCC section and a subframe section following the TMCC section are arranged in a time-division manner, and is equipped with a time interleaving means that performs time interleaving to distribute modulation symbols transmitted on data carriers in the time direction, the time interleaving means having a symbol buffer for buffering the modulation symbols for each data carrier, and when remaining carriers in the TMCC section to which a TMCC signal is not assigned are used as data carriers to which data of the subframe section is assigned, the time interleaving means determines a length of the symbol buffer based on the number of data carrier symbols in the subframe and the number of data carrier symbols in the TMCC section.

[0022] According to such a feature of the transmitting device, even when data is transmitted in the TMCC section in addition to the subframe section, the length of the symbol buffer can be appropriately determined by taking into consideration the number of data carrier symbols in the TMCC section. Therefore, even when data is transmitted in part of the TMCC section in addition to the subframe section, time interleaving can be applied to both the data in the subframe section and the data in the TMCC section.

[0023] A second feature of the transmitting device is, in the first feature, when a boundary pilot symbol is inserted in the subframe and inter-subframe interleaving is applied in which the subframe is divided and distributed in a time direction, the time interleaving means determines the number of data carrier symbols in the subframe based on a subframe division number in the inter-subframe interleaving.

[0024] According to the features of such a transmitting device, when a boundary pilot symbol is inserted into a subframe and inter-subframe interleaving is applied, the number of data carrier symbols in a subframe for determining the length of a symbol buffer can be appropriately determined, taking into account the number of subframe divisions in the inter-subframe interleaving.

[0025] A third feature of the present invention is a transmitting device according to the first or second feature, wherein the time interleaving means is configured to interleave the symbol buffer with a length q i of,

[0026]

number

[0027] The N k indicates the segment number in the hierarchy, and c indicates the number of data carriers in one segment, S indicates the number of data carrier symbols in the subframe, and S TMCC indicates the number of data carrier symbols in the TMCC section, I indicates the interleave length set in the layer, and N FFT denotes the FFT size,

[0028]

number

[0029] According to the features of the transmission device, even when data is transmitted in a part of the TMCC section in addition to the subframe section, the length q of the symbol buffer can be calculated by using the formula 1. i can be appropriately determined.

[0030] A fourth aspect of the present invention relates to a transmitting apparatus according to the third aspect, wherein when a boundary pilot symbol is inserted into the subframe and inter-subframe interleaving is applied in which the subframe is divided in a time direction and distributed, the time interleaving means sets the S to

[0031]

number

[0032] The S SUBFRAME indicates the number of symbols in the subframe specified by the TMCC information, and a indicates the number of data carriers of the boundary pilot symbol, and D indicates the number of subframe divisions in the inter-subframe interleaving.

[0033] A receiving device according to a fifth feature is a receiving device used in a broadcast transmission system that transmits an OFDM frame in which a TMCC section and a subframe section following the TMCC section are arranged in a time-division manner, and includes a time deinterleaving means that performs time deinterleaving, which is the inverse process of time interleaving that disperses modulation symbols transmitted by data carriers in the time direction, and the time deinterleaving means has a symbol buffer for buffering the modulation symbols for each data carrier, and when a remaining carrier in the TMCC section to which a TMCC signal is not assigned is used as a data carrier to which data of the subframe section is assigned, the time deinterleaving means determines a length of the symbol buffer based on the number of data carrier symbols in the subframe and the number of data carrier symbols in the TMCC section.

[0034] According to such a feature of the receiving device, even when data is transmitted in the TMCC section in addition to the subframe section, the length of the symbol buffer can be appropriately determined by taking into consideration the number of data carrier symbols in the TMCC section. Therefore, even when data is transmitted in part of the TMCC section in addition to the subframe section, time interleaving can be applied to both the data in the subframe section and the data in the TMCC section.

[0035] A program according to the sixth aspect is a program that causes a computer to function as the transmitting device according to the first aspect or the receiving device according to the fifth aspect.

[0036] (2) Broadcast transmission systems Next, a broadcast transmission system according to an embodiment will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0037] (2.1) Overview of the broadcast transmission system FIG. 1 is a diagram showing a broadcast transmission system 1 according to the present embodiment.

[0038] As shown in FIG. 1, the broadcast transmission system 1 is a system compatible with the terrestrial broadcasting advanced standard, and is a terrestrial digital television broadcast system that performs hierarchical transmission. In this embodiment, a plurality of hierarchical layers for transmitting data are used, and transmission parameters such as a carrier modulation method, an error correction code coding rate, and a time interleaving length can be variably set for each layer. The broadcast transmission system 1 includes a transmitting device 100 and a receiving device 200. The transmitting device 100 transmits a broadcast signal to the receiving device 200 via a broadcast transmission path 500. The receiving device 200 may be a fixed receiver that performs fixed reception or a mobile receiver that performs mobile reception. The receiving device 200 may be a narrowband receiver that performs narrowband reception (partial reception).

[0039] In the current terrestrial digital television broadcasting system, ISDB-T (see Non-Patent Document 1), the modulation method is orthogonal frequency division multiplexing (OFDM), which has excellent resistance to multipath, and has a segment structure that enables partial reception. The advantage of the ISDB-T system is that it can simultaneously realize services for fixed reception and services for mobile reception on one channel, and this advantage is retained in the broadcast transmission system 1 according to this embodiment.

[0040] On the other hand, the requirements for fixed reception and mobile reception are significantly different, and therefore the optimal transmission parameters for each are also different. In order to accommodate such different requirements, the broadcast transmission system 1 according to this embodiment employs a multiple symbol length OFDM format that realizes hierarchical structure by using two or more types of effective symbol lengths and guard interval (GI) lengths within one transmission channel.

[0041] (2.2) Frame configuration example FIG. 2 is a diagram showing an example of a frame structure used in the broadcast transmission system 1 according to this embodiment.

[0042] As shown in Fig. 2, the broadcast transmission system 1 according to this embodiment allows various hierarchical transmissions, such as allocating subframes in which multiple hierarchical layers are frequency-division multiplexed to services for mobile reception, and time-division multiplexing subframes allocated to services for fixed reception with different FFT sizes. Furthermore, an extension section (extension subframe) can be provided at the end of the frame.

[0043] A frame is made up of, from the beginning to the end of the frame, a frame synchronization signal section, a TMCC section, a subframe section, and an extension section, in that order.

[0044] A frame can store multiple subframes with different configurations. A subframe is composed of a single or multiple layers with a segment structure. One subframe is composed of multiple symbols with the same symbol length. The transmission control information transmitted in the TMCC section has a variable length of information, and an extension section can be provided at the end of the frame. Specifically, by arranging a subframe section after a TMCC section that transmits a transmission control signal (also called a "TMCC signal"), the receiving device 200 can demodulate the signal in the following subframe section using the transmission control signal after receiving it. Furthermore, an extension section can be arranged after the subframe section, and can be used in the future for purposes that have not yet been determined.

[0045] The broadcast transmission system 1 according to this embodiment is capable of intermittent reception in which only specific subframes are selectively received, and also supports partial reception in which only a portion of the frequency band of a transmission signal is selectively received.

[0046] The frame synchronization signal section is placed at the beginning of a frame, and is a section for transmitting a signal for synchronous reproduction in receiving device 200. The frame synchronization signal section is a signal obtained by rotating five OFDM symbols obtained by performing an inverse fast Fourier transform (IFFT) on a signal consisting of a frame synchronization symbol in the time domain, and then adding a cyclic prefix and a cyclic postfix. When a partial reception band is present, the frame synchronization signal section may be configured by repeating five OFDM symbols twice to form a total of 10 symbols. In addition, the frame synchronization signal section transmits a control signal related to the transmission method, etc. of the subsequent TMCC section.

[0047] The frame synchronization signal placed in the frame synchronization signal section is used by the receiving device 200 to detect the presence of a transmission signal from the transmitting device 100, perform synchronous reproduction, and receive the signal in the TMCC section. Since the frame synchronization signal needs to transmit several tens of bits of information, the frame synchronization signal is resistant to noise, multipath, and frequency offset. This enables a variety of hierarchical transmissions and ensures future expandability.

[0048] The TMCC section is a section for transmitting variable-length transmission control information (also called "TMCC information") related to the frame configuration and subframe sections. In order to realize diverse hierarchical transmission, the TMCC section is placed after the frame synchronization signal section at the beginning of the frame, independently of data transmission. Considering future expandability, it also supports the transmission of variable-length transmission control information.

[0049] For example, the TMCC information includes Frame_configuration, which includes information such as number_of_subframes, inter_subframe_interleave, and pilot_phase.

[0050] The TMCC information also includes Subframe_configuration for the number of subframes. The Subframe_configuration includes information such as partial_reception_flag, fft_size (FFT size), gi_fraction (GI ratio), number_of_symbols (number of symbols), and number_of_layers (number of layers).

[0051] Furthermore, the TMCC information includes Layer_configuration for the number of layers. Layer_configuration includes information such as number_of_sublayers (number of sublayers), sp_pattern (SP pattern), sp_coding (SP coding), start_boundary_pilot (start boundary pilot), end_boundary_pilot (end boundary pilot), sp_level (SP level), and time_interleave (time interleave). Here, time_interleave (time interleave) is a 3-bit field and indicates the time interleave length according to Table 1.

[0052] [Table 1]

[0053] The subframe section is the section in which video, audio, and other data is transmitted. One frame contains one or more subframes, which are called subframe 1, subframe 2, etc. Each subframe is composed of one or more symbols, and can be hierarchically organized using a segment structure. The maximum number of subframes is 8. For example, if multiple operators provide services within one channel, each operator can use their own subframe.

[0054] Each subframe is composed of one or more layers, and has a segment structure. The layers are called layer A, layer B, layer C, layer H, in order of decreasing transmission robustness. For each layer, the optimal transmission parameters can be set according to the assumed radio wave propagation environment. In the example of Figure 2, layer 1 for mobile reception is a layer with ultra-high robustness, and corresponds to layer A, for example. Layer 2 for mobile reception is a layer with high robustness, and corresponds to layer B, for example. The layer for fixed reception corresponds to layer C, for example.

[0055] When partial reception bandwidth is available, all segments in hierarchical A are stored within the central 9 segments. The bandwidth of these central 9 segments is called the partial reception bandwidth, and the 13 segments above and below it, totaling 26 segments, are called non-partial reception bandwidths. In this case, the maximum number of segments in a hierarchical layer that is subject to partial reception is 9. Note that when partial reception bandwidth is not available, the entire bandwidth is a non-partial reception bandwidth. The maximum number of hierarchical layers is 8.

[0056] (2.3) Inter-subframe interleaving 3 is a diagram for explaining inter-subframe interleaving applicable to the broadcast transmission system 1 according to this embodiment. In the broadcast transmission system 1, in order to ensure resistance to time fluctuations in the transmission path when time allocation to subframes for mobile reception is small, inter-subframe interleaving that distributes and allocates subframe sections in the time direction may be set by the TMCC signal.

[0057] 3(a) shows the case where inter-subframe interleaving is off (number of divisions = 1). When inter-subframe interleaving is off (number of divisions = 1), subframes are stored in the frame in the order of their subframe numbers.

[0058] FIG. 3(b) shows the case where inter-subframe interleaving is on (number of divisions = 2). When inter-subframe interleaving is on (number of divisions ≧ 2), each subframe section is divided into the number indicated by the number of divisions, and then stored in the frame in the order of subframe numbers. The on / off state of inter-subframe interleaving is indicated by a parameter (inter_subframe_interleave) related to the number of divisions in the TMCC information, and the value is set to '00' when it is off, and a value other than '00' when it is on, and inter-subframe interleaving is applied. For example, when the number of symbols in subframe 1 is 14, the number of symbols in subframe 2 is 48, and the number of divisions is 3, 4 symbols are placed in subframe 1 and 16 symbols are placed in subframe 2 after the frame synchronization signal section and the TMCC section. This is repeated for the number of divisions. When the number of symbols is not divisible by the number of divisions, the division result is truncated to an integer value from the beginning of the subframe, and the number of symbols obtained by adding 1 is assigned to the divided symbol group as necessary. That is, in the above example, all 14 symbols in subframe 1 are divided into 5, 5, and 4 symbols, and all 48 symbols in subframe 2 are divided into 16, 16, and 16 symbols, which are transmitted alternately.

[0059] (2.4) TMCC Section Figures 4 and 5 are diagrams for explaining the TMCC section according to this embodiment. Figure 4 shows the case without a partial reception band, and Figure 5 shows the TMCC section with a partial reception band. In Figures 4 and 5, "1A" represents layer A of subframe 1, and "1B" represents layer B of subframe 1.

[0060] The TMCC section is a section for transmitting a transmission control signal. The transmitting device 100 performs padding on the TMCC information to be transmitted in order to adjust the information bit length of the error-correcting outer code, and then performs energy dispersion processing. Furthermore, the transmitting device 100 performs BCH coding as the error-correcting outer code and LDPC coding as the inner code. Next, iterative coding is performed to repeatedly transmit the code. This is called a TMCC signal. Next, the transmitting device 100 performs carrier modulation on the TMCC signal, generates a TMCC symbol, and assigns the same TMCC symbol to both the partial reception band and the non-partial reception band. However, when there is no partial reception band, the entire transmission band is a non-partial reception band, so that the TMCC symbol is assigned only to the non-partial reception band, and a TMCC data segment for the non-partial reception band of 35 segments is configured. On the other hand, when there is a partial reception band, a TMCC data segment for the partial reception band of 9 segments and a TMCC data segment for the non-partial reception band of 26 segments is configured.

[0061] When a partial reception band is present, since a narrowband receiver needs to receive TMCC information using only partial reception band signals, the TMCC information is transmitted using only carriers in the partial reception band so that it is completed within the partial reception band.On the other hand, in a wideband receiver, the TMCC information is transmitted using carriers only in the non-partial reception band in order to transmit the TMCC information with a smaller number of symbols by utilizing the non-partial reception band, which is wider than the partial reception band.

[0062] In particular, in the non-partial reception band, even after the repetitively coded codes are assigned to the carriers (subcarriers) in the TMCC section, many remaining carriers may remain. Therefore, in consideration of transmission efficiency, the remaining carriers in the TMCC section can be used for transmitting data in each of the partial reception band and the non-partial reception band from the higher layer of subframe 1. In other words, the remaining carriers in each TMCC data segment after the TMCC symbols are assigned can be used as data carriers for transmitting the main transmission symbol for the subsequent subframe section.

[0063] Whether or not the remaining carriers in the TMCC section are used as data carriers can be specified by a control signal transmitted in the frame synchronization signal. For example, the transmitting device 100 transmits tmcc_data_allocation (TMCC data allocation flag) indicating whether or not the remaining carriers in the TMCC section are used as data carriers in the second symbol of the frame synchronization signal.

[0064] When tmcc_data_allocation is '0', the transmitting device 100 repeatedly allocates LDPC codes to the range that can be allocated to the subcarriers if there are remaining subcarriers after allocating LDPC codes for the specified number of repetitions to the non-partial reception band when there is no partial reception band, or to the partial reception band and non-partial reception band when there is a partial reception band. On the other hand, when tmcc_data_allocation is '1', the transmitting device 100 allocates the remaining data carriers after allocating LDPC codes for the specified number of repetitions to the partial reception band and non-partial reception band in order from the upper layer of subframe 1, with the number of data carriers being the upper limit.

[0065] 4 and 5 show an example where tmcc_data_allocation is '1'. In the example without a partial reception band shown in Fig. 4, the transmitting device 100 assigns code #1 of repetition 1 from the low frequency side to the high frequency side in the first half symbol of the TMCC section, then assigns part of code #1 of repetition 2, turns back at one end of the high frequency side, and assigns the remainder of code #1 of repetition 2 in the second half symbol of the TMCC section. Of the remaining carriers to which no code is assigned in the second half symbol of the TMCC section, carriers adjacent to layer 1A of the subframe section are assigned as data carriers of layer 1A, and carriers adjacent to layer 1B of the subframe section are assigned as data carriers of layer 1B.

[0066] In the example without partial reception band shown in Fig. 5, the transmitting device 100 assigns repetition 1 code #1 from the low frequency side to the high frequency side in the first symbol of the TMCC section for the non-partial reception band, then assigns part of repetition 2 code #1, turns back at one end of the high frequency side, and assigns the remainder of repetition 2 code #1 in the second symbol of the TMCC section. In each symbol from the second onwards in the non-partial reception band of the TMCC section, the remaining carriers to which no code is assigned are assigned as data carriers of the 1B layer of the subframe section. In addition, the transmitting device 100 assigns repetition 1 code #1 to the first symbol and to the middle of the second symbol in the TMCC section for the partial reception band, and then assigns repetition 1 code #1 from the middle of the second symbol and to the middle of the third symbol and the fourth symbol. In the fourth symbol of the partial reception band of the TMCC section, among the remaining carriers to which no code is assigned, the carrier adjacent to layer 1A of the subframe section is assigned as a data carrier of layer 1A, and the carrier adjacent to layer 1B of the subframe section is assigned as a data carrier of layer 1B.

[0067] (2.5) Subframe Section FIG. 6 is a diagram showing an example of transmission parameters in a subframe section according to the present embodiment.

[0068] As shown in Figure 6, when a 6 MHz channel is divided into multiple segments, the number is 36, of which a maximum of 35 segments are used for signal transmission. This allows for more flexible band allocation to fixed and mobile reception. In addition, the pilot signal arrangement allows optimal arrangements to be selected for each of fixed and mobile reception. Furthermore, one segment can be divided into three sub-segments. By configuring a high-resistance layer that uses primary modulation parameters with high noise resistance and an ultra-high-resistance layer that applies primary modulation parameters with even higher noise resistance, it is possible to increase service availability, especially during mobile reception.

[0069] The FFT size is 8k (8,192 (2 13 ) points), but in this embodiment, the maximum is 32k (32,768 (2 15 ) points). Increasing the FFT size reduces the carrier frequency interval, which increases the effective symbol length and reduces the GI ratio when the GI length is constant, reducing the overhead caused by GI. Also, considering compatibility with current terrestrial digital television broadcasting, parameters are provided that make the GI length and time interleave length equivalent to those of current terrestrial digital television broadcasting.

[0070] The error correction code uses a concatenated code of LDPC (Low Density Parity Check) code and BCH (Bose-Chaudhuri-Hocquenghem) code. This significantly improves noise resistance. In addition, by making the signal point arrangement non-uniform (NUC: Non-Uniform Constellation), noise resistance in multi-level modulation is improved.

[0071] FIG. 7 is a diagram showing an example of an OFDM segment configuration in a subframe period according to this embodiment.

[0072] As shown in Figure 7, in a subframe section, an OFDM segment is configured using SP, BP, Lch, and data. Both SP and BP are pilot signals, with SP meaning scattered pilot and BP meaning boundary pilot. In the figure, "Dx" indicates the interval of SP in the carrier direction (frequency direction), and "Dy" indicates the interval of SP in the symbol direction (time direction).

[0073] Here, the symbols at the beginning and end of a subframe are called boundary symbols, a pilot signal that is a demodulation reference for a main symbol transmitted by synchronous modulation and placed only at the boundary symbols is called a boundary pilot (BP) signal, and a symbol generated from a BP signal to which a power dispersal signal is added is called a BP symbol. Inserting a boundary pilot at the symbol at the end of a subframe makes it easier to interpolate the symbol direction when performing transmission channel estimation in the receiving device 200.

[0074] (3) Transmitter Next, the transmitting device 100 according to the present embodiment will be described with reference to FIGS.

[0075] (3.1) Configuration of the Frame Composition Unit of the Transmitter 8 is a diagram showing a frame configuration unit in the transmission device 100 according to this embodiment. Here, it is assumed that there are three subframes in a frame.

[0076] As shown in FIG. 8, the transmitting device 100 has an input interface (IF) 1100 to which various information is input, a frame synchronization signal generating unit 1200, a TMCC generating unit 1300, a subframe configuring unit 1400 (in the illustrated example, subframe configuring units 1400a to 1400c), an Lch separating unit 1500, and a time division multiplexing frame configuring unit 1600.

[0077] The frame synchronization signal generator 1200 generates a frame synchronization signal, and outputs the frame synchronization signal to the time division multiplexing frame constructor 1600. Here, the frame synchronization signal generator 1200 generates a frame synchronization signal that is configured from a predetermined number of symbols (in this embodiment, five OFDM symbols).

[0078] The TMCC generating unit 1300 receives the TMCC information from the input IF 1100 , generates a TMCC signal, and outputs the TMCC signal to a time division multiplexing frame configuring unit 1600 .

[0079] The subframe configuring section 1400 generates a subframe signal and outputs the subframe signal to the time division multiplexing frame configuring section 1600. In the illustrated example, the subframe configuring sections 1400a to 1400c output signals of subframes 1 to 3 to the time division multiplexing frame configuring section 1600, respectively.

[0080] The Lch separator 1500 distributes the Lch signal, which is a pilot signal that can also be used as a transmission path characterized by high resistance and low delay, over the entire frame excluding the frame synchronization signal section and the TMCC section.

[0081] Time division multiplexing frame composing section 1600 composes and outputs a frame by time division multiplexing the frame synchronization signal output by frame synchronization signal generating section 1200, the TMCC signal output by TMCC generating section 1300, and the subframe signals output by each subframe composing section 1400. The output signal of time division multiplexing frame composing section 1600 is converted into an analog signal by a digital / analog converting section (not shown), and then converted into a wireless signal by a wireless processing section (not shown), and output from an antenna (not shown).

[0082] (3.2) Configuration of OFDM Modulation Section in Subframe Configuration Section FIG. 9 is a diagram showing an OFDM modulation section in each subframe configuration section 1400 according to this embodiment.

[0083] As shown in FIG. 9, each subframe configuration unit 1400 includes an input IF 1401, a primary modulation unit 1402 (primary modulation units 1402a to 1402h) provided for each layer, a level adjustment unit 1403 (level adjustment units 1403a to 1403h) provided for each layer, a layer synthesis unit 1404, a band division unit 1405, a time interleaving (hereinafter also referred to as "time IL") unit 1406, a frequency interleaving (hereinafter also referred to as "frequency IL") unit 1407, a band synthesis unit 1408, a pilot generation unit 1409, a differential reference addition unit 1410, a DBPSK modulation unit 1411, an OFDM frame configuration unit 1412, an IFFT unit 1413, and a GI addition unit 1414.

[0084] Data constituting a frame for each layer of a single or multiple systems (layer-specific frame) and an Lch frame are input to the input IF 1401. The Lch frame may be an Lch FEC block packetized as a TLV (Type-length-value) packet.

[0085] The primary modulation unit 1402 performs primary modulation processing on the corresponding layered frame, and outputs the signal after the primary modulation processing to the level adjustment unit 1403. Specifically, the corresponding layered frame is converted into an FEC (Forward Error Correction) block that stores an error correction code, and then energy dispersal, BCH coding, LDPC coding, bit interleaving (hereinafter referred to as "bit IL"), and mapping are performed, and a carrier symbol is output. The level adjustment unit 1403 adjusts the level of the carrier symbol output by the primary modulation unit 1402, and outputs the level-adjusted carrier symbol to the layer combining unit 1404.

[0086] The hierarchical combining unit 1404 hierarchically combines the carrier symbols of each layer and outputs the combined data to the band dividing unit 1405. Specifically, the hierarchical combining unit 1404 combines the carrier symbols of each layer to form a data segment to be transmitted by one OFDM symbol, and assigns a segment number from 0 to 34. The band dividing unit 1405 divides the segments for each layer to which segment numbers have been assigned by the hierarchical combining again by layer, and outputs the divided data to the time IL unit 1406. The time IL unit 1406 distributes the carrier symbols in the time direction by the time IL, and outputs the distributed data to the frequency IL unit 1407. The frequency IL unit 1407 distributes the carrier symbols in the carrier direction (frequency direction) by the frequency IL, and outputs the distributed data to the band combining unit 1408. When a partial reception band is present, the band combining unit 1408 combines the 9 segments that constitute the partial reception band and the 26 segments that constitute the non-partial reception band by band combining to form 35 segments, and outputs the data segments to the OFDM frame constructing unit 1412. When there is no partial reception band, the number of segments constituting the non-partial reception band is 35, so there is no need to perform band synthesis.

[0087] The pilot generating unit 1409 generates pilot signals (specifically, SPs and BPs) based on the pilot arrangement information, and outputs the pilot signals to the OFDM frame configuring unit 1412.

[0088] Differential reference adding section 1410 adds a differential reference bit to the beginning of the Lch frame for each subframe and outputs the Lch frame to DBPSK modulation section 1411. DBPSK modulation section 1411 performs DBPSK modulation on the output signal of differential reference adding section 1410 to generate an Lch signal, and outputs the Lch signal to OFDM frame configuration section 1412.

[0089] The OFDM frame constructing unit 1412 adds a pilot signal and an Lch signal to the data segment to construct an OFDM frame. The IFFT unit 1413 OFDM-modulates the signal after the OFDM frame construction and outputs it to the GI adding unit 1414. The GI adding unit 1414 adds a GI to the output signal of the IFFT unit 1413 and outputs the signal.

[0090] 10 is a diagram for explaining the time IL unit 1406 and the frequency IL unit 1407 according to this embodiment. Note that the time IL is a process of dispersing carrier symbols in the time direction (symbol direction) in order to ensure resistance to time fluctuations in the propagation path. The frequency IL is a process of dispersing carrier symbols in the frequency direction (carrier direction) in order to ensure resistance to frequency selective fading.

[0091] As shown in FIG. 10, the time IL section 1406 includes a time IL section 2 (time IL sections 2a to 2h) provided for each layer. Each time IL section 2 performs time IL for the corresponding layer. Each time IL section 2 performs time IL in units of modulation symbols. The interleave length (I) is in units of subframe length, and there are eight types: '0', '0.25', '0.5', '0.75', '1', '1.5', '2', and '3' (see Table 1 above). Time IL is performed for each layer by combining the partial reception band and the non-partial reception band, and the interleave length (I) can be set independently for each layer. Details of the time IL section 2 will be described later.

[0092] The frequency IL unit 1407 has an intra-layer IL unit 11, a partial reception band separation unit 12, an inter-layer IL unit 13 (inter-layer IL units 13a and 13b), and an intra-segment (also referred to as "intra-segment") IL unit 14 (intra-segment IL units 14a and 14b). That is, the frequency IL according to this embodiment is mainly composed of three parts: an "intra-layer IL", an "inter-layer IL", and an "intra-segment IL (intra-segment IL)".

[0093] The intra-hierarchical IL unit 11 performs frequency IL processing on a carrier (data carrier) basis between segments included in each hierarchy. Such intra-hierarchical IL is performed to prevent errors caused by amplitude reduction in a specific segment due to multipath by applying frequency IL over a wide range in the carrier direction.

[0094] The partial reception band separation unit 12 generates a partial reception band and a non-partial reception band from segments of all layers such as layer A, layer B, layer C, etc. Here, when there are few segments allocated to layer A, the partial reception band separation unit 12 can allocate layer B within the partial reception band. This ensures that the partial reception band is always nine segments wide, and frequency IL is applied over a wide frequency range. This can improve resistance to frequency selective fading.

[0095] For example, if layer A has fewer than nine segments, the partial reception band separation unit 12 adds the required number of segments starting from the lowest segment number in layer B to create a partial reception band (9 segments). The remaining segments in layer B are treated as non-partial reception bands. Alternatively, if layer A has three segments and layer B has 32 segments, the partial reception band separation unit 12 divides layer B into six segments and 26 segments, and sets the three segments in layer A and the six segments in layer B as partial reception bands, and the 26 segments in layer B as a non-partial reception band. Alternatively, if layer A has nine segments, the partial reception band separation unit 12 sets layer A as a partial reception band and layer B as a non-partial reception band.

[0096] The inter-hierarchical IL unit 13 has an inter-hierarchical IL unit 13a that performs inter-hierarchical IL for the partial reception band (9 segments) and an inter-hierarchical IL unit 13b that performs inter-hierarchical IL for the non-partial reception band (26 segments). When a partial reception band is not set, the number of segments that make up the non-partial reception band is 35, and the inter-hierarchical IL unit 13b performs inter-hierarchical IL across all of these bands (35 segments).

[0097] The intra-segment IL unit 14 performs intra-segment IL. Intra-segment IL is performed to eliminate the periodicity of the carrier arrangement so as to prevent errors caused by successive low-amplitude carrier symbols when the carrier arrangement after inter-layer IL matches the period of the frequency characteristics. Intra-segment IL is processed for each segment, and includes intra-segment carrier rotation and intra-segment carrier randomization. The intra-segment IL unit 14 has an intra-segment IL unit 14a that performs intra-segment IL of the partial reception band (9 segments), and an intra-segment IL unit 14b that performs intra-segment IL of the non-partial reception band (26 segments). Note that when the partial reception band is not set, the number of segments constituting the non-partial reception band is 35, and the intra-segment IL unit 14b performs intra-segment IL for all of these bands (35 segments).

[0098] (3.3) Time IL section FIG. 11 is a diagram showing the configuration of the time IL unit 2 according to the present embodiment.

[0099] 11, the time IL section 2 has an in-data-segment time IL section 21 provided for each data segment in the layer. In the illustrated example, the number of segments in the layer is N seg The segments (data segments) in the hierarchy are numbered from No. 0 to No. N. seg The segment number is -1. c The time IL part 2 indicates the number of data carriers in one segment. The time IL part 2 indicates the number of data carriers in the time IL part 21 in the data segment No. 0 from data carrier '0' to No. N seg -1 data segment in time IL section 21 data carrier 'n c The corresponding modulation symbols are sequentially input from −1′ to . In this embodiment, the data segment time IL unit 21 corresponds to a time interleaving means that performs time IL to distribute the modulation symbols transmitted by the data carrier in the time direction.

[0100] FIG. 12 is a diagram showing the configuration of the data segment internal time IL section 21 according to the present embodiment.

[0101] 12, the data segment in-time IL unit 21 has a symbol buffer 211 for buffering modulation symbols for each data carrier. c Each symbol buffer 211 has a length of 'q i '(i=0,1,…,n c -1). In this way, by using a symbol buffer 211 with a different length for each data carrier, a different delay time can be imparted to the modulation symbol (carrier symbol) for each data carrier, and the carrier symbol can be dispersed in the time direction. Note that the receiver 200 can restore the data carriers simply by performing buffer processing for each data carrier in reverse order as time deinterleaving.

[0102] In this embodiment, when the remaining carriers in the TMCC section to which the TMCC signal is not assigned are used as data carriers to which data in the subframe section is assigned, the data segment intra-time IL unit 21 determines the length of the symbol buffer 211 based on the number of data carrier symbols in the subframe and the number of data carrier symbols in the TMCC section. This makes it possible to appropriately determine the length of the symbol buffer, taking into account the number of data carrier symbols in the TMCC section. Therefore, even when data is transmitted in part of the TMCC section in addition to the subframe section, the time IL can be applied to both the data in the subframe section and the data in the TMCC section.

[0103] FIG. 13 is a diagram for explaining the operation of the data segment internal time IL unit 21 according to the present embodiment.

[0104] As shown in FIG. 13, the data segment time IL portion 21 is a symbol buffer length q i of,

[0105]

number

[0106] shall be determined.

[0107] Here, N k indicates the segment number within the hierarchical layer. For example, if hierarchical layer A has 3 segments and hierarchical layer B has 32 segments, N k The value is 0 to 2 for stratum A and 0 to 31 for stratum B.

[0108] Also, n c denotes the number of data carriers in one segment, S denotes the number of data carrier symbols in a subframe, and S TMCC indicates the number of data carrier symbols in the TMCC section, I indicates the interleave length set in the layer, and N FFT indicates the FFT size.

[0109] However, since the data carriers in the TMCC section are assigned to the area after the LDPC code of the TMCC signal is assigned, S TMCC The value varies depending on the carrier number.

[0110] In addition,

[0111]

number

[0112] is a floor function that returns the largest integer less than or equal to its argument.

[0113] Also, when a boundary pilot symbol is inserted, the value of S varies depending on the data carrier number. In this embodiment, when a boundary pilot symbol is inserted in a subframe and inter-subframe interleaving is applied, which divides the subframe in the time direction and distributes it, the data segment intra-time IL unit 21 determines the number of data carrier symbols S in the subframe based on the number of subframe divisions in the inter-subframe interleaving.

[0114] Specifically, the data segment time IL unit 21 calculates the number of data carrier symbols S in a subframe as

[0115]

number

[0116] shall be determined.

[0117] Here, S SUBFRAME indicates the number of symbols in the subframe specified by the TMCC information, and n a denotes the number of data carriers of the boundary pilot symbol, and D denotes the number of subframe divisions in inter-subframe interleaving.

[0118] The data segment time IL unit 21 also performs delay correction associated with the time IL. The number of delay correction symbols is determined according to Table 2, based on the subframe symbol length and the time IL parameters.

[0119] [Table 2]

[0120] Here, the delay correction is performed on the signal before the time IL, specifically, before the time IL in the data segment shown in FIG.

[0121] (4) Receiving device An example of the receiving device 200 according to the present embodiment will be described with reference to Fig. 14. Note that hereinafter, deinterleaving is also referred to as "DIL".

[0122] 14, the receiving device 200 according to this embodiment is configured to perform the inverse process of the process performed by the transmitting device 100 according to this embodiment. Specifically, the receiving device 200 has a receiving unit 31, an FFT unit 32, a deframing unit 33, a band separating unit 34, an intra-segment DIL unit 35, an inter-layer DIL unit 36, a partial reception band synthesizing unit 37, an intra-layer DIL unit 38, a time DIL unit 39, and a demodulating unit 40.

[0123] The receiving unit 31 receives the broadcast signal transmitted by the transmitting device 100 , converts it into an OFDM signal, and outputs the OFDM signal to the FFT unit 32 .

[0124] The FFT unit 32 performs an FFT on the OFDM signal output by the receiving unit 31 to perform OFDM demodulation, and outputs the received data in frame units to the deframing unit 33.

[0125] The deframing unit 33 obtains a desired subframe from the received frame, and also obtains synthesized data of the partial reception band data and the non-partial reception band data, and outputs the obtained synthesized data to the band separation unit .

[0126] The band separation unit 34 separates the partial reception band data and non-partial reception band data from the combined data output by the deframing unit 33, and outputs the partial reception band data to the in-segment DIL unit 35a and the non-partial reception band data to the in-segment DIL unit 35b.

[0127] The intra-segment DIL unit 35a performs the inverse process of the intra-segment interleaving (carrier rotation and carrier randomization) in the transmitting device 100. Specifically, the intra-segment DIL unit 35a performs the inverse process of the intra-segment interleaving in the transmitting device 100 in a segment constituting the partial reception band data, and outputs the partial reception band data to the inter-layer DIL unit 36a. The intra-segment DIL unit 35b performs the inverse process of the intra-segment interleaving in the transmitting device 100 in a segment constituting the non-partial reception band data, and outputs the partial reception band data to the inter-layer DIL unit 36b.

[0128] The inter-layer DIL unit 36 ​​performs inter-layer DIL, which is the inverse process of the inter-layer interleaving in the transmission device 100. Specifically, the inter-layer DIL unit 36a performs frequency DIL between layers constituting the partial reception band data output by the intra-segment DIL unit 35a, and outputs the partial reception band data after frequency DIL to the partial reception band synthesis unit 37. The inter-layer DIL unit 36b performs frequency DIL between layers constituting the non-partial reception band data output by the intra-segment DIL unit 35b, and outputs the non-partial reception band data after frequency DIL to the partial reception band synthesis unit 37. The inter-layer DIL unit 36 ​​will be described in detail later.

[0129] The partial reception band synthesis unit 37 acquires data for each layer from the partial reception band data output by the inter-layer DIL unit 36a and the non-partial reception band data output by the inter-layer DIL unit 36b, and outputs the acquired data to the intra-layer DIL unit 38.

[0130] The intra-hierarchical DIL unit 38 performs frequency DIL on a carrier-by-carrier basis between segments within a hierarchy, and outputs the data after frequency DIL to a time DIL unit 39 .

[0131] The temporal DIL section 39 performs temporal DIL on the data output by the intra-hierarchical DIL section 38, and outputs the hierarchical data after the temporal DIL to the demodulation section 40.

[0132] In this embodiment, the time DIL unit 39 performs time DIL, which is the inverse process of time interleaving that distributes modulation symbols transmitted by data carriers in the time direction. As with the transmitting device 100, the time DIL unit 39 has a symbol buffer for buffering modulation symbols for each data carrier (see FIG. 11). When the remaining carriers in the TMCC section to which the TMCC signal is not assigned are used as data carriers to which data in the subframe section is assigned, the time DIL unit 39 determines the length of the symbol buffer based on the number of data carrier symbols in the subframe and the number of data carrier symbols in the TMCC section.

[0133] Here, the length of the symbol buffer in the time DIL unit 39 is q ri Then,

[0134]

number

[0135] Here, B and q i is the same as that explained in Equation 1 above.

[0136] The demodulation unit 40 performs demapping or the like on the hierarchical data from the carrier of each hierarchical data output by the time DIL unit 39 and outputs the hierarchical data.

[0137] (5) Other embodiments A program may be provided that causes a computer to execute each process performed by each of the above-mentioned devices (transmitting device 100, receiving device 200). The program may be recorded in a computer-readable medium. The computer-readable medium can be used to install the program in a computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM. In addition, circuits that execute each process performed by each of the above-mentioned devices (transmitting device 100, receiving device 200) may be integrated, and the device may be configured as a semiconductor integrated circuit (chip set, SoC).

[0138] The terms "based on" and "depending on / in response to" used in this disclosure do not mean "based only on" or "depending only on", unless otherwise specified. The term "based on" means both "based only on" and "based at least in part on". Similarly, the term "depending on" means both "based only on" and "depending at least in part on". The terms "include", "comprise", and variations thereof do not mean including only the recited items, but may include only the recited items or may include additional items in addition to the recited items. Additionally, the term "or" used in this disclosure is not intended to be an exclusive or. Additionally, any reference to elements using designations such as "first", "second", etc., used in this disclosure is not intended to generally limit the quantity or order of those elements. These designations may be used herein as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some manner. In this disclosure, where articles are added by translation, such as, for example, a, an, and the in English, these articles are intended to include the plural unless the context clearly indicates otherwise.

[0139] The above describes the embodiments in detail with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes can be made without departing from the spirit of the invention. [Explanation of symbols]

[0140] 1: Broadcast transmission system 2: Time IL section 11: Intra-layer IL part 12: Partial reception band separation unit 13:Interlayer IL section 14: IL section in segment 21: Time IL part in data segment 31: Receiving unit 32:FFT section 33: Deframing section 34: Band separation section 35: DIL section within segment 36: Inter-layer DIL section 37: Partial reception band synthesis unit 38: Intra-layer DIL section 39: Time DIL section 40: Demodulation section 100: Transmitting device 200: Receiving device 211: Symbol buffer 500: Broadcast transmission channel 1100: Input IF 1200: Frame sync signal generator 1300 :TMCC generation section 1400: Subframe configuration section 1401: Input IF 1402: Primary modulation section 1403: Level adjustment section 1404: Hierarchical synthesis section 1405: Band division section 1406: Time IL section 1407: Frequency IL section 1408: Band synthesis section 1409: Pilot generation unit 1410: Differential reference addition unit 1411: DBPSK modulation section 1412: OFDM frame configuration section 1413 :IFFT section 1414: GI Addition Section 1500 :Lch separation part 1600: Time division multiplexing frame component

Claims

1. A transmitting device used in a broadcast transmission system that transmits an OFDM frame in which a TMCC section and a subframe section following the TMCC section are arranged in a time division manner, a time interleaving means for performing time interleaving to distribute modulation symbols transmitted by a data carrier in a time direction, the time interleaving means comprises a symbol buffer for buffering the modulation symbols for each of the data carriers; When the remaining carriers to which the TMCC signal is not assigned in the TMCC section are used as data carriers to which data in the subframe section is assigned, the time interleaving means determines the length of the symbol buffer based on the number of data carrier symbols in the subframe. Transmitting device.

2. When the remaining carriers are used as the data carriers, the time interleaving means determines the length of the symbol buffer based on the number of data carrier symbols in the subframe and the number of data carrier symbols in the TMCC section. The transmitting device according to claim 1 .

3. The time interleaving means determines the number of data carrier symbols in the subframe based on the number of subframe divisions in the inter-subframe interleaving when a boundary pilot symbol is inserted in the subframe and inter-subframe interleaving is applied, in which the subframe is divided and distributed in the time direction. The transmitting device according to claim 1 .

4. The time interleaving means time-interleaves the symbol buffer of length q ｉ of, [0010] Determined by The N ｋ indicates the segment number within the hierarchy, The n ｃ indicates the number of data carriers in one segment, S indicates the number of data carrier symbols in the subframe, The S ＴＭＣＣ indicates the number of data carrier symbols in the TMCC section, The I indicates an interleave length set for the layer, The N ＦＦＴ indicates the FFT size, [0025] is a floor function that returns the largest integer less than or equal to the argument. The transmitting device according to claim 2.

5. When a boundary pilot symbol is inserted into the subframe and inter-subframe interleaving is applied in which the subframe is divided in a time direction and distributed, the time interleaving means divides the S into [0030] Determined by The S ＳＵＢＦＲＡＭＥ indicates the number of symbols in the subframe specified by the TMCC information, The n ａ indicates the number of data carriers of the boundary pilot symbol, The D indicates the number of subframe divisions in the inter-subframe interleaving. The transmitting device according to claim 4.

6. A receiving device used in a broadcast transmission system that transmits an OFDM frame in which a TMCC section and a subframe section following the TMCC section are arranged in a time division manner, a time deinterleaving means for performing time deinterleaving, which is the inverse process of time interleaving, for dispersing modulation symbols transmitted by data carriers in a time direction; the time deinterleaving means comprises a symbol buffer for buffering the modulation symbols for each of the data carriers; When the remaining carriers to which the TMCC signal is not assigned in the TMCC section are used as data carriers to which data in the subframe section is assigned, the time deinterleaving means determines the length of the symbol buffer based on the number of data carrier symbols in the subframe. Receiving device.

7. A computer is caused to function as the transmitting device according to claim 1 or the receiving device according to claim 6. program.

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