Modulator, demodulator, and program

Abstract

To enable easy specification of a main transmission station in each reception station.SOLUTION: A modulator 1 includes: sub-frame generation units (14, 15) that generate a sub-frame formed of a single or a plurality of layers having a segment structure; a transmission station identification code frame generation unit (17) that generates a transmission station identification code frame that is a sub-frame for transmitting a transmission station identification code by which a transmission station is identified; a TMCC generation unit (13) that generates a TMCC that is a control signal including transmission identification code frame information that is information relating to the transmission station identification code frame; and a time-division multiplexed frame construction unit (18) that time-division multiplexes the TMCC, the sub-frame, and the transmission station identification code frame.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a modulation device, a demodulation device, and a program.

Background Art

[0002] Conventionally, as a terrestrial digital broadcasting system, the ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) system is known. Furthermore, for the purpose of improving the quality and functionality of terrestrial digital broadcasting, studies on a next-generation advanced terrestrial broadcasting system (hereinafter referred to as the "advanced system") that inherits the features of the ISDB-T system are underway (see, for example, Non-Patent Document 1).

[0003] When migrating from analog broadcasting to the current ISDB-T system, measures were taken to broadcast both simultaneously (simulcast) over a long period of time to gradually encourage each household to migrate, rather than switching suddenly overnight. Similarly, simulcast is also assumed for the migration from the ISDB-T system to the advanced system, and it is considered necessary to change the transmission frequency of the broadcasting station according to the migration status, that is, channel repacking. In particular, after starting the service of the advanced system and turning off the ISDB-T, it is assumed that channel repacking of the advanced system, such as allocating the band remaining for ISDB-T to the advanced system and changing the transmission channel of the advanced system, will be required.

[0004] During channel repacking, receivers in some households may not operate as expected by broadcasters, and incorrect responses may lead to poor reception. Households that have fallen into such a situation are required to take some proactive measures such as re-channel scanning. Households that are unable to respond will lose the ability to watch TV, which is an undesirable result for both viewers and broadcasters. Alternatively, in some cases, broadcasters may have to take large-scale troubleshooting measures (specifically, measures that require a lot of manpower, such as call center support and individual home visits). Therefore, when performing channel repacking, it is desirable that means are taken to ensure that receivers can smoothly achieve this. As one of these means, if each household's receiver can identify the transmitting stations it is receiving, it is considered that it can be combined with channel repacking information distributed via ES (Engineering Stream) or the like to distinguish whether it is a channel repacking target, and it is considered that incorrect responses can be eliminated.

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In ISDB-T, it is not uncommon for there to be multiple transmitting stations of the same program on the same frequency as a Single Frequency Network (SFN), and it is not easy for a receiver to identify the transmitting station that it is mainly receiving from. Even in the advanced systems currently under consideration, there is no means provided in the receivers of each household to identify which transmitting station the signal is being received from. For example, the receiver itself cannot determine whether the station it is mainly receiving from is Tokyo Skytree or Odawara Station.

[0007] Therefore, it is considered to assign a unique identifier (hereinafter referred to as the "transmitting station identification code") to each transmitting station and transmit the transmitting station identification code to the receiver. As one method of transmitting the transmitting station identification code without affecting the data main line, it is first considered to provide one dedicated subframe. When transmitting in a subframe, it is required to comply with all the regulations defined in Non-Patent Document 1, but there are the following two problems.

[0008] The first problem is the order on the time axis within the frame. Since the subframe for transmitting the transmitting station identification code is not the data main line, it is considered preferable to place it at the end within the frame. Also, in order to minimize the impact on the transmission capacity of the data main line, it can be said that an FFT (Fast Fourier Transform) size of 8k, which is the smallest for a subframe (the symbol transmission time is the shortest), is preferable. On the other hand, in Non-Patent Document 1, it is stipulated that the order of subframes is generally arranged in ascending order of FFT size. When high FFT sizes such as 16k or 32k are adopted for the subframes of the data main line, the subframe with an FFT size of 8k for the transmitting station identification code cannot be placed at the end of the frame.

[0009] The second problem is that the signal structure within the subframe is restricted by the content of Non-Patent Document 1. Since the subframe that transmits the transmitting station identification code is not the main data line, it is an exceptional processing position that does not follow the processing block, but such a deviation is not allowed. Here, considering the number of transmitting stations for terrestrial broadcasting nationwide, the transmitting station identification code can have a value unique to all transmitting stations with at most about 12 bits, but the information bit length of the minimum FEC (Forward Error Correction) block of the subframe is 1992 bits, which is clearly excessive. Thus, there are two major problems in transmitting the transmitting station identification code in the subframe.

[0010] In view of such circumstances, an object of the present invention made is to provide a modulation device, a demodulation device, and a program that enable each receiver to easily identify the main transmitting station.

Means for Solving the Problem

[0011] The gist of the present invention for solving the above problems is as follows.

[0012] (1) A subframe generation unit that generates a subframe composed of a single or a plurality of hierarchical levels having a segment structure, a transmitting station identification code frame generation unit that generates a transmitting station identification code frame that is a subframe for transmitting a transmitting station identification code for identifying a transmitting station, a TMCC (Transmission and Multiplexing Configuration Control) generation unit that generates a TMCC that is a control signal including transmitting station identification code frame information that is information regarding the transmitting station identification code frame, and a time-division multiplexing frame configuration unit that time-division multiplexes the TMCC, the subframe, and the transmitting station identification code frame. A modulation device comprising:

[0013] (2) The modulation device according to (1), wherein the transmitting station identification code frame information indicates that the transmitting station identification code is transmitted in a future expansion frame in the terrestrial broadcasting enhancement system.

[0014] (3) The transmission station identification code frame information includes at least one of a flag indicating whether the transmission station identification code frame is being transmitted, the number of segments of the transmission station identification code frame, the number of the transmission station identification code frames included in the future expansion frame, the length of the transmission station identification code frame, the start position of the transmission station identification code frame in the future expansion frame, the transmission interval of the transmission station identification code frame, the number of frames of the advanced system that will arrive until the next transmission station identification code frame, the carrier modulation method of the transmission station identification code frame, and the PRBS generation polynomial used for the transmission of the transmission station identification code, in the modulation device according to (2).

[0015] (4) A demodulation device comprising: a sub-frame demodulation unit that demodulates a sub-frame composed of a single or a plurality of hierarchical levels having a segment structure; a transmission station identification code frame demodulation unit that demodulates a transmission station identification code frame which is a sub-frame for transmitting a transmission station identification code for identifying a transmission station; and a TMCC demodulation unit that demodulates a TMCC which is a control signal including transmission station identification code frame information which is information regarding the transmission station identification code frame, wherein the transmission station identification code frame demodulation unit demodulates the transmission station identification code frame based on the transmission station identification code frame information.

[0016] (5) The transmission station identification code frame information indicates that the transmission station identification code is being transmitted in a future expansion frame in the terrestrial broadcast advanced system, in the demodulation device according to (4).

[0017] (6) The transmission station identification code frame information in (5) above includes at least one of a flag indicating whether the transmission station identification code frame is being transmitted, the number of segments of the transmission station identification code frame, the number of transmission station identification code frames included in the future expansion frame, the length of the transmission station identification code frame, the start position of the transmission station identification code frame in the future expansion frame, the transmission interval of the transmission station identification code frame, the number of frames of the advanced method that will arrive until the next transmission station identification code frame, the carrier modulation method of the transmission station identification code frame, and the PRBS generation polynomial used for the transmission of the transmission station identification code, and is the demodulation device according to (5).

[0018] (7) A program for causing a computer to function as the modulation device according to any one of (1) to (3).

[0019] (8) A program for causing a computer to function as the demodulation device according to any one of (4) to (6).

Advantages of the Invention

[0020] According to the present invention, it becomes possible to identify the main transmission station in each receiver.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0022] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0023] FIG. 1 shows a frame configuration in an advanced system. In one frame, a frame synchronization signal, TMCC, and a sub-frame which is the main data line are arranged in the time direction. Although omitted in FIG. 1, the sub-frame has a segment structure and is composed of a single or a plurality of layers in the frequency direction. Note that ISDB-T has an A layer for one-segment and a B layer for full-segment. Here, the case where the number of sub-frames is 2 is shown as an example. In the present invention, the number and usage of sub-frames and layers are arbitrary. In the frequency direction, OFDM (Orthogonal Frequency Divided Modulation) sub-carriers are arranged.

[0024] Also, in the advanced system, it is assumed that in the future, a new signal different from the advanced system will be added in the time direction, and an interval called a Future Extension Frame (FEF) can be set. Fig. 2 shows an example of the FEF setting. The FEF exists between frames of the advanced system and can be set with a time length in units of the number of FFT clocks of the advanced system. In the advanced system, although there are such characteristics of the signal structure, no means for transmitting a signal similar to the transmitting station identification code is provided.

[0025] Therefore, in the present invention, the transmitting station identification code is transmitted using the FEF in the advanced system. Fig. 3 shows the frame configuration in the present invention. The transmitting station identification code is arranged in the FEF. The FEF may be composed only of the transmitting station identification code frame, or another signal may exist separately from the transmitting station identification code frame. Also, the transmitting station identification code frame may be inserted every time between frames of the advanced system, or may be inserted at an arbitrary interval, for example, once every 100 frames.

[0026] <Modulation device> Next, a modulation device according to an embodiment of the present invention will be described. The modulation device is installed at the transmitting station.

[0027] Fig. 4 shows a configuration example of a modulation device that can output the signal structure shown in Fig. 3. The modulation device 1 shown in Fig. 4 includes an input IF (interface) unit 11, a frame synchronization signal generation unit 12, a TMCC generation unit 13, a first sub-frame generation unit 14, a second sub-frame generation unit 15, an Lch separation unit 16, a transmitting station identification code frame generation unit 17, and a time-division multiplexed frame configuration unit 18. In this embodiment, the number of sub-frames is set to 2.

[0028] The frame synchronization signal generation unit 12 generates a frame synchronization signal and outputs it to the time-division multiplexed frame configuration unit 18. The frame synchronization signal is a synchronization signal transmitted at the head of the time-division multiplexed frame and is a signal for synchronization reproduction in the receiver.

[0029] The TMCC generation unit 13 inputs, via the input IF unit 11, existing transmission control information and information regarding a transmitting station identification code frame (hereinafter referred to as "transmitting station identification code frame information"), and generates a TMCC which is a control signal including these pieces of information. Then, the TMCC generation unit 13 outputs the generated TMCC signal to the time-division multiplex frame configuration unit 18. The transmitting station identification code frame information is information newly added in the present invention, and details thereof will be described later.

[0030] The Lch separation unit 16 inputs an Lch frame via the input IF unit 11, adds differential reference bits to the head for each sub-frame and then performs DBPSK modulation to generate an Lch signal. Lch is a pilot signal for wideband frequency synchronization and noise estimation and can also be used for data transmission. Then, the Lch separation unit 16 outputs the Lch signal generated for each sub-frame to the first sub-frame generation unit 14 and the second sub-frame generation unit 15.

[0031] The first sub-frame generation unit 14 inputs a hierarchical frame via the input IF unit 11, converts it into an FEC (Forward Error Correction) block for storing error correction codes, and performs processes such as energy diffusion, BCH coding, LDPC coding, bit interleaving, mapping, time interleaving, and frequency interleaving to constitute a data segment. Then, the first sub-frame generation unit 14 adds a pilot signal and the Lch signal input from the Lch separation unit 16 to the data segment to constitute an OFDM frame, OFDM-modulates the signal after the OFDM frame is configured, and generates a first sub-frame composed of a single or a plurality of hierarchies having a segment structure. Then, the first sub-frame generation unit 14 outputs the generated first sub-frame to the time-division multiplex frame configuration unit 18. Similarly, the second sub-frame generation unit 15 generates a second sub-frame composed of a single or a plurality of hierarchies having a segment structure and outputs it to the time-division multiplex frame configuration unit 18.

[0032] The transmission station identification code frame generation unit 17 inputs a transmission station identification code for identifying a transmission station via the input IF unit 11, and generates a transmission station identification code frame which is a sub-frame for transmitting the transmission station identification code. Then, the transmission station identification code frame generation unit 17 outputs the generated transmission station identification code frame to the time-division multiplex frame configuration unit 18. For example, when the transmission station identification code is a 12-bit numerical value, values from 0 to 4095 are assigned to the respective transmission stations. The assignment method can be arbitrary as long as the desired transmission stations can be distinguished. Also, the transmission station identification code may be multiplexed and sent via STL (Studio to Transmitter Link), TTL (Transmitter to Transmitter Link), etc. from a performance venue or the like, or may be recorded on a recording medium provided in the equipment or modulation device 1 installed at the transmission station.

[0033] The time-division multiplex frame configuration unit 18 time-division multiplexes the frame synchronization signal generated by the frame synchronization signal generation unit 12, the TMCC generated by the TMCC generation unit 13, the first sub-frame generated by the first sub-frame generation unit 14, the second sub-frame generated by the second sub-frame generation unit 15, and the transmission station identification code frame generated by the transmission station identification code frame generation unit 17, and outputs them in the order shown in Figure 3.

[0034] < <tmcc>> Next, the transmission control information related to the present invention will be described. As shown in FIG. 3, when a transmitter identification code frame exists between the frames of the advanced system (i.e., an FEF exists), it is required to signal (notify) this fact to the receiver by TMCC. Therefore, the transmitter identification code frame information indicates that the transmitter identification code is being transmitted in the future extension frame in the advanced system.

[0035] FIG. 5 shows the configuration of the future extension frame described in Table 3.2.1.5.13.1.2-1 of Non-Patent Document 1. According to Non-Patent Document 1, if the value of num_clocks is specified as the length of the FEF in Future_extention_frame_configuration() in the transmission control auxiliary information (Auxiliary_data) of TMCC, it can be notified to the receiver. Future_extention_frame_configuration() indicates the number of clocks of the transmitter identification code frame when transmitting the transmitter identification code frame, and is set to 0 when not transmitting the transmitter identification code frame. Also, when there is another extension frame in addition to the FEF, the total number of clocks is specified.

[0036] Although the existence of the FEF can be notified to the receiver of the advanced system by Future_extention_frame_configuration(), it is not possible to notify whether the FEF is transmitting the transmitter identification code. Therefore, there is a possibility that the receiver of the advanced system may not acquire the transmitter identification code frame of the FEF (since the FEF is basically an interval prepared for a signal different from the advanced system, the receiver of the advanced system will basically ignore it). Furthermore, even when a new different signal is added to the FEF, it is not possible to notify the receiver of the order and the like. Therefore, in the present invention, the transmitter identification code frame information is signaled in TMCC. An example of the transmitter identification code frame information will be described below.

[0037] To the left of FIG. 6, the configuration of transmission control auxiliary information in TMCC described in Table 3.2.1.5.13-29 of Non-Patent Document 1 is shown. To the right of FIG. 6, the transmission control auxiliary information identification (aux_data_type) described in Table 3.2.1.5.13-30 of Non-Patent Document 1 is shown. The modulation device 1 signals, by means of TMCC, the transmitting station identification code frame information including at least one of the following. · number_of_aux_data indicates the number of transmission control auxiliary information. It is incremented by 1 to send the transmitting station identification code frame information. · aux_data_type indicates the transmission control auxiliary information identification according to the table on the right of FIG. 6. Among the reserves, for example, 2 is assigned to the transmitting station identification code frame. · aux_data_size indicates the size (length) of the transmission control auxiliary information.

[0038] In the transmission control auxiliary information of TMCC, Transmitter_identification_frame_configuration() shown in FIG. 7 may be newly added as the transmitting station identification code frame information. When, for example, 2 is assigned to the transmitting station identification code frame with aux_data_type shown in FIG. 6, the transmitting station identification code frame information can be signaled by Transmitter_identification_frame_configuration().

[0039] Each piece of information shown in FIG. 7 is as follows. · transmitter_identification_code_valid (transmitting station identification code valid flag) is set to '1' when transmitting the transmitting station identification code frame, and '0' when not transmitting the transmitting station identification code frame. · number_of_segments (number of segments) indicates the number of segments of the transmitting station identification code frame. It is a value obtained by subtracting 1 from the number of segments. ·number_of_frames (the number of transmitter identification code frames) indicates the number of transmitter identification code frames included in one FEF. It is set to the value obtained by subtracting 1 from the number of transmitter identification code frames. In this embodiment, the number of transmitter identification code frames is assumed to be 1. ·num_clocks (the number of FFT clocks) indicates the length of the transmitter identification code frame in terms of the number of FFT clocks. ·pointer (transmitter identification code frame pointer) indicates the start position of the transmitter identification code frame in the FEF in terms of the number of FFT clocks. ·update (update flag) is a flag that is notified when the transmitter corresponding to the transmitter identification code is changed. Notification of the change content is assumed to be via the Internet or the like. ·interval (transmitter identification code frame transmission interval) indicates the transmission interval of the transmitter identification code frame. In the case of transmitting every time between the frames of the advanced method, it is set to 0, and in the case of transmitting at an interval of N frames, it is set to N. ·countdown_index (transmitter identification code frame arrival indicator) notifies the number of advanced method frames that will arrive until the next transmitter identification code frame arrives when the transmitter identification code frame is not transmitted every time between the frames of the advanced method. It is decremented every time an advanced method frame arrives, and becomes 0 when the transmitter identification code frame arrives immediately after that advanced method frame, or when the transmitter identification code frame is transmitted every time. ·carrier_modulation (carrier modulation method of the transmitter identification code frame) indicates the carrier modulation method of the transmitter identification code frame, such as BPSK, QPSK. · The prbs_generator_polynomial (PRBS generation polynomial used for the transmission of the transmitter identification code) notifies the M-sequence PRBS generation polynomial used for the generation of a PRBS (Pseudo Random Bit Sequence). It is assumed that a table in which serial numbers corresponding to each PRBS generation polynomial are provided in advance is shared by the transmitting and receiving apparatuses, and only the serial numbers are notified. In a method of transmitting the transmitter identification code according to the shift amount of the PRBS as described later, it becomes possible to prepare and selectively use a plurality of PRBS generation polynomials.

[0040] The transmitter identification code frame information may include at least one of transmitter identification code_valid, number_of_segments, number_of_frames, num_clocks, pointer, interval, and countdown_index. Further, in addition to any combination of these, it may include update.

[0041] <<Transmitter Identification Code Frame Generation Unit>> Next, the details of the transmitter identification code frame generation unit 17 will be described. The modulation method of the transmitter identification code may be arbitrary as long as the transmitter identification code unique to each transmitter can be transmitted within the transmitter identification code frame. For example, similar to the advanced subframe, the transmitter identification code may be LDPC-encoded and transmitted.

[0042] FIG. 8 shows a configuration example of the transmitter identification code frame generation unit 17 in the case where PRBSs are arranged in OFDM subcarriers and the transmitter identification code is transmitted according to the shift amount thereof. The transmitter identification code frame generation unit 17 shown in FIG. 8 includes a first PRBS generation unit 171, a second PRBS generation unit 172, a signal sequence shift unit 173, a carrier modulation unit 174, a pilot generation unit 175, a frequency frame configuration unit 176, an IFFT (Inverse Fast Fourier Transform) unit 177, and a GI (Guard Interval) addition unit 178.

[0043] The first PRBS generation unit 171 generates a PRBS that constitutes the real part signal. The second PRBS generation unit 172 generates a PRBS that constitutes the imaginary part signal. The PRBS can be generated using the M-sequence (Maximum Length Sequence), which is a pseudo-random number generation algorithm. The M-sequence is generated by an n-bit shift register and has a period of 2 n-1 of the sequence.

[0044] Fig. 9(a) shows a circuit example of the first PRBS generation unit 171, and Fig. 9(b) shows a circuit example of the second PRBS generation unit 172. Fig. 9 shows the M-sequences generated by two different 13th-order PRBS generation polynomials as W 1i , W 2i and shows the PRBS generation circuits based on Expressions (1) and (2) when the PRBS generation polynomials are Expressions (1) and (2). The initial values of the shift registers in the circuits are all set to 1. The first M-sequence signal obtained by assigning 0 in W 1i to 1 and 1 to -1 is denoted as a n , and the second M-sequence signal obtained by assigning 0 in W 2i to 1 and 1 to -1 is denoted as b n . The transmission station identification code frame generation unit 17 transmits a 12-bit transmission station identification code according to the shift amounts of the M-sequence signals (PRBS) generated by Expressions (1) and (2).

[0045]

Equation

[0046] Based on the transmission station identification code (a 12-bit numerical value), the signal sequence shift unit 173 generates c n obtained by shifting the first M-sequence signal a m,n and d n obtained by shifting the second M-sequence signal b m,n . Let the transmission station identification code be m (0 ≤ m < 4096). The shifted M-sequence signals c m,n , d m,n are represented by Expressions (3) and (4). Here, N represents the number of subcarriers per OFDM symbol (N > 4096).

[0047]

Number

[0048] The M series has an autocorrelation peak only once per period. Therefore, the correlation coefficient Φ(k) with the signal sequence before shifting is expressed by Equation (5), and signal detection can be performed by utilizing the fact that a peak occurs only at k = m when 0 ≤ k < N. The M series signal b n , d n is the same.

[0049]

Number

[0050] The carrier modulation unit 174 modulates the MSB (0th bit, I-axis, real axis) by c m,n and modulates the LSB (1st bit, Q-axis, imaginary axis) by d m,n to generate a QPSK modulation signal s m,n . That is, the carrier modulation unit 174 generates a QPSK modulation signal s m,n with the signal points on the I-axis being the sequence signal c m,n and the signal points on the Q-axis being the sequence signal d m,n . Here, let the sub-carrier number of the sub-frame for transmitting the transmitter identification code be n. The QPSK modulation signal s m,n is expressed by Equation (6).

[0051]

Number

[0052] The pilot generation unit 175 generates a predetermined pilot signal and outputs it to the frequency frame configuration unit 176.

[0053] The frequency frame forming unit 176 forms a frequency frame in which pilot signals are inserted at predetermined frequency intervals into the subcarriers QPSK - modulated by the carrier modulation unit 174. Then, the frequency frame forming unit 176 outputs the frequency - domain signal to the IFFT unit 177.

[0054] The IFFT unit 177 performs IFFT processing on the frequency - domain signal input from the frequency frame forming unit 176, generates a valid symbol signal, and outputs it to the GI addition unit 178.

[0055] The GI addition unit 178 adds a GI, which is a signal obtained by copying a part of the end of the valid symbol signal, to the head of the valid symbol signal input from the IFFT unit 177, and generates a transmitting station identification code frame. Then, the GI addition unit 178 outputs the transmitting station identification code frame to the time - division multiplexing frame forming unit 18. Note that the GI may or may not be added.

[0056] For the transmitting station identification code, neither frequency interleaving processing nor time interleaving processing is performed. The arrangement pattern of the pilot signals is, for example, (Dx, Dy)=(3, 1). Here, Dx is the interval between pilot signals in the carrier direction, and Dy is the interval between pilot signals in the symbol direction. Also, the FFT size is, for example, 8k (8192). Note that the transmitting station identification code frame generation unit 17 may perform only the processing after the carrier modulation unit 174 on the transmitting station identification code without generating a PRBS (that is, without including the first PRBS generation unit 171, the second PRBS generation unit 172, and the signal sequence shift unit 173).

[0057] <Demodulation device> Next, a demodulation device according to an embodiment of the present invention will be described. The demodulation device is incorporated in a receiver in each household or the like.

[0058] FIG. 10 shows a configuration example of a demodulation device that can receive the signals shown in FIG. 3. The demodulation device 2 shown in FIG. 10 includes a synchronous reproduction unit 21, a frame synchronization signal demodulation unit 22, a TMCC demodulation unit 23, a sub-frame demodulation unit 24, and a transmitting station identification code frame demodulation unit 25. The demodulation device 2 receives a time-division multiplexed frame synchronization signal, TMCC, sub-frame, and transmitting station identification code frame from the modulation device 1.

[0059] The synchronous reproduction unit 21 includes an ADC (Analog-Digital Converter) 211 that converts an input analog signal into a digital signal, a BPF (Band Pass Filter) 212 that extracts a signal of a predetermined band, and a quadrature demodulation unit 213 that performs quadrature demodulation processing. Detailed descriptions of each block are omitted because they are not directly related to the present invention.

[0060] The frame synchronization signal demodulation unit 22 performs propagation path estimation and demodulation on the frame synchronization signal received from the modulation device 1.

[0061] The TMCC demodulation unit 23 performs FFT, propagation path estimation, etc. on the TMCC received from the modulation device 1 and demodulates it. The TMCC demodulation unit 23 outputs control information such as modulation parameters of the sub-frame to the sub-frame demodulation unit 24 and outputs transmitting station identification code frame information to the transmitting station identification code frame demodulation unit 25.

[0062] The sub-frame demodulation unit 24 performs processing such as FFT, propagation path estimation, frequency deinterleaving, time interleaving, error correction decoding, and energy despreading on the sub-frame received from the modulation device 1 based on the control information input from the TMCC demodulation unit 23 and demodulates it.

[0063] The transmitting station identification code frame demodulation unit 25 grasps the reception of the transmitting station identification code frame based on the transmitting station identification code frame information input from the TMCC demodulation unit 23, extracts the transmitting station identification code frame, and demodulates it to obtain a desired transmitting station identification code.

[0064] <<Transmitter Identification Code Frame Demodulation Unit>> Next, the details of the transmitter identification code frame demodulation unit 25, which demodulates the transmitter identification code frame generated by the transmitter identification code frame generation unit 17 shown in FIG. 8, will be described.

[0065] FIG. 11 shows a configuration example of the transmitter identification code frame demodulation unit 25. The transmitter identification code frame demodulation unit 25 shown in FIG. 11 includes a first PRBS generation unit 251, a second PRBS generation unit 252, a transmission signal generation unit 253, an FFT unit 254, an equalization unit 255, a demodulation unit 256, a correlation coefficient calculation unit 257, and a transmitter identification code detection unit 258.

[0066] Similar to the transmitter identification code frame generation unit 17 of the modulation device 1, the first PRBS generation unit 251 generates an M-sequence signal a that constitutes the real part of the signal. n The second PRBS generation unit 252 generates an M-sequence signal b that constitutes the imaginary part of the signal. n to generate.

[0067] The transmission signal generation unit 253 generates, as a local replica, a transmission signal (M-sequence signals c 0,n , d 0,n ) of the transmitter identification code m = 0 and outputs it to the correlation coefficient calculation unit 257.

[0068] The FFT unit 254 performs an FFT process on the transmitter identification code frame to generate a complex baseband signal in the frequency domain and outputs it to the equalization unit 255.

[0069] The equalization unit 255 extracts a pilot signal from the transmitter identification code frame and estimates the channel response of the propagation path. Then, based on the channel response, the equalization unit 255 performs equalization processing on the complex baseband signal input from the FFT unit 254 and outputs an equalized signal with corrected propagation path distortion to the demodulation unit 256.

[0070] The demodulation unit 256 demodulates the equalized signal based on the transmitter identification code frame information and outputs it to the correlation coefficient calculation unit 257.

[0071] The correlation coefficient calculation unit 257 calculates the correlation coefficient between the transmission signal input from the transmission signal generation unit 253 and the demodulated signal of the transmission station identification code frame input from the demodulation unit 256 according to Equation (7). However, the second term W n ’ is a noise component, and its correlation with the transmission signal is so small that it can be ignored.

[0072]

Equation

[0073] The transmission station identification code detection unit 258 detects the transmission station identification code based on the position of the peak value of the correlation coefficient and outputs it outside the demodulation device 2.

[0074] In this way, the modulation device 1 transmits the TMCC including the transmission station identification code frame information and the transmission station identification code frame, so that the demodulation device 2 can demodulate the transmission station identification code frame based on the transmission station identification code frame information and obtain the transmission station identification code. Therefore, the receiver equipped with the demodulation device 2 can identify the main transmission station and smoothly perform channel repacking.

[0075] In addition, the present invention is also applicable to applications other than channel repacking. For example, when there are plans to implement decommissioning, reduced power broadcasting, etc., it is also possible to prompt the receiver to change the channel before implementation.

[0076] <Program> In order to function as the above-described modulation device 1 and demodulation device 2, it is also possible to use a computer capable of executing program instructions. Here, the computer may be a general-purpose computer, a dedicated computer, a workstation, a PC (Personal Computer), etc. The program instructions may be program codes, code segments, etc. for executing necessary tasks.

[0077] The computer includes a processor, a memory unit, an input unit, an output unit, and a communication interface. The processor can be a CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit), DSP (Digital Signal Processor), SoC (System on a Chip), etc., and may be composed of a plurality of processors of the same type or different types. The processor reads and executes a program from the memory unit to control each of the above components and perform various arithmetic operations. Note that at least a part of these processing contents may be realized by hardware. The input unit is an input interface that receives a user's input operation and obtains information based on the user's operation, such as a pointing device, a keyboard, a microphone, etc. The output unit is an output interface that outputs information, such as a display, a speaker, etc. The communication interface is an interface for communicating with an external device.

[0078] The program may be recorded on a computer-readable recording medium. By using such a recording medium, it is possible to install the program on the computer. Here, the recording medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a CD-ROM, a DVD-ROM, a USB (Universal Serial Bus) memory, etc. Also, this program may be in a form downloaded from an external device via a network.

[0079] For example, a program for causing a computer to function as a modulation device 1 includes steps of generating a subframe, generating a transmitting station identification code frame, generating a TMCC which is a control signal including transmitting station identification code frame information, and time-division multiplexing the TMCC, the subframe, and the transmitting station identification code frame. For example, a program for causing a computer to function as a demodulation device 2 includes steps of demodulating a subframe, demodulating a transmitting station identification code frame, and demodulating a TMCC which is a control signal including transmitting station identification code frame information, and causing the computer to execute the step of demodulating the subframe, and the step of demodulating the transmitting station identification code frame is to demodulate the transmitting station identification code frame based on the transmitting station identification code frame information.

[0080] Also, the above-described modulation device 1 may be configured by one or more semiconductor chips. This semiconductor chip may be equipped with a CPU that executes a program describing the processing content for realizing each function of the modulation device 1. The same applies to the demodulation device 2.

[0081] Although the above-described embodiments have been described as representative examples, it is obvious to those skilled in the art that many changes and substitutions can be made within the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications or changes are possible without departing from the scope of the claims. For example, it is possible to integrate a plurality of constituent blocks described in the configuration diagrams of the embodiments or to divide one constituent block.

Explanation of Reference Numerals

[0082] 1 Modulation device 2 Demodulation device 11 Input IF section 12 Frame synchronization signal generation section 13 TMCC generation section 14 First subframe generation section 15 Second subframe generation section 16 Lch separation section 17 Transmitting station identification code frame generation section 18 - time - division multiplexed frame configuration unit 21 Synchronous playback unit 22 Frame synchronization signal demodulation unit 23 TMCC demodulation unit 24 Sub - frame demodulation unit 25 Transmitting station identification code frame demodulation unit 171 First PRBS generation unit 172 Second PRBS generation unit 173 Signal sequence shift unit 174 Carrier modulation unit 175 Pilot generation unit 176 Frequency frame configuration unit 177 IFFT unit 178 GI addition unit 211 ADC 212 BPF 213 Quadrature demodulation unit 251 First PRBS generation unit 252 Second PRBS generation unit 253 Transmitting signal generation unit 254 FFT unit 255 Equalization unit 256 Demodulation unit 257 Correlation coefficient calculation unit 258 Transmitting station identification code detection unit< / tmcc>

Claims

1. a subframe generator for generating subframes having a single or multiple layers with a segment structure; a transmitting station identification code frame generating unit that generates a transmitting station identification code frame which is a subframe for transmitting a transmitting station identification code for identifying a transmitting station; a TMCC generating unit that generates a TMCC, which is a control signal including transmission station ID code frame information, which is information related to the transmission station ID code frame; a time division multiplexing frame constructing unit that time-division multiplexes the TMCC, the subframe, and the transmitting station identification code frame; A modulation device comprising:

2. 2. The modulation device according to claim 1, wherein the transmitting station identification code frame information indicates that the transmitting station identification code is transmitted in a future extension frame in an advanced terrestrial broadcasting standard.

3. The transmitting station identification code frame information is A flag indicating whether the transmitting station identification code frame is being transmitted; the number of segments of the transmitter identification code frame; the number of said transmitter identification code frames to be included in said future extension frame; the length of said transmitter identification code frame; a start position of the transmitter identification code frame in the future extension frame; a transmission interval of the transmitter identification code frame; the number of frames of the advanced system arriving until the next transmitter identification code frame; A carrier modulation method of the transmitter identification code frame; and A PRBS generating polynomial used to transmit the transmitter identification code; The modulation device of claim 2 , comprising at least one of:

4. a subframe demodulation unit that demodulates a subframe having a single or multiple layers with a segment structure; a transmitter identification code frame demodulation unit that demodulates a transmitter identification code frame, which is a subframe for transmitting a transmitter identification code for identifying a transmitter; a TMCC demodulation unit that demodulates a TMCC that is a control signal including transmission station identification code frame information that is information related to the transmission station identification code frame, The transmitter identification code frame demodulation unit demodulates the transmitter identification code frame based on the transmitter identification code frame information.

5. 5. The demodulation device according to claim 4, wherein the transmitting station identification code frame information indicates that the transmitting station identification code is transmitted in a future extension frame in an advanced terrestrial broadcasting standard.

6. The transmitting station identification code frame information is A flag indicating whether the transmitting station identification code frame is being transmitted; the number of segments of the transmitter identification code frame; the number of said transmitter identification code frames to be included in said future extension frame; the length of said transmitter identification code frame; a start position of the transmitter identification code frame in the future extension frame; a transmission interval of the transmitter identification code frame; the number of frames of the advanced system arriving until the next transmitter identification code frame; A carrier modulation method of the transmitter identification code frame; and A PRBS generating polynomial used to transmit the transmitter identification code; The demodulation device according to claim 5 , comprising at least one of the following:

7. A program for causing a computer to function as the modulation device according to claim 1.

8. A program for causing a computer to function as the demodulation device according to claim 4.

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