Transmission device and reception device

Abstract

To provide a transmission device and a reception device, capable of enabling a switching of a main system transmission frame (a transmission signal) and a reserve system transmission frame (a transmission signal) in seamless.SOLUTION: A transmission device comprises: a first transmission processing part; a second transmission processing part; and a transmission switching part that switches an output of the first transmission processing part and an output of the second transmission processing part. Each of the first transmission processing part and the second transmission processing part comprises a control part that generates a multiplex transmission frame in which one or more broadcast signals is overlapped. The output of the first transmission processing part and the output of the second transmission processing part are synchronized at a reference timing that is common in the first and second transmission processing part. The reference timing is a start timing of a specified transmission frame constructed by the one or more multiplex transmission frame. The specified transmission frame is defined so that a packet constructing the one or more broadcasting signals is not parted.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a transmitting device and a receiving device. [Background technology]

[0002] A transmission method is specified for a transmission frame in which a main signal and an SC (Service Channel) signal are multiplexed from a first device (e.g., a broadcasting station's studio or transmitting station) to a second device (e.g., a transmitting station). The main signal includes a first broadcast signal (e.g., a TS (Transport Stream) signal, a TMCC (Transmission and Multiplexing. Configuration Control) signal, etc.) related to terrestrial digital television broadcasting and V-Low terrestrial multimedia broadcasting. In such a transmission method, the link between the first device and the second device is called an STL (Studio to Transmitter Link) or a TTL (Transmitter to Transmitter Link) (e.g., Non-Patent Document 1).

[0003] In current STL / TTL, a redundant configuration is adopted in which a main system transmission frame (transmission signal) and a backup system transmission frame (transmission signal) are seamlessly switched and transmitted in order to prevent line interruptions due to equipment failure (for example, Patent Document 1). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] "Digital STL / TTL Transmission Method for Digital Terrestrial Broadcasting" Standard ARIB STD-B22 Version 2.1 [Patent documents]

[0005] [Patent Document 1] JP 2005-286674 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the current STL / TTL, the packet length and rate of the broadcast signal, broadcast TS, are constant and a single carrier system is used that is synchronized with this, so it is relatively easy to generate the same transmission signal in the main system and the backup system for seamless switching.

[0007] On the other hand, the transmission of IP signal format broadcast signals related to the advanced terrestrial broadcasting system is being considered by enhancing STL / TTL (advanced STL / TTL).In advanced STL / TTL, the packet length and rate of IP signals, which are broadcast signals, are not necessarily constant, and an OFDM system is assumed in which transmission signals are accumulated and processed in blocks, so it is not easy to generate the same transmission signal in the main line system and the backup system for seamless switching.

[0008] Under such a background, the inventors, after extensive investigation, have found that even in advanced STL / TTL, it is necessary to seamlessly switch between main system transmission frames (transmission signals) and protection system transmission frames (transmission signals).

[0009] Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide a transmitting device and a receiving device that enable seamless switching between a main system transmission frame (transmission signal) and a backup system transmission frame (transmission signal). [Means for solving the problem]

[0010] One aspect of the disclosure is a transmitting device that transmits a multiplex transmission frame in which one or more broadcast signals are multiplexed, comprising a first transmission processing unit, a second transmission processing unit, and a transmission switching unit that switches between an output of the first transmission processing unit and an output of the second transmission processing unit, each of the first transmission processing unit and the second transmission processing unit comprising a control unit that generates a multiplex transmission frame in which the one or more broadcast signals are multiplexed, the output of the first transmission processing unit and the output of the second transmission processing unit are synchronized with a reference timing common to the first transmission processing unit and the second transmission processing unit, the reference timing is the start timing of a specific transmission frame composed of the one or more multiplex transmission frames, and the specific transmission frame is defined so as not to fragment packets that constitute the one or more broadcast signals.

[0011] One aspect of the disclosure is a receiving device that receives a multiplex transmission frame in which one or more broadcast signals are multiplexed from a transmitting device, the receiving device comprising: a receiving unit that receives the multiplex transmission frame generated by a first transmission processing unit of the transmitting device or a second transmission processing unit of the transmitting device; and a control unit that performs demodulation processing including propagation path estimation for the multiplex transmission frame, wherein the receiving unit receives control information notifying switching between the output of the first transmission processing unit and the output of the second transmission processing unit, the control unit performs propagation path estimation that does not span the symbols before and after the switching timing notified by the control information, without performing propagation path estimation that spans the symbols before and after the switching timing notified by the control information, the output of the first transmission processing unit and the output of the second transmission processing unit are synchronized with a reference timing common to the first transmission processing unit and the second transmission processing unit, the reference timing is the start timing of a specific transmission frame composed of the one or more multiplex transmission frames, and the specific transmission frame is defined so as not to fragment packets that constitute the one or more broadcast signals. Effect of the Invention

[0012] According to the present invention, it is possible to provide a transmitting device and a receiving device that enable seamless switching between a main system transmission frame (transmission signal) and a protection system transmission frame (transmission signal). [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a digital wireless transmission system 10 according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a transmission device 100 according to the embodiment. [Diagram 3] FIG. 3 is a diagram illustrating a main system transmission processing unit 131 and a standby system transmission processing unit 133 according to the embodiment. [Figure 4] FIG. 4 is a diagram showing a receiving device 200 according to the embodiment. [Diagram 5] FIG. 5 is a diagram showing the main system reception processing unit 235 and the standby system reception processing unit 237 according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating an FEC block according to the embodiment. [Figure 7] FIG. 7 is a diagram showing parameters of an FEC block according to the embodiment. [Figure 8] FIG. 8 is a diagram showing the multiplexing section 150 according to the embodiment. [Figure 9] FIG. 9 is a diagram for explaining storage in a buffer according to the embodiment. [Figure 10] FIG. 10 is a diagram for explaining storage in a buffer according to the embodiment. [Figure 11] FIG. 11 is a diagram showing a separation unit 250 according to the embodiment. [Figure 12] FIG. 12 is a diagram illustrating an example of control information according to the embodiment. [Figure 13] FIG. 13 is a diagram showing a multiplexing section 150 according to the first modification. [Figure 14] FIG. 14 is a diagram showing a separator 250 according to the first modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Next, an embodiment of the present invention will be described. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the ratios of dimensions may differ from the actual ones.

[0015] Therefore, specific dimensions should be determined with reference to the following description. In addition, the drawings may of course include parts with different dimensional relationships and ratios.

[0016] [Disclosure Summary] A transmitting device in accordance with the outline of the disclosure is a transmitting device that transmits a multiplex transmission frame in which one or more broadcast signals are multiplexed, and is equipped with a first transmission processing unit, a second transmission processing unit, and a transmission switching unit that switches between the output of the first transmission processing unit and the output of the second transmission processing unit, each of the first transmission processing unit and the second transmission processing unit is equipped with a control unit that generates a multiplex transmission frame in which the one or more broadcast signals are multiplexed, the output of the first transmission processing unit and the output of the second transmission processing unit are synchronized with a reference timing common to the first transmission processing unit and the second transmission processing unit, the reference timing is the start timing of a specific transmission frame constituted by the one or more multiplex transmission frames, and the specific transmission frame is defined so as not to fragment packets that constitute the one or more broadcast signals.

[0017] In the outline of the disclosure, a transmission device generates a multiplexed transmission frame so as to be synchronized with a reference timing common to a first transmission processing unit (eg, main line system) and a second transmission processing unit (eg, backup system).

[0018] In the above-mentioned configuration, the reference timing is the start timing of a specific transmission frame composed of one or more multiplex transmission frames, and the specific transmission frame is defined so as not to divide packets that compose one or more broadcast signals. With such a configuration, it is possible to seamlessly switch between the transmission frame (transmission signal) of the main line system and the transmission frame (transmission signal) of the backup system.

[0019] A receiving device according to the outline of the disclosure is a receiving device that receives a multiplex transmission frame in which one or more broadcast signals are multiplexed from a transmitting device, and includes: a receiving unit that receives the multiplex transmission frame generated by a first transmission processing unit of the transmitting device or a second transmission processing unit of the transmitting device; and a control unit that performs demodulation processing including propagation path estimation for the multiplex transmission frame, wherein the receiving unit receives control information notifying switching between an output of the first transmission processing unit and an output of the second transmission processing unit, and the control unit performs propagation path estimation that does not span symbols before and after the switching timing notified by the control information, without performing propagation path estimation that spans symbols before and after the switching timing notified by the control information, and the output of the first transmission processing unit and the output of the second transmission processing unit are synchronized with a reference timing common to the first transmission processing unit and the second transmission processing unit, the reference timing is the start timing of a specific transmission frame composed of the one or more multiplex transmission frames, and the specific transmission frame is defined so as not to fragment packets that constitute the one or more broadcast signals.

[0020] In the outline of the disclosure, the receiving device does not perform channel estimation across symbols before and after the switching timing notified by the control information (i.e., the timing of switching between the output of the first transmission processing unit and the output of the second transmission processing unit), but performs channel estimation that does not span symbols before and after the switching timing notified by the control information. With this configuration, even if the transmission frame (transmission signal) of the main line system and the transmission frame (transmission signal) of the protection system are seamlessly switched, it is possible to appropriately perform channel estimation.

[0021] Although not particularly limited, the multiplex transmission frame may be a multiplex transmission frame in which two or more broadcast signals are multiplexed. In such a case, the control unit of each of the first transmission processing unit and the second transmission processing unit may divide each of the two or more broadcast signals into a predetermined unit, and generate a multiplex transmission frame in which the two or more broadcast signals divided into the predetermined unit are multiplexed based on the ratio of the rates of the two or more broadcast signals. In such a case, "the specific transmission frame is defined so as not to divide packets constituting one or more broadcast signals" may be read as "the number of predetermined units included in the specific transmission frame is divisible by the multiplexing period of two or more broadcast signals" in the case where multiplexing of two or more broadcast signals is assumed.

[0022] Although not particularly limited, the predetermined unit may be a unit constituted by an error correction block, or may be a unit constituted by a byte.

[0023] [Embodiment] (Digital Radio Transmission System) A digital wireless transmission system according to an embodiment will be described below. Fig. 1 is a diagram showing a digital wireless transmission system 10 according to an embodiment. As shown in Fig. 1, the digital wireless transmission system 10 includes a transmitting device 100 and a receiving device 200.

[0024] In an embodiment, in a case where two or more broadcast signals having different rates are transmitted from the transmitting device 100, the present invention relates to a system for transmitting a multiplexed transmission frame in which two or more broadcast signals are multiplexed from the transmitting device 100 to the receiving device 200. The transmitting device 100 may multiplex and transmit two or more broadcast signals in the form of an Orthogonal Frequency Division Multiplexing (OFDM) frame.

[0025] The location where the transmitting device 100 is installed may be a broadcasting station's studio or a transmitting station. The location where the receiving device 200 is installed may be a transmitting station. The link between the transmitting device 100 and the receiving device 200 may be called an STL (Studio to Transmitter Link) or a TTL (Transmitter to Transmitter Link). Hereinafter, the link between the transmitting device 100 and the receiving device 200 may be called an STL / TTL.

[0026] In the embodiment, the two or more broadcast signals include a first broadcast signal and a second broadcast signal. The rate of the second format for the second broadcast signal may be greater than the rate of the first format for the first broadcast signal. The broadcast signals may be referred to as program transmission signals.

[0027] The first broadcast signal may include broadcast signals related to terrestrial digital television broadcasting and V-Low terrestrial multimedia broadcasting, such as a TS (Transport Stream) signal, a TMCC (Transmission and Multiplexing. Configuration Control) signal, etc. The first broadcast signal may include an SC (Service Channel) signal, which is an auxiliary signal such as a control signal or a contact signal. The first system may be referred to as an ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) system.

[0028] The second broadcast signal may include a second broadcast signal related to an advanced terrestrial broadcasting standard. The advanced terrestrial broadcasting standard may be an example of the second standard. The second broadcast signal may include a Service Channel (SC) signal.

[0029] Although not particularly limited, the first broadcast signal may be represented in the form of TS packets, and the rate of the TS packets may be 31 Mbps. The second broadcast signal may be represented in the form of IP packets, and the rate of the IP packets may be 50 Mbps. The IP packets may be read as program transmission signal packets.

[0030] (Transmitting device) A transmitting device according to an embodiment will be described below. Fig. 2 is a block diagram showing the transmitting device 100 according to an embodiment.

[0031] As shown in FIG. 2, the transmission device 100 includes a main transmission processing unit 131, a standby transmission processing unit 133, a monitor and control unit 135, an RF changeover switch 137, and a transmission filter 139.

[0032] The mainline transmission processing unit 131 configures a mainline multiplex transmission frame (transmission signal). In an embodiment, the mainline transmission processing unit 131 may configure a first transmission processing unit. Details of the mainline transmission processing unit 131 will be described later (see FIG. 3).

[0033] The backup transmission processing unit 133 configures a backup multiplex transmission frame (transmission signal). In an embodiment, the backup transmission processing unit 133 may configure a second transmission processing unit. Details of the backup transmission processing unit 133 will be described later (see FIG. 3).

[0034] The monitoring control unit 135 monitors the mainline transmission processing unit 131 and detects a malfunction of a mainline transmission frame (transmission signal). The monitoring control unit 135 may detect a failure of the mainline transmission processing unit 131. When the monitoring control unit 135 detects a malfunction of a mainline transmission frame (transmission signal), the monitoring control unit 135 outputs an RF switching notification to the RF switching unit 137 for switching the output selection of the RF switching unit 137 from the mainline transmission processing unit 131 to the standby transmission processing unit 133.

[0035] Although not particularly limited, the monitoring control unit 135 may monitor the main line transmission processing unit 131 and detect recovery of the main line transmission frame (transmission signal). When the monitoring control unit 135 detects recovery of the main line transmission frame (transmission signal), the monitoring control unit 135 may output an RF switching notification to the RF switch 137 for switching the output selection of the RF switch 137 from the standby transmission processing unit 133 to the main line transmission processing unit 131. Also, the monitoring control unit 135 may output an RF switching notification to the RF switch 137 for manually switching the system selected by the RF switch 137 for maintenance or the like.

[0036] The RF changeover switch 137 changes the output of the main system transmission processing unit 131 to the output of the standby system transmission processing unit 133 based on an RF changeover notification input from the monitor and control unit 135. The RF changeover switch 137 changes the output of the main system transmission processing unit 131 to the output of the standby system transmission processing unit 133 within the guard interval of a specific symbol of the multiplex transmission frame.

[0037] Although not particularly limited, the RF changeover switch 137 may switch the output of the standby system transmission processing unit 133 to the output of the main system transmission processing unit 131 based on an RF changeover notification input from the monitoring control unit 135. The RF changeover switch 137 may switch the output of the standby system transmission processing unit 133 to the output of the main system transmission processing unit 131 within the guard interval of a specific symbol of the multiplex transmission frame.

[0038] In the embodiment, the RF changeover switch 137 constitutes a transmission changeover unit that switches between the output of the first transmission processing unit (mainline transmission processing unit 131) and the output of the second transmission processing unit (standby transmission processing unit 133).

[0039] The transmission filter 139 limits the band of the output (RF signal) of the RF switch 137. The band-limited RF signal is transmitted via an antenna.

[0040] (Transmission processing unit) The transmission processing unit according to the embodiment will be described below. Fig. 3 is a block diagram showing the main system transmission processing unit 131 and the standby system transmission processing unit 133 according to the embodiment. The main system transmission processing unit 131 and the standby system transmission processing unit 133 may have the same configuration. Hereinafter, the main system transmission processing unit 131 and the standby system transmission processing unit 133 will be simply referred to as the transmission processing unit.

[0041] As shown in Figure 3, the transmission processing unit has a block construction unit 101, an energy dispersal unit 102, an outer code processing unit 103, an outer interleaver 105, an inner code processing unit 107, an inner interleaver 109, a mapping unit 110, a frame construction unit 111, a modulation unit 113, and a transmission unit 115.

[0042] The block configuration unit 101 configures an error correction block. The error correction block is a block to which FEC (Forward Error Correction) is applied, and may be called an FEC block. The FEC block may have a fixed length.

[0043] The energy dispersal unit 102 randomizes the bit sequence output from the block configuration unit 101 (i.e., the block header, the main signal (TS packet / IP packet), and the stuff bits if there are any before the BCH code parity of the FEC block) using a PN sequence generated using a generator polynomial of a predetermined dimension. Here, an initial value input to the generator polynomial is given for each FEC block. In other words, the PN sequence may be reset for each FEC block.

[0044] The outer code processing unit 103 executes error correction coding using the outer code. A BCH code may be used as the outer code. In the following, a case where the outer code is a BCH code will be exemplified. The order of processing by the energy dispersal unit 102 and the outer code processing unit 103 may be reversed. In this case, the bit sequence randomized by the energy dispersal includes the block header, the main signal (TS packet / IP packet), stuff bits, and BCH code parity.

[0045] The outer interleaver 105 executes interleaving of the bit sequence or byte sequence output from the outer code processor 103. Interleaving is a process of changing the order of bits or bytes. The outer interleaver 105 may be omitted.

[0046] The inner code processing unit 107 executes error correction coding using the inner code. As the inner code, a low-density parity-check code (LDPC) may be used. In the following, a case where the inner code is an LDPC will be illustrated as an example.

[0047] The inner interleaver 109 executes interleaving of the sequence output from the inner code processor 107. The interleaving may include bit interleaving, which rearranges the order of bits. It may also include frequency interleaving, which rearranges the order of bits in the frequency axis direction in units of modulation orders, and may also include time interleaving, which rearranges the order of bits in the time axis direction in units of modulation orders.

[0048] The mapping unit 110 performs mapping on the sequence output from the inner interleaver 109 in units of modulation orders. As the modulation method, 64QAM (Quadrature Amplitude Modulation) may be used. As the modulation method, a modulation method other than 64QAM (for example, up to 4096QAM) may be used.

[0049] The frame configuration unit 111 configures a multiplex transmission frame in which two or more broadcast signals are multiplexed. In the embodiment, the multiplex transmission frame may include an FEC block of a first broadcast signal and an FEC block of a second broadcast signal. The multiplex transmission frame may also include an FEC block in which the first broadcast signal and the second broadcast signal are multiplexed in units of bytes. The multiplex transmission frame may be an OFDM frame. In the case of an OFDM frame, the data mapped by the mapping unit 110, the pilot, the TMCC signal, the AC (Auxiliary Channel), and the Null carriers are combined to configure an OFDM symbol. Furthermore, the OFDM frame is configured with a predetermined number of symbols per OFDM frame.

[0050] Here, control information for notifying switching between the output of the main system transmission processing unit 131 and the output of the backup system transmission processing unit 133 is input to the frame configuration unit 111. The control information may be included in a TMCC signal. The TMCC signal may be input from the above-mentioned monitor and control unit 135.

[0051] The modulation unit 113 performs orthogonal modulation on the multiplexed transmission frame. In the case of an OFDM frame, the modulation unit 113 performs inverse fast Fourier transform (IFFT) and GI (Guard Interval) addition processing before performing the orthogonal modulation.

[0052] The transmitting unit 115 transmits the multiplexed transmission frame modulated by the modulating unit 113 to the receiving device 200. The transmitting unit 115 may have a function of converting an IF (Intermediate Frequency) signal into an RF (Radio Frequency) signal and amplifying the signal to a rated transmission power.

[0053] In the embodiment, the transmission unit 115 constitutes a transmission unit that transmits control information notifying switching between the output of the first transmission processing unit and the output of the second transmission processing unit.

[0054] (Receiving device) The receiving device according to the embodiment will be described below. Fig. 4 is a block diagram showing the receiving device 200 according to the embodiment.

[0055] As shown in FIG. 4, the receiving device 200 includes a receiving filter 231, a distributor 233, a main system receiving processor 235, a standby system receiving processor 237, a monitor and controller 239, and a signal changeover switch 241.

[0056] The receiving filter 231 limits the band of the RF signal received via the antenna.

[0057] The distributor 233 distributes the main system multiplex transmission frame (or the protection system multiplex transmission frame) to the main system reception processing unit 235 and the protection system reception processing unit 237 .

[0058] The mainline reception processing unit 235 processes a mainline multiplex transmission frame (or a backup multiplex transmission frame) switched by the transmitting device 100, i.e., a multiplex transmission frame received from the transmitting device 100. In the embodiment, the mainline reception processing unit 235 may be referred to as a first reception processing unit. Details of the mainline reception processing unit 235 will be described later (FIG. 5).

[0059] The standby system reception processing unit 237 processes the multiplex transmission frame of the main system (or the multiplex transmission frame of the standby system) switched by the transmitting device 100, i.e., the multiplex transmission frame received from the transmitting device 100. In the embodiment, the standby system reception processing unit 237 may be referred to as a second reception processing unit. Details of the standby system reception processing unit 237 will be described later (FIG. 5).

[0060] The monitoring and control unit 239 monitors malfunctions of the main system reception processing unit 235 and the standby system reception processing unit 237. Specifically, when the main system reception processing unit 235 is selected by the signal changeover switch 241 and the monitoring and control unit 239 detects a malfunction of the main system reception processing unit 235, the monitoring and control unit 239 outputs a switching signal notification to the signal changeover switch 241 to switch the output selection of the signal changeover switch 241 from the main system reception processing unit 235 to the standby system reception processing unit 237. When the standby system reception processing unit 237 is selected by the signal changeover switch 241 and the monitoring and control unit 239 detects a malfunction of the standby system reception processing unit 237, the monitoring and control unit 239 outputs a switching signal notification to the signal changeover switch 241 to switch the output selection of the signal changeover switch 241 from the standby system reception processing unit 237 to the main system reception processing unit 235.

[0061] The signal changeover switch 241 changes the output of the main system receiving processor 235 to the output of the standby system receiving processor 237 based on a signal changeover notification input from the monitoring and control unit 239 .

[0062] Although not particularly limited, the signal changeover switch 241 may switch the output of the standby system receiving processor 237 to the output of the main system receiving processor 235 based on a signal changeover notification input from the monitoring and control unit 239.

[0063] In the embodiment, the signal changeover switch 241 may be referred to as a reception changeover section that switches between the output of the first reception processing section (mainline reception processing section 235) and the output of the second reception processing section (standby reception processing section 237).

[0064] (Receiving processing unit) The reception processing unit according to the embodiment will be described below. Fig. 5 is a block diagram showing the main system reception processing unit 235 and the standby system reception processing unit 237 according to the embodiment. The main system reception processing unit 235 and the standby system reception processing unit 237 may have the same configuration. Hereinafter, the main system reception processing unit 235 and the standby system reception processing unit 237 will be simply referred to as the reception processing unit.

[0065] As shown in Figure 5, the receiving processing unit includes a receiving unit 201, a demodulation unit 203, a frame processing unit 205, a demapping unit (likelihood calculation unit) 206, an inner deinterleaver 207, an inner code processing unit 209, an outer deinterleaver 211, an outer code processing unit 213, an energy despreading unit 214, and a block processing unit 215.

[0066] The receiving unit 201 receives the multiplexed transmission frame from the transmitting device 100. The receiving unit 201 may have a function of converting an RF signal into an IF signal. The receiving unit 201 may receive an OFDM frame as the multiplexed transmission frame.

[0067] In the embodiment, the receiving unit 201 constitutes a receiving unit that receives control information notifying switching between the output of the main system transmission processing unit 131 and the output of the standby system transmission processing unit 133 .

[0068] The demodulation unit 203 performs orthogonal demodulation on the multiplexed transmission frame. In the case of an OFDM frame, after the orthogonal demodulation, GI removal and FFT processing are performed.

[0069] The frame processing unit 205 detects the beginning of the multiplexed transmission frame and synchronizes the multiplexed transmission frame. In the case of an OFDM frame, the frame processing unit 205 detects the beginning of the OFDM frame from information on the TMCC carrier that can be differentially demodulated, and extracts the OFDM symbol.

[0070] The demapping unit (likelihood calculation unit) 206 performs equalization of the propagation path, and then performs demapping on the data in accordance with the modulation method. When soft decision is performed, the likelihood is calculated.

[0071] The inner deinterleaver 207 performs deinterleaving in a procedure reverse to that of the inner interleaver 109. The deinterleaving may include bit deinterleaving, frequency deinterleaving, and time deinterleaving.

[0072] The inner code processor 209 performs error correction on the FEC block based on the LDPC code parity. The inner code processor 209 removes the LDPC code parity from the FEC block.

[0073] Outer deinterleaver 211 performs deinterleaving in the reverse procedure to that of outer interleaver 105 .

[0074] The outer code processor 213 performs error correction on the FEC block based on the BCH code parity. The outer code processor 213 removes the BCH code parity from the FEC block.

[0075] The energy despreading unit 214 performs energy despreading in a procedure opposite to that of the energy dispersal unit 102. The target of energy despreading is the bit sequence output from the outer code processing unit 213 (i.e., the block header, the main signal (TS packet / IP packet), and the stuff bit if there is a stuff bit before the BCH code parity of the FEC block). Here, the initial value input to the generator polynomial is given for each FEC block. In other words, the PN sequence may be reset for each FEC block.

[0076] The block processing unit 215 separates the block header and the main signal (TS packets / IP packets) from the FEC block. Specifically, the block processing unit 215 extracts the TS packets from the FEC block of the first broadcast signal, and extracts the IP packets from the FEC block of the second broadcast signal. Alternatively, the block processing unit 215 extracts the TS packets and the IP packets from the FEC block in which the first broadcast signal and the second broadcast signal are multiplexed in byte units.

[0077] In the embodiment, the demapping unit 206 first performs channel estimation to estimate a channel response between the transmitting device and the receiving device from a known signal included in the multiplex transmission frame, and performs equalization of the channel. That is, the demapping unit 206 may configure a control unit that performs demodulation processing including channel estimation regarding the multiplex transmission frame. The demapping unit 206 performs channel estimation that does not span the symbols before and after the switching timing notified by the control information, without performing channel estimation across the symbols before and after the switching timing notified by the control information. That is, the demapping unit 206 does not perform channel estimation in a state in which the known signal of the transmission frame before switching and the known signal of the transmission frame after switching are mixed, and performs channel estimation using only the known signal in each transmission frame.

[0078] (FEC block) The FEC block according to the embodiment will be described below. Fig. 6 is a diagram showing the FEC block according to the embodiment.

[0079] As shown in Fig. 6, the FEC block includes a block header, a main signal (including stuff bits), a BCH code parity, and an LDPC code parity. The use of the block header is arbitrary. The type of the main signal of the FEC block may be described in the block header. The order of the BCH code parity and the stuff bits may be reversed.

[0080] Although not particularly limited, the size of the main signal (D) may vary according to the coding rate of the LDPC. ldpc ) may vary according to the LDPC coding rate. The number of TS packets or IP packets included in the main signal may vary according to the LDPC coding rate.

[0081] For example, the FEC block may have parameters as shown in Fig. 7. Fig. 7 illustrates a case where the number of stuff bits is 0. As shown in Fig. 7, the number of bits of the main signal (D) varies depending on the LDPC coding rate.

[0082] (Multiple Processing) The multiplexing process according to the embodiment will be described below. In the embodiment, a case will be described in which the first broadcast signal and the second broadcast signal are multiplexed in units of bytes.

[0083] As shown in FIG. 8, the multiplexing unit 150 includes a primary buffer 151A, a primary buffer 151B, a switching unit 152A, a switching unit 152B, a buffer 153A, a buffer 153B, a buffer 154A, a buffer 154B, a stuff packet 155A, a stuff packet 155B, a switching unit 156A, a switching unit 156B, a switching unit 157, an FEC block construction unit 158, and an input control unit 159.

[0084] The multiplexing unit 150 is an example of a control unit that generates a multiplex transmission frame in which one or more broadcast signals are multiplexed. The multiplexing unit 150 may divide each of the two or more broadcast signals into bytes, which are predetermined units, and multiplex the two or more broadcast signals divided into predetermined units based on the ratio of the rates of the two or more broadcast signals. The multiplexing unit 150 is provided in the block configuration unit 101 of the transmitting device 100.

[0085] The primary buffer 151A is a buffer that stores the first broadcast signal. For example, the buffer 153A stores TS packets having a rate of 31 Mbps.

[0086] The primary buffer 151B is a buffer that stores the second broadcast signal. For example, the buffer 153B stores IP packets having a rate of 50 Mbps.

[0087] The switching unit 152A switches the buffer that stores the first broadcast signal between the buffer 153A and the buffer 154A at a reference timing.

[0088] The switching unit 152B switches the buffer that stores the second broadcast signal between the buffer 153B and the buffer 154B at the reference timing.

[0089] The buffer 153A stores the first broadcast signal when the switching unit 152A connects the buffer 153A to the primary buffer 151A. In the embodiment, the buffer 153A is an example of a first buffer.

[0090] The buffer 153B stores the second broadcast signal when the buffer 153B is connected to the primary buffer 151B by the switching unit 152B. In the embodiment, the buffer 153B is an example of a first buffer.

[0091] The buffer 154A stores the first broadcast signal when the switching unit 152A connects the buffer 154A to the primary buffer 151A. In the embodiment, the buffer 154A is an example of a second buffer.

[0092] The buffer 154B stores the second broadcast signal when the switching unit 152B connects the buffer 154B to the primary buffer 151B. In the embodiment, the buffer 154B is an example of a second buffer.

[0093] The stuff packet 155A outputs a stuff packet when the first broadcast signal for constituting one TS packet is not stored in the buffer 153A or the buffer 154A. The stuff packet output from the stuff packet 155A may be considered as dummy data equivalent to the first broadcast signal.

[0094] The stuff packet 155B outputs a stuff packet when the second broadcast signal for constituting one IP packet is not stored in the buffer 153B or the buffer 154B. The stuff packet output from the stuff packet 155B may be considered as dummy data equivalent to the second broadcast signal.

[0095] The switching unit 156A switches the source of packets to be stored in the FEC block. Specifically, the switching unit 156A switches the source of inputting packets to the switching unit 157 between the buffer 153A and the buffer 154A at a timing (FEC block switching timing) when a configuration start time (γ shown in FIG. 9) has elapsed from the reference timing. When there is a shortage of packets for configuring the FEC block, the switching unit 156A switches the source of inputting packets to the switching unit 157 to the stuff packets 155A.

[0096] The switching unit 156B switches the source of packets to be stored in the FEC block. Specifically, the switching unit 156B switches the source for inputting packets to the switching unit 157 between the buffer 153B and the buffer 154B at a timing (FEC block switching timing) when a configuration start time (γ shown in FIG. 9) has elapsed from the reference timing. When there is a shortage of packets for configuring the FEC block, the switching unit 156B switches the source for inputting packets to the switching unit 157 to the stuff packets 155B.

[0097] The switching unit 157 switches the source of the data multiplexed into the FEC block in units of bytes. Specifically, the switching unit 157 switches the source of the data multiplexed into the FEC block between the switching unit 156A and the switching unit 156B.

[0098] Here, the switching unit 157 switches the data source (first broadcast signal / second broadcast signal) based on the ratio between the rates of two or more broadcast signals.

[0099] The FEC block constructing unit 158 ​​constructs an FEC block in which the first broadcast signal and the second broadcast signal are multiplexed. The FEC block constructing unit 158 ​​stores block header information in the block header of the FEC block, and stores the signal in byte units output from the switching unit 157 in the main signal portion of the FEC block.

[0100] The input control unit 159 instructs the primary buffer 151A to output packets (TS packets) corresponding to the first broadcast signal at packet intervals. The input control unit 159 instructs the primary buffer 151B to output packets (IP packets) corresponding to the second broadcast signal at packet intervals.

[0101] The input control unit 159 switches the switching unit 152A at a reference timing (a superframe head reference pulse, described later).The input control unit 159 switches the switching unit 152B at a reference timing (a superframe head reference pulse, described later).

[0102] The input control unit 159 switches the switching unit 156A at a timing (FEC block switching timing) when a configuration start time (γ shown in FIG. 9) has elapsed from a reference timing (a superframe head reference pulse described later). The input control unit 159 switches the switching unit 156B at a timing (FEC block switching timing) when a configuration start time (γ shown in FIG. 9) has elapsed from a reference timing (a superframe head reference pulse described later).

[0103] Here, even if the switching timing arrives in a state where the buffer 153A is connected by the switching unit 156A, the input control unit 159 suspends switching from the buffer 153A to the buffer 154A until all the packets (first broadcast signal) stored in the buffer 153A are exhausted. Similarly, even if the switching timing arrives in a state where the buffer 154A is connected by the switching unit 156A, the input control unit 159 suspends switching from the buffer 154A to the buffer 153A until all the packets (first broadcast signal) stored in the buffer 154A are exhausted.

[0104] Even if the switching timing arrives in a state where buffer 153B is connected by switching unit 156B, input control unit 159 suspends switching from buffer 153B to buffer 154B until all packets (second broadcast signal) stored in buffer 153B are exhausted. Similarly, even if the switching timing arrives in a state where buffer 154B is connected by switching unit 156B, input control unit 159 suspends switching from buffer 154B to buffer 153B until all packets (second broadcast signal) stored in buffer 154B are exhausted.

[0105] The input control unit 159 switches the switching unit 157 based on the ratio between the rates of two or more broadcast signals. For example, when the ratio between the rates of the first broadcast signal and the second broadcast signal is 3:5, the input control unit 159 switches the switching unit 156B in a manner such as BABBABBA, where A is a predetermined unit (here, bytes) corresponding to the first broadcast signal, and B is a predetermined unit (here, bytes) corresponding to the second broadcast signal.

[0106] In the embodiment, the first broadcast signal and the second broadcast signal are multiplexed into one FEC block, and therefore the FEC block constructing unit processes the signals in one system.

[0107] 8, a case has been described in which two broadcast signals, the first broadcast signal and the second broadcast signal, are multiplexed into an FEC block, but the embodiment is not limited thereto. Three or more broadcast signals may be multiplexed into an FEC block.

[0108] In an embodiment, the switching unit 152A and the switching unit 152B constitute a first buffer switching unit that switches the buffer that stores each of two or more broadcast signals between a first buffer (buffer 153A and buffer 153B) and a second buffer (buffer 154A and buffer 154B) at a switching timing.

[0109] In an embodiment, the switching unit 156A and the switching unit 156B constitute a second buffer switching unit that switches the buffer that outputs the broadcast signal used to generate the multiplexed transmission frame between the first buffer (buffer 153A and buffer 153B) and the second buffer (buffer 154A and buffer 154B) at the timing (FEC block switching timing) when the construction start time (γ shown in FIG. 9) has elapsed from the reference timing.

[0110] In the embodiment, the reference timing is a timing common to the main system transmission processing unit 131 and the backup system transmission processing unit 133. The reference timing is the start timing of a specific transmission frame composed of one or more multiplex transmission frames. The specific transmission frame is defined so as not to fragment packets that compose one or more broadcast signals. In other words, when multiplexing of two or more broadcast signals is assumed, the number of predetermined units included in the specific transmission frame is divisible by the multiplexing period of two or more broadcast signals. The switching timing is the timing when the composition start time has elapsed from the reference timing, and is therefore a timing defined by the reference timing.

[0111] Here, consider a case where the number of FEC blocks included in one multiplex transmission frame is expressed by 20 × modulation order in a case where the FEC block has the parameters shown in FIG. 7 described above. In such a case, a specific transmission frame composed of one or more multiplex transmission frames may be newly defined. The specific transmission frame may be called a superframe. The start timing of the specific transmission frame may be called a superframe head reference pulse. The superframe head reference pulse is a pulse that is output at a superframe period.

[0112] The number of predetermined units (bytes) included in the specific transmission frame is divisible by two or more multiplexing periods of the broadcast signal. In other words, the number of multiplexed transmission frames included in the specific transmission frame is determined so that the number of bytes included in the specific transmission frame is divisible by the multiplexing period. The multiplexing period is a period in which two or more broadcast signals are multiplexed at a rate ratio, and may be expressed in bytes.

[0113] For example, when the multiplexing period is 32 bytes, the number of multiplexed transmission frames included in the specific transmission frame may be 8. That is, since the number of FEC blocks included in the specific transmission frame, 160 × modulation order (= 20 × modulation order × 8), is divisible by 32, the total number of bytes of the main signal included in the specific transmission frame is divisible by the multiplexing period regardless of which of the parameters shown in Fig. 7 described above is adopted.

[0114] In other words, if the number of FEC blocks included in a multiplexed transmission frame is K, the number of bytes of the main signal included in the FEC blocks is L, the number of multiplexed transmission frames included in a specific transmission frame is M, and the multiplexing period (number of bytes) is N, M may be set so that L×K×M÷N is an integer.

[0115] Under such a premise, when two or more broadcast signals are each composed of packets (TS packets or IP packets), the specific transmission frame may include an integer number of packets. That is, although the fragmentation of a packet across two FEC blocks or two multiplex transmission frames is permitted, the fragmentation of a packet across two specific transmission frames may not be permitted.

[0116] Here, the multiplexing unit 150 is provided in each of the main system transmission processing unit 131 and the standby system transmission processing unit 133, and the reference timing is a timing common to the main system transmission processing unit 131 and the standby system transmission processing unit 133. Therefore, the output of the main system transmission processing unit 131 and the output of the standby system transmission processing unit 133 are synchronized with the reference timing common to the main system transmission processing unit 131 and the standby system transmission processing unit 133.

[0117] (Storage in buffer) Storage in the buffer according to the embodiment will be described below. Figures 9 and 10 are diagrams for explaining storage in the buffer according to the embodiment.

[0118] First, the operation of storing a packet associated with the first superframe leading reference pulse in a buffer will be described with reference to FIG.

[0119] 9, packets (TS packets or IP packets) are stored in primary buffer 151A and primary buffer 151B at packet intervals (α). Packets stored at a packet interval (α) prior to the packet interval (α) that includes the timing at which the first superframe head reference pulse is output are discarded.

[0120] Packets stored in primary buffer 151A or primary buffer 151B are stored in buffer 153A and buffer 153B (or buffer 154A and buffer 154B) after a packet interval (α). The time that one packet is stored in buffer 153A and buffer 153B (or buffer 154A and buffer 154B) may be referred to as storage time (β). FIG. 9 illustrates a case where packets are stored in buffer 153A and buffer 153B.

[0121] The packets stored in buffer 153A and buffer 153B are configured into an FEC block when configuration start time (γ) has elapsed from the superframe head reference pulse. Here, configuration start time (γ) is longer than the total time of the processing time for configuring one FEC block (hereinafter, FEC block processing interval), the packet interval (α), and the storage time (β).

[0122] Secondly, the operation of storing packets related to the second and subsequent superframe head reference pulses in the buffer will be described with reference to FIG.

[0123] As shown in Fig. 10, packets (TS packets or IP packets) are stored in primary buffer 151A and primary buffer 151B at packet intervals (α) in the same manner as in Fig. 9. Packets stored at a packet interval (α) prior to the packet interval (α) including the timing at which a superframe head reference pulse is output are stored in buffer 153A and buffer 153B (or buffer 154A and buffer 154B). Packets stored at a packet interval (α) after the packet interval (α) including the timing at which a superframe head reference pulse is output are stored in buffer 154A and buffer 154B (buffer 153A and buffer 153B). Fig. 10 illustrates a case in which the buffers are switched from buffer 153A and buffer 153B to buffer 154A and buffer 154B.

[0124] The packets stored in buffers 153A and 153B are configured into an FEC block at an FEC block processing interval. The packets stored in buffers 154A and 154B are configured into an FEC block at the next FEC block processing interval.

[0125] (Separation processing) The following describes the separation process according to the embodiment. In the embodiment, a case will be described in which the first broadcast signal and the second broadcast signal are separated in units of bytes.

[0126] As shown in FIG. 11, the demultiplexing unit 250 includes an FEC block processing unit 251, a switching unit 252, a stuff packet removal unit 253A, a stuff packet removal unit 253B, and an output control unit 259.

[0127] The separator 250 is an example of a control unit that separates two or more broadcast signals separated by bytes, which are predetermined units, based on the ratio of the rates of the two or more broadcast signals. The separator 250 is provided in the block processing unit 215 of the receiving device 200.

[0128] The FEC block processing unit 251 extracts, from the FEC block, the first broadcast signal (TS packets), the second broadcast signal (IP packets), and the main signal in which their stuff packets are multiplexed in byte units.

[0129] In the embodiment, the first broadcast signal and the second broadcast signal are multiplexed into one FEC block, and therefore the FEC block processor processes the signals in one system.

[0130] The switching unit 252 switches the target of the data separated from the FEC block. Specifically, the switching unit 252 switches the target of the data separated from the FEC block between the processing unit for the first broadcast signal and the processing unit for the second broadcast signal.

[0131] The stuff packet removal unit 253A removes the stuff packets from the main signal output from the switching unit 252, and extracts the first broadcast signal (TS packets).

[0132] The stuff packet removal unit 253B removes the stuff packets from the main signal output from the switching unit 252, and extracts the second broadcast signal (IP packets).

[0133] The output control unit 259 instructs the FEC block processing unit 251 to extract a main signal from the FEC block. The output control unit 259 switches the switching unit 252 based on the ratio between the rates of two or more broadcast signals. The output control unit 259 instructs the stuff packet removal unit 253A to remove stuff packets. The output control unit 259 instructs the stuff packet removal unit 253B to remove stuff packets.

[0134] (Control information) The control information according to the embodiment will be described below. The control information may be included in a TMCC signal.

[0135] The control information may be considered as control information for notifying switching between the output of the main system transmission processing unit 131 and the output of the backup system transmission processing unit 133. The control information may be considered as control information for notifying switching between the main system and the backup system.

[0136] For example, as shown in FIG. 12, the control information may include a unit switching notification valid flag (b143) and a unit switching notification (b215) as bits related to switching.

[0137] The unit switching notification valid flag (b143) is a flag indicating whether the unit switching notification (b215) is valid or invalid. For example, the unit switching notification valid flag (b143) may have a value of "0" indicating that the unit switching notification (b215) is invalid and a value of "1" indicating that the unit switching notification (b215) is valid.

[0138] The unit switching notification (b215) is information notifying switching between the main system and the backup system. The unit switching may mean switching from the main system to the backup system, or from the backup system to the main system. The unit switching notification (b215) can take a value of "0" indicating that there will be no unit switching at the beginning of the next symbol, or "1" indicating that there will be a unit switching at the beginning of the next symbol.

[0139] (Action and Effects) In the embodiment, the transmission device 100 generates a multiplexed transmission frame so that the main line transmission processing unit 131 and the standby line transmission processing unit 133 are synchronized with a common reference timing.

[0140] In the above-mentioned configuration, the reference timing is the start timing (superframe leading reference pulse) of a specific transmission frame composed of one or more multiplex transmission frames, and the specific transmission frame is defined so as not to divide packets that compose one or more broadcast signals. With this configuration, it is possible to seamlessly switch between the main line transmission frame (transmission signal) and the backup system transmission frame (transmission signal).

[0141] In the embodiment, the multiplex transmission frame may be a multiplex transmission frame in which two or more broadcast signals are multiplexed. The main line transmission processing unit 131 and the backup system transmission processing unit 133 may divide each of the two or more broadcast signals into a predetermined unit, and generate a multiplex transmission frame in which the two or more broadcast signals divided into the predetermined unit are multiplexed based on the ratio of the rates of the two or more broadcast signals. The number of predetermined units included in the specific transmission frame is divisible by the multiplexing period of the two or more broadcast signals. With this configuration, it is possible to seamlessly switch between the main line system transmission frame (transmission signal) and the backup system transmission frame (transmission signal) while appropriately ensuring the rates of the two or more broadcast signals.

[0142] [Change Example 1] Modification 1 of the embodiment will be described below. Differences from the embodiment will be mainly described below.

[0143] In the embodiment, a case where two or more broadcast signals are multiplexed has been described. In contrast to this, in Modification 1, a case where no broadcast signals are multiplexed and one broadcast signal is transmitted will be described.

[0144] As shown in FIG. 13, the multiplexing section 150 of the transmitting device 100 in the modified example 1 has a configuration similar to that shown in FIG. 8, except that it does not have the configuration related to the second broadcast signal (primary buffer 151B, switching section 152B, buffer 153B, buffer 154B, stuff packet 155B, switching section 156B) and switching section 157.

[0145] Here, we have described a case in which the configuration related to the second broadcast signal is omitted, but the configuration related to the first broadcast signal (primary buffer 151A, switching unit 152A, buffer 153A, buffer 154A, stuff packet 155A, switching unit 156A) may also be omitted.

[0146] As shown in FIG. 14, the separation unit 250 of the receiving device 200 in the modified example 1 has a configuration similar to that shown in FIG. 11, except that it does not have the switching unit 252 and the configuration related to the second broadcast signal (stuff packet removal unit 253B).

[0147] Here, the case where the configuration related to the second broadcast signal is omitted has been described, but the configuration related to the first broadcast signal (stuff packet removal unit 253A) may be omitted.

[0148] In the first modification as well, the reference timing may be the start timing (superframe head reference pulse) of a specific transmission frame that is composed of one or more multiplexed transmission frames.

[0149] [Other embodiments] Although the present invention has been described by the above disclosure, the description and drawings forming a part of this disclosure should not be understood as limiting the present invention. From this disclosure, various alternative embodiments, examples and operating techniques will become apparent to those skilled in the art.

[0150] In the above disclosure, the case where the multiplex transmission frame is an OFDM frame is exemplified. However, the above disclosure is not limited thereto. The above disclosure may be applied to the case where the multiplex transmission frame is a MIMO (Multiple-Input Multiple-Output)-OFDM frame.

[0151] In the above disclosure, a case where two broadcast signals are multiplexed into a multiplex transmission frame is exemplified. However, the above disclosure is not limited thereto. The above disclosure may be applied to a case where three or more broadcast signals are multiplexed into a multiplex transmission frame.

[0152] In the above disclosure, a case has been exemplified in which the predetermined unit to which multiplexing or demultiplexing is applied is a unit constituted by bytes. However, the above disclosure is not limited to this. The predetermined unit to which multiplexing or demultiplexing is applied may be a unit constituted by FEC blocks. In such a case, bytes may be read as FEC blocks, and FEC blocks may be read as transmission frames.

[0153] Although not specifically mentioned in the above disclosure, the IFFT clock used in the OFDM modulation of the first broadcast signal and the second broadcast signal and the IFFT clock used in the OFDM modulation of advanced STL / TTL may have an integer ratio relationship.

[0154] Although not specifically mentioned in the above disclosure, the period of the transmission frames of the first broadcast signal and the second broadcast signal and the period of the transmission frames of the advanced STL / TTL may have an integer ratio relationship.

[0155] Although not particularly mentioned in the above disclosure, a program may be provided that causes a computer to execute each process performed by the transmitting device 100 and the receiving device 200. The program may also be recorded in a computer-readable medium. Using the computer-readable medium, it is possible 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.

[0156] Alternatively, a chip may be provided that is configured by a memory that stores a program for executing each process performed by the transmitting device 100 and the receiving device 200, and a processor that executes the program stored in the memory.

[0157] (Additional Note) The above disclosure may be expressed as follows:

[0158] A first feature is a transmitting device that transmits a multiplex transmission frame in which one or more broadcast signals are multiplexed, comprising a first transmission processing unit, a second transmission processing unit, and a transmission switching unit that switches between an output of the first transmission processing unit and an output of the second transmission processing unit, each of the first transmission processing unit and the second transmission processing unit comprising a control unit that generates a multiplex transmission frame in which the one or more broadcast signals are multiplexed, the output of the first transmission processing unit and the output of the second transmission processing unit are synchronized with a reference timing common to the first transmission processing unit and the second transmission processing unit, the reference timing is the start timing of a specific transmission frame composed of the one or more multiplex transmission frames, and the specific transmission frame is defined so as not to fragment packets that constitute the one or more broadcast signals.

[0159] A second feature is a transmitting device in which, in the first feature, each of the first transmission processing unit and the second transmission processing unit includes a first buffer switching unit that switches a buffer that stores the one or more broadcast signals between a first buffer and a second buffer at the reference timing, and a second buffer switching unit that switches a buffer that outputs a broadcast signal used to generate the multiplex transmission frame between the first buffer and the second buffer at a switching timing defined by the reference timing.

[0160] A third feature is the transmitting device of the second feature, wherein the second buffer switching unit suspends switching of the buffer until the broadcast signal stored in the buffer connected by the second buffer switching unit is depleted, even when the switching timing arrives.

[0161] A fourth feature is a transmitting device in at least one of the first to third features, comprising a transmitting unit that transmits control information notifying switching between the output of the first transmitting processing unit and the output of the second transmitting processing unit.

[0162] A fifth feature is a transmitting device in which, in at least one of the first feature to the fourth feature, when the multiplex transmission frame is a multiplex transmission frame in which two or more broadcast signals are multiplexed, the control unit divides each of the two or more broadcast signals by a predetermined unit, and generates a multiplex transmission frame in which the two or more broadcast signals divided by the predetermined unit are multiplexed based on a rate ratio of each of the two or more broadcast signals, and the number of the predetermined units included in the specific transmission frame is divisible by the multiplexing period of the two or more broadcast signals.

[0163] A sixth feature is a receiving device that receives a multiplex transmission frame in which one or more broadcast signals are multiplexed from a transmitting device, the receiving device comprising: a receiving unit that receives the multiplex transmission frame generated by a first transmission processing unit of the transmitting device or a second transmission processing unit of the transmitting device; and a control unit that executes demodulation processing including propagation path estimation for the multiplex transmission frame, wherein the receiving unit receives control information notifying switching between an output of the first transmission processing unit and an output of the second transmission processing unit, the control unit executes propagation path estimation that does not straddle symbols before and after the switching timing notified by the control information, without executing propagation path estimation that straddles symbols before and after the switching timing notified by the control information, the output of the first transmission processing unit and the output of the second transmission processing unit are synchronized with a reference timing common to the first transmission processing unit and the second transmission processing unit, the reference timing is a start timing of a specific transmission frame constituted by the one or more multiplex transmission frames, and the specific transmission frame is defined so as not to fragment packets that constitute the one or more broadcast signals. [Explanation of symbols]

[0164] 10...digital wireless transmission system, 100...transmitting device, 101...block configuration section, 102...energy dispersal section, 103...outer code processing section, 105...outer interleaver, 107...inner code processing section, 109...inner interleaver, 110...mapping section, 111...frame configuration section, 113...modulation section, 115...transmitting section, 131...main line transmission processing section, 133...standby line transmission processing section, 135...monitoring control section, 137...RF changeover switch, 139...transmitting filter, 150...multiplexing section, 151...primary buffer, 152...switching section, 153...buffer, 154...buffer, 155...stuff packet, 156...switching section, 157...switching section, 158...F EC block configuration unit, 159...input control unit, 200...receiving device, 201...receiving unit, 203...demodulation unit, 205...frame processing unit, 206...demapping unit (likelihood calculation unit), 207...inner deinterleaver, 209...inner code processing unit, 211...outer deinterleaver, 213...outer code processing unit, 214...energy despreading unit, 215...block processing unit, 231...receiving filter, 233...distributor, 235...main line receiving processing unit, 237...standby line receiving processing unit, 239...monitoring control unit, 241...signal changeover switch, 250...separation unit, 251...FEC block processing unit, 252...switching unit, 253...stuff packet removal unit, 259...output control unit

Claims

1. A transmitting device for transmitting a multiplex transmission frame in which one or more broadcast signals are multiplexed, A first transmission processing unit; A second transmission processing unit; a transmission switching unit that switches between an output of the first transmission processing unit and an output of the second transmission processing unit, Each of the first transmission processing unit and the second transmission processing unit includes a control unit that generates a multiplex transmission frame in which the one or more broadcast signals are multiplexed, an output of the first transmission processing unit and an output of the second transmission processing unit are synchronized with a reference timing common to the first transmission processing unit and the second transmission processing unit; the reference timing is a start timing of a specific transmission frame composed of the one or more multiplex transmission frames, A transmitting device, wherein the specific transmission frame is defined so as not to fragment packets constituting the one or more broadcast signals.

2. Each of the first transmission processing unit and the second transmission processing unit is a first buffer switching unit that switches a buffer for storing the one or more broadcast signals between a first buffer and a second buffer at the reference timing; The transmitting device according to claim 1, further comprising: a second buffer switching unit that switches a buffer that outputs a broadcast signal used to generate the multiplex transmission frame between the first buffer and the second buffer at a switching timing defined by the reference timing.

3. The transmitting device according to claim 2, wherein the second buffer switching unit suspends switching of the buffer until the broadcast signal stored in the buffer connected by the second buffer switching unit runs out, even when the switching timing arrives.

4. The transmitting device according to claim 1 , further comprising a transmitting unit that transmits control information notifying switching between an output of the first transmission processing unit and an output of the second transmission processing unit.

5. When the multiplex transmission frame is a multiplex transmission frame in which two or more broadcast signals are multiplexed, the control unit divides each of the two or more broadcast signals into a predetermined unit, and generates a multiplex transmission frame in which the two or more broadcast signals divided into the predetermined unit are multiplexed based on a ratio of the rates of the two or more broadcast signals; The transmitting device according to claim 1 , wherein the number of the predetermined units included in the specific transmission frame is divisible by the multiplexing periods of the two or more broadcast signals.

6. A receiving device that receives a multiplex transmission frame in which one or more broadcast signals are multiplexed from a transmitting device, a receiving unit that receives the multiplexed transmission frame generated by a first transmission processing unit of the transmitting device or a second transmission processing unit of the transmitting device; A control unit that executes a demodulation process including a propagation path estimation for the multiplex transmission frame, the receiving unit receives control information notifying switching between the output of the first transmission processing unit and the output of the second transmission processing unit; the control unit does not perform channel estimation across symbols before and after the switching timing notified by the control information, but performs channel estimation that does not span symbols before and after the switching timing notified by the control information; an output of the first transmission processing unit and an output of the second transmission processing unit are synchronized with a reference timing common to the first transmission processing unit and the second transmission processing unit; the reference timing is a start timing of a specific transmission frame composed of the one or more multiplex transmission frames, A receiving device, wherein the specific transmission frame is defined so as not to fragment packets constituting the one or more broadcast signals.

Images