JP2013121092A - Broadcasting system, transmitter and receiver used therefor, broadcasting method and program, reception reproduction method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a broadcasting system of ISDB-T transmission system capable of increasing error correction performance.SOLUTION: The broadcasting system of an ISDB-T transmission system has a transmitter including: a TS re-multiplexing section that multiplexes TS; a hierarchy parallel processing section that performs a processing including byte interleaving and convolution encoding on the multiplexed TS to generate an OFDM transmission signal; and a transmitting section that transmits the OFDM transmission signal. The receiver includes a receiving section and a decoding section that performs a viterbi decoding on the received OFDM transmission signal. The TS re-multiplexing section disposes a main packet and a delay packet alternately with an identical repeating unit so that the positional relationship between each main packet and each of corresponding delay packets is constant. The decoding section determines a piece of data of a delay packet corresponding to the main packet in the viterbi decoding based on a piece of data of a main packet which is previously decoded to obtain a path for the data of the main packet neighboring the data of the determined delay packet.

Description

  The present invention relates to a broadcasting system to which terrestrial digital broadcasting is applied, a transmitter and a receiver used therefor, a broadcasting method and a program, and a reception reproduction method and a program.

  Emergency broadcasting such as disaster information is being considered by multimedia broadcasting for mobile terminals and Area One Seg using the technology of terrestrial digital broadcasting (ISDB-T: Integrated Services Digital Broadcasting-Terrestrial). For example, install transmitters that capture and transmit images at disaster sites, deploy receivers to police, fire, and emergency vehicles so that the images of disaster sites can be checked on those vehicles as needed. Is considered.

  In multimedia broadcasting for mobile terminals and Area One Seg, it is assumed that the receiver moves and the reception state temporarily deteriorates, so that the video can be stably reproduced by the receiver. In addition, when multimedia broadcasting for mobile terminals and Area One Seg are applied as emergency broadcasting, it is required that there is little video delay due to the urgency.

  In order to reduce the video delay, it is conceivable to reduce the time interleaving when modulating the carrier wave of the video data to be transmitted. However, by reducing the time interleaving, the delay is reduced, but packets are likely to be dropped due to temporary deterioration of the reception state due to fading. As a result, the video is likely to be disturbed, especially when the receiver moves.

  Patent Document 1 discloses a technique for stabilizing a broadcast video. In this case, it is assumed that the mobile body is deteriorated in the reception state for several seconds. The transmitter multiplexes and transmits video data (main packet) and video data (delay packet) obtained by delaying the video data (main packet) by a time interleave length or more. In the receiver, when the main packet is lost due to the deterioration of the reception state, the video is reproduced using the delay packet. With this configuration, even if the reception state is deteriorated beyond the time interleave length, the disturbance of the video can be suppressed as long as the packet is delayed.

  However, according to the technique of Patent Document 1, since the video is played back by the main packet at all times after receiving the delayed packet, or by the delayed packet when the main packet has not been received, Playback will be delayed. In other words, Patent Document 1 does not devise for reproducing video with low delay. Further, Patent Document 1 does not devise a technique for improving the error correction capability itself that prevents the loss of the main packet.

JP 2004-140506 A

  As described above, with the conventional technology, it is difficult to achieve low delay and video stabilization in multimedia broadcasting for mobile terminals and area one segment.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a broadcasting system that can improve error correction capability and stabilize video. Another object of the present invention is to provide a broadcasting system capable of reducing video delay. It is another object of the present invention to provide a broadcasting system that can reduce image disturbance.

  The broadcast system of the present invention is a broadcast system that includes a transmitter and a receiver, and performs ISDB-T data transmission from the transmitter to the receiver. The transmitter multiplexes one or a plurality of transport streams into a transport stream including a main packet and a delayed packet obtained by delaying the main packet, and the TS remultiplexing unit. The transport stream is configured to include a processing unit that performs processing including byte interleaving and convolutional coding to generate an OFDM transmission signal, and a transmission unit that transmits the OFDM transmission signal. Yes. The receiver includes a receiving unit that receives the OFDM transmission signal, a decoding unit that performs Viterbi decoding on the OFDM transmission signal received by the receiving unit, and reproduces data decoded by the decoding unit. And a reproducing unit. The TS remultiplexing unit arranges the main packet and the delayed packet alternately in the same repeating unit, and the positional relationship between each main packet and each corresponding delayed packet is a constant relationship. In the Viterbi decoding, the decoding unit determines the delayed packet data corresponding to the main packet based on the previously decoded main packet data, and then adjoins the determined delayed packet data. Find the data path.

  With this configuration, the TS remultiplexing unit of the transmitter alternates the main packet and the delayed packet in the same repetition unit, and the positional relationship between each main packet and each corresponding delayed packet becomes a fixed relationship. The transport unit multiplexes the transport stream, and the processing unit performs byte interleaving and convolutional coding of the ISDB-T transmission method for such a transport stream. At the time of decoding, the data of the delayed packet can be determined by referring to the data of the corresponding main packet that has been previously decoded, and thereby the main packet adjacent to the data of the delayed packet thus determined. Can improve the likelihood of finding the path of the data and improve the error correction capability, so the video can be stabilized. .

  In the broadcast system, the reproducing unit may reproduce the decoded main packet without waiting for a delayed packet corresponding to the decoded main packet after the decoding unit decodes the main packet.

  With this configuration, while the main packet can be received, the reproduction is performed without waiting for the delay packet, so that the video delay can be reduced as compared with the case where the reproduction is performed after receiving the delay packet.

  In the above broadcasting system, when some of the OFDM transmission signals cannot be received by the receiving unit, the receiving unit receives a delayed packet corresponding to a main packet included in the OFDM transmission signal that could not be received. When received, the decoding unit may obtain a route for the delayed packet by the Viterbi decoding, and the reproducing unit may reproduce the decoded data of the delayed packet.

  With this configuration, when the main packet is lost due to the deterioration of the reception state, the video can be reproduced with the delayed packet corresponding to the lost main packet.

  In the above broadcasting system, when the decoding unit also decodes the delayed packet because the receiving unit cannot receive a part of the OFDM transmission signal, the reproducing unit mainly performs reproduction. Fast forward playback may be performed until the packet is received.

  With this configuration, even when the reception state deteriorates and playback is temporarily interrupted, it is possible to reduce video delay and video disturbance after playback is resumed.

  In the above broadcasting system, the TS remultiplexing unit may alternately arrange the main packet and the delayed packet for each packet.

  With this configuration, since the processing unit performs byte interleaving, the main packet data and the delayed packet data are alternately arranged for each byte in the OFDM transmission signal. When the Viterbi decoding of the data is performed, the number of places where the data of the adjacent delayed packets can be used increases, so that the likelihood becomes higher and the error correction capability is further improved.

  The above broadcasting system may perform multimedia broadcasting for mobile terminals or area one segment broadcasting.

  With this configuration, even in an environment where the receiver can move and the reception state can become unstable, video can be stably reproduced.

  Another aspect of the present invention is a transmitter in the above broadcasting system, and yet another aspect is a receiver in the above broadcasting system.

  Still another aspect of the present invention is a broadcasting method for performing ISDB-T data transmission to a receiver. This broadcasting method includes one or a plurality of transport streams, a main packet, and the main packet. A TS re-multiplexing step for multiplexing the transport stream including the delayed packet obtained by delaying the packet, and processing including byte interleaving and convolutional coding for the transport stream multiplexed in the TS re-multiplexing step. Performing a process for generating an OFDM transmission signal and a transmission step for transmitting the OFDM transmission signal, wherein the TS remultiplexing step includes alternating the main packet and the delayed packet in the same repetition unit, and Arrange so that the positional relationship between each main packet and each corresponding delayed packet is a fixed relationship. .

  This method can also improve the likelihood when the receiver obtains the data path of the main packet, thereby improving the error correction capability.

  Still another aspect of the present invention is a reception / reproduction method for receiving and reproducing an OFDM transmission signal transmitted by a ISDB-T system from a transmitter, wherein the reception / reproduction method receives the OFDM transmission signal. A decoding step of performing Viterbi decoding on the OFDM transmission signal received in the receiving step, and a reproducing step of reproducing the data decoded in the decoding step, In Viterbi decoding, after determining the data of the delayed packet corresponding to the main packet based on the previously decoded main packet data, the route of the data of the main packet adjacent to the determined delayed packet data is obtained. .

  This reception / reproduction method can also improve the likelihood when determining the route of the data of the main packet, and improve the error correction capability.

  Still another aspect of the present invention is a broadcast program characterized by causing the transmitter to execute the above-described broadcasting method by being executed by the transmitter, and yet another aspect is the receiver. A reception program that, when executed, causes the receiver to execute the reception reproduction method described above.

  The present invention can provide a broadcasting system that can improve the error correction capability by improving the likelihood when determining the route of the data of the main packet, and thereby stabilize the video.

The figure explaining the multiplexing in TS remultiplex part of this Embodiment The figure which shows the whole structure of the broadcast system of this Embodiment. The figure which shows the structure of the signal conversion part of the transmitter of this Embodiment. The figure which shows the byte interleaving in the hierarchical parallel processing part of this Embodiment The figure which shows the structure of TS obtained by performing the byte interleaving of this Embodiment Trellis diagram in Viterbi decoding in decoding section of this embodiment The figure explaining the reproduction | regeneration method when a part of OFDM transmission signal of this Embodiment is missing

  Hereinafter, a broadcasting system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a diagram showing an overall configuration of the broadcasting system of the present embodiment. The broadcast system 100 includes a transmitter 200 and a plurality of receivers 300. The transmitter 200 and the receiver 300 communicate wirelessly.

  The transmitter 200 can be installed at an arbitrary place, and the receiver 300 can move while receiving a transmission wave from the transmitter 200. For example, when the broadcasting system 100 is used as an emergency broadcasting system at the time of a disaster, the transmitter 200 is disposed at a disaster site, and the receiver 300 is disposed in a vehicle such as a police, a fire department, or an emergency.

  A data transmission method from the transmitter 200 to the receiver 300 is an ISDB-T method compliant with a transmission method standard (ARIB STD-B31) for digital terrestrial television broadcasting. Therefore, in the following, the technical contents defined in this standard will be briefly described or omitted.

  As illustrated in FIG. 2, the transmitter 200 includes an input unit 201, a signal conversion unit 202, and a transmission unit 203. The input unit 201 inputs a video signal, an audio signal, and a data signal to the signal conversion unit 202. The input unit 201 generates a video signal by shooting and generates an audio signal by recording. The input unit 201 includes an operation unit, and generates a data signal based on a user operation on the operation unit. In addition, the input unit 201 may acquire part or all of the video signal, the audio signal, and the data signal from the outside of the transmitter 200.

  A video signal, an audio signal, and a data signal are input to the signal conversion unit 202 from the input unit 201. The signal conversion unit 202 is also referred to as an OFDM (Orthogonal Frequency Division Multiplexing) transmission signal (hereinafter referred to as “OFDM transmission wave”) for transmitting the input video signal, audio signal, and data signal from the transmission unit 203 to the receiver 300. To say.) The transmission unit 203 wirelessly transmits the OFDM transmission signal generated by the signal conversion unit 202.

  The receiver 300 includes a receiving unit 301, a decoding unit 302, and a reproducing unit 303. The receiver 301 receives the OFDM transmission wave transmitted by the transmitter 203 of the transmitter 200. Decoding section 302 decodes the OFDM transmission signal received by receiving section 301. The reproduction unit 303 reproduces the video signal, the audio signal, and the data signal obtained by the decoding in the decoding unit 302. The playback unit 303 includes a display and a speaker. The video signal and the data signal are displayed on the display, and the audio signal is output from the speaker. The decoded data signal may be used for control of the reproduction unit 303.

  FIG. 3 is a diagram illustrating a configuration of the signal conversion unit 202 of the transmitter 200 according to the present embodiment. The signal conversion unit 202 includes an information source encoding unit 21, an MPEG-2 multiplexing unit 22, and a transmission path encoding unit 23. The information source encoding unit 21 includes a video encoding unit 211 that inputs and encodes a video signal, an audio encoding unit 212 that inputs and encodes an audio signal, and data that is encoded by inputting a data signal And an encoding unit 213. The video encoded data encoded by the video encoding unit 211, the audio encoded data encoded by the audio encoding unit 212, and the data encoded data encoded by the data encoding unit 213 are MPEG-2. Input to the multiplexing unit 22.

  The MPEG-2 multiplexing unit 22 multiplexes video encoded data, audio encoded data, and data encoded data, and as a transport stream (Transport Stream: hereinafter referred to as “TS”) defined by MPEG2 Systems. Output.

  The transmission path encoding unit 23 receives one or a plurality of TSs, performs re-multiplexing, performs a plurality of transmission path encodings as one TS according to the service intention, and outputs the result as an OFDM transmission wave . The transmission path encoding unit 23 includes a TS remultiplexing unit 231, a hierarchical parallel processing unit 232, and an IFFT (Inverse Fast Fourier Transform) unit 233.

  The TS remultiplexing unit 231 receives one or a plurality of TSs from the MPEG-2 multiplexing unit 22 and performs remultiplexing. The TS re-multiplexing unit 231 converts a plurality of TSs input from the MPEG-2 multiplexing unit 22 into a burst signal format of 188 bytes using a clock four times the IFFT sample clock, and adds an outer code. Convert to a single TS.

  When hierarchical transmission is performed, the hierarchical parallel processing unit 232 divides the TS input from the TS remultiplexing unit 231 into layers according to the designation of the hierarchical information, and performs processing for each layer. The layer parallel processing unit 232 performs processing including error correction coding, byte interleaving, convolutional coding, and carrier modulation for each layer.

  The hierarchical parallel processing unit 232 synthesizes the signals that have undergone the above processing for each hierarchy. The hierarchical parallel processing unit 232 performs time interleaving and frequency interleaving processing on the synthesized signal in order to effectively exhibit error correction coding capability against electric field fluctuation and multipath interference in mobile reception. .

  The hierarchical parallel processing unit 232 adds a synchronous pilot signal, a TMCC (Transmission and Multiplexing Configuration Control) signal, and an AC (Auxiliary Channel) signal to the interleaved signal, and configures and outputs an OFDM frame.

  IFFT section 233 performs an IFFT operation on the OFDM frame generated by hierarchical parallel processing section 232, generates an OFDM transmission signal, and outputs it to transmission section 203. The combined configuration of the hierarchical parallel processing unit 232 and the IFFT unit 233 corresponds to the processing unit of the present invention.

  FIG. 1 is a diagram for explaining multiplexing in the TS remultiplexing unit 231. In the example of FIG. 1, the TS re-multiplexing unit 231 re-multiplexes the TS with a multiplex frame composed of eight transport stream packets (hereinafter referred to as “TSP”) of the same layer as a basic unit. To do. The TS remultiplexing unit 231 inserts a delayed TSP (delayed packet) between TSPs (main packets) when remultiplexing the TS.

  At this time, the TS remultiplexing unit 231 arranges the main packet and the delay packet so that the main packet and the delay packet are located at the same position in the multiplexed frame. That is, in each multiplexed frame, the position where the main packet is arranged and the position where the delayed packet is arranged are fixed. In the example of FIG. 1, in each of the nth to n + 2th frames, the odd-numbered packet is a delayed packet, and the even-numbered packet is a main packet. The position of the main packet is the same and the position of the delayed packet is the same for the frames before the nth and after the (n + 2) th.

  In addition, the position of the delayed packet corresponding to each main packet is also fixed. Thus, if the position of the main packet is specified, the position of the delayed packet corresponding to the main packet can be specified. If the position of the delayed packet is specified, the position of the main packet corresponding to the delayed packet can be specified. . In the example of FIG. 1, the delay packet corresponding to the main packet in each frame is arranged at the position immediately before the next frame. In this way, by fixing the positional relationship between the main packet and the delayed packet, for example, the first packet of the (n + 1) th frame in FIG. 1 is a delayed packet with respect to the second packet of the previous nth frame. Identified as being.

  Also, the TS remultiplexing unit 231 alternately arranges main packets and delayed packets in the same repeating unit. In the example of FIG. 1, main packets and delayed packets are alternately arranged by 1 TSP. In addition, the TS remultiplexing unit 231 may alternately arrange the main packet and the delayed packet by 2 TSP.

  FIG. 4 is a diagram illustrating byte interleaving in the hierarchical parallel processing unit 232. The packet length of TSP subjected to byte interleaving processing is 204 (12 × 17) bytes, and the interleaving length I of 64QAM is 12. At this time, as shown in FIG. 4, the data of the first byte is arranged 204 (12 × 17 × 1) bytes ahead of each of the 12 bytes, excluding the synchronization pilot signal, and the data of the second byte is 408 (12 The data of the third byte is arranged 612 (12 × 17 × 3) bytes ahead, and the data is interleaved in units of bytes in the same manner.

  FIG. 5 is a diagram showing the configuration of a bit string obtained by performing byte interleaving as described above. As shown in FIG. 5, in the bit string after byte interleaving, the data of the main packet and the data of the delayed packet are alternately arranged for each byte.

  It should be noted here that, as described above, in the TS before the byte interleaving process shown in FIG. 1, the position of the main packet and the position of the delayed packet are known, and the positions of the main packet and the delayed packet corresponding to each other. Since the relationship is already known, in the bit string of FIG. 5 obtained by performing the byte interleaving process shown in FIG. 4 on such a TS, for each byte, whether it is delayed packet data or main packet data. It is known that, if it is data of a delayed packet, it is also known where the data of the corresponding main packet is.

  When the TS remultiplexing unit 231 alternately arranges the main packet and the delayed packet every two, in the TS after byte interleaving, the data of the main packet and the data of the delayed packet are every two bytes. They will be lined up alternately.

  The decoding unit 302 of the receiver 300 performs FFT (Fast Fourier Transform), frequency deinterleaving, and time deinterleaving on the received OFDM transmission signal, and then convolves with the hierarchical parallel processing unit 232. Viterbi decoding is performed on the encoded TS.

  FIG. 6 is an example of a trellis diagram in Viterbi decoding at the decoding unit 302. In Viterbi decoding, the decoding unit 302 uses the fact that the same value as the received main packet is received as a delayed packet at a known position to narrow down the maximum likelihood path in the path metric calculation. Specifically, for the bit string to be decoded, the decoding unit 302 has already received the data having the same content as the data of the delayed packet as the data of the main packet corresponding to the delayed packet. Since the data position of the main packet is known, the data of the delayed packet can be known by referring to the data at the known position.

  In the example of FIG. 6, since the value of the delayed packet is known as “1”, for example, the route passes “1” (any of the bold frames in FIG. 6) at t = 9. Therefore, in the path metric calculation, it is only necessary to select a route that passes through one of these bold frames as a candidate and select a route with the highest likelihood.

That is, the decoding unit 302 determines the value of the delayed packet data based on the data of the corresponding main packet that has been previously decoded. By determining the data of the delayed packet in this way, possible values for the main packet data before and after the delayed packet can be narrowed in the path metric calculation. It can be improved. For example, in the example of FIG. 6, if the normal path metric calculation is performed without determining the data of the delayed packet based on the previously received main packet, the likelihood is estimated from 2 ⁶ (= 64) paths. Where the highest route is selected, the delay packet data is determined by the corresponding main packet received earlier as in the present embodiment, so that the route selection candidate is 2 ⁵ (= 32 ) Street.

  Then, when performing the Viterbi decoding of the main packet, the decoding unit 302 narrows down the possible values of the main packet data before and after the delayed packet data by making the data of the delayed packet before and after the known data. Therefore, as the number of locations where the main packet and the delayed packet are adjacent to each other (the location indicated by the arrow in FIG. 5) increases in the decoding target data string, in other words, the data of the delayed packet that is known data becomes smaller. The more distributed, the greater the effect of improving the likelihood of path metric calculation using delay packet data that is known data.

  As described above, the TS remultiplexing unit 231 according to the present embodiment multiplexes so that the main packet and the delayed packet are alternately arranged every 1 TSP. Therefore, by byte interleaving in the hierarchical parallel processing unit 232, The data of the main packet and the data of the delayed packet are alternately arranged for each byte. Therefore, according to the present embodiment, it is possible to sufficiently improve the likelihood of path metric calculation using delay packet data that is known data.

  As described above, the decoding unit 302 determines the data value of the delayed packet with reference to the data of the corresponding main packet that has been decoded previously, but when the data of the main packet cannot be received. As usual, the delay packet data corresponding thereto is also decoded by performing path metric calculation. As a result, even if the main packet is not received by the receiver 300, if the delay packet corresponding to the main packet is received, the data of the part can be obtained.

  The reproduction unit 303 reproduces the video signal, the audio signal, and the data signal obtained by the decoding in the decoding unit 302. At this time, when the decoding unit 302 can decode the main packet, the reproducing unit 303 reproduces the data of the main packet without waiting for the delayed packet corresponding to the main packet. Thereby, the delay of reproduction of video, audio and data can be reduced. When the main packet is lost, the reproducing unit 303 reproduces the decoded delayed packet instead of the main packet.

  FIG. 7 is a diagram for explaining a reproduction method when a part of the OFDM transmission signal transmitted from the transmitter 200 to the receiver 300 is lost. FIG. 7 shows a case where one frame is delayed. In the example of FIG. 7, the receiver 300 can receive the nth OFDM transmission signal, the reception state of the receiver 300 cannot be received for the (n + 1) th OFDM frame, and the reception state is received for the (n + 2) th OFDM frame. Shows a case where the message can be recovered and received.

  The missing n + 1-th OFDM frame includes packet # 4, packet # 5, and packet # 6 as main packets. Therefore, the receiver 300 cannot receive the main packets of the packet # 4, the packet # 5, and the packet # 6, and the packet # 1, the packet # 2, and the packet # 3 in which the main packet is included in the nth OFDM frame. When the reproduction of the packet # 4, the packet # 4, the packet # 5, and the packet # 6 cannot be reproduced. Therefore, the reproduction is interrupted when the reproduction of packet # 1, packet # 2, and packet # 3 is completed.

  Since the data of packet 4, packet # 5, and packet # 6 are included as delay packets in the (n + 2) th OFDM frame, the decoding unit 302 decodes the delay packets. At this time, packet # 7, packet # 8, and packet # 9 are also included as main packets in the (n + 2) th OFDM frame. That is, at the time when the n + 2th OFDM frame is decoded, as the packet to be reproduced, the past reproduction content obtained by decoding the delay packet and the content to be currently reproduced obtained by decoding the main packet are: Obtained as content to be reproduced.

  Therefore, if the reproducing unit 303 reproduces these contents to be reproduced as usual, a delay occurs. On the other hand, since a packet in which the main packet is lost can be decoded by the delayed packet, it is also inefficient to discard the decoded data.

  Therefore, when the reception state is deteriorated and the OFDM frame or a part of the packet is lost, when the reception state is recovered, the decoding unit 302 includes the delayed packet for the data string received after the recovery. Then, the decoding is performed by path metric calculation, and the reproducing unit 303 reproduces the data obtained by the decoding at a faster speed than usual (fast forward reproduction). In the example of FIG. 7, playback is performed at twice the speed.

  When the playback content catches up with the reception of the main packet by fast-forward playback, the playback unit 303 returns the playback speed to the normal speed. Note that the fast-forward playback speed may be set according to the delay time (number of delay frames) of the delayed packet with respect to the main packet, or may be automatically adjusted according to the number of missing OFDM frames.

  In this way, when playback resumes after interruption of reception due to the loss of an OFDM frame, the disturbance of the video and audio to be output is reduced, and the state where the video and audio are delayed is not immediately delayed. Can recover to the state.

  As described above, according to the broadcasting system 100 of the embodiment of the present invention, the transmitter 200 performs remultiplexing of one or more TSs defined by MPEG-2 Systems by the TS remultiplexing unit 231. , A delay packet obtained by delaying the main packet is inserted between the main packets, and the delay packet corresponding to the main packet is arranged at a position having a predetermined relationship with respect to the position of the main packet. Are interleaved, the data of the main packet and the data of the delayed packet are alternated for each byte. Therefore, when the OFDM transmission signal convolutionally encoded by the transmitter 200 is Viterbi-decoded by the receiver 300, for the delayed packet data, the previously decoded main packet data may be determined as known data. It is possible to narrow down the possible values of data when obtaining a route by path metric calculation for the data of the main packet adjacent to such a delayed packet. As a result, the accuracy of decoding the main packet data can be improved.

  In addition, when the reproduction unit 303 of the receiver 300 receives and decodes the main packet, the decoded main packet is reproduced without waiting for the delay packet corresponding to the main packet, so that the video delay can be reduced.

  Further, when the reception state in the receiver 300 deteriorates and a part of the OFDM transmission signal is lost, the decoding unit 302 decodes a delayed packet transmitted later, and the reproducing unit 303 reproduces it. Therefore, stable reproduction can be realized against the deterioration of the reception state. Moreover, after resuming after reception is interrupted, fast-forward playback is performed until playback catches up with reception of the main packet, so that it is possible to suppress image disturbance due to deterioration in reception status and to recover video delay early. it can.

  In the above embodiment, the input unit 201, the information source encoding unit 21, and the MPEG-2 multiplexing unit 22 of the transmitter 200 are configured as a digital video camera, and the transmission path encoding unit 23 and the transmission unit 203 are digital. You may comprise as a computer connected to a video camera. Further, the transmitter 200 may be configured as a bi-digital video camera that includes all of the input unit 201, the signal conversion unit 202, and the transmission unit 203. The receiver 300 may be incorporated in a mobile phone or a car navigation device.

  As described above, the broadcasting system of the present invention has an effect that video stabilization can be realized, a broadcasting system that applies terrestrial digital broadcasting, a transmitter and a receiver used therefor, a broadcasting method and a program, and reception and reproduction. It is useful as a method and program.

DESCRIPTION OF SYMBOLS 21 Information source encoding part 22 Multiplexing part 23 Transmission path encoding part 100 Broadcast system 200 Transmitter 201 Input part 202 Signal conversion part 203 Transmitting part 211 Video encoding part 212 Audio | voice encoding part 213 Data encoding part 231 TS remultiplexing Unit 232 hierarchical parallel processing unit 233 IFFT unit 300 receiver 301 receiving unit 302 decoding unit 303 reproducing unit

Claims (12)

A broadcasting system including a transmitter and a receiver, and performing ISDB-T data transmission from the transmitter to the receiver,
The transmitter is
A TS remultiplexing unit that multiplexes one or a plurality of transport streams into a transport stream including a main packet and a delayed packet obtained by delaying the main packet;
A processing unit that performs processing including byte interleaving and convolutional coding on the transport stream multiplexed by the TS remultiplexing unit, and generates an OFDM transmission signal;
A transmission unit for transmitting the OFDM transmission signal,
The receiver
A receiver for receiving the OFDM transmission signal;
A decoding unit that performs Viterbi decoding on the OFDM transmission signal received by the reception unit;
A reproducing unit for reproducing the data decoded by the decoding unit,
The TS remultiplexing unit arranges the main packet and the delayed packet alternately in the same repetition unit, and the positional relationship between each main packet and each delayed packet corresponding thereto is a fixed relationship,
In the Viterbi decoding, the decoding unit determines the delayed packet data corresponding to the main packet based on the previously decoded main packet data, and then adjoins the determined delayed packet data. A broadcasting system characterized by finding the path of data.   2. The reproduction unit according to claim 1, wherein after the decoding unit decodes the main packet, the reproduction unit reproduces the decoded main packet without waiting for a delayed packet corresponding to the decoded main packet. The described broadcast system. When a part of the OFDM transmission signal cannot be received by the reception unit, when the reception unit receives a delayed packet corresponding to the main packet included in the OFDM transmission signal that could not be received, The decoding unit also obtains a route for the delayed packet by the Viterbi decoding,
The broadcasting system according to claim 1, wherein the reproduction unit reproduces the decoded data of the delayed packet.   When the decoding unit has also decoded the delayed packet because the receiving unit cannot receive a part of the OFDM transmission signal, the reproducing unit fast forwards until reproduction catches up with reception of the main packet. The broadcast system according to claim 3, wherein reproduction is performed.   The broadcasting system according to any one of claims 1 to 4, wherein the TS remultiplexing unit alternately arranges the main packet and the delayed packet for each packet.   The broadcasting system according to any one of claims 1 to 5, which performs multimedia broadcasting for mobile terminals or area one-segment broadcasting.   The transmitter in the broadcast system according to any one of claims 1 to 6.   The receiver in the broadcast system as described in any one of Claims 1 thru | or 6. A broadcasting method for performing ISDB-T data transmission to a receiver,
A TS re-multiplexing step of multiplexing one or a plurality of transport streams into a transport stream including a main packet and a delayed packet obtained by delaying the main packet;
A process step of performing processing including byte interleaving and convolutional coding on the transport stream multiplexed in the TS remultiplexing step to generate an OFDM transmission signal;
Transmitting the OFDM transmission signal; and
Including
In the TS re-multiplexing step, the main packet and the delayed packet are arranged alternately in the same repetition unit, and the positional relationship between each main packet and each corresponding delayed packet is a fixed relationship. A broadcasting method characterized by the above. A reception and reproduction method for receiving and reproducing an OFDM transmission signal transmitted by a ISDB-T method from a transmitter,
Receiving the OFDM transmission signal; and
A decoding step of performing Viterbi decoding on the OFDM transmission signal received in the receiving step;
A reproduction step of reproducing the data decoded in the decoding step;
Including
In the Viterbi decoding, the decoding step determines the delayed packet data corresponding to the main packet based on the previously decoded main packet data, and then adjoins the determined delayed packet data. A receiving and reproducing method characterized by obtaining a data path.   A broadcast program that, when executed by a transmitter, causes the transmitter to execute the broadcast method of claim 9.   A reception program that, when executed by a receiver, causes the receiver to execute the reception reproduction method of claim 10.

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