JP2007311893A - Digital broadcast system, digital broadcast transmitter, digital broadcast receiver, digital broadcast method, digital broadcast transmission method, and digital broadcast reception method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for economically receiving digital broadcasting with high quality by means of the complementarity between broadcasting and communication. <P>SOLUTION: A digital broadcast transmitter for applying compression and other processing to broadcast program data to broadcast program data to generate broadcast data and allowing a broadcast radio wave transmission station to transmit the broadcast data as a broadcast radio wave includes a means for generating error correction redundant data for the broadcast data and transmitting the data as communication data for multicast to a communication network. A digital broadcast receiver for receiving the broadcast radio wave to demodulate the broadcast data and reproducing the program data includes: a communication data receiving means for receiving the communication data multicasted from the communication network; and a means for measuring reception quality of the broadcast data, disabling the communication data receiving means when the reception quality is higher than a reference value to reproduce the program data from the broadcast data, enabling the communication data receiving means when the reception quality is the reference value or below, identifying communication data corresponding to the broadcast data, and reproducing the program data by combining them. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital broadcast system, a digital broadcast transmission apparatus, a digital broadcast reception apparatus, and respective methods for receiving various digital broadcasts with a portable or stationary reception terminal. Here, digital broadcasting refers to terrestrial digital broadcasting, BS digital broadcasting, CS digital broadcasting, and the like.

  When a conventional portable receiving terminal receives a digital broadcast, it will receive the broadcast wave with the antenna attached to the receiving terminal, but the program data cannot be received correctly in a building or an underground city where the broadcast wave is weak. There was a problem that the image was disturbed or the sound was interrupted. As one of methods for dealing with this problem, measures such as installing a device for retransmitting broadcast radio waves in a place where broadcast radio waves are difficult to reach are considered. By the way, broadcasting radio waves can cover a wide area at one transmitting station, so it is possible to transmit program data economically to a large number of viewers. If such measures are taken, a large amount of money is required, and there is a problem that the economic efficiency of broadcasting is lost.

Therefore, when broadcasting radio waves are weak and difficult to receive, a method of utilizing a communication system (mobile phone, wireless LAN, etc.) that can be used in buildings or underground shopping malls has been proposed as an economical method for transmitting broadcast data. (Non-Patent Document 1). This constitutes a broadcasting / communication modulation / demodulation device using software radio technology, and is used depending on the situation. In other words, the reception quality is measured by the strength of the received radio wave of digital broadcasting, bit error rate, etc., and if the reception quality of the broadcast radio wave is higher than the predetermined criterion, the broadcast radio wave is received, and the broadcast radio wave becomes weak and the reception quality When the value falls below the criterion, the communication function is switched to receive.
Naohiko Iiai et al., "Broadcasting and Communication Media Modulator / Demodulator Using Software Defined Radio Technology", IEICE Technical Report MoMuC2004-47, Vol.104, No.278, pp.7-12, September 2004

  The conventional method of switching between reception of broadcast radio waves and reception by communication function according to the reception quality of digital broadcasts at the receiving terminal cannot predict the occurrence of the situation, so the same program data as digital broadcasts uses IP multicast etc. in the communication system. Must be transmitted constantly. However, since digital broadcast program data includes video and audio, it has a large capacity and requires a large transmission band.

  Further, in an area where a plurality of broadcast channels are provided, the plurality of program data are simultaneously transmitted by the communication system. For example, when transmitting 1 Mbps program data on one broadcast channel, the bandwidth required to transmit 8 channel program data is 8 Mbps, which occupies many transmission bandwidths of the communication network and puts pressure on the use of other communications. Will be a factor. In particular, a communication system using wireless communication such as a wireless LAN generally has a smaller transmission band than a wired communication system, and is greatly affected by transmission of program data.

  The present invention relates to a digital broadcast system, a digital broadcast transmission apparatus, a digital broadcast reception apparatus, a digital broadcast method, a digital broadcast transmission method, and a digital broadcast system capable of receiving a digital broadcast at high quality and economically by mutually complementing broadcast and communication. An object is to provide a broadcast receiving method.

  A first invention compresses program data to be broadcast and generates other broadcast data by transmitting the broadcast data as a broadcast wave from a broadcast wave transmission station, and demodulates the broadcast data by receiving the broadcast wave In addition, in a digital broadcast system provided with a digital broadcast receiver that reproduces program data, the digital broadcast transmitter generates redundant data for error correction for the broadcast data and transmits it to the communication network as communication data to be multicast. The digital broadcast receiving apparatus includes a communication data receiving means for receiving communication data multicast from the communication network, and measures the reception quality of the broadcast data, and turns off the communication data receiving means if the reception quality is higher than a reference value. If program data is reproduced from broadcast data and the reception quality is below the reference value Identify the communication data and the corresponding broadcast data communication data receiving means as one, and means for reproducing the program data in combination.

  Here, the digital broadcast transmission device includes the first redundant data for error correction in the broadcast data and is configured to transmit redundant data to be transmitted as communication data as the second redundant data. Depending on the reception quality of the broadcast data, error correction may be performed using only the first redundant data, or error correction may be performed by combining the first redundant data and the second redundant data.

  Further, the digital broadcast transmission device includes the first redundant data for error correction in the broadcast data and transmits redundant data to be transmitted as communication data as the second redundant data. Depending on the data reception quality, error correction may be performed using the first redundant data, or error correction may be performed by exchanging the first redundant data and the second redundant data.

  The digital broadcast transmitting apparatus is configured to add packet synchronization information used for identifying communication data corresponding to broadcast data to the broadcast data and communication data as a header. The digital broadcast receiving apparatus is configured to add broadcast data and communication data. The identification processing may be performed by collating information for packet synchronization in each header.

  The second invention is a digital broadcast transmitter for generating broadcast data by compressing or other processing the broadcast program data and transmitting it as a broadcast radio wave from a broadcast radio wave transmitting station, and demodulating the broadcast data by receiving the broadcast radio wave Further, in a digital broadcast transmission apparatus of a digital broadcast system provided with a digital broadcast reception apparatus that reproduces program data, means for generating redundant data for error correction for broadcast data as communication data, broadcast data and communication data Means for adding packet synchronization information as a header, transmitting broadcast data to a broadcast radio wave transmitting station, and transmitting communication data as multicast data to a communication network.

  A third invention is a digital broadcast receiving device corresponding to the digital broadcast transmitting device of the second invention, wherein communication data receiving means for receiving communication data multicast from a communication network, and reception quality of the broadcast data are measured, If the reception quality is higher than the reference value, the communication data receiving means is turned off and the program data is reproduced from the broadcast data. If the reception quality is lower than the reference value, the communication data receiving means is turned on and the communication data corresponding to the broadcast data is identified. And a control means for reproducing the program data by combining them.

  Here, the broadcast data includes the first redundant data for error correction, the redundant data transmitted as the communication data is set as the second redundant data, and the control means determines the first redundant data according to the reception quality of the broadcast data. A configuration may be adopted in which error correction is performed on data, or error correction is performed by combining the first redundant data and the second redundant data.

  The broadcast data includes the first redundant data for error correction, the redundant data transmitted as communication data is set as the second redundant data, and the control means sets the first redundant data according to the reception quality of the broadcast data. Alternatively, the error correction may be performed by exchanging the first redundant data and the second redundant data.

  The fourth invention is a digital broadcast transmitting apparatus for generating broadcast data by compressing or other processing the broadcast program data and transmitting it as a broadcast radio wave from a broadcast radio wave transmitting station, and demodulating the broadcast data by receiving the broadcast radio wave In addition, in the digital broadcasting method for transmitting broadcast data, further comprising: a digital broadcast receiving apparatus that reproduces program data, wherein the digital broadcast transmitting apparatus generates redundant data for error correction for the broadcast data and performs multicast communication data The digital broadcast receiving apparatus measures the reception quality of the broadcast data and, if the reception quality is higher than the reference value, turns off the communication data receiving means for receiving the communication data multicast from the communication network and broadcasts it. If program data is reproduced from the data and the reception quality is below the reference value, communication data is received. Identified communication data corresponding to the broadcast data means as one, to reproduce the program data in combination.

  The fifth aspect of the invention is a digital broadcast transmitting apparatus for generating broadcast data by compressing or other processing the broadcast program data and transmitting it as a broadcast radio wave from a broadcast radio wave transmitting station, and demodulating the broadcast data by receiving the broadcast radio wave Further, in a digital broadcast transmission method of a digital broadcast system provided with a digital broadcast receiving apparatus for reproducing program data, redundant data for error correction with respect to broadcast data is generated as communication data, and packet synchronization is performed with the broadcast data and communication data. Information is added as a header, broadcast data is transmitted to the broadcast radio wave transmitting station, and communication data is transmitted as multicast data to the communication network.

  A sixth invention is a digital broadcast reception method corresponding to the digital broadcast transmission method of the fifth invention, wherein the reception quality of the broadcast data is measured, and if the reception quality is higher than the reference value, the communication data multicast from the communication network The communication data receiving means for receiving the data is turned off and the program data is reproduced from the broadcast data. If the reception quality is lower than the reference value, the communication data receiving means is turned on to identify the communication data corresponding to the broadcast data, Play program data.

  Here, the first redundant data for error correction is included in the broadcast data, the redundant data to be transmitted as communication data is the second redundant data, and error correction is performed with the first redundant data according to the reception quality of the broadcast data. Alternatively, error correction may be performed by combining the first redundant data and the second redundant data.

  The broadcast data includes the first redundant data for error correction, the redundant data transmitted as communication data is the second redundant data, and error correction is performed with the first redundant data according to the reception quality of the broadcast data. Alternatively, error correction may be performed by exchanging the first redundant data and the second redundant data.

  The present invention combines broadcast data and communication data when only redundant data for error correction of broadcast data is transmitted as communication data via a communication system, and program data cannot be reproduced correctly only with broadcast data due to weak broadcast radio waves. Thus, the program data can be correctly reproduced. On the other hand, when broadcast radio waves are strong, program data can be reproduced only with broadcast data, and there is no need to receive communication data. Therefore, the receiving means can be stopped to reduce the power consumption of the receiving terminal. . Redundant data transmitted as communication data has a significantly smaller capacity than broadcast data, so communication bandwidth efficiency is significantly higher than when transmitting communication data of the same capacity as broadcast data as in the past. Can be achieved.

  In this way, even within a digital broadcast service area, for example, in a place where broadcast radio waves are weakened in a building, redundant data for error correction is acquired using a communication service such as a wireless LAN, and a program is acquired. By reproducing data, it is possible to perform satisfactory reproduction while saving the communication band, and it is possible to supplement the service area of digital broadcasting. This makes it possible to receive digital broadcasts with high quality and economically.

  FIG. 1 shows a configuration example of a digital broadcasting system of the present invention. In the figure, the broadcasting station 1 has a digital broadcast transmitting apparatus 10 of the present invention, which generates broadcast data to be transmitted by broadcast from program data including video and audio to be broadcast and communication data to be transmitted via a communication network. Each is transmitted to the broadcast radio wave transmitting station 2 and the communication network 3. The communication data to be transmitted to the communication network 3 is redundant data for error correction used for improving the reception quality of broadcast data, and the program data is used as communication data for the communication network as it is conventionally. Is different. In detail, it divides and demonstrates to two embodiment mentioned later. Communication data transmitted via the communication network 3 is transmitted from the radio base station 4. Although a communication system using wireless communication such as a wireless LAN is assumed here, the communication network 3 and the wireless base station 4 may be other wireless systems or wired systems.

  The receiving terminal 5 has the digital broadcast receiving apparatus 50 of the present invention, and broadcast data transmitted from the broadcast radio wave transmitting station 2 and communication data transmitted from the radio base station 4 (redundant data for error correction of broadcast data). Receive. The error correction capability is adjusted according to whether the reception function of communication data is turned on or off according to the reception state of the broadcast wave, and reception processing is performed only with broadcast data, and reception processing is performed in combination with broadcast data and communication data. The program data is played back.

  In such a digital broadcasting system, it is not necessary to send the program data itself as communication data, and it is only necessary to transmit redundant data for error correction of the broadcast data in a complementary manner, so that the transmission band of the communication system is efficiently used. Digital broadcasting can be realized with high quality and economically.

  The receiving terminal 5 is not limited to a portable type, for example, a stationary television, which receives broadcast radio waves with an antenna installed outdoors and uses a communication cable (such as an optical fiber line or an ADSL line) as a communication system. Also good. For example, in the case of BS digital broadcasting, transmission errors may occur due to the attenuation of broadcast radio waves due to rain. However, program data can be transmitted without error by transmitting redundant data through a communication system and using it for error correction of broadcast data. Can be played. Further, the present invention can be applied to digital radio broadcasting in which program data is only audio.

(First embodiment)
FIG. 2 shows a configuration example of the digital broadcast transmission apparatus according to the first embodiment of the present invention. FIG. 3 shows a processing flow of the digital broadcast transmitting apparatus (method) according to the first embodiment of the present invention.

  In FIG. 2, the digital broadcast transmission device 10 </ b> A includes an encoder 11, an error correction code encoding unit 12, a broadcast data generation unit 13 </ b> A, a communication data generation unit 14 </ b> A, a broadcast data transmission unit 15, and a communication data transmission unit 16. Hereinafter, the configuration and operation of the digital broadcast transmitting apparatus 10A will be described with reference to FIG. 2 and FIG.

  Program data including video and audio to be broadcast is input to the encoder 11 and encoded using a compression method such as MPEG-2 to generate a transport packet (S1). The error correction code encoder 12 generates an error correction code for correcting an error during transmission for this transport packet, and adds the error correction code as redundant data 1 and redundant data 2 (S2). As the error correction code, for example, a Reed-Solomon code or a turbo code can be used. However, error correction is possible only with the first half redundant data 1, and further by using redundant data 1 and redundant data 2, An error correction code having high error correction capability and capable of error correction is used.

  The transport packet to which redundant data 1 and redundant data 2 are added by the error correction code encoder 12 is branched into two and input to the broadcast data generator 13A and the communication data generator 14A, respectively. The broadcast data generation unit 13A extracts the transport packet and the redundant data 1 from which the redundant data 2 is removed, and further generates a broadcast data by adding a header including a packet synchronization ID (S3). On the other hand, the communication data generation unit 14A extracts the redundant data 2 and adds a header including a packet synchronization ID similar to the broadcast data generation unit 13A to generate communication data (S4). This packet synchronization ID indicates that broadcast data and communication data are data at the same time in the receiving device. Therefore, a header including the same packet synchronization ID is added to the data input to the broadcast data generation unit 13A and the communication data generation unit 14A at the same time, and a different packet synchronization ID is given to each input data. Is done.

  The broadcast data generated by the broadcast data generation unit 13A is transmitted to the broadcast radio wave transmission station 2 via the broadcast data transmission unit 15 (S5), and is transmitted from the broadcast radio wave transmission station 2 as a broadcast radio wave. The communication data generated by the communication data generation unit 14A is input to the communication data transmission unit 16 and transmitted to the communication network 3 as an IP multicast packet (S6).

  FIG. 4 shows a configuration example of the digital broadcast receiving apparatus according to the first embodiment of the present invention. FIG. 5 shows a processing flow of the digital broadcast receiving apparatus (method) according to the first embodiment of the present invention.

  In FIG. 4, the digital broadcast receiving device 50 </ b> A includes a broadcast data receiving unit 51, a communication data receiving unit 52, a data synthesis unit 53, an error correction code decoding unit 54, and a decoder 55. Hereinafter, the configuration and operation of the digital broadcast receiving device 50A will be described with reference to FIGS. 4 and 5. FIG.

  The broadcast data receiving unit 51 receives broadcast radio waves including broadcast data transmitted from the broadcast radio wave transmitting station 2, performs a process of demodulating the broadcast data, and receives reception quality according to the strength of the received radio waves and the bit error rate. Measure (S11). Here, a reference value of reception quality capable of reproducing the program data only with the broadcast data is determined in advance, and the measured reception quality is compared with the reference value (S12). The broadcast data receiving unit 51 measures the reception quality at a constant period, and when the measured value is equal to or less than the reference value, sends a control signal for turning on the function of the communication data receiving unit 52 to the communication data receiving unit 52 (S13) and measures it. When the value is higher than the reference value, a control signal for turning off the function of the communication data receiving unit 52 is sent to the communication data receiving unit 52 (S14).

  When the reception quality is higher than the reference value and the communication data receiving unit 52 is off, the communication data transmitted from the radio base station 4 is not received, and the data synthesizing unit 53 outputs the broadcast data output from the broadcast data receiving unit 51. The transport packet from which the header is removed and the redundant data 1 are output to the error correction code decoding unit 54. The error correction code decoding unit 54 corrects the transport packet using the redundant data 1 (S17). In this case, since the reception quality is high and the transmission error of the broadcast data is small, error correction is possible only with the redundant data 1. The decoded transport packet is input to the decoder 55, and program data composed of video and audio is reproduced (S18).

  On the other hand, when the reception quality is equal to or lower than the reference value and the communication data receiving unit 52 is on, the communication data transmitted from the radio base station 4 is received and output to the data combining unit 53 (S15). In the data synthesis unit 53, the broadcast data output from the broadcast data reception unit 51 and the communication data output from the communication data reception unit 52 are input, and the packet synchronization ID in each header is used to make the same time Are synthesized (S16). The synthesized data includes a transport packet, redundant data 1 and redundant data 2, and these are output to the error correction code decoding unit 54. The error correction code decoding unit 54 performs error correction of the transport packet using the redundant data 1 and the redundant data 2 (S17). In this case, although the reception quality is low and there are many broadcast data transmission errors, the error correction is performed by combining the redundant data 1 and the redundant data 2, so that the error correction capability is higher than that in the case of performing error correction using only the redundant data 1. Can be demonstrated. The decoded transport packet is input to the decoder 55, and program data composed of video and audio is reproduced (S18).

(Second Embodiment)
FIG. 6 shows a configuration example of a digital broadcast transmission apparatus according to the second embodiment of the present invention. FIG. 7 shows a processing flow of the digital broadcast transmitting apparatus (method) according to the second embodiment of the present invention.

  In FIG. 6, a digital broadcast transmission device 10B includes an encoder 11, error correction code encoding units 12-1 and 12-2, a broadcast data generation unit 13B, a communication data generation unit 14B, a broadcast data transmission unit 15, and a communication data transmission unit. 16. In the present embodiment, the error correction code encoders 12-1 and 12-2 that generate error correction codes having different error correction capabilities are used, and the error correction code encoder 12-2 having a high error correction capability is used. The redundant data 2 is transmitted through a communication system. Hereinafter, the configuration and operation of the digital broadcast transmitting apparatus 10B will be described with reference to FIG. 6 and FIG.

  Program data including video and audio to be broadcast is input to the encoder 11 and encoded using a compression method such as MPEG-2 to generate a transport packet (S21). This transport packet is branched into two and input to the error correction code encoding units 12-1 and 12-2. The error correction code encoder 12-1 generates a first error correction code for correcting an error during transmission for this transport packet and adds it as redundant data 1 (S22). As the error correction code, for example, a Reed-Solomon code or a turbo code can be used. The transport packet to which redundant data 1 is added by the error correction code encoder 12-1 is input to the broadcast data generator 13B. The broadcast data generating unit 13B generates broadcast data by adding a header including a packet synchronization ID to the transport packet and the redundant data 1 (S23).

  On the other hand, the error correction code encoding unit 12-2 generates a second error correction code having a higher error correction capability than the error correction code encoding unit 12-1 for this transport packet, and redundant data 2 (S24). The transport packet to which the redundant data 2 is added by the error correction code encoding unit 12-2 is input to the communication data generation unit 14B. The communication data generation unit 14B extracts redundant data 2 and adds a header including a packet synchronization ID similar to the broadcast data generation unit 13B to generate communication data (S25). This packet synchronization ID indicates that broadcast data and communication data are data at the same time in the receiving device. Therefore, a header including the same packet synchronization ID is added to the data input to the broadcast data generation unit 13B and the communication data generation unit 14B at the same time, and a different packet synchronization ID is assigned to each input data. Is done.

  Broadcast data generated by the broadcast data generating unit 13B is transmitted to the broadcast radio wave transmitting station 2 via the broadcast data transmitting unit 15 (S26), and transmitted from the broadcast radio wave transmitting station 2 as broadcast radio waves. The communication data generated by the communication data generation unit 14B is input to the communication data transmission unit 16 and transmitted to the communication network 3 as an IP multicast packet (S27).

  FIG. 8 shows a configuration example of a digital broadcast receiving apparatus according to the second embodiment of the present invention. FIG. 9 shows a processing flow of the digital broadcast receiving apparatus (method) according to the second embodiment of the present invention.

  In FIG. 8, the digital broadcast receiving device 50 </ b> B includes a broadcast data receiving unit 51, a communication data receiving unit 52, a data switching unit 56, an error correction code decoding unit 54 and a decoder 55. Hereinafter, the configuration and operation of the digital broadcast receiving device 50B will be described with reference to FIG. 8 and FIG.

  The broadcast data receiving unit 51 receives broadcast radio waves including broadcast data transmitted from the broadcast radio wave transmitting station 2, performs a process of demodulating the broadcast data, and receives reception quality according to the strength of the received radio waves and the bit error rate. Measure (S31). Here, a reference value of reception quality capable of reproducing program data from broadcast data is determined in advance, and the measured reception quality is compared with the reference value (S32). The broadcast data receiving unit 51 measures the reception quality at regular intervals, and when the measured value is less than the reference value, sends a control signal for turning on the function of the communication data receiving unit 52 to the communication data receiving unit 52 (S33) and measures it. When the value is higher than the reference value, a control signal for turning off the function of the communication data receiving unit 52 is sent to the communication data receiving unit 52 (S34).

  When the reception quality is higher than the reference value and the communication data receiving unit 52 is off, the communication data transmitted from the radio base station 4 is not received, and the data switching unit 56 outputs the broadcast data output from the broadcast data receiving unit 51. And the transport packet from which the header is removed and the redundant data 1 are output to the error correction code decoding unit 54. The error correction code decoding unit 54 performs error correction of the transport packet using the redundant data 1 (S37). In this case, since reception quality is high and broadcast data transmission errors are small, error correction is possible with redundant data 1 having relatively low error correction capability. The decoded transport packet is input to the decoder 55, and program data consisting of video and audio is reproduced (S38).

  On the other hand, when the reception quality is below the reference value and the communication data receiving unit 52 is on, the communication data transmitted from the radio base station 4 is received and output to the data switching unit 56 (S35). In the data switching unit 56, the broadcast data output from the broadcast data receiving unit 51 and the communication data output from the communication data receiving unit 52 are input, and the broadcast data is transmitted using the packet synchronization ID in each header. The redundant data 2 of the communication data at the same time as the redundant data 1 is exchanged (S36). This data consists of a transport packet and redundant data 2, which are output to the error correction code decoding unit 54. The error correction code decoding unit 54 performs error correction of the transport packet using the redundant data 2 (S37). In this case, the reception quality is low and there are many broadcast data transmission errors, but error correction is performed using redundant data 2 having relatively high error correction capability, so that error correction is performed using redundant data 1. High error correction capability can be demonstrated. The decoded transport packet is input to the decoder unit 55, and program data composed of video and audio is reproduced (S38).

  The error correction code encoding units 12-1 and 12-2 of the digital broadcast transmission apparatus according to the present embodiment may be configured to generate redundant data 1 and 2 including error correction codes having the same error correction capability. The error correction code encoding unit may be integrated. Even in that case, when the reception quality of the broadcast data is below the reference value, the error correction of the transport packet is ensured by replacing the redundant data 1 of the broadcast data with the redundant data 2 having no error in the communication data at the same time. It can be carried out.

  In the embodiment described above, the broadcast data reception unit 51 measures the reception quality of broadcast data by measuring the following values and receiving any one or a combination of two or more of the measurement values. Quality can be sought.

(1) Broadcast radio wave reception strength
(2) Bit error rate of broadcast data (However, in this case, a bit pattern known to the receiving side is embedded in the header on the transmitting side, and the bit pattern error rate is obtained on the receiving side.)
(3) Packet error rate of broadcast data (However, in this case, the transmitting side transmits a packet known to the receiving side at a predetermined cycle, and the receiving side calculates the error rate of the packet)

The figure which shows the structural example of the digital broadcasting system of this invention. The figure which shows the structural example of the digital broadcast transmitter of the 1st Embodiment of this invention. The figure which shows the processing flow of the digital broadcast transmission apparatus (method) of the 1st Embodiment of this invention. The figure which shows the structural example of the digital broadcast receiver of the 1st Embodiment of this invention. The figure which shows the processing flow of the digital broadcast receiver (method) of the 1st Embodiment of this invention. The figure which shows the structural example of the digital broadcast transmitter of the 2nd Embodiment of this invention. The figure which shows the processing flow of the digital broadcast transmission apparatus (method) of the 2nd Embodiment of this invention. The figure which shows the structural example of the digital broadcast receiver of the 2nd Embodiment of this invention. The figure which shows the processing flow of the digital broadcast receiver (method) of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Broadcasting station 2 Broadcasting radio wave transmission station 3 Communication network 4 Wireless base station 5 Receiving terminal 10, 10A, 10B Digital broadcast transmitter 11 Encoder 12 Error correction code encoding part 13A, 13B Broadcast data generation part 14A, 14B Communication data generation part DESCRIPTION OF SYMBOLS 15 Broadcast data transmission part 16 Communication data transmission part 50, 50A, 50B Digital broadcast receiver 51 Broadcast data reception part 52 Communication data reception part 53 Data synthesis part 54 Error correction code decoding part 55 Decoder 56 Data switching part

Claims (13)

A digital broadcast transmission device that generates broadcast data by compressing or other processing the program data to be broadcast, and transmits it as a broadcast radio wave from a broadcast radio wave transmission station;
In a digital broadcast system comprising: a digital broadcast receiving device that receives the broadcast radio waves, demodulates the broadcast data, and further reproduces the program data;
The digital broadcast transmission device includes means for generating redundant data for error correction for the broadcast data and transmitting the data to a communication network as communication data to be multicast.
The digital broadcast receiving apparatus comprises: communication data receiving means for receiving the communication data multicast from the communication network; and measuring the reception quality of the broadcast data, and if the reception quality is higher than a reference value, the communication data receiving means The program data is reproduced from the broadcast data as off, and if the reception quality is below a reference value, the communication data receiving means is turned on to identify the broadcast data and the corresponding communication data, and they are combined to form the program A digital broadcast system comprising means for reproducing data. The digital broadcasting system according to claim 1, wherein
The digital broadcast transmission device includes a first redundant data for error correction in the broadcast data, and transmits the redundant data to be transmitted as the communication data as second redundant data.
The digital broadcast receiving apparatus performs error correction only with the first redundant data or performs error correction by combining the first redundant data and the second redundant data according to the reception quality of the broadcast data. A digital broadcasting system characterized by being configured to perform. The digital broadcasting system according to claim 1, wherein
The digital broadcast transmission device includes a first redundant data for error correction in the broadcast data, and transmits the redundant data to be transmitted as the communication data as second redundant data.
The digital broadcast receiving apparatus performs error correction with the first redundant data or exchanges the first redundant data with the second redundant data according to the reception quality of the broadcast data. A digital broadcasting system characterized by being configured to perform. The digital broadcasting system according to claim 1, wherein
The digital broadcast transmission device is configured to add information for packet synchronization used for identification of the communication data corresponding to the broadcast data to the broadcast data and the communication data as a header,
The digital broadcast receiving apparatus is configured to perform identification processing by collating information for packet synchronization in each header of the broadcast data and the communication data. A digital broadcast transmission device that generates broadcast data by compressing or other processing the program data to be broadcast, and transmits it as a broadcast radio wave from a broadcast radio wave transmission station;
In a digital broadcast transmission device of a digital broadcast system comprising: a digital broadcast reception device that receives the broadcast radio wave, demodulates the broadcast data, and further reproduces the program data;
Means for generating redundant data for error correction for the broadcast data as communication data;
Means for adding packet synchronization information as a header to the broadcast data and the communication data, transmitting the broadcast data to the broadcast radio wave transmitting station, and transmitting the communication data to a communication network as multicast data. A digital broadcast transmitter characterized by the above. In the digital broadcast receiver corresponding to the digital broadcast transmitter according to claim 5,
Communication data receiving means for receiving the communication data multicast from the communication network;
The reception quality of the broadcast data is measured. If the reception quality is higher than a reference value, the communication data receiving means is turned off and the program data is reproduced from the broadcast data. If the reception quality is lower than the reference value, the communication data reception is received. A digital broadcast receiving apparatus comprising: control means for turning on the means to identify the communication data corresponding to the broadcast data and combining them to reproduce the program data. The digital broadcast receiver according to claim 6, wherein
The broadcast data includes first redundant data for error correction, and the redundant data transmitted as the communication data is second redundant data,
The control means is configured to perform error correction with the first redundant data or perform error correction with a combination of the first redundant data and the second redundant data according to the reception quality of the broadcast data. A digital broadcast receiving apparatus characterized by that. The digital broadcast receiver according to claim 6, wherein
The broadcast data includes first redundant data for error correction, and the redundant data transmitted as the communication data is second redundant data,
The control means performs error correction with the first redundant data or performs error correction by exchanging the first redundant data and the second redundant data according to the reception quality of the broadcast data. A digital broadcast receiver characterized by the above. A digital broadcast transmission device that generates broadcast data by compressing or other processing the program data to be broadcast, and transmits it as a broadcast radio wave from a broadcast radio wave transmission station;
A digital broadcast receiving apparatus that receives the broadcast radio wave, demodulates the broadcast data, and further reproduces the program data, and transmits the broadcast data;
The digital broadcast transmission device generates redundant data for error correction with respect to the broadcast data, and transmits it to a communication network as communication data to be multicast.
The digital broadcast receiving apparatus measures the reception quality of the broadcast data, and if the reception quality is higher than a reference value, turns off the communication data receiving means for receiving the communication data multicast from the communication network, and starts from the broadcast data. The program data is reproduced, and if the reception quality is below a reference value, the communication data receiving means is turned on to identify the communication data corresponding to the broadcast data, and the program data is reproduced by combining them. Digital broadcasting method. A digital broadcast transmission device that generates broadcast data by compressing or other processing the program data to be broadcast, and transmits it as a broadcast radio wave from a broadcast radio wave transmission station;
In a digital broadcast transmission method for a digital broadcast system, comprising: a digital broadcast receiver that receives the broadcast radio wave, demodulates the broadcast data, and further reproduces the program data;
Generating redundant data for error correction for the broadcast data as communication data;
Packet synchronization information is added to the broadcast data and the communication data as a header, the broadcast data is transmitted to the broadcast radio wave transmitting station, and the communication data is transmitted as multicast data to a communication network. Digital broadcast transmission method. In the digital broadcast reception method corresponding to the digital broadcast transmission method of Claim 10,
If the reception quality of the broadcast data is measured and the reception quality is higher than a reference value, the communication data receiving means for receiving the communication data multicast from the communication network is turned off and the program data is reproduced from the broadcast data, A digital broadcast receiving method comprising: turning on the communication data receiving means to identify the communication data corresponding to the broadcast data, and reproducing the program data by combining them if reception quality is below a reference value. The digital broadcast receiving method according to claim 11,
The broadcast data includes first redundant data for error correction, the redundant data transmitted as the communication data is second redundant data, and the first redundant data is determined according to the reception quality of the broadcast data. A digital broadcast receiving method, wherein error correction is performed, or error correction is performed by combining the first redundant data and the second redundant data. The digital broadcast receiving method according to claim 11,
The broadcast data includes first redundant data for error correction, the redundant data transmitted as the communication data is second redundant data, and the first redundant data is determined according to the reception quality of the broadcast data. A digital broadcast receiving method, wherein error correction is performed or error correction is performed by exchanging the first redundant data and the second redundant data.

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