JP3231130B2 - Digital information receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISDB for integrally transmitting various digital information such as video, audio and data.
The present invention relates to a digital information receiving device in (integrated digital broadcasting).

[0002]

2. Description of the Related Art Conventional techniques for transmitting digital information include a structure method and a packet method.

[0003] The structure system is a system in which the time multiplex position of service information is fixed in a transmission path and transmitted. As an example of the structure system, there is a transmission system for audio transmitted in the digital domain of satellite television broadcasting. Once the transmission system is determined, it is difficult to add a new service or change transmission parameters. It is.

On the other hand, the packet system is a system in which a multiplexing position in a transmission path is not fixed, and the data is multiplexed and transmitted in a packet format including a header and data. As an example of the packet system, there is a data transmission system for transmitting in the digital domain of satellite television broadcasting. In this method, services are transmitted in a packet format, so that new services can be flexibly added.

[0005] For this reason, in the future digital transmission system, transmission in a packet format is considered, and service identification in the packet transmission is conventionally performed using a packet header.

[0006]

By the way, in recent years, ISDB (Integrated Digital Broadcasting), which integrates and broadcasts not only video and audio but also various data services such as still image, text, facsimile, and software, has been considered. Have been.

In ISDB, it is considered that individual services having different data amounts and data rates are transmitted at high speed in a packet system.

When receiving a service transmitted by ISDB, if the transmission speed increases, the receiver must perform signal processing such as error correction and header identification for all packets at high speed.

However, in this system, high-speed signal processing must be performed even for a service having a small data amount and data rate such as a data service and a low-speed signal processing is sufficient. This leads to higher machine costs.

[0010] In view of the above circumstances, the present invention can sufficiently reduce the speed of signal processing such as error correction and header identification when receiving only a service with a small data amount or data rate such as a data service. It is an object of the present invention to provide a digital information receiving apparatus capable of greatly reducing the cost of the receiver side.

[0011]

In order to achieve the above object, the present invention divides a transmission path of digital information into a plurality of transmission slots and transmits digital information such as video, audio and data in a packet format. In addition, after adding information indicating the continuity of the packet to a packet composed of digital information belonging to the same service, digital information to be multiplexed and transmitted only to one or a plurality of specific transmission slots in the transmission path. A digital information receiving apparatus for use in a transmission system, comprising: means for sequentially determining whether or not a packet of digital information belonging to each service is transmitted in each of the divided transmission slots, and continuity of the received packet. Is determined to have been received continuously for a predetermined period of time, the digital information A transmission slot to receive the packet is characterized by comprising means for limiting the transmission slots received so far.

[0012]

According to the above arrangement, when it is determined that the information indicating the continuity of the received packet has been continuously received for a predetermined period, the transmission of the packet of the digital information is performed. By limiting slots to transmission slots received so far, even if all continuity is not checked, if continuity for a certain period at some point can be confirmed, then continuity You no longer need to check.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the detailed description of the present invention, the basic principle of a digital information transmission system related to the present invention will be described.

Now, in order to solve the above-mentioned conventional problems, a digital signal transmission line is time-divided to form a plurality of slots, each service is multiplexed into a specific slot and transmitted, and the reception side is transmitted. Then, only a specific slot in which a received service is multiplexed is extracted and processed. As a result, the time required to perform signal processing such as error correction and header identification is secured, and even a low-speed receiver can
Reception processing can be performed to reduce the cost of the receiver.

At this time, in the conventionally known structure system, the time multiplex position of the service to be transmitted is fixed, but in the digital information transmission system related to the present invention, the service to be transmitted is fixed. Is not fixed, and a plurality of services can be mixed in one slot in a packet format.
Then, information indicating the slot position where the service is multiplexed (slot information) is transmitted from the transmitting side to the receiving side, or the receiver itself searches for the packet multiplexed in the slot to be received. And let it be processed.

FIG. 1 is a block diagram showing a first reference example of a transmission / reception system according to the present invention to which the above-described basic principle is applied.

The transmission / reception system 1 shown in FIG. 1 fetches video data, audio data, and other data to be transmitted, generates a packet-type transmission signal having a plurality of slots, and places the transmission signal on the digital information transmission path 3. A transmitting device 2 for transmitting the data; and a receiving device 4 for receiving and decoding the transmission signal transmitted on the digital information transmission path 3 to reproduce a plurality of packet data. Data and other data are fetched from a service encoder (not shown) and packetized, and then set in advance or input from outside as slot information (one or more transmission slots for transmitting digital information belonging to each service). Each packet data in each slot assigned to each service based on the The transmission signal is generated on the digital information transmission path 3 and is transmitted to the digital information transmission path 3. The transmission signal transmitted on the digital information transmission path 3 is taken in the receiving device 4 and multiplexed in each slot. In addition to extracting each packet data, the packet data belonging to the slot including the service to be received is limited and processed and reproduced based on the preset slot information or the slot information input from the outside. ,
This is output to a service decoder (not shown).

The transmission device 2 includes an error correction encoder circuit 5
, A slot encoder circuit 6, a frame encoder circuit 7, and a modulation circuit 8, and fetches video data, audio data, and other data to be transmitted from a service encoder (not shown) to correct errors. After adding a check bit to make a packet and multiplexing by allocating each packet data to a corresponding slot for each service based on preset slot information or slot information inputted from the outside, a frame A transmission signal is generated by adding a synchronization signal, and the transmission signal is sent out onto the digital information transmission path 3.

The error correction encoder circuit 5 fetches video data, audio data, and other data to be transmitted from the service encoder, and adds an error correction check bit to each data as shown in FIG. Data is generated and supplied to the slot encoder circuit 6.

The slot encoder circuit 6 assigns each packet data output from the error correction encoder circuit 5 to a slot corresponding to each service based on preset slot information or slot information input from the outside, and multiplexes the data. This is supplied to the frame encoder circuit 7.

In this case, for example, as shown in FIG. 2B, video data TV1 is multiplexed into a first slot and a third slot, and video data TV2 is multiplexed into a fourth slot and a sixth slot.
The first data and the second data are multiplexed into the seventh slot and supplied to the frame encoder circuit 7.

The frame encoder circuit 7 takes in the packet data of each slot output from the slot encoder circuit 6, adds a frame synchronization signal for frame synchronization to each packet data as shown in FIG. Each data of the eighth slot is sequentially and cyclically selected, and in this case, an 8-bit interleave effect is applied to supply the data to the modulation circuit 8.

The modulation circuit 8 takes in the frame data sequentially output from the frame encoder circuit 7 and performs a digital modulation by a preset modulation method to generate a transmission signal. And transmits it to the receiving device 4.

The receiving device 4 includes a demodulation circuit 9, a frame decoder circuit 10, a slot decoder circuit 11, and an error correction decoder circuit 12, and fetches a transmission signal transmitted on the digital information transmission path 3, Each packet data multiplexed in each slot is extracted, and packet data belonging to a slot including a service to be received is determined based on preset slot information or slot information input from the outside. Reproduction is performed with limited error correction, and this is output to a service decoder (not shown).

The demodulation circuit 9 fetches the transmission signal on the digital information transmission line 3, reproduces the received data by digital demodulation according to a preset demodulation method, and supplies it to the frame decoder circuit 10.

The frame decoder circuit 10 captures the received data output from the demodulation circuit 9 to capture a frame synchronization signal, and separates the received data based on the captured result to reproduce packet data for each slot. Are supplied to the slot decoder circuit 11.

The slot decoder circuit 11 fetches packet data for each slot sequentially output from the frame decoder circuit 10 and converts the packet data based on preset slot information or externally input slot information. The packet data is selected by limiting the slot containing the packet data to be received, and the packet data obtained by this selection processing is supplied to the error correction decoder circuit 12.

In this case, in the receiving device 4, if the video data TV1 is designated as a receiving object, the packet data multiplexed in the first slot and the third slot is selected, and the video data TV2 is If it is specified as a reception target, packet data multiplexed in the fourth slot and the sixth slot is selected, and if other first data and second data are specified as reception targets, Seventh
The packet data multiplexed in the slot is selected, and the packet data obtained by this selecting operation is supplied to the error correction decoder circuit 12.

The error correction decoder circuit 12 takes in the packet data output from the slot decoder circuit 11, corrects the data error based on the error correction check bits included in the packet data, and then corrects the error-corrected packet data. To the service decoder, and the service decoder identifies the header of the packet data and processes the data.

As described above, in this reference example, video data and audio data to be transmitted by the transmission device 2,
After fetching other data and packetizing, based on preset slot information or slot information inputted from the outside, each packet data is multiplexed into each slot allocated to each service and transmitted. Is generated and sent out onto the digital information transmission path 3, and the digital information transmission path 3
The transmission signal transmitted above is taken in, the packet data multiplexed in each slot is extracted, and the packet data belonging to the slot containing the service to be received is limited based on the slot information. Processing and playback, and output this to the service decoder, so that when applied to ISDB for integrated transmission of various information such as video data, audio data, and other data, the digital Information can be multiplexed into an arbitrary slot and transmitted, and the time required for signal processing such as error correction and header identification on the receiving side can be secured, so that even a low-speed receiver can perform reception processing. This can be done to reduce the cost of the receiver.

FIG. 4 is a block diagram showing a second reference example of the transmission / reception system related to the present invention. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals.

The transmission / reception system 1b shown in this figure is different from the system 1 shown in FIG. 1 in that a packet encoder circuit 15 is added to the transmission device 2b and the reception device 4
b, a packet decoder circuit 16 is added to the transmission device 2
That is, the slot information used on the side b is packetized and transmitted to the receiving apparatus 4b side, whereby the slot information is supplied to the receiving apparatus 4b side.

When the packet encoder circuit 15 provided on the transmitting device 2b side is set to control the slot encoder circuit 6 based on slot information from the outside and allocate packet data for each service to each slot, After fetching the slot information and packetizing it, it is input to the error correction encoder circuit 5, and the slot encoder circuit 6, the frame encoder circuit 7,
The digital information is transmitted on the same digital information transmission line 3 via the modulation circuit 8.

When packet data separated for each slot is input to the slot decoder circuit 11 via the demodulation circuit 9 and the frame decoder circuit 10, the packet decoder circuit 16 provided on the receiver 4b side first After controlling the slot decoder circuit 11 to select the packet data multiplexed in the slot in which the slot information is transmitted, input the packet data to the error correction decoder circuit 12 and correct the error. The packet data output from the error correction decoder circuit 12 is fetched to reproduce slot information, and thereafter, the slot decoder circuit 11 is controlled based on the slot information to specify a transmission slot to be received.

As described above, in this reference example, as in the first reference example described above, video data, audio data, and other data to be transmitted are fetched by the transmission device 2b, packetized, and input from the outside. Each packet data is allocated to a slot corresponding to each service based on the slot information to be multiplexed and multiplexed.
Since the packet data multiplexed in each slot by the b side is extracted and the packet data belonging to the slot including the service to be received is limitedly processed and reproduced, the video data is When applied to ISDB for transmitting various information such as voice, voice data, and other data in an integrated manner, digital information to be transmitted can be multiplexed and transmitted to any slot, and error correction on the receiving side can be performed. And the time required for signal processing such as header identification and the like can be secured, whereby even a low-speed receiver can perform reception processing and reduce the cost of the receiver.

Further, in this reference example, a packet encoder circuit 15 is added to the transmitting device 2b, and a packet decoder circuit 16 is added to the receiving device 4b, so that slot information used by the transmitting device 2b can be converted into packets. Since the slot information is transmitted to the receiving device 4b side and the slot information is supplied to the receiving device 4b side, even when the content of each service multiplexed in each slot is changed, the transmitting device 2b side The slot information on the receiving device 4b side can be changed only by changing the slot information.

FIG. 5 is a block diagram showing an example of a transmission / reception system to which a third reference example of the digital information transmission system related to the present invention is applied. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals.

The transmission / reception system 1c shown in this figure is different from the system 1 shown in FIG. 1 in that a slot information transmission device 18 is added to the transmission device 2c and a reception device 4c
Side, a slot information receiving device 19 is added to the transmitting device 2c.
Side transmits the digital information transmission path 3 to the receiver 4c side.
Transmission device 2c via slot information transmission path 20 different from
This means that the slot information used on the receiving side is transmitted, whereby the slot information is supplied to the receiving apparatus 4c side.

When the slot information transmitting device 18 provided on the transmitting device 2c side is set so as to control the slot encoder circuit 6 based on slot information from the outside and allocate packet data for each service to each slot. , And fetches the slot information, sends the slot information to the slot information transmission line 20, and transmits the slot information to the receiving device 4c.

The slot information receiving device 19 provided on the receiving device 4c side receives and reproduces the slot information via the slot information transmission line 20, and controls the slot decoder circuit 11 based on the slot information. Let the user select the slot to be received.

As described above, in this reference example, similarly to the above-described first and second reference examples, the transmission device 2c takes in video data, audio data, and other data to be transmitted and packetizes them. At the same time, based on slot information input from the outside, each packet data is allocated to a slot corresponding to each service and multiplexed, and each packet data multiplexed into each slot by the receiving device 4c is extracted and Since the packet data belonging to the slot including the service to be received is limitedly processed and reproduced, various information such as video data, audio data, and other data is transmitted in an integrated manner. When applied to ISDB, digital information to be transmitted can be multiplexed into any slot and transmitted. At the same time, the time required for signal processing such as error correction and header identification on the receiving side can be ensured, so that even a low-speed receiver can perform the receiving process and reduce the cost of the receiver. it can.

Further, in this embodiment, a slot information receiving device 19 is added to the receiving device 4c, and a slot information transmitting line 20 different from the digital information transmitting line 3 is provided from the transmitting device 2c to the receiving device 4c. When the slot information used in the transmitting device 2c is transmitted through the transmitting device 2c, and the slot information is supplied to the receiving device 4c, the content of each service multiplexed in each slot is changed. However, it is possible to change the slot information on the receiving device 4c only by changing the slot information on the transmitting device 2c while reducing the load on the digital information transmission line 3.

FIG. 6 is a block diagram showing a fourth reference example of the transmission / reception system related to the present invention. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals.

The transmission / reception system 1d shown in this figure is different from the system 1 shown in FIG. 1 in that the slot information recording device 21 is added to the transmission device 2d and the reception device 4d
Side, a slot information reproducing device 23 is added to the transmitting device 2d.
Side, the slot information is recorded on an external recording medium 22 such as a magnetic card or an IC card, and this is recorded on the receiving device 4d.
To the external recording medium 2 in the receiving device 4d.
The slot information recorded in No. 2 is reproduced to determine the slot for reception processing.

The slot information recording device 21 provided on the transmission device 2d side is set so as to control the slot encoder circuit 6 based on slot information from the outside and allocate packet data for each service to each slot. At this time, the slot information is fetched, recorded on an external recording medium 22 such as a magnetic card, an IC card, or a floppy disk, and transferred to the receiving device 4d.

The slot information reproducing device 23 provided on the receiving device 4d side reads out the external recording medium 22 passed from the transmitting device 2d side and reproduces the slot information, and the slot decoder circuit 11 is operated based on the slot information. Control is performed to determine the slot to be received.

As described above, in this embodiment, as in the first to third embodiments described above, video data, audio data, and other data to be transmitted are fetched and packetized by the transmission device 2d. At the same time, based on slot information input from the outside, each packet data is allocated to a corresponding slot for each service and multiplexed, and each packet data multiplexed in each slot by the receiving device 4d is extracted and Since the packet data belonging to the slot including the service to be received is limitedly processed and reproduced, various information such as video data, audio data, and other data is transmitted in an integrated manner. When applied to ISDB, digital information to be transmitted can be multiplexed into any slot and transmitted. At the same time, the time required for signal processing such as error correction and header identification on the receiving side can be ensured, so that even a low-speed receiver can perform the receiving process and reduce the cost of the receiver. it can.

Further, in this reference example, a slot information recording device 21 is added to the transmitting device 2d side, and a slot information reproducing device 23 is added to the receiving device 4d side. The information is recorded on an external recording medium 22 such as a card or an IC card, and is passed to the receiving device 4d. The receiving device 4d reproduces the slot information recorded on the external recording medium 22 and specifies a slot for receiving processing. Since the content of each service multiplexed in each slot is changed, only the external recording medium 22 is passed from the transmitting device 2d to the receiving device 4d, and the packet to be serviced is changed. The slot containing the data can be selected and processed.

As a result, a pay broadcast or the like in which service contents are specified using a magnetic card or an IC card can be efficiently performed.

FIG. 7 is a block diagram showing a fifth reference example of the transmission / reception system related to the present invention. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals.

The transmission / reception system 1e shown in this figure is different from the system 1 shown in FIG. 1 in that a header identification circuit 25 is provided in the reception device 4e, and the header identification circuit 25 is used only on the reception device 4e side. The content of the transmission slot is detected, and the transmission slot to be received is limited based on the detection result.

The header identification circuit 25 provided on the receiving device 4e first controls the slot decoder circuit 11 to
The packet data separated for each slot via the demodulation circuit 9 and the frame decoder circuit 10 is sequentially selected and received for all slots, and the error correction circuit 1
The process of identifying the header of the packet data output from 2 and detecting the transmission slot to which the packet data of the service to be received is allocated is repeated several times to obtain the packet of the service to be received. Slot information indicating a transmission slot to which data is allocated is created, and thereafter, the slot decoder circuit 11 is controlled based on this slot information, and packet data multiplexed to the slot to be received is selected.

Thus, for example, when the received data input to the frame decoder circuit 10 has the slot relationship shown in FIG. 8, the receiving device 4e is designated to receive a specific service, for example, the service 2. Then, after the header identification circuit 25 completes the identification processing of the header of the packet data multiplexed in each slot, slot information is created based on the identification result, and the slot decoder is created based on the slot information. The circuit 11 is controlled to provide the service 2 as shown in FIG.
Of the second, fourth and sixth packet data in which the
Only the slot is selected, which is processed by the error correction decoder circuit 12.

As described above, in this reference example, similarly to the above-described first to fourth reference examples, the transmission device 2 captures video data, audio data, and other data to be transmitted and packetizes them. At the same time, based on preset slot information or slot information input from the outside, each packet data is assigned to a corresponding slot for each service and multiplexed, and multiplexed into each slot by the receiving device 4e. Each packet data is extracted, and the packet data belonging to the slot containing the service to be received is limitedly processed and reproduced, so that video data, audio data,
I to transmit various information such as other data in an integrated manner
When applied to SDB, digital information to be transmitted can be multiplexed into an arbitrary slot and transmitted, and the time required for signal processing such as error correction and header identification on the receiving side can be secured. As a result, even a low-speed receiver can perform a reception process, thereby reducing the cost of the receiver.

Further, in this reference example, a header identification circuit 25 is provided on the receiving device 4e side, and the content of the transmission slot is detected only on the receiving device 4e side by using the header identifying circuit 25, and the detection result is obtained. Transmission slots are limited based on the
Even if the packet data belonging to one service is distributed and multiplexed into a plurality of slots, the receiving device 4e can detect this and determine the slot to be serviced. Even if packet data belonging to one service is multiplexed into an arbitrary slot, the receiving device 4e can receive only the slot containing the packet data to be serviced.

FIG. 10 is a block diagram showing an example of a transmitting / receiving system to which an embodiment of the digital information receiving apparatus according to the present invention is applied. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals.

The transmission / reception system 1f shown in this figure differs from the system 1 shown in FIG. 1 in that a header identification circuit 26 and a continuity determination circuit 27 are provided in the reception device 4f, and the transmission device 2 or the service encoder ( The information indicating the continuity of the digital information belonging to the same service is added to the header of the packet on the side of the receiver (not shown). Only the 4f side detects the continuity of the contents of the transmission slot, and based on the detection result, limits the transmission slot to receive and process continuous digital information belonging to the same service.

The header identification circuit 26 provided on the side of the receiving device 4f is inputted to the slot decoder circuit 11 via the demodulation circuit 9 and the frame decoder circuit 10, and after being separated for each slot by the slot decoder circuit 11, the error correction decoder The header of each packet data that has been error-corrected by the circuit 12 is identified, and it is determined whether or not the packet data is of the service to be received. The information indicating the continuity added to the packet data is supplied to the continuity determination circuit 27.

The continuity judging circuit 27 firstly causes the slot decoder circuit 11 to select the packet data of each slot based on a preset rule, and outputs the information indicating the continuity output from the header identifying circuit 26. While capturing and holding this, the continuity of the packet data to be received is determined based on the held content,
Based on this determination result, slot information for limiting one or a plurality of slots in which packet data of the service to be received is multiplexed is created, and thereafter, the slot decoder circuit 11 is controlled based on this slot information. Only the limited slots are selectively received.

Next, the operation of this embodiment will be described with reference to the schematic diagrams shown in FIGS.

In this case, the receiving apparatus that receives all services from the first slot to the eighth slot needs to process eight packets from the first slot to the eighth slot during one round of reception. In the embodiment, the operation of the receiving device 4f will be described by taking a low-speed receiving device having a processing capability of up to four packets during one round of reception as an example.
The continuity determination circuit 27 holds information indicating continuity for two rounds.

In the following description, it is assumed that the service 4 is received on the receiving device 4f side, and the number added to the packet data, for example, “2-1” means the packet data of the service 2, and the continuity. Is "1".

[First Round] First, information indicating the continuity of digital information belonging to the same service is added to the packet header on the transmitting device 2 side or the service encoder side so as to have a continuity relationship shown in FIG. When the transmission signal of the first round is transmitted onto the digital information transmission path 3, the demodulation circuit 9 on the receiving device 4f side
Is received and the first round of received data is output, and the frame decoder circuit 10
This is packet data for each slot.

Next, the slot to be processed in the first round set in advance by the slot decoder circuit 11 in accordance with the processing speed of the receiving device 4f side, for example, the second slot and the third slot as shown by the shaded portions in FIG. , 5th and 7th packet data are selected,
The error correction decoder circuit 12 corrects the error of each packet data, and the header identification circuit 26
The content of the header is identified by this, it is determined that the packet data of the service 2 to be received is multiplexed in the second slot, and a value "1" indicating the continuity of this packet data is set to a continuity determining circuit. 27.

As a result, the continuity determination circuit 27 captures and holds "1" indicating the continuity of the packet data, and sets the second slot in which the packet data has been multiplexed as the selected reception slot. Slots other than the third slot, the fifth slot, and the seventh slot in which the service to be received by the process is not detected, for example, the first slot, the sixth slot, and the eighth slot.
The slot information is made to be the next selected receiving slot, and the slot decoder circuit 11 is controlled.

<< Second Round >> Thereafter, when a transmission signal of the second round is transmitted from the transmitting apparatus 2 side to the digital information transmission line 3, the signal is received by the demodulation circuit 9 of the receiving apparatus 4f side and the second round is transmitted. The received data of the third time is output and the frame decoder circuit 10
This is fetched and made into packet data for each slot.

Next, based on the slot information created in the first round of reception processing by the slot decoder circuit 11, the first slot and the second slot as shown by the shaded portions in FIG.
After the packet data of the slot, the sixth slot, and the eighth slot are selected, the error correction decoder circuit 12 performs error correction on each of the packet data,
The header identification circuit 26 identifies the content of the header,
It is determined that the packet data of the service 2 to be received is multiplexed in the second slot and the sixth slot, and a value “3” indicating the continuity of the packet data is set to “3”.
“4” is supplied to the continuity determination circuit 27.

As a result, the continuity determining circuit 27 fetches “3” and “4” indicating the continuity of the packet data, and holds it together with the previous value “1”.
Since these values are discontinuous such as "1", "3", and "4", it is determined that it is necessary to perform further round-trip reception.

At this time, the continuity judging circuit 27 sets the second slot in which the packet data of the service 2 is multiplexed as the selected reception slot, and determines the first slot for which the service to be received was not detected in the current processing. The slot decoder circuit 11 is controlled by creating slot information other than the slot and the eighth slot, for example, the third slot, the fourth slot, and the seventh slot as the next selected reception slot.

<< Third Circuit >> Thereafter, when the transmission signal of the third circuit is transmitted from the transmitting device 2 side to the digital information transmission line 3, the signal is received by the demodulation circuit 9 of the receiving device 4f side and is transmitted for three cycles. The received data of the second time is output, and is taken in by the frame decoder circuit 10 to be converted into packet data for each slot.

Next, based on the slot information created in the second round of reception processing by the slot decoder circuit 11, the second slot and the third slot are indicated by the shaded portions in FIG.
After the packet data of the slot, the fourth slot, and the seventh slot are selected, the error correction decoder circuit 12 performs error correction on each of the packet data,
The header identification circuit 26 identifies the content of the header,
It is determined that the packet data of the service 2 to be received is multiplexed in the second slot and the fourth slot, and a value “5” indicating the continuity of the packet data is determined.
“6” is supplied to the continuity determination circuit 27.

As a result, the continuity determining circuit 27 fetches “5” and “6” indicating the continuity of the packet data, and sets the continuity among the values “1”, “3” and “4” up to the previous time. Are held together with the value “3” and the value “4”, and these values are “3”, “4”, “5”,
Since the value is a continuous value of “6”, slot information for limiting the slot to be received to the second, fourth, and sixth slots is created, and the slot decoder circuit 11 is controlled.

<Fourth Circuit> Next, when the transmission signal of the fourth circuit is transmitted from the transmitting device 2 side to the digital information transmission path 3, the signal is received by the demodulation circuit 9 of the receiving device 4f and the fourth circuit is performed. The received data is output by the frame decoder circuit 10 and taken into the packet data for each slot.

Thereafter, based on the slot information created in the third round of reception processing by the slot decoder circuit 11, the second slot and the fourth slot are displayed as shown by the shaded portions in FIG.
After the packet data of the slot and the sixth slot is selected, the error correction of the respective packet data is performed by the error correction decoder circuit 12, and the content of the header is identified by the header identification circuit 26, which is to be received. When the packet data of the service 2 is the fourth slot,
It is determined that the packet data is multiplexed with the sixth slot, and the values “7” and “8” indicating the continuity of the packet data are supplied to the continuity determination circuit 27.

As a result, the continuity determining circuit 27 fetches “7” and “8” indicating the continuity of the packet data, and obtains the previous values “3”, “4”, “5”,
Of "6", the value is held together with a continuous value "5" and a value "6", and these values are "5", "6",
Since the value is a continuous value of “7” and “8”, the slot decoder circuit 1 holds slot information for limiting the slot to be received to the second, fourth, and sixth slots.
Control 1

<Fifth Circuit> When the transmission signal of the fifth circuit is transmitted from the transmitting device 2 to the digital information transmission path 3, the signal is received by the demodulation circuit 9 of the receiving device 4f and the fifth circuit is performed. Are output by the frame decoder circuit 10 and are separated into frame data. The hatched portion of FIG. 16 is generated by the slot decoder circuit 11 based on the slot information created in the third round of reception processing. The second slot, the fourth slot, the sixth slot
After the packet data of the slot is selected, the error correction decoder circuit 12 corrects the error of each packet data, the header identification circuit 26 identifies the contents of the header, and the packet of the service 2 to be received. The data is a second slot, a fourth slot,
It is determined that the packet data is multiplexed with the sixth slot, and values “9”, “10”, “1” indicating the continuity of the packet data
1 "is supplied to the continuity determination circuit 27.

Thus, the continuity judging circuit 27 outputs “9” and “10” indicating the continuity of the packet data,
"11" is fetched and the previous values "5", "6",
Of “7” and “8”, the value is held together with a continuous value “7” and a value “8”, and these values are “7”, “8”, “9”, “10”, and “11”. Therefore, the slot decoder circuit 11 is controlled while holding slot information for limiting slots to be received to the second, fourth, and sixth slots.

<< Fifth or later laps >> Thereafter, the above-described operation is repeated, and the second slot and the fourth
The slot and the sixth slot are selected, and the packet data belonging to the service 2 extracted by the selection operation is processed.

When the discontinuity occurs in the value by the continuity determination circuit 27, the reception slot inspection process is performed again from the above-described first round process.

As described above, in this embodiment, as in the first to fifth embodiments described above, the transmission device 2 takes in video data, audio data, and other data to be transmitted and packetizes them. At the same time, based on preset slot information or slot information inputted from the outside, each packet data is allocated to a corresponding slot for each service and multiplexed, and multiplexed into each slot by the receiving device 4f. Each packet data is extracted, and the packet data belonging to the slot containing the service to be received is limited and processed and played back, so various information such as video data, audio data, and other data ISD for integrated transmission
When applied to B, digital information to be transmitted can be multiplexed and transmitted in an arbitrary slot, and the time required for signal processing such as error correction and header identification on the receiving side can be secured. As a result, even a low-speed receiver can perform a reception process, thereby reducing the cost of the receiver.

Further, in this embodiment, a header identifying circuit 26 and a continuity determining circuit 27 are provided in the receiving device 4f, and the transmitting device 2 or the service encoder has a digital header belonging to the same service as the packet header. In addition to adding information indicating the continuity of information, the receiving device 4
The continuity of the contents of the transmission slot is detected only by the receiving device 4f side by the header identification circuit 26 and the continuity determination circuit 27 provided on the f side, and based on this detection result, the transmission slot is limited to the same service. The receiving device 4f detects the continuous digital information belonging to the service 4c even if the packet data of each service is distributed to a plurality of slots and multiplexed on the transmitting device 2 side. The target slot can be determined, so that even if packet data belonging to each service is multiplexed into an arbitrary slot on the transmitting device 2 side, this is detected on the receiving device 4f side and becomes a service target. The reception processing can be performed only for the slot containing the packet data.

[0082]

As described above, according to the present invention, when the information indicating the continuity of a received packet is determined to be continuously received for a predetermined period, the digital information By limiting the transmission slots that receive the packet to the transmission slots received so far, even if all continuity is not checked, if the continuity of a certain period at some point can be confirmed After that, there is no need to check continuity. As a result, signal processing such as error correction and header identification of a receiver that receives only a data amount such as a data service or a service with a small data rate can be sufficiently slowed down, thereby greatly reducing the cost of the receiver side. Can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first reference example of a transmission / reception system related to the present invention.

FIG. 2 is a schematic diagram showing an example of a slot assignment operation of the transmitting apparatus shown in FIG.

FIG. 3 is a schematic diagram illustrating an example of a transmission procedure of the transmission device illustrated in FIG. 1;

FIG. 4 is a block diagram showing a second reference example of the transmission / reception system related to the present invention.

FIG. 5 is a block diagram showing a third reference example of the transmission / reception system related to the present invention.

FIG. 6 is a block diagram showing a fourth reference example of the transmission / reception system related to the present invention.

FIG. 7 is a block diagram showing a fifth reference example of the transmission / reception system related to the present invention.

FIG. 8 is a schematic diagram showing an example of a slot assignment operation of the transmitting apparatus shown in FIG. 7;

FIG. 9 is a schematic diagram showing an example of a slot subjected to reception processing in the receiving device shown in FIG. 7;

FIG. 10 is a block diagram showing an example of a transmission / reception system to which an embodiment of the digital information receiving apparatus according to the present invention is applied.

11 is a schematic diagram showing an example of a slot assignment operation of the transmitting apparatus shown in FIG.

12 is a schematic diagram illustrating an example of a slot in a first round of reception processing performed by the reception device illustrated in FIG. 10;

13 is a schematic diagram illustrating an example of a slot in a second round of reception processing performed by the reception device illustrated in FIG. 10;

14 is a schematic diagram illustrating an example of a slot in a third round of reception processing performed by the reception device illustrated in FIG. 10;

FIG. 15 is a schematic diagram showing an example of a slot in a fourth round of receiving processing performed by the receiving apparatus shown in FIG. 10;

FIG. 16 is a schematic diagram showing an example of a slot in a fifth turn subjected to reception processing in the receiving apparatus shown in FIG. 10;

[Explanation of symbols]

 1 to 1f transmission / reception system 2 to 2d transmission device 3 digital information transmission line 4 to 4f reception device 5 error correction encoder circuit 6 slot encoder circuit 7 frame encoder circuit 8 modulation circuit 9 demodulation circuit 10 frame decoder circuit 11 slot decoder circuit 12 error correction Decoder circuit 15 Packet encoder circuit 16 Packet decoder circuit 18 Slot information transmitting device 19 Slot information receiving device 20 Slot information transmission line 21 Slot information recording device 22 External recording medium 23 Slot information reproducing device 25, 26 Header identification circuit 27 Continuity determination circuit

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naoki Kawai 1-10-11 Kinuta, Setagaya-ku, Tokyo Inside the Japan Broadcasting Corporation Broadcasting Research Institute (72) Inventor Takeshi Kimura 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Broadcasting Research Institute (72) Inventor Hiroyuki Hamada 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Broadcasting Research Institute (56) References JP-A-62-18155 (JP, A) Kimura, "Investigation of ISDB Transmission Signals in BCS92-13 12 GHz Band Digital Satellite Broadcasting," Television Society Technical Report, March 23, 1992, Vol. 16, NO. 26, p. 7-12 Yoshimura et al., "Transmission Characteristics of BCS92-12 Satellite Data Broadcasting Transmission Control Method", Television Society Technical Report, VOL. 16, NO. 26, p. 1-6 (58) Field surveyed (Int. Cl. ⁷ , DB name) H04J 3/00 H04L 12/56

Claims (1)

(57) [Claims] When a digital information transmission path is divided into a plurality of transmission slots and digital information such as video, audio, data, etc. is transmitted in a packet format, a packet composed of digital information belonging to the same service is transmitted. A digital information receiving apparatus for use in a digital information transmission system in which information indicating packet continuity is added and multiplexed and transmitted only to one or a plurality of specific transmission slots in the transmission path, Means for sequentially determining whether or not a packet of digital information belonging to each service is transmitted in each of the transmission slots, and information indicating the continuity of the received packet is continuously received for a predetermined period. If it is determined that
Means for limiting a transmission slot for receiving the packet of digital information to a transmission slot that has been received so far.