JPH0451653A - Facsimile broadcasting reception device - Google Patents

Abstract

PURPOSE:To execute a processing as against an error without providing a new memory by dividing a memory for writing frame data into a mode control part and a data packet part and judging the number of transmission packets at every service of the data packet transmitted in a frame and a transmission position in the frame. CONSTITUTION:A frame memory circuit having the mode control part memory 12 of one system and a data packet part memory 15 independent of the memory 12 is provided. When the transmission of the mode control part terminates, the error of the mode control part is corrected and service is identified. The number of the transmission packets of facsimile broadcasting transmitted by the frame and the transmission position in the frame are judged. Thus, the processing as against the transmission error is executed without the need of the new memory.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a facsimile broadcast receiving apparatus that receives digital television multiplex facsimile broadcasts.

[Summary of the Invention] The present invention relates to a receiving device for digital television multiplex facsimile broadcasting, and in configuring a frame memory for receiving and processing facsimile signals, a mode control section and a memory for storing a data packet section are provided independently. The mode control section performs error correction and service identification after the pressure has been sent.
Specifies that the number of facsimile broadcast packets transmitted within a frame and the transmission position within the frame are detected without waiting for the transmission of all frame data to be completed, and the results and the transmission format of the facsimile signal are transmitted continuously within the frame. Therefore, even if an error is detected or corrected in the mode control section and the broadcast is determined to be a non-facsimile broadcast, if the mode control assigned to the facsimile broadcast is transmitted after that mode control section. In this method, the data packet corresponding to the mode control unit in which an error has been detected or which is determined to be non-facsimile broadcasting is treated as a data packet of facsimile broadcasting for subsequent reception processing.

[Prior art 1] In a receiver that receives digital television multiplex facsimile broadcasting, two systems of frame memories are prepared in order to process facsimile signals that are transmitted in an interleaved manner for each frame, and the writing side, And, while switching the read side and writing data transmitted in frames to one frame memory,
A method of deinterleaving and reading the other frame memory in which the data of the previous frame has already been written, and repeating error correction of the mode control section, service identification judgment, and error correction of the data packet section for transmission packets. is common.

In addition, in the case of this type of processing, a transmission error occurs in the mode control unit that specifies the service identification for each packet, and if an uncorrectable error is detected, or even if correction is possible, the result of the service identification judgment The general error handling method for cases where the facsimile broadcast mode control is not performed is to discard the data packet.

[Problem to be solved by the invention]

In digital television multiplex facsimile broadcasting, during the transmission period of program data, packets designated with different mode control sections are not interrupted and transmitted within a frame.

Therefore, even if an error occurs in the mode control section due to a transmission error and an uncorrectable error is detected, and even if it is determined that the mode control section is not assigned to facsimile broadcasting, If a mode control packet assigned to facsimile broadcasting is transmitted after that packet in the frame, it can be determined that the mode control section in which the error occurred was originally assigned to facsimile broadcasting. It turns out.

However, as described above, the processing method that de-interleaves and reads frame data transmitted within a frame and repeats error correction in the mode control section, service identification judgment, and error correction in the data packet section for transmitted packets does not allow errors to occur. A packet memory for temporarily saving generated packets is prepared separately from the frame memory, and subsequent packets are processed in the same way, and it is determined whether or not to actually discard the saved packets.
This would require new packet memory.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a facsimile broadcast receiving apparatus that is capable of handling the above-described errors without requiring a new memory.

[Means for Solving the Problems 1] A facsimile broadcast receiving apparatus according to the present invention includes a frame memory circuit having one system of mode control section memory and a data packet section memory independent of the memory, and a mode control section memory. When the transmission is completed, the mode control section performs error correction and service identification, and without waiting for the transmission of frame data to end,
a first processing means for determining the number of transmission packets of the facsimile broadcast transmitted in the frame and the transmission position within the frame; and a transmission error occurring in the mode control section; Even if it is determined that the data packet was not transmitted, if the mode control section after the occurrence of the transmission error is assigned to facsimile broadcasting, the data packet is not discarded at that stage and the data packet is not discarded at that stage. The present invention is characterized by further comprising second processing means for processing the data packet corresponding to the mode control section as a data packet for facsimile broadcasting.

[Function] The present invention focuses on the fact that in a transmission signal in digital television multiplex facsimile broadcasting, mode control section data and data packet section data are transmitted sequentially following a framing code, and in order to write one frame data. By configuring the memory of the mode control section and the data packet section independently, the mode control section memory is read when the transmission and writing of the mode control section data is completed, and the data packet section is transmitted. During this time, the mode control unit completes error correction and service identification determination processing, and determines the number of packets transmitted for each service and the transmission position within the frame for the data packets transmitted within the frame, thereby creating new memory. It is possible to handle errors such as those described above.

[Embodiment 1] Before explaining the present invention in detail, first, a transmission signal of digital television multiplex facsimile broadcasting will be briefly explained.

FIG. 2 is a diagram showing a frame structure for transmitting a facsimile channel signal defined in digital television multiplex facsimile broadcasting. l frame is 3
Consists of 2 lines x 288 bits, with 16 bits at the beginning of the frame.
There is a bit framing code. Each row of 288 bits takes the form of a packet. Figure 3 shows the packet structure. The packet length is 288 bits and consists of a 16-bit mode control section and a 272-bit data packet section.

The mode control section performs packet service identification. BCH (16,5) in the mode control section
Error protection is provided by code.

A total of three service identifications are assigned to the codes of the mode control unit: for general programs, for paid programs, and for sending dummy data.

Facsimile broadcast program data is transmitted by the data packet section. In the data packet part (272, 190)
Code error protection is provided.

For the frame with the above configuration, the writing order of packet data and the reading order of data are determined as shown in FIG. 2. Therefore, as shown in FIG. Data is transmitted sequentially frame by frame. However, the mode control part data and data packet part data of each packet have an interleaving length of 32
Data is transmitted by bit interleaving.

The transmission speed of the facsimile signal is 16 kbps, and the total number of bits in one frame is 9232, so the transmission time of frame data is 577 m5ec. Of these, the framing code section is 1 m5ec, the mode control section is 32m5ec, and the packet data section is 544m5ec.
It is.

The above is an explanation of the transmission signal of digital television multiplex facsimile broadcasting.

Next, one embodiment of the present invention will be described.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In this figure, signal A is a pit stream signal obtained by demodulating a facsimile channel signal. Signal A
has the configuration shown in FIG. 4 above.

A framing code detection section 10 detects a framing code from the signal A. When the framing code is detected, a detection pulse signal B is output.

When the MC section memory write address control section 11 receives the framing code detection signal B, it controls the write address for writing 512 bits of mode control section data transmitted immediately after the framing code into the MCC section memory 12. do.

According to the address signal C from the MC section memory write address control section 11, 512 bits of data immediately after the framing code of the signal A is written into the memory 12 on the MCC section.

The MC unit memory write address control unit 11 has 512
When bit write address control is completed, the mode control section outputs a data write end pulse signal.

When the DPAC memory write address control unit 14 receives the mode control unit data write end signal, the DPAC memory write address control unit 14 performs an address control function to input 8704 bits of data packet data to be transmitted subsequent to the mode control unit data into the DPAC memory 15. Control write address. According to the address signal E from the DPAC section memory write address control section 14, 8704 bits of data after the mode control section data of the signal A is written into the DF'AC section memory 15.

DPAC section memo memory: Consists of two memory systems with a capacity to store 1504 bits of data. In order to process the data packet part data that is interleaved and transmitted for each frame, it switches between the write side and the read side for each frame, and writes the data packet part data that is transmitted in one DPAC memory memory. While the data packet data transmitted in the previous frame has already been written, the other DPAC memorandum memory is interleaved and read out, and the transmitted data packets are subjected to error correction using the (272,190) code. It is for the purpose of doing.

The DPAC memory selection unit 13 generates eight DPAC memory switching signals F for switching and controlling the writing side and the reading side of the two systems of DPAC memorandum memory based on the framing code detection signal B from the framing code detection unit. . Due to signal F, two lines of D
The writing side and the reading side are switched for each PAC section memo dam. The data packet part data transmitted in the frame is written to the memory on the writing side.

On the other hand, the MC unit memory read address control unit 16
Upon receiving the mode control section data write end pulse signal from the MC section memory write address control section 11, control of the read address for reading out the mode control section data written in the MCC section upper memory 12 is started.

Since the mode control section data is written in the transmission section of the MCC section upper memory 12, the MC section memory read address control section performs address control for de-interleaving and reads out the mode control section data for each block. Output as signal G.

The MC error correction section 17 corrects the mode control section of 32 blocks based on the signal G using the BCH (16,5) code, and outputs the correction result as the signal H.

The MC determination unit 18 determines whether the signal H is a service identification indicating a general program or a paid program, a service identification indicating a dummy, or a service identification that does not correspond to any of the above (for convenience, this case is considered to be a non-facsimile broadcast). (referred to as service identification), whether an uncorrectable error has been detected 4
It determines the street and outputs a flag signal indicating the determination result.

The signal T needs to be a flag of at least 2 bits for each mode control section in order to indicate four different determination results for one mode control section.

By repeating the above operations 32 times, error correction and identification determination operations for 32 mode control unit data transmitted in one frame are completed.

The signal signal is a flag signal indicating whether or not the service identification is assigned to facsimile broadcasting for each mode control unit, and is output in 64 bits for each frame.

Here, as a result of correcting and determining the mode control section,
Even if an uncorrectable error is detected or something is determined to be a non-facsimile broadcast, the possibility that the mode control unit can handle it as a facsimile broadcast will be explained.

In digital television multiplex facsimile broadcasting, during the transmission period of program data, packets designated with different mode control sections are not interrupted and transmitted within the frame. Therefore, within one frame, program data is transmitted continuously with a maximum of 32 packets. The maximum value of 32 means that a method that guarantees the minimum scanning line time for reception in one frame transmission time unit is allowed as an image signal transmission method, and in this case, for example, 20 packets are transmitted from the beginning of the frame. This is because the transmission of image data may be interrupted at this stage. When the transmission of image data is interrupted, dummy data is transmitted in the relevant frame.

However, it is currently being considered that auxiliary information for facsimile broadcasting may be transmitted using this interruption period. When a mode control is assigned to auxiliary information, the auxiliary information may be transmitted using the assigned mode control, but here it is assumed that dummy data is transmitted for boat fishing.

On the other hand, the BCH (16,5) code used for error protection in the mode control section can correct all errors within 3 bits, and can detect all 4-bit errors. .

Therefore, if an error of 5 bits or more occurs, there is a possibility that it will be erroneously corrected.

However, among the 32 codewords of the BGH (16,5) code, only three codewords (general, paid, and dummy) are valid for facsimile broadcasting, so even if an error correction occurs, it happens to be a general codeword. program.

Generally, the probability of matching any of the three things assigned to the paid program and dummy is extremely low.

The probability that the result determined as paid or dummy is incorrect is extremely low.

Considering the above two points, even if a transmission error occurs in the mode control section and an uncorrectable error is detected, or if it is determined that it is a non-facsimile broadcast due to an error correction, the mode control of the frame If it is determined that the following part is the mode control assigned to facsimile broadcasting, it can be determined that the uncorrectable or incorrectly corrected mode control was also transmitted as facsimile broadcasting. . As a condition for judgment, we do not only refer to the immediately following mode control, but also refer to subsequent mode controls, and if all of them are mode controls assigned to facsimile broadcasting, then the mode control section where the transmission error occurred is determined. The probability that it was a facsimile broadcast is even higher.

In order to perform these processes, the MC complementing unit 19 takes into memory a total of 64 bits of flag signal 1 every 2 bits, and stores a flag indicating that an uncorrectable error has been detected and a flag indicating non-facsimile broadcasting. If there is, and the subsequent flag is a flag indicating facsimile broadcasting, that flag is replaced with the facsimile broadcasting flag. Similarly, if the subsequent flags are set as dummy signals, they are replaced with the dummy signal flags.

However, if the flag of the last packet in the frame indicates non-facsimile broadcasting, this cannot be determined, so the flag is not replaced.

After the MC complementing unit 19 performs complementation, the number of packets for each service transmitted within one frame can be calculated by counting the flags for each state.

Further, the flag itself in the memory indicates the transmission position of the packet transmitted within the l frame.

It is necessary to perform the above operation at the same time as the operation of writing the data in the data packet part of the DPAC memory.
It is 44m5ec and can be sufficiently processed.

When the transmission of the data packet section data is completed and the operation of loading the DPAC section memo memory 15 is completed, the framing code is transmitted again, so the operations described above are repeated. Since all processing has been completed for the mode control section and the information is stored as a flag, only one system of MC section memory 12 is required.

At the time when the framing code is detected, the DPAC memory select section reverses the previous control on the write side and the read side.

At this stage, the DPAC unit memory that had been operating as a write side during the previous frame period switches to the read side, so the DPAC unit memory read address control unit 20 uses the DPAC unit memory read address control unit 20 to read out the data packet unit data stored in the DPAC unit memory 15. Start address control and signal N by 8 times.

Since the data packet part data is written in the order of transmission in the DPAC part memo memory 15, the DPAC part memory read address control unit 20 performs read address control for de-interleaving, and reads out each data packet part data by the signal N. 8 as signal J.

The DPAC error correction unit 21 performs error correction on the signal J using the (272,190) code for each data packet part data by referring to the flag information for each packet in the MC complementation unit 19 as a signal. Error correction is performed on the data packet part at the packet position corresponding to the flag for which service identification of facsimile broadcasting has been determined and the flag replaced as facsimile broadcasting, and 190 bits of error-corrected data packet part data are output as a signal.

The MC complementing unit 19 digitizes the signal M by 8 when the reference from the DPAC error correction unit is completed, and loads the mode control unit determination flag information I for the new frame that has already been processed from the MC determining unit 18. Then, the mode control section complements the operation and prepares for the data packet section error correction operation of the new frame.

〔Effect of the invention〕

According to the present invention, even if a transmission error occurs in the mode control unit and an uncorrectable error is detected, and even if the mode control unit is determined to be non-facsimile broadcasting, the subsequent mode control unit If the data packet can be identified as a broadcast, it is assumed that it was originally transmitted as a facsimile broadcast, and the data packet is processed as a facsimile broadcast data packet without being discarded.
) By discarding only the cases where correction cannot be made using the code, packet omission can be prevented and image quality deterioration can be reduced.

In addition, one system of memory for writing data in the mode control section is sufficient to handle facsimile signal reception processing, and the memory for storing flag information can be small at 64 bits, reducing the memory burden on the receiver. can do.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of a facsimile receiver according to the present invention, FIG. 2 is a diagram showing a frame configuration of facsimile broadcasting using a digital system, FIG. 3 is a diagram showing a bucket configuration, and FIG. FIG. 3 is a diagram showing the transmission order of facsimile signals. 19...Mode control section complementing section, 20...Data packet section memory read address control section, 21...Data packet section error correction section. FC...Framing code, MC...Mode control section data, DPAC...
・Data packet part data, IO...Framing code detection part, 11...Mode control part Memory write address control part, 12...Mode control part Memory 13...Data packet part memory selection part, 14...・Data data packet section memory write address control section, 15...Data packet section memory (1), (2
), 16...Mode control unit memory reading ratio address control unit, 17...Mode control unit error correction unit, 18...
・Mode control department judgment department, patent applicant Japan Broadcasting Corporation

Claims (1)

[Scope of Claims] 1) A frame memory circuit having one system of mode control section memory and a data packet section memory independent of the memory; a first processing means that performs error correction and service identification of the control unit and determines the number of transmission packets of facsimile broadcasting transmitted in the frame and the transmission position within the frame without waiting for the end of frame data transmission; If a transmission error occurs in the control section and the error is detected, and even if it is determined that the control section is not assigned to facsimile broadcasting, the mode control section after the transmission error occurs will not be assigned to facsimile broadcasting. If the data packet is a facsimile broadcast data packet, the second processing means does not discard the data packet at that stage and processes the data packet corresponding to the mode control unit in which the transmission error has occurred as a facsimile broadcast data packet. A facsimile broadcast receiving device characterized by: