JP3152667B2 - Data channel receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data channel receiving apparatus suitable for receiving a data broadcast using a satellite broadcast data channel.

[0002]

SUMMARY OF THE INVENTION The present invention relates to a data channel receiving apparatus, for example, an apparatus for separating a packet from a bit stream output from a BS tuner in a data broadcasting receiving section using a satellite broadcasting data channel. By adding decoded information consisting of multiplexed position information and error detection information to the check bit position of the original header part and outputting it to the receiving terminal together with the data part, a plurality of identifiers can be output at one terminal. Packets can be output, and packets can be classified according to multiplex positions within one identifier.

[0003]

2. Description of the Related Art Data output formats used in a conventional data channel decoder are shown in FIGS. 1a, 2a and 2b.

FIG. 4 shows a connection between a data channel decoder and various service decoders in a data broadcast receiving unit using a satellite broadcast data channel .
As described in the report to the Telecommunications Technology Council Advisory Council No. 18, "Technical conditions on the use of satellite broadcast data channels", a 288-bit packet is used as it is (data output format 1a : see FIG. 2 ). 272, identified by the identifier (SI) after error correction of the header part
Only the data part of the bit (data output format 2a : see FIG. 2)
In the case where (272, 190) difference set cyclic code (BEST) is used in the data part, this BEST is decoded and only 190 information bits are used (data output format 2b : see FIG. 2 ). Was going.

[0005] As described above, in the conventional output format, information relating to the multiplex position is discarded because of packet transmission.

[0006]

The prior art has the following problems.

[0007] In the output format 1a of FIG. 2, the decoder of each service respectively has a header part (BCH (16, 5)),
Since the error correction of the data part (BEST) is performed, there is much waste.

In the output formats 2a and 2b shown in FIG.
Since it is narrowed down to one identifier SI, a data channel decoder is required for each SI in order to receive program data composed of a plurality of SIs.

[0009] Further, in a packet of a data channel multiplex-transmitted together with the sound of the satellite broadcast, it is possible to identify the packet other than the identifier SI depending on where in the frame matrix the packet to be transmitted is located.
The output formats 1a, 2a and 2b cannot be used because they do not output position information.

[0010] Also, BCH (16, 5) or BEST
Even if the error cannot be corrected by the error correction, the service decoder cannot switch the reception processing.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a data channel receiving apparatus configured to efficiently separate packets.

[0012]

In order to achieve the above object, the present invention provides a receiving apparatus provided with a data channel decoder for separating a packet from a transmission signal, wherein the multiplexed position information of the packet and information about an error are provided. Is added to the position of the check bit in the original header portion of the packet, a new header portion is formed together with the error-corrected identifier, and the new header portion is received together with the data portion after error correction decoding. A decoding information adding circuit for outputting to the terminal side is provided so that the receiving terminal side can use the multiplex position information for packet identification.

[0013]

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a circuit configuration example of a data channel decoder according to one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a clock recovery circuit for recovering a clock from a bit stream.

Reference numeral 2 denotes a synchronous reproduction circuit that reproduces a frame synchronization signal and a master frame synchronization signal, and performs a majority decision on an audio mode flag and a data suppression flag.

Reference numeral 3 denotes a descrambling circuit for descrambling transmission scrambling in the case of an NTSC signal.

4 is to solve the interleave and to set the NTS
B signal (63, 56) signal, MUSE
This is a deinterleave circuit that performs error correction on a signal using a BCH (82, 74) code.

Reference numeral 5 denotes a superframe memory for storing data for one superframe in order to convert an array of data into packets.

Reference numeral 6 denotes an address control circuit for performing control of returning obliquely multiplexed data from the superframe memory 5 to a packet.

The output of the 288-bit packet data read from the super frame memory 5 has the data output format 1a shown in FIG.

Reference numeral 7 denotes an error correction / detection circuit for performing error correction / detection of a BCH (16, 5) code in the header portion of the 288-bit packet data.

Reference numeral 8 denotes an error correction / detection circuit that performs error correction / detection of a BEST code in the data portion of the 288-bit packet data.

9 is an externally set identifier SI, 2
This is an SI selection circuit that selects a data portion of 72 bits or 190 bits and outputs it as data output formats 2a and 2b.

Reference numeral 10 denotes a 190-bit data portion after the BEST decoding, in which the identifier SCH after the BCH (16, 5) error correction has been performed.
I and information A about errors, multiplexed position information B from the address control circuit 6 , and error information C about BEST are added, and data is output in a data output format 1b (see FIG. 2). This is an information adding circuit.

The data section 19 of the output format 1b shown in FIG.
As shown in FIG. 3, the header part preceding the 0 bit is 5 bits.
In addition to the bit identifier SI, as decoding information, 8-bit position information indicating the order of the packet in the master frame, and a BCH (16, 5) error flag 1
It is composed of a total of 16 bits including a bit, a 1-bit BEST error flag, and a 1-bit superframe end flag indicating the last packet of the superframe.

Here, in the position information, in the NTSC signal, 6 bits indicate the position in the superframe, the remaining 2 bits indicate the superframe number in the master frame, and 7 bits in the MUSE signal indicate the superframe. And the remaining one bit indicates the number of the superframe in the master frame.

[0029]

According to the present invention, the identifier of the packet head and the decoded information including the multiplexed position information and the error detection information are added to the check bit position of the original header part and are combined with the data part. Receiving terminal (shown as a conventional example
(Corresponding to the various service decoders shown in FIG. 4) can output packets with a plurality of identifiers at one terminal, and further classify packets according to the multiplex position within one identifier. Can be.

In the data channel, when the packet is identified by the identifier SI, only 32 types can be distinguished. By adding the location information and using the identification based on the multiplexed position of the packet, the NTSC system has a maximum of 70
Forty types and 4,736 types of packets can be distinguished in the MUSE system.

In order to improve the reliability of data by continuously transmitting packets and making a majority decision for each bit, the conventional output format is limited by the error correction capability of the BCH (16, 5) code. In the output format according to the present invention, since highly reliable position information can be used, the correction capability by majority decision can be sufficiently exhibited.

In order to obtain a time reference, conventionally, there has been no other choice but to output the master frame synchronization separately from the data channel decoder or reproduce the time from the time packet inside the data channel decoder and output the time.
In the output format according to the present invention, since the master frame synchronization can be reproduced from the position information, there is no need to provide an output for a new time.

Conventionally, on the service decoder side (as a conventional example)
(Corresponding to the various service decoders shown in FIG. 4 shown in FIG. 4) , there is no other way than to detect a packet loss or a transmission error by using a continuity index or a CRC code. Then BEST
An error can be detected only by detecting an error flag. Also B
By detecting the CH (16,5) error flag, it can be seen that a packet loss has occurred.

In the conventional output format, it is necessary to prepare a large number of output terminals of the data channel decoder and a selection circuit of the identifier SI in advance, but in the output format according to the present invention, only one output terminal is required.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of an NTSC / MUSE shared data channel decoder.

FIG. 2 is a diagram showing a format of an output signal in FIG.

FIG. 3 is a diagram illustrating bit allocation of a header section in the present embodiment.

FIG. 4 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 clock recovery circuit 2 synchronous recovery circuit 3 descramble circuit 4 deinterleave circuit 5 superframe memory 6 address control circuit 7 error correction / detection circuit for header section 8 error correction / detection circuit for data section 9 SI selection circuit 10 decoding Information addition circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04H 1/00 H04L 12/56 H04N 7/08

Claims (1)

(57) [Claims] 1. A receiving apparatus comprising a data channel decoder for separating a packet from a transmission signal, comprising: decoding information having multiplex position information of the packet and information on an error in a position of a check bit in an original header portion of the packet; And a decoding information adding circuit for configuring a new header section together with the error-corrected identifier and outputting the new header section together with the data section after error-correction decoding to the receiving terminal side. 2. The data channel receiving device according to claim 1, wherein said multiplexed position information can be used for packet identification.