JP3300520B2 - Multiplexer for data transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for multiplexing transmission data to be multiplexed on an FM multiplex broadcast for mobile reception.

[0002]

2. Description of the Related Art JP-A-5-122197 (Japanese Patent Application No. 3-122197)
No. 282899) As described in the specification of "data transmission apparatus", transmission data to be multiplexed on a conventional FM multiplex broadcast for mobile reception has a frame configuration as shown in FIG. In the FM multiplex broadcast for mobile reception, in order to cope with a severe continuous error at the time of mobile reception, both the horizontal direction and the vertical direction have a configuration of a product code encoded by a (272, 190) code. Still further, as shown in FIG. 3, the frame configuration is such that the parity in the vertical direction is distributed and transmitted between one frame.

In the conventional frame configuration shown in FIG. 2, BIC1 of reference numeral 201 and BIC2 of 202 are block identification codes for synchronizing blocks. 203
Is a parity obtained by horizontally encoding 190 bits excluding the block identification code using a (272, 190) code. The parity 2 of 204 is obtained by vertically coding each packet in the vertical direction with a (272, 190) code for each bit of the 190 packets. Parity 3 of 205 is a parity attached to both the vertical and horizontal directions.
Due to the nature of the product code, the parity is both vertical and horizontal. 2
06 is a CRC attached to each block, (27
2,190) to detect a missing code error. The transmission order is the order indicated by the arrow 207 in the figure, and the data is transmitted in this order.

[0004] By using the frame structure shown in FIG. 2, the receiver transmits the transmitted signal to 272 × 272.
Even if not all of the frames have been received, they can be decoded as they are in block units, and are suitable for transmission of data to be displayed instantaneously, such as display of station names. Also, whether the transmitted block is a data portion or a parity portion can be identified by the block identification code added to the head of the block, and the parity portion is not mistaken for the data portion and decoded. If the transmission conditions are poor,
In some cases, decoding cannot be performed by error correction only in the horizontal direction. In the normal error correction method that protects only one direction, it was necessary to wait until the same data is sent next time. However, when this method is used, the vertical direction is set when a 272 × 272 frame can be received. And 272 × 272 bits of errors are averaged by decoding in the horizontal direction, and the error correction code can be decoded twice more, so that the error correction effect increases and without waiting for the next data. Data decoding becomes possible.

[0005] In the frame configuration shown in FIG. 3, after the frame configuration shown in FIG. 2, the blocks are exchanged so that the parity blocks are not transmitted in a concentrated manner to 82 blocks. By doing so, it is possible to prevent information that is necessary in real time from being transmitted during the period of the parity section, thereby preventing the information from being transmitted. Although two types of block identification codes are used in the case of the configuration shown in FIG. 2, two types of block identification codes can be transmitted in the case of the present configuration. However, since the frame configuration is slightly complicated, four types of block identification codes are used. Is used. Note that the transmission order is the same as the configuration in FIG. The frame configuration according to the present invention mainly targets the frame configuration shown in FIG. 3 as described later.

[0006] The conventional multiplexing apparatus for FM multiplex broadcasting disclosed in Japanese Patent Laid-Open Publication No. HEI 10-19710 has a configuration as shown in FIG. Reference number 4
01 is input data. Reference numeral 402 denotes a portion for adding a parity in the horizontal direction. Reference numeral 403 denotes a bit rate clock 410 input from a digital modulation device for FM multiplex broadcasting.
Is a part for creating frame synchronization and block synchronization. Reference numeral 404 denotes a frame synchronization created by the 403. An input switch 405 switches between inputs of two frame memories. 406 and 40
Reference numeral 8 denotes a frame memory which stores an input signal in accordance with a frame format of FM multiplex broadcasting.
Reference numeral 407 denotes a vertical parity, which calculates a vertical parity of 82 packets when 190 frames of input data are stored in the frame memory. An output switch 409 is connected to the frame memory on the opposite side of the input switch 405, and changes the contents of the memory according to a bit clock.
11 is output.

[0007]

In a conventional multiplexing apparatus, after receiving input data from reference numeral 401,
There was a delay of at least one frame before being output to 411. In the mobile reception FM multiplex broadcasting, the bit rate is 16 kbit / s, so that one frame is about 5 seconds.

[0008] In ordinary programs such as traffic information, news, and weather forecast, a delay of about 5 seconds is not a problem at all, but real-time information such as GPS (Global Positioning System) error information is processed on the receiving side. If necessary, a 5 second delay can be a problem. SUMMARY OF THE INVENTION It is an object of the present invention to provide a data transmission multiplexer capable of preparing ten or more packets in one frame for real-time information and transmitting the real-time information with a small delay time.

[0009]

To achieve this object, a data transmission multiplexing apparatus according to the present invention provides a data multiplexing apparatus for transmitting FM multiplex broadcast data, which comprises a product code using a block code of a block having information data and a parity. In the frame, a plurality of blocks for storing real-time information data and a plurality of other blocks for storing normal information data are prepared, and the real-time information is stored after the normal information data is stored in the plurality of other blocks. Frame forming means for storing information data in the plurality of blocks to form a frame; and forming the frame formed by the frame forming means in the same direction as the horizontal encoding direction and sequentially from the top to the bottom of the frame. And at least sending means for reading and sending data.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the data transmission multiplexer according to the present invention. Reference numeral 101 is real-time information, which can be transmitted with almost no delay by this configuration. 102 is normal information. 10
Numerals 3 and 104 are portions for adding a horizontal parity. Reference numeral 105 denotes a part for creating frame synchronization and block synchronization from a bit rate clock 113 input from a digital modulation device for FM multiplex broadcasting. Reference numeral 106 denotes the frame synchronization created by 105. Reference numeral 107 denotes an input changeover switch that switches input of two frame memories for real-time information. Reference numeral 108 denotes an input changeover switch, which switches input of two frame memories for normal information. However, the switching is controlled independently of the switch 107, and switching is performed according to a time chart of FIG. 5 described later.

Reference numerals 109 and 111 are frame memories 1 and 2, respectively, which store input signals in accordance with the frame format of FM multiplex broadcasting.
Reference numeral 110 denotes a vertical parity, which calculates a vertical parity of 82 packets when 190 frames of input data are stored in the frame memory. An output switch 112 is controlled in accordance with a later-described time chart, similarly to the input switches 107 and 108. 115 is 101
These are frame synchronization and block synchronization signals that serve as data request signals when inputting real-time information. Note that the frame synchronization indicates the leading time when transmitting a frame in the format of FIG. 3, and the block synchronization indicates the leading time of each packet in FIG.

FIG. 5 shows an example of a time chart of the multiplexer shown in FIG. Note that in FIG.
3 shows a case where the information is divided into real-time information and the others as normal information. All flows are shown in FIG.
5 is controlled by the frame synchronization 106 (501 in FIG. 5). 502 is output data (114 in FIG. 1)
And output according to the FM multiplex broadcast frame configuration of FIG. D1, D2,--------------------------------------------------------------------------------------------------------
Indicates a parity packet number.

Reference numeral 503 indicates the input timing of the frame memory 1. First, of the information to be transmitted in the frame memory 1, the normal information D14 to D19
0 is input in advance before the real-time information D1 to D13 is input. The input timing is input at an arbitrary time from when the final parity P82 of the previous frame has been output to when the real-time information D1 is input. On the other hand, for the real-time information D1 to D13, the following time management is performed by frame synchronization and block synchronization in order to minimize the delay time. That is, D1 is input in the block synchronization immediately before the frame synchronization, and D1 follows D1.
2, and D1 is output with frame synchronization. D3 is input following D2, and D2 is output with block synchronization. This is continued, and the parity calculation in the vertical direction is performed as soon as D13 is input, to prepare for the P1 output. During this time, the output data outputs D14 and D15 that have been input earlier. At this stage, the calculation of all the parity packets has been completed. Therefore, as shown in FIG. 3, the remaining P1, D16,.
, D190, and P82 are all in the frame memory 1 and may be sequentially output.

When the transmission of P82 is completed, that is, when the next frame synchronization signal comes, the output switch is switched to the frame memory 2 side, and the frame memory 1 starts inputting the normal data D14 to D190. Further, D1 is input at the block synchronization immediately before the next frame synchronization, and the above operation is performed again. In addition,
The input timing of D1 may be read so as to be output with frame synchronization, so that it is possible to input the trigger other than the immediately preceding block synchronization as a trigger. Thus, the frame memory 1 operates with two frame times as one unit. As indicated by 504, the frame memory 2 performs exactly the same operation as the frame memory 1, but the timing is shifted by one frame time.

By employing the above configuration and time chart, more than a dozen packets of real-time information (in this example, 1
3 packets).

The embodiment described herein is merely an embodiment of the present invention, and does not limit the present invention. It is obvious that various modifications and changes can be made within the gist of the invention. Will.

[0017]

According to the present invention, transmission data multiplexed to FM multiplex broadcasting can be transmitted as real-time information with a small delay time without changing the receiver in FM multiplex broadcasting.

[Brief description of the drawings]

FIG. 1 is an embodiment of a data transmission multiplexer according to the present invention.

FIG. 2 is a data frame configuration example of a conventional FM multiplex broadcast.

FIG. 3 is another data frame configuration example of FM multiplex broadcasting according to the related art and the present invention.

FIG. 4 is an example of a conventional FM multiplex broadcast multiplexing apparatus.

FIG. 5 is an example of a time chart of the FM multiplex broadcast multiplexing device according to the present invention.

[Explanation of symbols]

 Reference Signs List 101 Real-time information 102 Normal information 103, 104 Horizontal parity 105 Synchronization 106 Frame synchronization 107, 108, 112 Switch 109, 111 Frame memory 110 Vertical parity 113 Bit rate clock 114 Output 115 Frame and block synchronization 201, 202 Block identification Codes 203, 204, 205 Parity 206 CRC 207 Transmission order 401 Input data 402 Horizontal parity 403 Synchronization generation 404 Frame synchronization 405, 409 Switch 406, 408 Frame memory 407 Vertical parity 410 Bit rate clock 411 Output 501 Frame synchronization 502 Output Data 503 Input to frame memory 1 504 Input to frame memory 2

Continuation of the front page (72) Inventor Satoshi Yamada 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Research Institute of Broadcasting Technology (56) References JP-A-5-122197 (JP, A) JP-A-7- 66770 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 1/00 H03M 13/00 H04J 3/00

Claims (7)

(57) [Claims] 1. A plurality of blocks for storing real-time information data and normal information data should be stored in a frame for transmitting FM multiplex broadcast data constituting a product code by a block code of a block having information data and a parity. Frame forming means for preparing a plurality of other blocks, and storing the real-time information data in the plurality of blocks to form a frame after the normal information data is stored in the plurality of other blocks; Sending means for reading and sending data sequentially from the top to the bottom of the frame formed by the frame forming means in the same direction as the horizontal encoding direction and from the top to the bottom of the frame. Multiplexer for transmission. 2. The multiplexing apparatus for data transmission according to claim 1, wherein said plurality of blocks are prepared in a plurality of continuous blocks from the top of said frame. 3. The apparatus according to claim 1, wherein the real-time information data input later is input to the frame in synchronization with frame synchronization and block synchronization.
Or the multiplexing device for data transmission according to 2. 4. A block identification signal for a block in which the real-time information data is to be stored, a block in which the normal information data is to be stored, and a block in which only a parity is to be stored are different from each other. 4. The multiplexing apparatus for data transmission according to any one of claims 1 to 3. 5. The method according to claim 1, wherein the block code is (272, 1
90) The multiplexing apparatus for data transmission according to any one of claims 1 to 4, wherein a code is used. 6. The data transmission multiplexer according to claim 5, wherein an error detection code (CRC) is further added to the horizontal code of the product code. 7. The real-time information data and the normal information data are allocated to be stored in first to xth blocks and (x + 1) th to 190th blocks, respectively, counted from the top of the frame. 7. The multiplexing device for data transmission according to claim 5, wherein the multiplexing device is used.