KR20110024335A - System for time division multiplexing in satellite digital multi media broadcasting and the method therefor - Google Patents

Abstract

PURPOSE: A time division multiplexing system and a method thereof are provided to convert a CDM(Code Division Multiplexing) type channel data into a TDM(Time division Multiplexing) type data. CONSTITUTION: A time division multiplexing system(400) of a satellite digital multimedia broadcasting which uses an unidentified area among a TDM gap filler is comprised as follows. A CDM FEC unit(700) CDM-FEC encodes a channel data including a pilot channel and a plurality of broadcasting channels in a time division multiplexing system of a satellite digital multimedia broadcasting of digital system E method.

Description

System for Time Division Multiplexing in Satellite Digital Multi media Broadcasting and the method therefor}

The present invention relates to a time-division multiplexing system and method for satellite digital multimedia broadcasting, and more particularly, to the system E system of ITU-R BO.1130-4, which is a standard of the International Telecommunication Union wireless communication sector. The present invention relates to a time division multiplexing system and method for satellite digital multimedia broadcasting for converting channel data in a CDM (Code Division Multiplexing) format into a data in a Time Division Multiplexing (TDM) format in a satellite digital multimedia broadcasting system.

The system E type digital satellite broadcasting system is one of five digital satellite broadcasting systems recommended by ITU-R BO.1130-4, a standard for the international telecommunication union wireless communication sector, and has a frequency range of 2630 MHz to 2655 MHz. I use it.

1 is a block diagram of a basic circuit for making broadcast data into CDM and TDM signals in a satellite broadcast system of the prior art.

As shown in FIG. 1, the code division multiplexing (CDM) and time division multiplexing (TDM) are performed on 32 channels such as a pilot channel for transmitting one control data and CH1 to CH31 for paying 31 channels, respectively. It shows a device transmitting to a satellite.

The broadcast data of each channel is passed through CDM FEC encoders such as Reed-Solomon Encoder, Byte Interleaver, Convolutional Encoder and Bit Interleaver, and CDM Modulator. ) Is converted into a CDM signal and transmitted to the satellite. In addition, CDM FEC encoded broadcast channels and pilot channels are multiplexed through a TDM multiplexer, and then additional TDM FEC encoders such as separate energy spreading, convolutional codes, and Reed-Solomon encoders are added. By applying QPSK modulator, it is made into TDM signal and transmitted to satellite.

Each of the 32 channels has a data rate of 512 Kbps and the frame period is 12.75 msec. Therefore, the transmission data of one frame of each channel,

512 * 12.75 = 6528 bit / frame = 816 byte / frame. The pilot channel transmits control data, a pilot sync signal for synchronization of a receiver, and is repeatedly transmitted every frame.

2 is a time division multiplexing (TDM) format of prior art satellite DMB transmissions.

Each channel should transmit 1632bytes of data for 25.5msec by tying two frames of 12.75msec, and using 188byte MPEG packet of DVB-S standard, 9 MPEG packets are used and 51 bytes of unused free area are generated. . The 51 bytes are all filled with FFh for convenience.

As described above, since a blank area filled with 51 bytes of FFh has 51 bytes of space in 32 channels, 32 * 51 = 1632 bytes are transmitted every 25.5 msec, which wastes a transmission capacity of 512 kbps.

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a time division multiplexing system and method for satellite digital multimedia broadcasting using 32 51 bytes, which are empty empty frame bands, for each 32 TDM channels, and using them as additional data. In providing.

Another object of the present invention is to provide a system and method for time division multiplexing of satellite digital multimedia broadcasting for synchronization of transmission and reception of the additional data.

Another object of the present invention is to provide a time division multiplexing system and method for satellite digital multimedia broadcasting for correcting errors occurring during transmission of the additional data.

The present invention provides a time division multiplexing system for satellite digital multimedia broadcasting of digital system E system, comprising: a CDM FEC unit for CDM FEC encoding channel data including a pilot channel and a plurality of broadcast channels; The input data received through the input means is converted into a 1504 byte data packet, RS parity is added to the converted data packet, converted into 1632 byte data, distributed through a byte interleaver, and the 1632 byte data for each channel. An interface unit for dividing into 51 byte data packets; And a time division multiplexing unit for time division multiplexing the CDM FEC encoded channel data of the CDM FEC unit and the 51 byte data packet for each channel of the interface unit instead of 51 bytes of FFh. Characterized in that it comprises a.

On the other hand, a method using a time division multiplexing system of satellite digital multimedia broadcasting, comprising: (a) receiving input data received by an interface unit through an input means; (b) classifying the input data received by the interface unit into an MPEG-2 TS and an IP data packet and converting the input data into a synchronous 1504 byte data packet; (c) the interface unit adding RS Parity to the Reed-Solomon encoder and distributing the converted synchronous data packet through a byte interleaver, and then dividing the converted synchronous data packet into 51 byte data packets per channel; (D) time division multiplexing by time division multiplexing the pilot channel, the plurality of broadcast channels, and the 51-byte data packet for each channel of step (c); Characterized in that it comprises a.

As described above, the present invention has the effect of combining 32 51 bytes, which are empty spaces, for every 32 TDM channels and using them as additional data.

In addition, the present invention has the effect of providing a time division multiplexing system and method for satellite digital multimedia broadcasting for transmission and reception synchronization of additional data.

In addition, the present invention has the effect of correcting errors that occur during the transmission of additional data.

In addition, the present invention can use additional data for other services using unused areas to more efficiently use time-division multiplexed (TDM) signals transmitted for Gap Fillers in the satellite digital multimedia broadcasting system. There is an effect that can be used without affecting the satellite DMB system.

The above-mentioned objects, features and advantages will become more apparent from the following detailed description in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention provides a time division multiplexing system for satellite digital multimedia broadcasting of digital system E system, comprising: a CDM FEC unit for CDM FEC encoding channel data including a pilot channel and a plurality of broadcast channels; The input data received through the input means is converted into a 1504 byte data packet, RS parity is added to the converted data packet, converted into 1632 byte data, distributed through a byte interleaver, and the 1632 byte data for each channel. An interface unit for dividing into 51 byte data packets; And a time division multiplexing unit for time division multiplexing the CDM FEC encoded channel data of the CDM FEC unit and the 51 byte data packet for each channel of the interface unit instead of 51 bytes of FFh. Characterized in that it comprises a.

Preferably, a TDM FEC unit for outputting a satellite broadcast time division multiplexing signal by encoding the output of the time division multiplexer to correct an error occurring during transmission; And a QPSK modulator for modulating the satellite broadcast time division multiplexed signal output from the TDM FEC unit into a QPSK signal. It characterized in that it further comprises.

Also preferably, the input data may be in the form of an MPEG-2 TS of 188 bytes or an IP data packet of 1504 bytes.

Also preferably, the interface unit, a conversion module 310 for converting the input data received through the input means into a 1504 byte data packet; A Reed-Solomon encoder 320 for converting the 1504 byte data packet generated by the conversion module into 1632 bytes by adding 128 bytes of parity to the RS (204, 188 t = 8) encoder; A byte interleaver (330) for distributing 1632 bytes of the Reed-Solomon encoder; And a splitting module 340 for dividing the distributed 1632 bytes into 51 byte data packets for each channel.

In addition, the byte interleaver 330 preferably interleaves the 204 byte unit MPEG-2 TS data packet at which the sync word starts using the convolutional byte interleaver.

Preferably, the interface unit receives MPEG-2 TS or IP data packets received through the input means and converts the MPEG-2 TS or IP data packets into 1504 bytes, respectively. When gathered, the first byte of 1504 bytes is 47h or B8h, and for the IP data packet, the first byte is specified by specifying a certain byte to collect the remaining 1503 bytes, converting them into 1504 bytes, and RS encoded 1632 byte packets. Among the first 51 bytes of the pilot channel is characterized in that the position.

Preferably, the byte interleaver may include a sync word in byte interleaving. The first byte of the last 51 bytes corresponding to Pilot CH, CH4, CH8, CH12, CH16, CH20, CH24, and CH28 in the TDM frame is' 0 of the interleaver and the deinterleaver. It is characterized by passing through the branch.

And preferably, a TDM receiver for receiving the QPSK modulated satellite broadcast time division multiplexing signal from a satellite and performing QPSK demodulation to decode the TDM FEC; A time division demultiplexer for detecting a pilot word by detecting a unique word of the TDM frames received from the TDM receiver, and then separating a pilot channel, a plurality of broadcast channels, and the last 51 bytes of each channel; A byte deinterleaver unit for collecting the last 51 bytes of the respective channels in order and converting them into 1632 bytes, and allocating the first byte to the '0' branch of the deinterleaver; A Reed-Solomon decoder which corrects an error occurring during the transmission and removes an RS Parity and converts it into a 1504 byte packet; And a data processing unit for determining an MPEG-TS packet when the first byte of the 1504 bytes is 47h or B8h and an IP packet when the first byte is 47h or B8h. It characterized in that it further comprises.

On the other hand, a method using a time division multiplexing system of satellite digital multimedia broadcasting, comprising: (a) receiving input data received by an interface unit through an input means; (b) classifying the input data received by the interface unit into an MPEG-2 TS and an IP data packet and converting the input data into a synchronous 1504 byte data packet; (c) the interface unit adding RS Parity to the Reed-Solomon encoder and distributing the converted synchronous data packet through a byte interleaver, and then dividing the converted synchronous data packet into 51 byte data packets per channel; (D) time division multiplexing by time division multiplexing the pilot channel, the plurality of broadcast channels, and the 51-byte data packet for each channel of step (c); Characterized in that it comprises a.

Preferably, (e) TDM FEC encoding the output of the time division multiplexer by the TDM FEC unit, and outputting the time division multiplexed satellite broadcast time division multiplexing frame signal through the step (d); And (f) modulating and outputting a satellite broadcasting time division multiplexed frame signal output from the TDM FEC unit into a QPSK signal by a QPSK modulator; It characterized in that it further comprises.

Also preferably, the step (c) may include: (c-1) converting the input data received by the interface unit through the input unit into a 1504-byte data packet at a constant rate through a conversion module; (c-2) converting the 1504-byte data packet generated by the conversion module into 1632 bytes by adding 128 bytes of parity to an RS (204, 188 t = 8) encoder; (c-3) the interface unit distributing 1632 bytes of the Reed-Solomon encoder through a byte interleaver; And (c-4) the interface unit dividing the 1632 bytes of the step (c-3) into 51-byte data packets for each channel.

Also preferably, in the step (b), the MPEG-2 TS or IP data packet received through the input unit may be received and converted into MPEG-2 TS or IP data packet of 1504 bytes, respectively. In the case of collecting 1504 bytes, the first byte of 1504 bytes is 47h or B8h, and for the above IP data packet, the first byte is designated by specifying a certain specific byte, collecting the remaining 1503 bytes, converting them into 1504 bytes, and RS Placing the first 51 bytes of the encoded 1632 byte packets in the last 51 bytes of the Pilot channel; Characterized in that it comprises a.

Also, in the step (c), the first byte of the last 51 bytes corresponding to the pilot CH, CH4, CH8, CH12, CH16, CH20, CH24, and CH28 in the TDM frame is an interleaver. Passing through the '0' branch of the deinterleaver; Characterized in that it comprises a.

And preferably, receiving and QPSK demodulating TDM FEC decoding the QPSK modulated time division multiplexed signal; Determining a pilot channel by detecting a unique word in the received TDM frame, and then separating the pilot channel, the plurality of broadcast channels, and the last 51 bytes of each channel; Collecting the last 51 bytes of each channel one by one, converting them into 1632 bytes, and assigning the first byte to the '0' branch of the deinterleaver for deinterleaving; Correcting the error occurring during the transmission, removing the RS Parity, and converting the packet into a 1504 byte packet; And processing the input data by determining that the first byte of the 1504 bytes is 47h or B8h as an MPEG-TS packet, and otherwise, as an IP packet. It characterized in that it further comprises.

Hereinafter, the present invention will be described in detail.

3 is a block diagram illustrating a transmitter of a time division multiplexing system for satellite digital multimedia broadcasting according to an embodiment of the present invention.

In the time division multiplexing system for satellite digital multimedia broadcasting according to an embodiment of the present invention, as shown in FIG. 3, the input unit 100, the code division multiplexing modulation unit 200, the interface unit 300, and the time division multiplexing unit 400 are described. ), A TDM FEC unit 500, QPSK modulator 600 comprises a transmitter configuration.

The input unit 100 functions to receive input data through the input means.

Here, the input data is an MPEG-2 TS packet in 188 byte units or IP in 1504 byte units for a disaster alert according to XML-based CAP (Common Alert Protocol) including multimedia of text, video, and voice corresponding to a disaster situation. It is characterized in that the data packet form.

In addition, the code division multiplexing modulator 200 functions to code division multiplex (CDM) a plurality of CDM FEC-coded broadcast channels and pilot channels.

In addition, the interface unit 300 converts the synchronous or asynchronous data packet received through the input unit into a synchronous data packet of a constant speed, and RS Parity to the input data in the form of MPEG-2 TS or IP data packet through the Reed-Solomon encoder. After the 1504-byte data packet is converted into 1632 bytes, distributed through the byte interleaver, the 1632 byte is divided into 32 51-byte data packets.

In order to perform this function, the interface unit 300 includes a conversion module 310 for classifying input data in the form of MPEG-2 TS or IP data packet received through the input unit and converting the input data into synchronous 1504 byte data packets. The Reed-Solomon encoder 320 converts the 1504-byte data packet generated by the conversion module into 1632 bytes by adding a 128-byte parity to the RS (204,188, t = 8) encoder. And a splitting module 340 for distributing 1632 bytes through the byte interleaver 330 and dividing the 1632 bytes into 32 51 byte data packets.

Here, the conversion module 310 of the interface unit receives the MPEG-2 TS or the IP data packet received through the input unit and converts the MPEG-2 TS and the IP data packet into 1504 bytes, respectively, wherein the MPEG-2 TS is 1504 bytes. If the first byte of is 47h or B8h, and is an IP data packet, when collecting 1504 bytes, the first byte is specified as a random byte (except 47h or B8h), and the remaining 1503 bytes are collected and converted into 1504 bytes. Ensure that the first 51 bytes of the RS-encoded 1632 byte packet are always located in the last 51 bytes of the Pilot channel.

At the time of transmission, external inputs inputted to the interface unit are classified into MPEG-2 TS and IP, and these are each made into different 1504 byte packets. In this case, any specific ID (other than 47 and B8) is assigned.

The receiving end looks at the first byte of 1504 bytes to determine whether the entire 1504 byte is an MPEG-2 TS or IP.

In the frame format according to the embodiment of the present invention, as shown in FIG. 4, when 32 bytes of pilot, CH1, CH2, etc. are sent, 51 * 32 = 1632 bytes are sequentially collected. This is eight 204 byte packets. If RS parity is used for 16 bytes using RS (204, 188, t = 8), 8 188 byte packets can be used. Since the format is the same as that of the MPEG-2 TS, any data can be transmitted in a format such as MPEG-TS data or 8 data of 188 bytes and a 188 * 8 = 1504 byte IP data packet.

In this case, when 1632 bytes of two frames of each CDM channel are divided into 187 byte units for transmission in MPEG-2 TS packet format of DVB-S standard, eight 187 byte packets and one 136 byte remain. If 136 Byte is made into 187 Byte packet, it is characterized by 51 bytes for each channel.

In addition, the error correcting encoder composed of the Reed-Solomon encoder 320 and the byte interleaver 330 is a function that can correct the transmission error that occurs during transmission, by distributing 1632 bytes of the Reed-Solomon encoder, generated during transmission It distributes Burst Error and helps to correct error in Reed-Solomon decoder (not shown).

5 is a diagram illustrating a Reed Solomon encoder according to an exemplary embodiment of the present invention. For reference, the RS (204, 188, t = 8) code of the Reed-Solomon encoder 320 is implemented using the RS (255, 239, t = 8) code, and the code generation polynomial g (x) is represented by [ Equation 1].

[Equation 1]

이다.here,

to be.

On the other hand, the field generation polynomial p (x) is as shown in [Equation 2].

[Equation 2]

Meanwhile, the RS (204, 188, t = 8) encoder is implemented as follows.

First, 51 bytes of '0' are added to 188 bytes of information data. Then, 239 bytes of information data are input to the RS (255, 239, t = 8) encoder.

Next, 204 bytes of RS encoded packets are removed by removing 51 bytes of '0' inserted from the encoded 255 byte output data.

The byte interleaver according to the embodiment of the present invention is as shown in FIG. 6.

The byte interleaver 330 according to the present embodiment uses a convolutional byte interleaver having the structure of FIG. 6 to remove time correlation between adjacent byte units. Stream) interleaves the packet.

Here, the convolutional byte interleaver is composed of 12 branches, each branch is composed of 17 bytes x N (where N = 0, 1, 2, ..., 11) memory, respectively, It works in synchronization with each other.

Synchronization words are always transmitted through the '0' branch for synchronization, and the deinterleaver's synchronization determines that the received TDM frame detects a unique word to determine the pilot channel, and then the last 51 bytes of the pilot channel indicate the first byte. Obtained by assigning to the '0' branch of the deinterleaver.

Meanwhile, the sync word always corresponds to the first byte of the last 51 bytes corresponding to Pilot CH, CH4, CH8, CH12, CH16, CH20, CH24, and CH28 in the TDM frame. In the byte interleaver according to the present embodiment, the first word of the last 51 bytes corresponding to the pilot CH, CH4, CH8, CH12, CH16, CH20, CH24, and CH28 in the TDM frame is a sync word in byte interleaving. Characterized by passing through the '0' branch.

In addition, the time division multiplexer 400 time division multiplexes a plurality of broadcast channels, pilot channels, and 32-byte 51 byte data packets formed in a code division multiplexed frame form.

In addition, the TDM FEC unit 500 functions to output a satellite broadcast time division multiplexed frame signal by encoding the output of the time division multiplexer to correct an error occurring during transmission. The TDM FEC unit 500 (Forward Error Correction) is an energy for performing an irregular process for balanced binary transition for energy diffusion of the data packets of the plurality of broadcast channels, the pilot channel and the interface unit from a time division multiplexer. A dispersion unit 510, a Reed-Solomon encoder 520 for reed-solomon encoding the output signal of the energy dissipation unit, and the encoded plurality of broadcast channels, pilot channels, and data of the interface unit from the Reed-Solomon encoder. An interleaver 530 for interleaving the packet, and a convolutional encoder 540 for encoding the output of the interleaver.

In addition, the QPSK modulator 600 modulates the satellite broadcast time division multiplexed frame signal output from the TDM FEC unit into a QPSK signal.

The receiver of the time division multiplexing system for satellite digital multimedia broadcasting according to an embodiment of the present invention receives a QPSK-modulated satellite broadcast time division multiplexing signal from a satellite, QPSK demodulates the TDM FEC decoding unit, and performs a TDM FEC decoding. (10) a time division demultiplexer for detecting a pilot word by detecting a unique word in a TDM frame received from a TDM receiver, and then separating a pilot channel, a plurality of broadcast channels, and the last 51 bytes of each channel ( 20), the byte deinterleaver 30 to deinterleave by collecting the last 51 bytes of each channel in turn to 1632 bytes and assigning the first byte to the '0' branch of the deinterleaver, correcting the error occurred during transmission Reed-Solomon decoder 40 for removing RS parity and converting it into 1504 byte packets, wherein the first byte of the 1504 bytes is 4 In the case of 7h or B8h, it is characterized by including a data processing unit 50 which determines that it is an MPEG-TS packet, and in other cases, it is an IP packet.

Meanwhile, the overall flow of the method (hereinafter, 'time division multiplexing method') using the time division multiplexing system of the satellite digital multimedia broadcasting having the above-described configuration will be described with reference to FIG. 8.

In the time division multiplexing method according to an embodiment of the present invention, as shown in FIG. 8, first, the interface unit receives synchronous or asynchronous input data from the input unit through the input unit (S2). Herein, the input data is in the form of MPEG-2 TS in 188 bytes or IP data in 1504 bytes.

Next, the interface unit converts the input data in the form of MPEG-2 TS or IP data packet into a synchronous 1504-byte data packet at a constant speed through the conversion module (S4).

Here, the conversion module of the interface unit receives the input data in the form of an MPEG-2 TS or an IP data packet received through the input unit, and converts each of the MPEG-2 TS and the IP data packet of 1504 bytes separately. If the first byte of the byte becomes 47h or B8h, and is an IP data packet, when collecting 1504 bytes, the first byte is specified to be arbitrary (except 47h or B8h) and the remaining 1503 bytes are collected and converted into 1504 bytes. The first 51 bytes of the RS encoded 1632 byte packet are always located in the last 51 bytes of the Pilot channel.

In this case, in the case of MPEG-2 TS, the first byte of 1504 bytes is always 47h or B8h (inverted byte of 47h), and in case of an IP packet, a byte other than 47h (B8h), that is, an arbitrary specific byte, can be designated and used. .

For reference, when the input data is MPEG-2 TS, PCR resampling is performed for synchronization.

Next, the interface unit adds RS Parity through the Reed-Solomon encoder 321 to the synchronous data packet generated in the conversion module through the Reed-Solomon encoder 321 to convert the 1504-byte data packet into 1632-byte data, and converts the byte interleaver 322 into After distributing through, transmit at a rate of 512 Kbps (S6).

Next, the interface unit divides the 1632 byte data packet generated in the step S6 into 32 51 byte data packets (S8).

Next, the time division multiplexing unit time division multiplexes 31 broadcast channels, pilot channels, and 32 51-byte data packets generated in step S8 (S10). Here, the time division multiplexing unit time-division multiplexes the channel data including the CDM FEC-coded pilot channel and the plurality of broadcast channels in the CDM FEC unit and the 32 51-byte data packets generated in step S8.

Next, the TDM FEC unit performs TDM FEC encoding on the output of the time division multiplexing unit, and outputs a satellite broadcast time division multiplexing signal including a plurality of broadcast channels, pilot channels, and data packets generated from the interface unit (S12).

The QPSK modulator modulates the satellite broadcast time division multiplexed signal output from the TDM FEC unit into a QPSK signal and outputs the modulated signal (S14).

The time division multiplexing signal reception method according to an embodiment of the present invention is illustrated in FIG. 9.

The QPSK modulated time division multiplexed signal is received and QPSK demodulated to decode TDM FEC (S22).

Next, the pilot channel is determined by detecting a unique word in the received TDM frame, and then the pilot channel and the plurality of broadcast channels and the last 51 bytes of each channel are separated (S24).

Next, the last 51 bytes of each channel are sequentially collected and converted into 1632 bytes, and the first byte is allocated to the '0' branch of the deinterleaver to deinterleave (S26).

Next, the error generated during the transmission is corrected and the RS parity is removed and converted into a 1504 byte packet (S28).

If the first byte of the 1504 bytes is 47h or B8h, it is determined as an MPEG-TS packet, otherwise, it is determined as an IP packet (S30).

As described above, the present invention combines and utilizes 32 51 bytes each of 32 TDM channels, which are empty areas, provides a time division multiplexing system and method for satellite digital multimedia broadcasting for transmission and reception synchronization, and provides a satellite digital multimedia broadcasting. Among the systems, in order to use TDM signal transmitted for Gap Filler more efficiently, it can be used for other services using unused area and can be used without affecting existing satellite DMB system. It works.

As described above and described with reference to a preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as described above, it is a deviation from the scope of the technical idea It will be appreciated by those skilled in the art that many changes and modifications to the present invention are possible without departing from the scope of the present invention. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

1 is a structural diagram of a conventional satellite DMB multiplexing transmission apparatus.

2 illustrates a time division multiplexing (TDM) format of prior art satellite DMB transmissions.

3 is a structure diagram of a transmitter of a time division multiplexing system for satellite digital multimedia broadcasting according to an embodiment of the present invention;

4 illustrates a frame format according to an embodiment of the present invention.

5 illustrates a Reed Solomon encoder according to an embodiment of the present invention.

6 illustrates byte interleaving according to an embodiment of the present invention.

7 is a diagram illustrating a receiver structure of a time division multiplexing system for satellite digital multimedia broadcasting according to an embodiment of the present invention.

8 is a flowchart illustrating a method using a time division multiplexing system for satellite digital multimedia broadcasting according to an embodiment of the present invention.

9 is a flowchart illustrating a method of receiving a time division multiplexing signal according to an embodiment of the present invention.

<Detailed Description of Drawing>

100 input unit 200 code division multiplexing modulation unit

300: interface unit 310: conversion module

320: Reed-Solomon encoder 330: byte interleaver

340: split module 400: time division multiplexer

500: TDM FEC part 510: energy dispersing part

520: Reed-Solomon encoder 530: interleaver

540: Convolutional Encoder

600: QPSK modulator 700: CDM FEC part

Claims (14)

In the time division multiplexing system of satellite digital multimedia broadcasting of digital system E system, A CDM FEC unit for CDM FEC encoding channel data including a pilot channel and a plurality of broadcast channels; The input data received through the input means is converted into a 1504 byte data packet, RS parity is added to the converted data packet, converted into 1632 byte data, distributed through a byte interleaver, and the 1632 byte data for each channel. An interface unit for dividing into 51 byte data packets; And A time division multiplexing unit for time division multiplexing the CDM FEC encoded channel data of the CDM FEC unit and the 51 byte data packet for each channel of the interface unit instead of 51 bytes of FFh; Time division multiplexing system of a satellite digital multimedia broadcasting comprising a. The method of claim 1, A TDM FEC unit which outputs a satellite broadcasting time division multiplexing signal by encoding an output of the time division multiplexing unit to correct an error occurring during transmission; And A QPSK modulator for modulating a satellite broadcast time division multiplexed signal, which is an output of the TDM FEC unit, into a QPSK signal; Time-division multiplexing system for satellite digital multimedia broadcasting further comprising. The method of claim 1, The input data is, A time division multiplexing system for satellite digital multimedia broadcasting, characterized in that it is in the form of an MPEG-2 TS of 188 bytes or an IP data packet of 1504 bytes. The method of claim 1, The interface unit, A conversion module 310 for converting the input data received through the input means into a 1504 byte data packet; A Reed-Solomon encoder 320 for converting the 1504 byte data packet generated by the conversion module into 1632 bytes by adding 128 bytes of parity to the RS (204, 188 t = 8) encoder; A byte interleaver (330) for distributing 1632 bytes of the Reed-Solomon encoder; And And a division module (340) for dividing the distributed 1632 bytes into 51 byte data packets for each channel. The method according to claim 1 or 4, The byte interleaver 330, A time division multiplexing system for satellite digital multimedia broadcasting, comprising: interleaving MPEG-2 TS data packets in units of 204 bytes at which a synchronization word starts using a convolutional byte interleaver. The method according to any one of claims 1 to 4, The interface unit, Receive MPEG-2 TS or IP data packets received through the input means and convert them into MPEG-2 TS or IP data packets of 1504 bytes, respectively. In the case of the MPEG-2 TS, when collecting 1504 bytes, the first byte of 1504 bytes is 47h or B8h, In the case of the IP data packet, the first byte is designated by specifying a specific byte, collecting the remaining 1503 bytes, converting them into 1504 bytes, and placing the first 51 bytes of the RS-encoded 1632 byte packets in the last 51 bytes of the Pilot channel. A time division multiplexing system for satellite digital multimedia broadcasting, characterized in that. The method according to claim 1 or 4, The byte interleaver, In byte interleaving, the sync word causes the first byte of the last 51 bytes corresponding to Pilot CH, CH4, CH8, CH12, CH16, CH20, CH24, and CH28 in the TDM frame to pass through the '0' branch of the interleaver and deinterleaver. A time division multiplexing system for satellite digital multimedia broadcasting. The method according to claim 1 or 2, A TDM receiver for receiving the QPSK-modulated satellite broadcast time division multiplexed signal from a satellite and performing QPSK demodulation and TDM FEC decoding; A time division demultiplexer for detecting a pilot word by detecting a unique word of the TDM frames received from the TDM receiver, and then separating a pilot channel, a plurality of broadcast channels, and the last 51 bytes of each channel; A byte deinterleaver unit for collecting the last 51 bytes of the respective channels in order and converting them into 1632 bytes, and allocating the first byte to the '0' branch of the deinterleaver; A Reed-Solomon decoder which corrects an error occurring during the transmission and removes an RS Parity and converts it into a 1504 byte packet; And A data processing unit for judging an MPEG-TS packet when the first byte of the 1504 bytes is 47h or B8h, and an IP packet when the first byte is 47h or B8h; Time-division multiplexing system for satellite digital multimedia broadcasting further comprising. In the method using time division multiplexing system of satellite digital multimedia broadcasting, (a) receiving, by the interface unit, input data received through the input means; (b) classifying the input data received by the interface unit into an MPEG-2 TS and an IP data packet and converting the input data into a synchronous 1504 byte data packet; (c) the interface unit adding RS Parity to the Reed-Solomon encoder and distributing the converted synchronous data packet through a byte interleaver, and then dividing the converted synchronous data packet into 51 byte data packets per channel; And (d) time division multiplexing by time division multiplexing a pilot channel, a plurality of broadcast channels, and a 51-byte data packet for each channel of step (c); Time division multiplexing method comprising a. The method of claim 9, (e) TDM FEC encoding the output of the time division multiplexer by TDM FEC, and outputting the time division multiplexed satellite broadcast time division multiplexing frame signal through step (d); And (f) modulating and outputting a satellite broadcast time division multiplexed frame signal output from the TDM FEC unit into a QPSK signal by a QPSK modulator; Time division multiplexing method comprising a further. The method of claim 9, In step (c), (c-1) converting, by the interface unit, input data received through the input means into a 1504-byte data packet at a constant rate through a conversion module; (c-2) converting the 1504-byte data packet generated by the conversion module into 1632 bytes by adding 128 bytes of parity to an RS (204, 188 t = 8) encoder; (c-3) the interface unit distributing 1632 bytes of the Reed-Solomon encoder through a byte interleaver; And and (c-4) the interface unit dividing the 1632 bytes of the step (c-3) into 51-byte data packets for each channel. The method of claim 9, In step (b), Receive MPEG-2 TS or IP data packets received through the input means and convert them into MPEG-2 TS or IP data packets of 1504 bytes, respectively. In the case of the MPEG-2 TS, when collecting 1504 bytes, the first byte of 1504 bytes is 47h or B8h, In the case of the IP data packet, the first byte is designated as a specific byte, and the remaining 1503 bytes are collected and converted into 1504 bytes so that the first 51 bytes of the RS-encoded 1632 byte packets are located in the last 51 bytes of the pilot channel. Making; Time division multiplexing method comprising a. The method of claim 9, In step (c), In the byte interleaver, the first word of the last 51 bytes corresponding to Pilot CH, CH4, CH8, CH12, CH16, CH20, CH24, and CH28 in the TDM frame passes through the '0' branch of the interleaver and the deinterleaver. step; Time division multiplexing method comprising a. 11. The method according to claim 9 or 10, Receiving and QPSK demodulating the TPS FEC decoding the QPSK modulated time division multiplexing signal; Determining a pilot channel by detecting a unique word in the received TDM frame, and then separating the pilot channel, the plurality of broadcast channels, and the last 51 bytes of each channel; Collecting the last 51 bytes of each channel one by one, converting them into 1632 bytes, and assigning the first byte to the '0' branch of the deinterleaver for deinterleaving; Correcting the error occurring during the transmission, removing the RS Parity, and converting the packet into a 1504 byte packet; And Processing the input data by determining that the first byte of the 1504 bytes is 47h or B8h as an MPEG-TS packet, and otherwise, as an IP packet; Time division multiplexing method comprising a further.

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