KR100907705B1 - IF signal generator and modulation device of digital broadcasting signal generator - Google Patents

Abstract

The present invention relates to an IF (Intermediate Frequency) signal generator and a modulation device of a digital broadcasting signal generator. A modulation apparatus of a digital broadcast signal generating apparatus according to the present invention comprises: condition input means for inputting an arbitrary transmission standard by a user; A symbol for receiving a MPEG (Moving Picture Experts Group) (MPEG) -2 broadcast signal as input data and generating a symbol in a manner determined according to an arbitrary transmission standard set in the condition input means. (symbol) generating means; An IF signal generator for generating an IF signal by receiving the symbol data generated from the symbol generating means and modulating the symbol data according to the variable clock signal corresponding to the set random transmission standard; And an interface for signal exchange and symbol data transmission between the symbol generation means and the IF signal generator.

Digital Broadcast, IF Signals, Symbols, Modulation, Variable Clocks

Description

IF signal generator and modulation device of digital broadcasting signal generator {A Intermediate Frequency Signal Generator And A Means For Modulation Wherein A Digital Brodcasting Signal Generator}

1 is a schematic diagram illustrating the configuration of a conventional VSB modulator.

2 is a control block diagram illustrating a modulation device of a digital broadcast signal generator according to an embodiment of the present invention.

Fig. 3 is a control block diagram illustrating a configuration of software symbol generation means of a modulation device of a digital broadcast signal generating device of an embodiment of the present invention.

4 is a control block diagram illustrating an IF signal generator of a digital broadcast signal generator according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100 ....... symbol generating means 110 ............. condition input means

120 ....... Main CPU (Central Processing Unit; central processing unit; hereinafter referred to as 'CPU')
130 ........ Memory

200 ....... Interface 300 ........ IF Signal Generator

310 ....... Input buffer 320 ........ Variable clock generator

330 ............ Modulation means 350 ............ IF signal generating means

400 ....... UP Converter

The present invention relates to an IF (Intermediate Frequency) signal generator and a modulation device of a digital broadcasting signal generator, and more specifically, to a symbol corresponding to various transmission standards by a single device. symbol) is an IF signal generator and a modulation device of a digital broadcasting signal generator capable of generating an IF signal by performing generation and modulation.

Conventional digital broadcast signal generator (or mobile broadcast signal generator) is composed of each modulator according to transmission standard, and each modulator outputs modulated signal in I, Q signal format and transmits it to IF signal generator. It may be a configuration, or may have a form including an IF signal generator in the modulator.

1 is a configuration example of a conventional VSB (Vestigial SideBand Modulation) (hereinafter referred to as 'VSB') modulator. The conventional VSB modulator shown is constructed in two ways. One is a symbol generation module and a VSB signal generator 10, in which a VSB modulation module is composed of one hardware chip, generates I and Q signals, and the IF signal generator 20 receives these I and Q signals. It is a configuration that generates with 44MHz IF signal.

The conventional VSB modulator externally receives a Moving Picture Experts Group (MPEG) TS (Transport Stream) signal (TS), and a symbol generator is ATSC (Advanced Television Systems). Committee) Generate symbol data by symbol generation algorithm and input to VSB (Vestigial SideBand) modulation module, and VSB modulation module converts input data into I, Q signal to IF signal generator 20. Enter it.

Another VSB modulator 30 of FIG. 1 has a structure in which a symbol generation module, a VSB modulation module, and an IF signal generator are formed of integral hardware, and operations of each unit are as described above.

However, the modulation standards for digital defense and mobile broadcasting include transmission bands and technical standards, DVB-C (Digital Video Broadcasting-Cable), Opencable (Digital Cable Broadcasting), and DVB-S (Digital Video Broadcasting-Satellite). , DVB-S2 (Digital Video Broadcasting-Satellite-Second Generation), DVB-T (Digital Video Broadcasting-Terrestrial), DVB-H (Digital Video Broadcasting-Handheld), ISDB-T (Integrated Services Digital Broadcasting-Terrestrial), DMB Digital Multimedia Broadcast-Terrestrial / Handheld (TH) or Digital Terrestrial Multimedia Broadcast (DTMB), Satellite and terrestrial interactive multiservice infrastructure (S-TIMI), and Terrestrial-Digital Multimedia Broadcasting (T-DMB) are used. As a result, new technical standards are being added.

These various standards are generally used to generate generated symbol data modulations, such as Quadrature Phase Shift Keying (QPSK), VSB, Quadrature amplitude modulation (QAM), and OFDM (QAM). Orthogonal frequency-division multiplexing (hereinafter referred to as 'OFDM') is used, and differences and new technical specifications are being added in generating symbol data.

Therefore, the following problems have arisen in the conventional modulator of the above structure.

Since the conventional VSB modulator 30 configures each part of the modulator in hardware, it is difficult to flexibly apply a symbol generation method according to various transmission standards. symbol) There has been a problem that the generation module must be implemented in hardware.

In addition, although a limited method such as QPSK, VSB, QAM, or OFDM is used as a modulation method for the generated symbol data, each symbol generation module and a modulation module may be used to correspond to each symbol generation method. There is a problem that must be provided to correspond to each. Therefore, there is a problem that the cost required to implement a modulator supporting multiple transmission standards increases rapidly and the equipment becomes large.

An object of the present invention is to generate an IF generator for generating an IF (Intermediate Frequency, IF) signal by modulating the symbol data, and generating a symbol for generating symbol data. By separating the units and configuring the modulation device, it is possible to reduce the number of modules required for the application of the existing standard and to implement the IF signal generator and the modulation device of the digital broadcasting signal generator having the structure of adding and expanding the new standard.

Another object of the present invention, in order to support the new transmission standard predicted in the future in digital broadcasting (or mobile broadcasting), symbol generation is generated by software and input to the hardware IF signal generator via the interface IF signal generator Implementing the IF signal generator and modulation device of the digital broadcast signal generator to enable the modulation of the transmission standard to transmit this signal in.

In order to achieve the above object, an IF (Intermediate Frequency) signal generator of an apparatus for generating a digital broadcasting signal according to the present invention comprises: an input buffer to which symbol data is input; A variable clock generator for generating a variable clock signal according to a condition of an externally set transmission standard so that an input speed of symbol data input to the input buffer can be adjusted; A plurality of modulation modules are built in, and any one of the plurality of modulation modules is selected according to a condition of the transmission standard set externally, and the symbol data input to the input buffer is selected according to the variable clock signal. Modulation means for modulating in a manner set in the modulation module; And an IF signal generating means for generating the IF signal again in accordance with the variable clock signal of the variable clock generator by modulating the symbol data by the modulating means.

The plurality of modulation modules embedded in the modulation means may be referred to as Quadrature Phase Shift Keying (QPSK), VSB (Vestigial Sideband modulation), QAM (Quadrature amplitude modulation) And at least two of orthogonal frequency-division multiplexing (OFDM) modulation modules.

Modulation apparatus of the digital broadcast signal generating apparatus according to the present invention for achieving the above object comprises: condition input means for inputting any transmission standard by the user; Symbol generation means for receiving an MPEG-2 broadcast signal as input data and generating symbol data in a manner determined according to an arbitrary transmission standard set in the condition input means; An IF signal generator for generating an IF signal by receiving the symbol data generated from the symbol generating means and modulating the symbol data according to the variable clock signal corresponding to the set random transmission standard; And an interface for transmitting the symbol data from the symbol generating means to the IF signal generator.

The symbol generation means may include ATSC (Advanced Television Systems Committee; ATSC), DVB-C (Digital Video Broadcasting-Cable; DVB-C), Opencable Cable broadcasting), DVB-T (Digital Video Broadcasting-Terrestrial) (DVB-T), DVB-H (Digital Video Broadcasting-Handheld), ISDB-T (Integrated Services) Digital Broadcasting-Terrestrial; hereinafter referred to as 'ISDB-T'), DVB-S (Digital Video Broadcasting-Satellite; hereinafter referred to as 'DVB-S'), DVB-S2 (Digital Video Broadcasting-Satellite-Second Generation; hereinafter) DVB-S2 '), DMB-TH (Digital Multimedia Broadcast-Terrestrial / Handheld; `` DMB-TH' '), and S-TIMI (Satellite and terrestrial interactive multiservice infrastructure; `` S-TIMI' ') , T-DMB (Terrestrial-Digital Multimedia Broadcasting) (S-DMB) and S-DMB (Stellite-Digital Multimedia Broadcasting) (S-DMB) Memory for storing at least two of each symbol generating program and a symbol generating program stored in the memory to generate symbol data corresponding to a setting condition of the condition input means; Characterized in that it comprises a.

The IF signal generator includes at least two of QPSK, VSB, QAM, and OFDM modulation modules, and selects a specific modulation module corresponding to a setting condition of the condition input means to select the symbol data according to the variable clock signal. Performing modulation and generating a modulated signal as an IF signal.

The interface may be any one of PCI (Peripheral Component Interconnect (hereinafter referred to as 'PCI')), Express PCI (Peripheral Component Interconnect Express (hereinafter referred to as "Express PCI")), USB (Universal Serial Bus (hereinafter referred to as "USB")). It is characterized by.

Hereinafter, the configuration of a preferred embodiment of a digital broadcasting IF signal generator and a digital broadcasting modulation apparatus according to the present invention having the above configuration will be described in detail with reference to the accompanying drawings.

2 is a schematic diagram illustrating a modulation apparatus of a digital broadcast signal generator according to an embodiment of the present invention, FIG. 3 is a schematic diagram illustrating a configuration of a symbol generating means according to the present invention, and FIG. 4 is an IF according to the present invention. It is a schematic diagram which illustrates the structure of a signal generator.

The modulation apparatus of the apparatus for generating broadcast signals according to the present invention for achieving the above object includes a condition input means 110 for inputting a transmission condition, and a symbol for receiving a MPEG-2 as input data and generating a symbol. symbol generating means 100, an IF signal generator 300 for generating an IF signal by modulating symbol data input from the symbol generating means 100, and the symbol generating means ( 100) and an interface 200 for signal exchange between the IF generator 300.

The condition input means 110 of the present embodiment is a means for allowing any transmission standard to be input by a user. The condition input means 110 includes ATSC 131, DVB-C 132, Opencable 133, and DVB-T 134. , DVB-H (135), ISDB-T (136), DVB-S (137), DVB-S2 (138), DMB-TH (139), S-TIMI (140), T-DMB (141), S-DMB 142 includes a means for selecting any one of the transmission standards.

In addition, the condition input means 110 may further include means for inputting additionally or newly added changed conditions and detailed options in order to correspond to a newly generated or changed transmission standard, wherein the condition is a data bit included in a symbol. It includes information such as the number of bits and the number of symbols generated per unit time.

The condition input unit 110 according to the present embodiment includes a condition for generating a symbol according to an arbitrary transmission standard and a means for selecting a modulation method and condition for generating an IF signal. The condition input means 110 of the present embodiment includes a visually implemented on the user interface. For example, the user may select a specific transmission standard or directly input an arbitrary transmission standard on the user interface. In addition, the condition input unit 110 of the present embodiment is preferably provided with an input window so that the user can input the detailed options for each transmission standard selected with the selection of the specific transmission standard on the user interface.

The symbol generating means 100 of the present embodiment is a software symbol generator, which is an ATSC 131, a DVB-C 132, an Opencable 133, a DVB-T 134, and a DVB-H 135. ), ISDB-T (136), DVB-S (137), DVB-S2 (138), DMB-TH (139), S-TIMI (140), T-DMB (141), S-DMB (142) It is characterized by generating a symbol of the transmission standard in software. In addition, it may be configured to generate a symbol in a manner according to an arbitrary condition corresponding to the new transmission standard.

To this end, the symbol generation means 100 of the present embodiment may be configured to include a main CPU 120 and a memory 130 in which a plurality of symbol generation programs corresponding to a specific transmission standard are embedded. The main CPU 120 executes any one of the symbol generation programs of the memory 130 and generates a symbol corresponding to the input condition and inputs it to the interface.

The symbol generating means 100 according to the present embodiment includes the 12 kinds stored in the memory 130, that is, the ATSC 131, the DVB-C 132, the Opencable 133, the DVB-T 134, and the DVB. -H (135), ISDB-T (136), DVB-S (137), DVB-S2 (138), DMB-TH (139), S-TIMI (140), T-DMB (141), S- In addition to the symbol generation program according to the DMB 142 transmission standard, a new symbol generation program may be provided to externally receive and store the new symbol generation program so as to correspond to the changed transmission standard.

The interface 200 between the symbol generator 100 and the IF signal generator 300 of the present embodiment may be selectively selected from any one of PCI, Express PCI, and USB for high-speed mass data transmission. Therefore, the noise of the symbol data that can occur in the transmission using the I, Q signal does not occur, thereby improving the quality of the IF signal.

The IF signal generator 300 according to the present embodiment includes a variable clock generator 320 for generating a variable clock signal according to a condition of a transmission standard set by the condition input means 110, and a symbol (according to the variable clock signal). symbol) an input buffer 310 for adjusting the speed at which data is input, a modulation means 330 for selecting one of a plurality of modulation modules according to a set condition and performing modulation in a set manner according to a variable clock signal, and IF signal generating means 350 for generating a modulated signal as an IF signal according to the variable clock signal.

In the present embodiment, the input buffer 310 temporarily stores symbol data input through the interface 200 as a FIFO buffer (First In First Out Buffer) and modulates the symbol data according to the variable clock signal. Enter (330).

In the present embodiment, the IF signal generator 300 includes a module for modulation of the VSB 331, the QAM 332, the OFDM 333, and the QPSK 331 as the modulation means 330. It is implemented to be included in a single device and may be configured as a single hardware chip.

Accordingly, any one of the modulation modules may be selectively designated according to the condition of the transmission standard of the user input.

The condition input means 110 of the present embodiment may be configured such that a user inputs an arbitrary transmission standard so that a corresponding modulation module can be automatically selected, and at the same time, a VSB 331, a QAM 332, an OFDM 333, Means may be provided to allow manual selection of any of the modules for modulation of the QPSK 331.

The IF signal generator 300 of the present embodiment is characterized by using the variable clock generator 320 to support various symbol rates. By using the variable clock generator 320 as described above, the error range of each IF signal generation according to the change of the transmission standard can be lowered to 1 ppm or less.

In one embodiment of the present invention, each part of the IF signal generator 300 is controlled by the main CPU 120 of the digital broadcast signal generator, but is not limited thereto.

The following describes the operation of the modulation apparatus of the digital broadcast signal generating apparatus of the preferred embodiment of the present invention having the above configuration.

When any one of the specific transmission standards is selected and the detailed options are input on the user interface, the main CPU 120 calls a symbol generation program of the corresponding transmission standard to generate a symbol of the specified method. Input to interface 200.

Since the interface 200 is based on PCI, Express PCI, and USB, it is possible to prevent noise generation of symbol data in transmission using I and Q signals, which has an effect of increasing the quality of an IF signal.

Under the control of the main CPU 120, the variable clock generator 320 generates a clock signal corresponding to a condition of a set transmission standard to adjust the speed of the input buffer 310.

In addition, the modulation means 330 is any one of a specific modulation module, for example VSB modulation module 01, QAM modulation module 402, OFDM modulation module 403, QPSK modulation module 404 corresponding to the conditions of the set transmission standard Select and perform modulation in a specified manner according to the variable clock signal to input the I and Q signals to the IF generating means 350.

The IF generator 300 generates a signal modulated according to the variable clock signal generated by the variable clock generator 320 as an IF signal of 34 to 44 MHz and inputs it to the up-converter 400.

The scope of the present invention is not limited to the above embodiments, but is defined by the matters described in the claims, and it is obvious that it includes various modifications and adaptations made by those skilled in the art in the claims and equivalents.

According to the present invention, a symbol generator for digital broadcasting and mobile broadcasting is configured in software, and the generated symbol data using an interface is an IF (Intermediate Frequency) signal. By inputting into the generator and generating the IF signal through the IF signal generator that supports four modulations consisting of hardware, the modulator of the corresponding transmission standard can be configured by modifying the software symbol generation means when applying the new transmission standard. can do.

Therefore, the present invention enables the production of a modulator supporting various transmission standards through the above configuration, thereby reducing the production cost of the modulator for digital broadcasting and mobile broadcasting.

In addition, the present invention can prevent the noise of the symbol data that can occur in the transmission using the I, Q signals by using the PCI, Express PCI, USB interface between the symbol generation means and the IF signal generator. This has the effect of improving the quality of the IF signal.

Claims (6)

An input buffer into which symbol data is input; A variable clock generator for generating a variable clock signal according to a condition of an externally set transmission standard so that an input speed of symbol data input to the input buffer can be adjusted; A plurality of modulation modules are built in, and any one of the plurality of modulation modules is selected according to a condition of the transmission standard set externally, and the symbol data input to the input buffer is selected according to the variable clock signal. Modulation means for modulating in a manner set in the modulation module; And, IF signal generation means for generating the IF signal is modulated by the modulation means by the symbol (symbol) data in accordance with the variable clock signal of the variable clock generator again IF signal of the digital broadcast signal generator Generator. The IF signal generator of claim 1, wherein the plurality of modulation modules included in the modulation means comprises at least two of QPSK, VSB, QAM, and OFDM modulation modules. Condition input means for inputting an arbitrary transmission standard by a user; Symbol generation means for receiving an MPEG-2 broadcast signal as input data and generating symbol data in a manner determined according to an arbitrary transmission standard set in the condition input means; An IF signal generator for generating an IF signal by receiving the symbol data generated from the symbol generating means and modulating the symbol data according to the variable clock signal corresponding to the set random transmission standard; And, And an interface for transmitting the symbol data from the symbol generating means to the IF signal generator. The method according to claim 3, wherein the symbol (symbol) generating means, Each symbol by ATSC, DVB-C, Opencable, DVB-T, DVB-H, ISDB-T, DVB-S, DVB-S2, DMB-TH, S-TIMI, T-DMB, S-DMB symbol) a memory in which at least two of the generators are stored, And a CPU which executes a symbol generating program stored in the memory to generate symbol data corresponding to a setting condition of the condition input means. The method according to claim 3, wherein the IF signal generator comprises at least two of the QPSK, VSB, QAM, OFDM modulation module, the specific modulation module corresponding to the set condition of the condition input means to select the symbol according to the variable clock signal (symbol) The modulation device of the digital broadcast signal generator, characterized in that for modulating the data and generating a modulated signal as an IF signal. The apparatus of claim 3, wherein the interface is one of PCI, Express PCI, and USB.

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