KR20010054155A - Apparatus for generating local digital TV - Google Patents

Abstract

PURPOSE: A local digital television signal generating apparatus is provided to be capable of generating an RF signal of advanced television system committee(ATSC) rule suitable for a test or a demonstration. CONSTITUTION: A local digital television signal generating apparatus includes a vestigial side band(VSB) signal reproducer(200). The VSB signal reproducer(200) includes a download unit(204) for downloading data from an external device storing data for digital broadcasting, a storage(201) for storing the downloaded data, a VSB remodulator(202) for VSB-modulating the stored data at the storage to produce RF signals, a control unit(203) for controlling downloading of the download unit(204) and VSB modulation of the VSN remodulator(202), and a microcontroller(205) for controlling and reading of data stored at the storage(201).

Description

Apparatus for generating local digital TV

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital television (DTV) compliant with the Advanced Television Systems Committee (ATSC) standard, and more particularly, to a local DTV signal generator that generates an ATSC RF signal that can be received by a digital TV.

The National Television Standards Committee (NTSC) has been in use for decades in television transmission, and has come into the age of coexistence with DTV in the next few years as the digital TV era has come. The DTV has a North American standard and a European standard, and the North American standard follows the standard of the Advanced Television Systems Committee (ATSC).

Our country complies with the North American standard ATSC standard, and the development of digital TV-related equipment which follows this ATSC standard is in progress.

Therefore, companies developing ATSC-related DTV-related devices should be equipped with an ATSC RF generator to generate an ATSC standard RF signal for development, test, after service, and demonstration. .

1 illustrates an ATSC RF signal using an MPEG Test Streamer (MTS), a VSB modulator, an RF up-converter, and the like as an example of such a conventional ATSC RF generator. That is, the MPEG Test Streamer (MTS) analyzes the data compressed in MPEG to generate an MPEG2 stream. For example, the first byte of the MPEG2 compressed stream always starts with 0x47, and 188 bytes constitute one packet.

The VSB modulator performs error correction (FEC), reed-solomon (RS) coding, DC insertion, etc. on the MPEG2 compressed stream to generate a VSB IF (Vestigial Side Band Intermediate Frequency) signal. That is, VSB modulation modulates only the remaining part of one sideband signal of two sidebands generated up and down about a carrier when amplitude is modulated. The terrestrial wave uses 8VSB (8T VSB). Modulation method is adopted.

The RF up-converter converts the VSB IF signal into a desired high frequency (RF) band and then sends the cable or airwave through an RF cable or antenna.

However, the above-described conventional ATSC RF generator is expensive and complicated in various aspects such as installation and usage. That is, the ATSC RF generating apparatus is about hundreds of millions of won, the equipment is large, the movement is inconvenient, and there is a complicated problem of installation and usage.

Therefore, a local DTV signal generating apparatus has been filed by the present applicant to solve this problem (application number: 99-45907, filing date: 99/10/21). The previously applied local DTV signal generating apparatus includes a control unit for performing an interface such as a memory device storing data for DTV, a VSB remodulator for generating an RF signal, and clock synchronization between the memory device and the VSB remodulator. It is used to generate an ATSC standard RF signal that can be easily used for testing or demonstration.

The present invention is another embodiment of a local DTV signal generating device previously filed by the present applicant.

Accordingly, it is an object of the present invention to provide a local DTV signal generator that generates an ATSC standard RF signal suitable for testing or demonstration because of its low cost and small size without any external equipment.

Another object of the present invention is to provide a local DTV signal generating apparatus having a function of storing a VSB signal and reproducing an RF signal of an ATSC standard when necessary.

1 is a block diagram of a conventional ATSC RF generator

2 is a block diagram illustrating an apparatus for generating a local DTV signal according to a first embodiment of the present invention.

3 is a block diagram illustrating an apparatus for generating a local DTV signal according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a local DTV signal generator further including a DVD driver in FIG. 3. FIG.

Fig. 5 is a block diagram of a local DTV signal generator according to the present invention in the case where only the reproduction of stored data is desired using a notebook PC or a desktop PC.

Explanation of symbols for main parts of the drawings

100: download device 200: VSB signal reproducing unit

201: storage unit 202,309: VSB remodulation unit

203: control unit 204: download unit

205: Micom 206: power supply

300: VSB signal processing unit 301: tuner

302: IF demodulator 303: channel decoder

304: audio / video processing unit 305: display unit

306: First interface 307: Storage

308: second interface 401: DVD driver

The local DTV signal generating apparatus according to the present invention for achieving the above object includes a download unit for downloading data from an external device that stores digital broadcasting data, a storage unit for storing the downloaded data, and the storage Reproducing VSB signal including a VSB modulator for modulating the data frame residual sideband (VSB) stored in the unit and outputting the RF signal as a high frequency (RF) signal, and a control unit for controlling downloading of the download unit and reading of data stored in the storage unit. It is characterized in that the additional configuration.

The storage unit may be configured as a nonvolatile memory (eg, flash memory) capable of reading and writing.

The storage unit is characterized by consisting of a ROM that can only be read once written.

The external device storing the digital broadcasting data is a hard disk mounted in a general PC, and outputs a transport stream coded according to the ATSC standard.

The external device storing the digital broadcasting data is a DVD mounted on a general PC.

The VSB signal reproducing unit is designed in the form of a PC card and can be embedded in a general PC.

The VSB signal reproducing unit is designed in the form of a separate external set-top box and can be mounted outside of a general PC.

The local digital TV signal generating apparatus according to the present invention comprises a storage unit for storing a transport stream encoded by an MPEG algorithm and a VSB signal processing unit for outputting an RF signal by VSB modulating the data stored in the storage unit. The VSB signal processing unit reads a transport stream stored in the storage unit if necessary, modulates a residual side band (VSB), and outputs a high frequency (RF) signal, and a clock between the storage unit and the VSB modulation unit. And a controller for synchronizing, converting the data read through the storage unit according to the data input form of the VSB modulator if necessary and outputting the data to the VSB modulator.

The storage unit is characterized in that the hard disk mounted on a general PC.

The storage unit is characterized in that the digital multi-function disk (DVD) mounted on a general PC.

In accordance with an aspect of the present invention, a local digital TV signal generating apparatus includes a demodulator for receiving a digital broadcast signal broadcast from a broadcasting station and then demodulating the VSB to output a transport stream, and an audio signal and a video signal from the transport stream output from the demodulator. After separation, the separated audio signal is decoded using the AC-3 algorithm and the video signal is decoded using the audio / video signal processor for performing video decoding using the MPEG2 algorithm and the transport stream output from the demodulator. A storage unit for storing, a VSB modulator for modulating the transport stream stored in the storage unit as a residual side band (VSB), and outputting a high frequency (RF) signal, and a transport stream output from the demodulator To save the data in the storage or save it in the storage. And a control unit which reads the LANForce stream, converts the data according to the data input format of the VSB modulator, and outputs the result to the VSB modulator.

The remaining blocks except for the storage unit may be designed in the form of at least one PC card to be embedded in the PC.

The remaining blocks except for the storage unit may be designed in a separate set-top box form to be mounted outside the PC.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First embodiment

The present invention stores a transport stream coded according to the ATSC standard and enables playback with an RF signal of the ATSC standard when necessary, which will be described as a first embodiment.

2 is a block diagram illustrating a local DTV signal generating apparatus according to a first embodiment of the present invention, where 200 is a VSB signal reproducing unit.

The VSB signal reproducing unit 200 includes a storage unit 201 for storing a transport stream, a VSB remodulator 202 for converting a transport stream stored in the storage unit 201 to an RF signal of an ATSC standard, and the storage. Control unit 203 for controlling the reading of data stored in the unit 201, and VSB modulation of the VSB re-modulator 202, the download device 100 when the storage unit 201 is composed of a flash memory A download unit 204 for downloading a transport stream from the storage unit 201 and storing it in the storage unit 201, and a microcomputer 205 for controlling the download of the download unit 204.

The unmentioned 206 is a power supply unit for supplying power to each of the blocks described above. The device 100 for downloading may be any device that stores an MPEG stream. For example, a general personal computer (PC) may be used.

In FIG. 2 configured as described above, the storage unit 201 of the VSB signal reproducing unit 200 stores a transport stream coded according to the ATSC standard. In this case, the storage unit 201 may be configured as a non-volatile memory (for example, a ROM) that can only be read once stored, or may be configured as a nonvolatile memory (for example, a flash memory) that can be read and written. Here, the storage unit 201 may be applied to a wider and more various applications, and thus the present invention will not be limited to the example provided.

If the storage unit 201 is configured as a ROM, only the data stored in the ROM may be reproduced through the VSB remodulator 202.

On the other hand, when the storage unit 201 is configured as a flash memory, another bitstream may be downloaded and used if necessary through the download port of the download unit 204. If the storage unit 201 is configured as a flash memory, the user can download the desired bitstream at any time and reproduce the desired bitstream as a VSB modulated RF signal. Therefore, the storage unit 201 can be used more effectively than a general ROM.

In this case, the size of the storage unit 201 depends on how many transport streams are to be stored. In the ATSC, about 2.69 MBytes of data are transmitted per second, for example, to store a transport stream of about 10 seconds. In order to do this, a size of about 27MByte is required.

The download port of the download unit 204 is used as a port for downloading a transport stream from the outside and storing the transport stream in the flash memory when the storage unit 201 is configured as a flash memory. For example, when a stream stored in a flash memory is to be replaced, a desired stream may be downloaded from a download device (for example, a PC) using the download port and stored in the flash memory.

The microcomputer 205 controls the system when a new transport stream is downloaded from the external download apparatus 100. That is, when the transport stream is downloaded from an external download device (for example, a PC), the new transport stream to be downloaded is stored in the flash memory.

As such, the transport stream stored in the storage unit 201 is converted into an ATSC standard RF signal through the VSB remodulation unit 202 and outputted when necessary, for example, in a test, research and development, after-sales service, or demonstration. do.

That is, the VSB remodulation unit 202 performs channel coding (that is, randomize, RS coding, interleaving, trellis coding, synchronization insertion, etc.) to conform to the ATSC transmission standard. Pilot insertion, etc.), and RF modulation is performed to transmit the channel coded data to the channel. In this case, the VSB remodulation unit 202 can be designed in various forms as long as the VSB remodulator 202 is designed to output a VSB RF signal defined in the ATSC standard through VSB modulation, and can be made in a single chip form. .

The controller 203 controls the process of reading the data stored in the storage 201 and sending the data to the VSB remodulator 202. That is, the controller 203 generates a memory address and various control signals for reading data. In this case, the controller 203 may be configured with other discrete devices, but may also be configured by using an FPGA chip such as Altera.

In this case, the VSB signal reproducing unit 200 may be designed in the form of a PC card and embedded in the PC. In addition, only the VSB signal reproducing unit 200 may be made into a separate external box form. If it can be made into an external box, it can generate ATSC-compliant RF signals from PCs such as laptops.

Thus, the first embodiment of the present invention can be used inexpensively and effectively as a signal source for developing / demonstrating / service / producing DTV related products.

Second embodiment

In addition, the present invention is to receive and store the signal being broadcast in the actual broadcasting station, for example, the VSB signal of the transmission method of the North American and domestic DTV, and to enable the reproduction of the stored VSB signal when necessary, the second embodiment Explain.

3 is a block diagram illustrating a local DTV signal generator according to a second embodiment of the present invention, where 300 is a VSB signal processor.

The VSB signal processor 300 tunes an RF signal of a corresponding channel from an antenna and converts it into an intermediate frequency (IF) signal, and down-converts an IF signal output from the tuner 301 to a baseband signal. An output IF demodulator 302, a channel decoder 303 for performing channel decoding on the baseband signal and outputting the result as a transport (TP) stream, and separating the multiplexed video signal and an audio signal from the channel decoded signal, and The separated audio signal is decoded using an AC (Audio coding) -3 algorithm, and the separated video signal is decoded using a Moving Picture Experts Group-2 (MPEG-2) algorithm and then output to the display unit 305. An audio / video (A / V) processing unit 304, a first interface 306 for converting the transport stream output from the channel decoder 303 into a form for storing in the storage unit 307, ATSC standard The second interface 308, which reads the transport stream stored in the storage unit 307, to convert the transport stream input through the second interface 308 to the RF signal of the ATSC standard to output the RF signal of the A control unit for controlling the first and second interfaces 306 and 308 and the storage unit 307 to store VSB remodulation unit 309 and the data stored in the storage unit 307 and read out the stored data for VSB modulation; It consists of 310.

The first and second interfaces 306 and 308 may use a general I / O card (eg, PCI).

In FIG. 3 configured as described above, when a VSB modulated high frequency (RF) signal is received through an antenna, the tuner 301 selects only an RF signal of a desired channel by tuning, converts the IF signal into an IF signal, and outputs the IF signal to the IF demodulator 302. . The IF demodulator 302 down-converts the IF signal output from the tuner 301 to a baseband (BB) signal and outputs it to the channel decoder 303.

The channel decoder 303 compensates for channel distortion generated during transmission of data through a transport channel, and restores the original transport stream. To this end, the channel decoder 303 performs derandomize, R-S decoding, trellis decoding, synchronization recovery, deinterleaving, etc. on the baseband signal to restore data broken by noise on the channel. That is, when the DTV signal is transmitted through the channel, the original data may be broken by noise on the channel. Thus, the data broken by the noise on the channel is restored to the original data. In this case, the channel decoder 303 is also referred to as a VSB demodulator.

In this case, depending on the chip maker, the IF demodulator 302 and the channel decoder 303 may be formed as one chip.

The A / V processing unit 304 separates the audio signal and the video signal from the transport stream decoded by the channel decoder 303, and then performs Dolby AC-3 audio decoding and MPEG2 video decoding on each of them.

That is, the separated audio signal is decoded using the Dolby AC-3 algorithm and then output to the speaker of the display unit 305. Here, AC-3 is a method adopted as an audio standard of digital terrestrial TV, and refers to a third type of audio coding method newly developed by Dolby Laboratories in the United States, which is famous for audio noise reduction technology.

The separated video signal is decoded using the MPEG-2 algorithm and then output to the monitor of the display unit 305. Here, the MPEG-2 algorithm removes overhead (various header information, start codes, etc.) from a video signal, performs variable length decoding (VLD) on pure data information, and then dequantizes and inverse discrete cosine transform (VLD). IDCT) means restoring the pixel value of the original screen through a motion compensation process using a motion vector.

Meanwhile, the transport stream decoded by the channel decoder 303 is stored in the storage unit 307 through the first interface 306. That is, the first interface 306 converts the transport stream output from the channel decoder 303 into a form for storing in the storage unit 307 and stores it in the storage unit 307. The second interface 308 reads the transport stream stored in the storage unit 307 and outputs it to the VSB remodulator 309 when necessary.

If the channel decoded transport stream, that is, the MPEG compressed stream, is stored in the storage unit 307, the second interface 308 converts the MPEG compressed stream into an ATSC standard stream to convert a VSB remodulator 309. ) For example, a parity of a predetermined byte is added to each packet of the MPEG compressed stream read from the storage unit 307, and converted into a stream conforming to the ATSC standard.

In this case, if a general PCI card is used as the second interface 308 and data is read out in 32 bits, the second interface 308 converts the data into a unit of 1 byte (ie, 8 bits) and the VSB remodulator 309. ) If data stored in the storage unit 307 is read in units of 8 bits, the data is output to the VSB remodulator 309 without data conversion.

Here, the storage unit 307 can store any data, and if the display unit 305 and the storage unit 307 are used as a general PC, the storage unit 307 is a hard disk (HDD). ) Can be used. Here, the storage unit 307 may be applied in a wider variety of applications will not be limited to the example presented above.

As such, the transport stream stored in the storage unit 307 is converted into an RF signal of the ATSC standard through the VSB remodulation unit 309 and outputted when necessary, for example, in a test, research and development, after-sales service, or demonstration. do.

That is, the VSB remodulation unit 309 performs channel coding (that is, randomize, RS coding, interleaving, trellis coding, synchronization insertion, etc.) to conform to the ATSC transmission standard. Pilot insertion, etc.), and RF modulation is performed to transmit the channel coded data to the channel. In this case, the VSB remodulation unit 309 can be designed in various forms as long as it is designed to output a VSB RF signal defined in the ATSC standard through VSB modulation, and can be made in a single chip form. .

The controller 310 controls the first interface 306 to store the transport stream in the storage unit 307, and controls the second interface 308 to store the transport stream stored in the storage unit 307. Read it. In addition, a memory address for reading data is generated and output to the storage unit 307.

In this case, the VSB signal processor 300 may be designed in the form of one or several PC cards and embedded in a PC (eg, a desktop PC). In addition, only the VSB signal processing unit 300 may be made into a separate set-top box form, and in this case, the present invention may be performed using a PC such as a notebook computer.

If the VSB signal processing unit 300 is implemented in a PC card form and embedded in a PC, the VSB signal processing unit 300 may be driven using a PC power supply, but the VSB signal processing unit 300 may be implemented externally. In the VSB signal processor 300, a separate power supply unit must be configured.

Here, when the VSB signal processing unit 300 is configured externally, it is easy to move, and thus may be used as a personal signal transmitting / receiving device for a demonstration, service, or DTV developer.

In addition, the present invention may store the RF signal instead of the transport stream in the storage unit 307, in which case a separate tuner is also required.

As described above, according to the second embodiment of the present invention, the broadcast signal may be received in the area where the DTV broadcast is currently performed and stored in the hard disk in the PC, and the stored data may be reproduced and used at a desired time. In particular, since the broadcast signal is used, the source is not limited. That is, there is no burden of separately purchasing the sauce.

Therefore, in the related art, it is expensive to obtain a bit stream required for developing / demonstrating / service / producing a DTV, but the present invention is very inexpensive because the present invention can receive and store a stream that is currently being broadcast and use it again. A variety of rich bit streams can be provided at a price.

In addition, since the capacity of the storage unit 307 can be expanded to a sufficient degree, the function of a digital video cassette recorder (VCR) at home can also be performed.

That is, the user may store the necessary part, for example, a scene or a program that he / she wants to watch again in the storage unit 307, and play it back at any time while watching the DTV broadcast.

In addition, when a general PC is used as a storage and display unit, a PC is usually equipped with a digital multifunction disk (DVD) driver. In this case, not only a function of receiving, storing, and playing back a broadcast DTV signal may also perform a function of a DVD player.

FIG. 4 is a block diagram illustrating this example, and illustrates a case in which the DVD driver 401 is further mounted in FIG. 3.

At this time, if the DVD title stored in the DVD is produced in accordance with the ATSC transport standard, data can be read from the DVD 401 and played back without additional hardware or software. That is, when the transport stream stored in the DVD 401 is read through the second interface 308 and output to the VSB remodulator 309, the VSB remodulator 309 performs RF coding of the ATSC standard through channel coding and RF modulation. Output as a signal. Therefore, whenever desired, the output of the VSB remodulator 309 can be input through an RF channel (eg, channels 3 and 4) to view the contents stored in the DVD 401 on a general TV monitor or a PC monitor.

As described above, the DVD title can be converted into a transport stream by encoding a movie, for example, MPEG2, and stored in the DVD 401. When such a DVD title is provided, the currently broadcasted signal is stored in the method proposed by the present invention. And both reproduction and signal reproduction from the DVD can be performed, and the function as a digital recording / reproducing apparatus can be sufficiently performed at low cost.

On the other hand, when only the reproduction of the data stored using a notebook PC or a desktop PC, etc. is desired, it can be configured as shown in FIG. That is, when the transport stream stored in the storage unit 601 or the DVD 602 such as the HDD is output to the VSB remodulation unit 502 through the interface 501 at a desired time point, the VSB remodulation unit 502 is the storage unit. Channel coding is performed on the transport stream read from the 601 or the DVD 602 in accordance with the ATSC transmission standard, and RF modulation is performed to transmit the channel coded data to the channel. The RF signal is converted to an analog signal and then output to a specific channel number (eg, RF channels 3 and 4) to be viewed on a TV or PC monitor. In this case, the interface 501 synchronizes the clock between the storage unit 601 and the VSB remodulation unit 502 and, if necessary, matches the data stored in the storage unit 601 with the input format of the VSB remodulation unit 502. Perform data conversion.

As such, the present invention can be designed for regeneration and can be used inexpensively and effectively.

In addition, since the present invention is intended for driving on a general PC, it can be used as an analysis function of ATSC signal by using software for analyzing received data.

In addition, the present invention can be used in all sectors adopting the ATSC transmission scheme, and in particular, it is possible to replace the existing expensive equipment used to generate the ATSC signal, thereby obtaining a high quality ATSC signal at low cost.

On the other hand, the present invention can be designed to have the same function for the ATSC signal (VSB), QAM, QPSK, etc., if the respective sub-blocks of the present invention is modified to match the QAM or QPSK.

In addition, the field to which the present invention can be applied is roughly useful for research institutes, broadcasting stations, homes, digital TV production plants, department stores, service centers, electronic product distributors, exhibition halls, various tests, and software development.

As described above, according to the local DTV signal generating apparatus according to the present invention, since the DTV signal currently being broadcast can be received and stored, a rich and diverse source can be provided without a separate purchase, and depending on whether it is utilized, it can be digitally used at home. It can also play the role of a VCR. In addition, if a title such as a movie is provided from the DVD to comply with the ATSC transport standard, it can be used as a DVD player.

In addition, the present invention can be run on a commonly used PC, and in particular, since the stream stored in the storage unit can be independently reproduced without the help of an external device, mobility, economy, maintenance and repair are easy. In addition, the user can download the desired stream back to the storage unit, and can be extended to ATSC signal analysis according to the software application on the PC.

In addition, the present invention can be applied to an expanded concept in which all programs can be generated directly from a computer by replacing an ATSC signal generator such as a digital TV used in broadcasting stations in the future.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (19)

A download unit which downloads data from an external device storing data for digital broadcasting; A storage unit to store the downloaded data; A VSB modulator for modulating the data frame residual sidebands (VSB) stored in the storage unit and outputting a high frequency (RF) signal; And And a VSB signal reproducing unit including a control unit for controlling downloading of the download unit and reading of data stored in the storage unit. The method of claim 1, wherein the storage unit Local digital TV signal generating device comprising a nonvolatile memory capable of reading and writing. The method of claim 2, wherein the storage unit Local digital TV signal generating device, characterized in that consisting of flash memory. The method of claim 2, wherein the storage unit Local write TV signal generator, characterized in that consisting of read-only ROM once written, in this case does not require a download. The method of claim 1, The external device storing the digital broadcasting data is a hard disk mounted in a general PC, and outputs a transport stream coded according to the ATSC standard. The method of claim 1, And an external device storing the digital broadcasting data is a digital multi-function disk (DVD) mounted in a general PC. The apparatus of claim 6, wherein the DVD stores a transport stream encoded by an MPEG algorithm. The method of claim 1, wherein the VSB signal reproducing unit Local digital TV signal generating device characterized in that the design in the form of a PC card can be embedded in a general PC. The method of claim 1, wherein the VSB signal reproducing unit Local digital TV signal generating device characterized in that the design in the form of a separate external set-top box can be mounted on the outside of the general PC. A storage unit for storing the transport stream encoded by the MPEG algorithm; And And a VSB signal processing unit for outputting an RF signal by VSB modulating the data stored in the storage unit. The VSB signal processing unit reads a transport stream stored in the storage unit if necessary, modulates a residual side band (VSB), and outputs a high frequency (RF) signal, and a clock synchronization between the storage unit and the VSB modulation unit. And a controller for converting the data read through the storage unit according to a data input form of the VSB modulator if necessary and outputting the data to a VSB modulator. The method of claim 10, wherein the storage unit Local digital TV signal generating device, characterized in that the hard disk mounted on a normal PC. The method of claim 10, wherein the storage unit Local digital TV signal generating device, characterized in that the digital multi-function disk (DVD) mounted on a general PC. A demodulator configured to receive a digital broadcast signal being broadcast by a broadcasting station and then output a VSB demodulated signal as a transport stream; After the audio signal and the video signal are separated from the transport stream output from the demodulator, the separated audio signal is audio decoded using the AC-3 algorithm and the video signal is displayed by performing video decoding using the MPEG2 algorithm. A video signal processor; A storage unit for storing the transport stream output from the demodulator; A VSB modulator for modulating the transport stream stored in the storage unit as a residual side band (VSB) and outputting a high frequency (RF) signal; And The transport stream output from the demodulator is converted into a form for storing in a storage unit and stored in the storage unit, or the transport stream stored in the storage unit is read and converted according to the data input format of the VSB modulator to be output to the VSB modulator. Local digital TV signal generating device comprising a control unit. The method of claim 13, wherein the storage unit Local digital TV signal generating device, characterized in that the hard disk mounted on a normal PC. The method of claim 13, wherein the storage unit Local digital TV signal generating device, characterized in that the digital multi-function disk (DVD) mounted on a general PC. The method of claim 15, And a transport stream encoded by an MPEG algorithm is stored in the DVD. The local digital TV signal generating apparatus of claim 13, wherein the remaining blocks except for the storage unit are designed in the form of at least one PC card to be embedded in the PC. The method of claim 13, The remaining digital blocks except for the storage unit is designed in the form of a separate set-top box can be mounted on the outside of the PC. The method of claim 18, If the remaining blocks except the storage unit is designed in the form of a separate set-top box, the local digital TV signal generating device further comprising a power supply therein.