KR100667191B1 - T-dmb repeater by using antenna for receiving tv broadcasting - Google Patents

Abstract

A T-DMB repeater using an antenna for receiving broadcasting waves is provided to connect to a television broadcasting wave receiving terminal pre-installed in a house, divide a broadcasting signals inputted from the television broadcasting wave receiving terminal into two signals, extract a DMB signal having a pre-designated frequency band from one of the divided broadcasting signals to wirelessly transmit the signal, and transmit the other broadcasting signal to a television, thereby easily solving a poor-reception problem of a house, a shadow area, as well as television broadcasting watching. A T-DMB(Terrestrial Digital Multimedia Broadcasting) repeater using an antenna for receiving broadcasting waves comprises the followings: a coaxial cable terminal which is connected to the antenna for receiving broadcasting waves, is connected to a connection terminal installed at a proper position of an internal wall of a house, and receives a broadcasting signal from the connection terminal; a filter(220,257,275) which removes frequency components except DMB signals from the broadcasting signal inputted from the coaxial cable terminal, and outputs the broadcasting signal; a signal processor(245,250) which down-converts a frequency of the DMB signal outputted from the filter(220,257,275), removes frequency components except a pre-designated DMB signal from the down-converted DMB signal, and up-converts the pre-designated DMB signal to an original frequency before outputting the signal; a DMB transmitting antenna; and a case.

Description

T-DMB repeater by using antenna for receiving TV broadcasting

1 is an exemplary view showing a DMB channel allocated for each region;

2 is an exemplary view showing a frequency band of a terrestrial DMB channel allocated to a metropolitan area;

3 is an exemplary installation diagram of a terrestrial DMB repeater using an antenna for receiving broadcast waves according to the present invention;

Figure 4 is a front view showing the appearance of the terrestrial DMB repeater that can be applied to the present invention

5 is an electrical block diagram of a terrestrial DMB repeater according to an embodiment of the present invention;

FIG. 6 is a detailed block diagram illustrating the signal processor shown in FIG. 5.

*** Explanation of symbols for the main parts of the drawing ***

10: broadcast wave receiving antenna 20: receiving line

30: connection terminal 40: electric wire

50: outlet 60: wall

100: terrestrial DMB repeater 110: broadcast signal input terminal

120: TV signal output terminal 130: power line

140: DMB signal output terminal 150: DMB transmitting antenna

210: control unit 215: first signal distribution unit

220: first filter unit 225: low noise amplifier

230: impedance matching unit 235: first switching unit

240: second signal distributor 245: first signal processor

250: second signal processor 251: first mixing unit

252: amplifier 253: intermediate frequency filter

254: variable gain amplifier 255: second mixing unit

256: variable frequency generator 257: second filter unit

260: signal coupling unit 265: second switching unit

270: power amplifier 275: third filter unit

280: TV signal amplification unit 285: key input unit

290: a high frequency power detector

The present invention relates to a terrestrial DMB repeater using an antenna for receiving a broadcast wave, and more particularly, to a terrestrial DMB repeater using an antenna for receiving a broadcast wave which enables smooth DMB reception in a shadow area.

In general, DMB (Digital Multimedia Broadcasting) is a broadcasting service developed to provide users who want to watch high-quality video / audio broadcasting anytime, anywhere, such as on the subway or in a vehicle. Terrestrial DMB (Terrestrial DMB) And satellite DMB (Satellite-DMB).

In particular, terrestrial DMB is based on Eureka-147 Digital Audio Broadcasting (DAB) system in Europe, adopts H.264, MPEG Part10 AVC, for multimedia video support, and BASC (Bit Sliced Arithmetic) as audio. Coding) was adopted. In addition, the frequency allocated to terrestrial DMB is a very high frequency (VHF) used as a TV channel, and terrestrial DMB is currently serviced through channels 8 (180 to 186 MHz) and channel 12 (204 to 210 MHz) in the metropolitan area. In addition, the Ministry of Information and Communication divides the regions requiring frequency adjustment with local broadcasting into a plurality of DMB service areas and allocates one or more TV channels to each area, thereby promoting the introduction of nationwide terrestrial DMB service. For example, as shown in FIG. 1, a DMB channel will be allocated to each region.

2 is a diagram showing the frequency band of the terrestrial DMB channel allocated to the metropolitan area, the channel allocated for the DMB service is divided into three frequency blocks (hereinafter, multiplex), one per multiplex DMB operators are selected. As shown in FIG. 2, each multiplex has a bandwidth of 1.536 MHz, and can implement 1 to 2 videos and 3 to 4 audio or text broadcasts, and the images are clumped or appear to be somewhat out of pixel. It provides up to 7 inches of screen without stepping.

On the other hand, when the DMB service is provided, there is a shadow area in which the DMB signal is not smoothly provided. Thus, the problem of blindness can be solved by separately installing the DMB repeater in the shadow area. On the other hand, it is necessary to establish a separate wired network for transmitting the DMB signal to such a DMB repeater, and there is a problem that a huge construction cost is required for the wired network. However, there is a problem in that the use frequency bands are different from each other in order to use a repeater for a mobile communication terminal installed nationwide.

Therefore, as a solution to the problems discussed above, a miniature repeater for digital multimedia broadcasting using a television coaxial distribution network has been proposed in Utility Model Registration No. 404167, which is a broadcast signal (TV signal). And a first amplifier for compensating for attenuation of the broadcast signal received from the headend, a headend for amplifying the broadcast signal received from the antenna with a predetermined gain, and a broadcast signal received from the amplifier. A television coaxial distribution network comprising a first distributor for distributing the required number of paths and a second amplifier for amplifying a broadcast signal of each path distributed from the first distributor with a predetermined gain; A connection terminal for transmitting a broadcast signal output from the television coaxial distribution network to an arbitrary broadcast receiver; It is connected to a second distributor and a second distributor that distributes the broadcast signal input from the connection terminal into two broadcast signals and transmits one broadcast signal to the TV receiver, and receives another broadcast signal to pass and amplify only the DMB signal. It includes a DMB relay that transmits wirelessly.

On the other hand, according to the statistical data analyzing the acceptance of the recent DMB service, the main use place of the DMB service appeared in the order of vehicle, home, school / work and walking. In this case, the second highest assumption is that it is because the DMB service is not only mobile but also high in personality.

In other words, according to the conventional miniature repeater for digital multimedia broadcasting using a television coaxial distribution network, it is possible to solve the problem of difficulty viewing in a large area such as an apartment complex or a building. In the same subunit house, there was a problem that it was not suitable for the individual to easily install and use.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and is connected to a TV broadcast wave receiving terminal pre-installed in a home, and distributes two broadcast signals input from the TV broadcast wave receiving terminal to one broadcast signal. It is an object of the present invention to provide a terrestrial DMB repeater using a broadcasting wave receiving antenna for extracting and wirelessly transmitting a DMB signal having a predetermined frequency band and transmitting another broadcast signal to a television.

In addition, there is another object to provide a terrestrial DMB repeater using a broadcasting wave receiving antenna for transmitting a DMB signal having a frequency band corresponding to the region for each DMB service.

Furthermore, another object is to provide a terrestrial DMB repeater using an antenna for receiving a broadcast wave directly attachable to a TV broadcast wave receiving terminal without a connection line.

In order to achieve the above object, a terrestrial DMB repeater using the antenna for receiving a broadcast wave of the present invention is connected to a antenna for receiving a broadcast wave and is connected to a connection terminal installed at an inner wall of a house, and a broadcast signal from the connection terminal. Receiving a coaxial cable terminal; A filter unit which removes and outputs a frequency component other than a DMB signal from a broadcast signal input from the coaxial cable terminal; A signal for down-converting the frequency of the DMB signal output from the filter unit, removing frequency components other than a predetermined DMB signal from the down-converted DMB signal, and up-converting the predetermined DMB signal to the original frequency for output. Processing unit; A broadcast wave including a case in which a DMB transmitting antenna for transmitting the DMB signal output from the signal processing unit, the filter unit, and the signal processing unit are built-in, and the coaxial cable terminal and the DMB transmitting antenna are exposed in place on the outer side; Provides a terrestrial DMB repeater using a receiving antenna.

Hereinafter, a terrestrial DMB repeater using an antenna for receiving broadcast waves will be described in detail with reference to the accompanying drawings.

3 is an exemplary diagram illustrating the installation of a terrestrial DMB repeater using an antenna for receiving a broadcast wave according to the present invention, which schematically illustrates a TV broadcast receiving network in a home which is a shadow area of the DMB, and FIG. 4 may be applied to the present invention. Front view showing the appearance of terrestrial DMB repeater.

3 and 4, a broadcast signal transmitted from a broadcasting station is received through a broadcast wave receiving antenna (hereinafter referred to as a receiving antenna) 10, and the broadcast signal is introduced into a building through the receiving line 20. As shown in FIG. It is input to the terrestrial DMB repeater 100 through the connection terminal 30 fixed to the building wall 60. Meanwhile, a broadcast signal input terminal (hereinafter referred to as an input terminal) 110 connected to the connection terminal 30 to receive a broadcast signal is formed at one side of the terrestrial DMB repeater 100 and a TV for outputting a TV signal at the other side. A signal output terminal (hereinafter referred to as a TV terminal) 120 is formed to be connected to the television 300 through a connecting line 310, and the DMB signal output terminal for outputting a DMB signal in place of the side where the TV terminal 120 is formed ( DMB terminal (140) is formed, the DMB terminal 140 is detachable and is attached to the DMB transmitting antenna 150 for transmitting a DMB signal to a free space. Therefore, the DMB receiver 400 in the shadowed area can watch the smooth DMB. In addition, the other side of the terrestrial DMB repeater 100 is a power line 130 is connected to the outlet 50, which is a connection mechanism with the wire 40 for supplying AC power, the terrestrial DMB repeater 100 In order to supply the driving power of each of the electrical components of the terrestrial DMB repeater 100 to be described later, the transformer is supplied with AC power through the power line 130 to step down the voltage and convert it to DC power and its Peripheral circuitry is built in.

In the above-described configuration, the receiving line 20 and the connecting line 310 are preferably a coaxial cable having a characteristic impedance of 75 ohm, and the input terminal 110 is implemented as a terminal for a coaxial cable. In particular, it is preferable that the structure protrudes from the terrestrial DMB repeater 100 to be directly attached to the connection terminal 30 without a line. In addition, an adapter jack (not shown) may be formed at one side of the terrestrial DMB repeater 100, and an external DC adapter may be connected to the adapter jack to receive DC power.

5 is an electrical block diagram of a terrestrial DMB repeater according to an exemplary embodiment of the present invention, and FIG. 6 is a detailed block diagram of a signal processor shown in FIG.

As shown in FIG. 5, the electrical configuration of the terrestrial DMB repeater 100 according to the present invention includes a first signal distribution unit 215 for distributing and outputting two broadcast signals input from the input terminal 110; The size of the broadcast signal output through the first signal distribution unit 215 is attenuated by -3dB, the TV signal amplification unit 280 for amplifying the size of the broadcast signal to output to the TV terminal 120 to compensate for this; Among the broadcast signals distributed and output from the first signal distributor 215, a broadcast signal other than the broadcast signal output to the TV signal amplifier 280 is received and a frequency band designated as a DMB signal, for example, 174 to 216 MHz ( A first filter unit 220 passing only a band of channels 7 to 13; A low noise amplifier 225 for amplifying the DMB signal passing through the first filter unit 220 while suppressing a noise signal as much as possible; An impedance matching unit 230 matching an impedance to maximize the power of the DMB signal passing through the low noise amplifier 225; A first switching unit 235 selectively outputting the DMB signal received from the impedance matching unit 230 based on a predetermined bar; A second signal distributor 240 for dividing and outputting two DMB signals inputted from the first switching unit 235; A first signal processor 245 and a second signal processor 250 for processing and outputting a DMB signal of a predetermined channel, that is, a frequency band, from each DMB signal input from the second signal distributor 240; A signal combiner 260 coupling the DMB signal output from the first signal processor 245 and the second signal processor 250; A second filter unit 257 which passes only a predetermined channel, that is, a frequency band, in the DMB signal input from the first switching unit 235; A second switching unit 265 which receives a DMB signal from either the second filter unit 257 or the signal combiner 260 based on a predetermined bar; A power amplifier 270 for amplifying and outputting the magnitude of the DMB signal input from the second switching unit 265; A third filter unit 275 which removes a noise component generated by the power amplifier 270, that is, a harmonic signal component, and outputs the harmonic signal component to the DMB terminal 140; A high frequency power detector 290 for detecting power of the DMB signal output from the third filter unit 275; Control unit 210 and the control unit to collectively control the first switching unit 235, the first signal processing unit 245, the second signal processing unit 250, the second filter unit 257, the second switching unit 265 And a key input unit 285 for generating a key signal for the control operation of 210.

Meanwhile, as shown in FIG. 6, the detailed configuration of the second signal processor 250 (and the first signal processor 245) is used to down-convert the frequency of the DMB signal input from the second signal distributor 240. a first mixing unit 251 for down converting; An amplifier 252 for compensating the magnitude of the DMB signal passing through the first mixing unit 251; An intermediate frequency filter 253 which passes only a predetermined frequency band from the DMB signal output from the amplifier 252; A variable gain amplifier 254 for compensating and outputting the magnitude of the DMB signal attenuated by the intermediate frequency filter 253; The second mixing unit 255 and the first mixing unit which up-convert and output the frequency of the DMB signal input from the variable gain amplifier 254 to the frequency before being input to the first mixing unit 251. 251 and a variable frequency generator 256 for supplying a variable frequency for frequency conversion performed by the second mixing unit 255. That is, it is well known that the lower the frequency band, the more effective the filtering characteristic. The signal processing units 245 and 250 remove the frequency components other than the desired frequency band from the down-converted DMB signal than the input frequency. The selectivity, sensitivity, stability, and isolation of the DMB signal transmitted to 150 may be increased.

In the above-described configuration, the first signal divider 215 and the second signal divider 240 may be implemented as a power divider for distributing and outputting input signal power, and the signal combiner 260. May be implemented as a combiner.

Next, the first filter unit 220, the second filter unit 257, the third filter unit 275 and the intermediate frequency filter unit 253 is implemented as a band pass filter, the second filter A channel, ie, a frequency band, filtered by the unit 257 and the intermediate frequency filter unit 253 may be varied under the control of the controller 210.

Next, the TV signal amplifier 280, the amplifier 252, the variable gain amplifier 254, the low noise amplifier 225 and the power amplifier 270 is implemented as an amplifier, in particular low noise amplification The unit 225 is preferably implemented as a low noise amplifier, and may further include an image reject filter for removing the image frequency generated by the amplification. In addition, the variable gain amplifier 254 may be implemented as a variable gain amplifier (VGA), and the power amplifier 270 may be a power amplifier (PA) or a power amplifier module (Power Amp Module). : PAM). Meanwhile, the position of the low noise amplifier 225 may be located in front of the first signal distributor 215.

Next, the impedance matching unit 230 is implemented as an impedance transformer, and converts 75 ohm, which is a characteristic impedance of a DMB signal input through a coaxial cable, into 50 ohms, and stands for standing waves. Lower the Wave Ratio (VSWR) to improve signal transmission efficiency.

Next, the first mixing unit 251 is implemented as an RF down mixer, the second mixing unit 255 is implemented as an RF up mixer, and the variable frequency generator 256 is Local oscillator (RF local oscillator) and phase locked loop (Phase Locked Loop) may be implemented.

Next, the key input unit 285 may be implemented as a key button for selecting a channel of the DMB signal transmitted through the DMB transmitting antenna 150 and a peripheral circuit element that generates a key signal corresponding to the input of the key button. have.

Next, the controller 210 is implemented as a microcomputer or a hardware configuration for performing a predetermined logic operation. The controller 210 controls the switching of the switching units 235 and 265 based on a key signal input from the key input unit 285. Filtering of the signal processing units 245 and 255 and the second filter unit 257 is controlled. As mentioned earlier, DMB service is allocated to each channel differently. In the metropolitan area, DMB service is supported through dual channels, that is, channel 8 and channel 12. One or more channels will be allocated for DMB service.

For example, when a key signal corresponding to channel selection of channels 8 and 12 is input from the key input unit 285, the control unit 210 outputs the second signal distribution unit 240 to the output terminal of the first switching unit 235. The first switching unit 235 is controlled to be connected to the input terminal of the control panel, and the second switching unit 265 is controlled to be connected to the input terminal of the second switching unit 265 and the output terminal of the signal combination unit 260. . In addition, when the above-described channels 8 and 12 are selected, the controller 210 controls the first signal processor 245 to pass only the channel 8, that is, the 180 to 186 MHz band, and the second signal processor 250 Channel 12, that is, controls to pass only the 204 ~ 210MHz band. On the other hand, when a key signal corresponding to a single channel, for example, channel 13, which is not a dual channel is input, the switching units 235 and 265 are controlled to perform operations opposite to those illustrated above. The second filter unit 257 is controlled to pass through the 210 to 216 MHz band.

On the other hand, the Ministry of Information and Communication has enacted legislation that allows high-frequency power per channel of terrestrial DMB repeaters to be unlicensed and can be installed and used in homes without additional type approval.

Accordingly, when the power value detected by the high frequency power detector 290 is greater than a predetermined value, for example, 10 mW / MHz, the controller 210 may determine the magnitude of the DMB signal input from the intermediate frequency filter unit 253. By controlling the variable gain amplifier 254 to lower the compensation rate, the power value of the DMB signal output through the DMB terminal 140 is lowered.

The terrestrial DMB repeater using the antenna for receiving a broadcast wave of the present invention is not limited to the above-described embodiments, and may be modified in various ways within the scope of the technical idea of the present invention. For example, the second filter unit 257 may be replaced by a signal processor which down-converts the frequency of the input DMB signal, filters a predetermined frequency band, that is, a channel, and then up-converts and outputs the channel again. In addition, the signal processor may be further provided by the number of channels output through the DMB transmitting antenna 150.

According to the terrestrial DMB repeater using the broadcasting wave receiving antenna of the present invention as described above, it is connected to a TV broadcasting wave receiving terminal pre-installed in a home, and distributes the broadcasting signals inputted from the TV broadcasting wave receiving terminal into two, The distributed one broadcast signal extracts the DMB signal having a predetermined frequency band and transmits it wirelessly, and the other broadcast signal is transmitted to the television, so that the problem of hearing loss can be easily solved. It has an effect.

In addition, the broadcasting signal input terminal is directly attached to the connecting terminal without a connecting line, thereby preventing the surrounding space from becoming dirty by the connecting line and increasing the space utilization of the wall where the connecting terminal is installed. The effect is that the lines can be easily connected.

In addition, it is possible to transmit a DMB signal having a frequency band corresponding to the region for each DMB service, thereby providing a DMB service regardless of the region by simply operating a key button. Furthermore, the signal processing unit down-converts the frequency of the input DMB signal to remove frequency components other than the predetermined frequency band, and then up-converts and removes the remaining DMB signal, thereby improving filtering characteristics of the terrestrial DMB repeater. It is effective to let.

In addition, since the power value of the DMB signal output through the DMB terminal does not exceed a predetermined specific value, it is an unlicensed object as specified in the above-mentioned law, so that the free terrestrial DMB repeater can be installed and used. have.

Claims (7)

A coaxial cable terminal connected to an antenna for receiving a broadcast wave and connected to a connection terminal installed at an inner wall of a house, and receiving a broadcast signal from the connection terminal; A filter unit which removes and outputs a frequency component other than a DMB signal from a broadcast signal input from the coaxial cable terminal; A signal for down-converting the frequency of the DMB signal output from the filter unit, removing frequency components other than a predetermined DMB signal from the down-converted DMB signal, and up-converting the predetermined DMB signal to the original frequency for output. Processing unit; A DMB transmitting antenna for transmitting a DMB signal output from the signal processing unit; The terrestrial DMB repeater using the antenna for receiving a broadcast wave, wherein the filter unit and the signal processing unit are included, and the coaxial cable terminal and the DMB transmitting antenna are exposed in place on the outer side. The method of claim 1, A broadcast signal distribution unit for distributing a broadcast signal input from the coaxial cable terminal in two and outputting one broadcast signal to the filter unit; A terrestrial DMB repeater using an antenna for receiving broadcast waves, comprising an output terminal for outputting another broadcast signal distributed from the broadcast signal distribution unit to a television. The method of claim 2, The coaxial cable terminal is a terrestrial DMB repeater using a broadcast receiving antenna, characterized in that the structure protruding from the case so that the connection terminal can be connected without a connection line. The method of claim 3, wherein And a low noise amplifier configured to further reduce and amplify the broadcast signal on the circuit board. The method according to any one of claims 1 to 4, Although provided with a plurality of the signal processing unit, A DMB signal distribution unit for distributing the DMB signals output from the filter unit by the number of signal processing units provided in the plurality and outputting the same to each signal processing unit; A key input unit for generating a key signal for selecting a DMB channel corresponding to a frequency band of the DMB signal output to the DMB transmitting antenna; And a control unit for controlling each of the signal processing units to remove a predetermined frequency component based on a key signal input from the key input unit. The method of claim 5, The signal processor amplifies the predetermined DMB signal to have a predetermined gain and then up-converts the original frequency to output the same. And the control unit controls the signal processing unit to lower the gain when the power of the DMB signal transmitted from the DMB transmitting antenna is greater than or equal to a predetermined value. The method of claim 6, Terrestrial DMB repeater using an antenna for receiving a broadcast wave, characterized in that the adapter jack for receiving DC power is exposed in place on one side of the case.

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