KR0142730B1 - Satellite broadcasting receiver for multi-user - Google Patents

Abstract

The satellite broadcasting joint receiving circuit is posted, which is advantageous for receiving and distributing satellite broadcasting through a common antenna and transmitting it to a small number of subscribers through a common receiving system line. A transmission circuit which selects a predetermined channel according to channel selection data transmitted by a subscriber and a unique clock of each subscriber, performs FM modulation on the UHF band, and then combines and outputs the UHF-FM modulated signal that is combined and output from the transmission circuit. It consists of a receiving circuit having a predetermined subscriber circuit for tuning the channel of the corresponding channel according to the channel tuning data and the unique clock of the predetermined channel frequency and converting the frequency of the corresponding channel into a satellite intermediate frequency and outputting it to the satellite receiver. Each subscriber receives a satellite signal of horizontal polarization and vertical polarization using The channel is tuned by the preset data and the unique clock of UHF-FM. The channel is modulated by UHF-FM and transmitted through the common reception system line. By converting to frequency, channel tolling and stereo are possible, and since the demodulator and modulator are not required as many as the number of satellite channels, it is suitable for small systems while reducing the cost.

Description

Satellite broadcasting joint reception circuit

1 is a block diagram showing a conventional satellite broadcasting joint reception circuit.

2 is a block diagram showing a satellite broadcasting joint reception circuit according to the present invention.

3 is a detailed block diagram of the matrix of FIG.

* Explanation of symbols for main parts of the drawings

100: transmitting circuit 110: matrix

111, 112: low noise block 113: power supply

114, 115: distributor 116, 117: switching element

120, 170: station selection part 121, 161: mixer

122, 162: phase synchronization loop 123, 163: oscillator

124, 164: filter 180: coupling portion

190 divider 195 control unit

200: receiving circuit 210: first subscriber circuit

211: station selection unit 212: distributor

213 mixer 214 phase locked loop

215: generator 216: filter

217: high frequency modem 218: satellite receiver

260: sixth subscriber circuit

The present invention relates to a satellite broadcast joint reception circuit, and more particularly, to a satellite broadcast joint reception circuit which is advantageous for receiving and distributing satellite broadcasts through a common antenna and transmitting them to a plurality of subscribers through a joint reception system line.

In general, satellite master antenna television (hereinafter, abbreviated as SMATV) refers to satellite broadcasting through a central antenna that is commonly used, and then to a public hearing area (for example, an apartment, a hotel, a hospital, etc.). System to distribute.

FIG. 1 is a block diagram illustrating a conventional satellite broadcasting joint reception circuit, and a satellite signal received through a common antenna ANT is distributed to a predetermined channel by the distribution unit 10.

At this time, as the two C-bands and Ku-bands allocated for television satellite broadcasting, the downlink spectrum for the C-band satellite system is composed of 24 channels in the 3.7 to 4.2 GHz frequency band, and each channel has a bandwidth of 40 MHz.

Meanwhile, predetermined channel frequencies output through the distribution unit 10 are demodulated by demodulators 21 to 24 of the demodulator 20 connected as many as the number of channels to the output terminal of the distribution unit 10 so as to output audio and video signals. To be separated.

The audio and video signals demodulated in the respective demodulators 21 to 24 are further converted to ultra high frequency (UHF) in the modulators 31 to 34 of the modulation unit 30 connected to the respective demodulators 21 to 24. Is modulated into a band.

The modulated frequencies of the predetermined channel are transmitted by the joint reception system line after being combined by the combiner 40.

In this case, the satellite signal transmitted through the common reception system line is amplified by the amplifier 50 and then distributed by the distributor 60 and connected to the public reception area (eg, an apartment, a hotel, a hospital, a building, etc.) connected to the common reception system line. Is entered.

Therefore, the television receiving satellite broadcast can select and view a desired channel.

However, the first diagram described above is not suitable for small-scale systems because it is suitable for large-scale building or apartment systems and requires expensive investment.

In addition, since demodulators and modulators are needed as many as the number of satellite channels, there is a problem in that the cost is high.

In addition, since the satellite signal received by FM (Frequency Modulation) through an antenna is modulated and output by AM (Amplitude Modulation) through a mono modulator, anyone can watch by connecting a common receiver system line to a TV even in a home without a satellite receiver As a result, channels cannot be paid, stereo is not available, and digital processing is not possible.

The present invention is to solve the above problems, an object of the present invention is to receive the horizontal and vertical polarized satellite signals by using two common antennas, respectively, and then modulates with UHF-FM through the joint reception system line By converting the UHF-FM signal to the satellite intermediate frequency at each subscriber's satellite receiver in the public area, the demodulator and modulator are not required as many as the number of satellite channels, reducing the cost, making it suitable for small systems. Therefore, it is possible to have a stereo, and to provide a satellite broadcasting joint receiving circuit that allows the channel to pay.

The satellite broadcasting joint reception circuit according to the present invention for achieving the above object is characterized in that, in the satellite broadcasting joint reception circuit for receiving satellite broadcasts through a central antenna used in common and then distributes it to the public hearing area, the center A transmission means for selecting a channel according to channel selection data transmitted from each subscriber in the public hearing area and a specific clock of each subscriber in the satellite broadcasting received through an antenna, frequency modulating the microwave in a microwave band, and outputting the combined channel; The subscriber circuit outputs the satellite frequency by converting the frequency of the corresponding channel according to the channel tuning data and the unique clock of each subscriber out of the microwave frequency modulated channel frequencies combined and outputted by the transmitting means, and converting the channel frequency into a satellite receiver. It consists of a receiving means provided with two.

Hereinafter, a preferred embodiment of a satellite broadcast joint reception circuit according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a satellite broadcasting joint reception circuit according to the present invention, and assumes that the number of subscribers joining the public hearing area is 6;

Referring to FIG. 2, a transmission circuit 100 which is an outdoor unit which transmits satellite broadcasts received through two central satellite antennas ANT1 and ANT2 that are commonly used to each subscriber in a public hearing area, It consists of a receiving circuit 200 which is an indoor (In-Door) unit composed of each subscriber in the public hearing area.

Here, the outdoor circuit of the transmitting circuit 100 and the indoor unit of the receiving circuit 200 is connected by an equiaxed cable.

In this case, the transmitting circuit 100 receives the vertically polarized wave (V) and the horizontally polarized wave (H) satellite broadcast through two common antennas ANT1 and ANT2, respectively, and then distributes the satellite signals by the number of subscribers. ) Has a unique clock of each subscriber and is connected to a tuning unit 120 to 170 for tuning a predetermined channel according to the channel tuning data DT output from each subscriber.

Here, the matrix 110 includes first and second low noise clocks (hereinafter referred to as LNBs) 111 and 112 connected to respective antennas ANT1 and ANT2, and the LNBs 111 and 112. A vertical polarization output through the first and second LNBs 111 and 112 according to a power supply 113 supplying a DC of 14V or more, that is, 14V or 18V, and a voltage supplied from the power supply 113. V) or the first and second distributors 114 and 115 for distributing the satellite signals of horizontal polarization B by the number of subscribers in the public hearing area, and the first and second through control signals a and b. A predetermined number of switches corresponding to the number of subscribers in the public hearing area which respectively switch satellite signals of vertical polarization (V) and horizontal polarization (H) output from the distributors 114 and 115 and output them to the tuning stations 120 to 170, respectively. Elements 116 and 117.

That is, when the power supply unit 113 supplies 14V to the first LNB 111 and 18V to the second LNB 112, the first LNB 111 outputs only the vertically polarized satellite signal V. The second LNB 112 outputs only the horizontally polarized satellite signal H.

At this time, the even channel is polarized horizontally and the odd channel is vertically polarized and separated by at least 30 dB.

In addition, the first channel selector 120 of the transmission circuit 100 includes a mixer 121 for mixing and outputting the frequencies of satellite broadcasts output from the matrix 110 of the oscillation frequency corresponding to the selected channel, and a channel. A phase locked loop (hereinafter referred to as a PLL) 122 that always maintains a constant signal frequency according to the tuning data DT and the unique clock CLK1 of each subscriber; and the PLL 122 Oscillator 123 to oscillate according to the output of the output to the mixer 121, and a filter 124 to pass only a predetermined frequency of the frequency output from the mixer 121.

In this case, the filter 124 is a surface acoustic wave (SAW) filter, and when the double side band (DSB) signal is converted into a residual side band (VSB) signal, interference of adjacent frequencies is generated. It is used to remove.

Here, since the present invention assumes that the number of subscribers joining the public hearing area is six, six tuning parts are required, and thus six tuning parts have the same configuration as the first tuning part 120.

On the other hand, each of the tuning unit 120 to 170 is coupled to the coupling unit 180 for coupling the corresponding frequency according to the channel selection output from each tuning unit (120 to 170), the output terminal of the coupling unit 180 A distributor 190 for distributing satellite signals to each subscriber of the receiving circuit 200 is connected.

The transmitting circuit 100 includes channel selection data DT output from each subscriber through bidirectional communication with the receiving circuit 200, unique clocks CLK1 to CLK6 and error data of each subscriber, and the like. The control part 195 which outputs to 120-170 is provided.

In this case, the controller 195 is composed of a radio frequency (RF) modem and a central processing unit (hereinafter referred to as a CPU) for long-distance communication, and the switching element 116 of the matrix 110. 117 outputs control signals a and b for selecting vertical polarization V or horizontal polarization H. FIG.

On the other hand, the receiving circuit 200, the predetermined number of subscribers are composed of a circuit, in the present invention, the first to sixth subscriber circuits (210 to 260) as an example.

In this case, the first subscriber circuit 210 converts a frequency corresponding to the channel selection data value DT output from the first subscriber circuit 210 into an intermediate frequency among the frequencies output from the transmission circuit 100. Tuning data DT output to the control unit 195 of the transmitting circuit 100 through the tuning unit 211 according to the channel selection unit 211 outputted to the receiver 217 and the channel tuning in the satellite receiver 217. It consists of an RF modem 218 for outputting.

Here, the channel selection unit 211 receives satellite signals transmitted through the distributor 190 of the transmission circuit 100 or outputs channel channel selection data output from the RF modem 218 to the transmission circuit 100. A divider 212, a mixer 213 for mixing and outputting an oscillation frequency corresponding to a selected channel and a satellite broadcasting frequency output through the divider 212, and channel selection data output from the RF modem 218 ( DT) and a PLL 214 that always maintains a constant signal frequency according to the unique clock CLK1 of each subscriber, and an oscillator which oscillates according to the output of the PLL 214 and outputs it to the mixer 213 ( 215 and a SAW filter 216 that passes only a predetermined frequency among the frequencies output from the mixer 213.

In this case, the RF modem 218 modulates a signal using frequency shift keying (FSK) or quadrature phase shift keying (QPS K).

Here, the frequency shift modulation is a frequency modulation method in which '1' and '0', which are transmission data, correspond to two frequencies, and have a constant amplitude and are less susceptible to level fluctuations or noise than amplitude modulation.

In addition, orthogonal phase shift modulation is a case where the modulation signal is digital in phase modulation, and the phase difference of the carrier corresponds to '1' and '0'.

On the other hand, since the second to sixth subscriber circuit is also the same configuration as the first subscriber circuit, illustration and description are omitted.

When the satellite signal is received through the two central antennas ANT1 and ANT2 which are commonly used as described above, the power supply 113 of the matrix 110 of the transmission circuit 100 moves to the first LNB 111. 14V is supplied to the 2nd LNB 112 and 18V.

Accordingly, the first LNB 111 receives only the vertically polarized satellite signal V, and the second LNB 113 receives only the horizontally polarized satellite signal H to the distributors 114 and 115 connected to the respective output terminals. Output

In this case, when the horizontally polarized satellite signal is received through the first LNB 111 and the vertically polarized satellite signal is received through the second LNB 112, the first LNB 111 may be used by the power supply 113. 18V is supplied, and 14V is supplied to the second LNB 112.

On the other hand, since the first distributor 114 that receives the vertically polarized satellite signal V and the second distributor 115 that receives the horizontally polarized satellite signal H assume 6 subscribers in the public hearing area, Distributes satellite signals into six channels.

Accordingly, the first vertical polarized satellite signal and the horizontal satellite signal are input to the first switching element 116, and likewise, the sixth vertical polarized satellite signal and the horizontal polarized satellite signal are input to the sixth switching element 117.

In addition, when a selection signal for selecting a vertically polarized or horizontally polarized satellite signal is transmitted to the controller 195 through the first subscriber circuit 210 of the receiver circuit 200, the controller 195 controls the first switching element ( 116 outputs the selection control signal a, and the first switching element 116 selects the first vertical polarized wave or the first horizontal polarized satellite signal according to the selection control signal a, 120).

Similarly, the second to sixth switching elements perform the same operation as the first switching element 116 according to the selection signal transmitted from the second to sixth subscriber circuits.

At this time, when each subscriber, for example, the first subscriber of the first subscriber circuit 210 of the reception circuit 200 tunes a channel through the satellite receiver 217, the channel data DT and the unique clock of the first subscriber are tuned. CLK1 is transmitted to the RF modem of the control unit 195 of the receiving circuit 100 through the RF modem 210.

The RF modem of the controller 195 outputs the channel data DT and the unique clock CLK1 of the first subscriber to the PLL 122 of the channel selection unit 120 of the first subscriber. Is output to the oscillator 123 while maintaining a constant signal frequency of the output according to the channel selection data DT and the unique clock CLK1.

At this time, the oscillator 123 controlled by I ² C oscillates according to the output of the PLL 122 to output an oscillation frequency to the mixer 121, the mixer 121 is the oscillation frequency and the matrix ( The vertically polarized or horizontally polarized satellite signal output from the 110 is mixed and then output to the combiner 180 through the SAW filter 124.

That is, the signal output from the channel selection unit 120 is a channel frequency tuned by the first subscriber, and is FM-modulated in the UHF band and output.

In this case, the channel selection unit of the second to sixth subscribers outputs the UHF-FM satellite frequency of the channel tuned by each subscriber to the combiner 180 through the same process as that of the first subscriber.

The combiner 180 outputs satellite frequencies of channels tuned to the subscriber circuits 210 and 260 of the receiver circuit 200 through the distributor 190.

In this case, taking the first subscriber as an example, the RF modem 218 of the selecting unit 211 of the first subscriber circuit 210 receives error data when an error occurs in the first subscriber circuit 210, and selects a channel when the channel is selected. The station data DT is transmitted to the RF modem of the control unit 195 of the transmitting circuit 100 together with the first subscriber station clock CLK1 through the divider 212.

That is, the divider 212 receives error data when the satellite signal is received from the transmitting circuit 100 or when an error occurs in the first subscriber circuit 210, and when selecting a channel, the distributor data together with the unique clock CLK1. It is a bidirectional coaxial cable output to the control unit 195 of the transmitting circuit 100.

Accordingly, the FM modulated satellite signal in the UHF band received through the distributor 212 is output to the mixer 213.

On the other hand, when the channel is tuned in the satellite receiver 217 of the first subscriber circuit 210, the channel data is output to the RF modem 218 through the signal input / output terminal I / O, and the RF modem 218 is a transmission circuit. The channel selection data DT and the clock CLK1 are outputted to the control unit 195 of 100 and the PLL 214 of the first subscriber circuit 210 of the receiving circuit 200.

The PLL 214 maintains a constant signal frequency of the output according to the channel selection data DT and the clock CLK1 of the first subscriber and outputs it to the oscillator 215.

The oscillator 215 controlled by I ² C oscillates according to the output of the PLL 214 to output an oscillation frequency to the mixer 213, and the mixer 213 performs the oscillation frequency and the divider 212. Outputs a mixture of satellite signals.

That is, when a predetermined channel frequency is combined and output from the transmission circuit 100, only the frequency of the channel tuned by the first subscriber by the channel data DT tuned by the first subscriber and the clock CLK1 is mixed. Is output via

In addition, a satellite intermediate frequency (eg, 479.5 MHz) is provided through the SAW filter 216 so that the UHF-FM signal output from the mixer 213 and the satellite receiver 217 that is the frequency of the channel selected by the first subscriber can be recognized. ) Is output to the satellite receiver 217.

Similarly, in the second to sixth subscriber circuits, the same operation as the first subscriber circuit 210 is performed, and only the frequency of the channel tuned by each subscriber is tuned in each subscriber circuit, and then the satellites of each subscriber circuit are converted to the satellite intermediate frequency. Output to the receiver.

Thus, through the satellite receiver of each subscriber circuit, each subscriber can watch the channel tuned by each subscriber.

Meanwhile, the RF modem used for the long distance transmission in the present invention may be eliminated if it is not the long distance transmission.

As described above, according to the satellite broadcasting joint reception circuit according to the present invention, after receiving a dominant signal of horizontal polarization and vertical polarization by using a common antenna, the predetermined channel is tuned by the channel tuning data and the unique clock of each subscriber. It is possible to pay for the channel and stereo by converting the signal through the common reception system line through the FM and converting the UHF-FM signal of the channel selected by each subscriber to the satellite intermediate frequency at the receiver of each subscriber in the public hearing area. There is no need for demodulators and modulators as many as the number of satellite channels, reducing costs and making them suitable for small systems.

Claims (2)

A satellite broadcasting joint reception circuit for receiving satellite broadcasting through a central antenna that is commonly used and then distributing the satellite broadcasting to a public hearing area, the channel tuning data transmitted by each subscriber of the public hearing area in the satellite broadcasting received through the central antenna; A transmission means for tuning a predetermined channel according to a unique clock of each subscriber, frequency shifting in the microwave band, and then combining and outputting each of the subscribers; A satellite broadcasting joint reception circuit comprising a receiving means having a predetermined number of subscriber circuits for tuning a channel frequency and converting the channel frequency into a satellite intermediate frequency for output to a satellite receiver. 2. The transmitting apparatus of claim 1, wherein the transmitting means comprises: a matrix for receiving a satellite signal vertically or horizontally polarized by the common antenna and distributing the number of subscribers in the public hearing area; and channel selection by each subscriber of the receiving means. A presetting circuit having a predetermined tuning section for tuning the frequency of the corresponding channel among the vertically polarized or horizontally polarized satellite signals distributed and output from the matrix according to the data and the unique clock of each subscriber; A control unit for outputting the channel tuning data transmitted from the channel and the unique clock of each subscriber to the tuning unit of the tuning circuit, and a coupling unit for combining the channel frequencies output from each tuning unit of the tuning circuit and outputting them to the receiving unit. Satellite broadcasting joint reception circuit.