KR100238147B1 - Multi-channel decider of satellite broadcastin recelving system for a public hearing - Google Patents

Abstract

end. FIELD OF THE INVENTION The present invention relates to a multi-channel decoder of a satellite broadcasting reception system for public hearing.

I. The present invention has been made in an effort to provide a multi-channel decoder capable of increasing cost and reliability by reducing the number of distributors in a satellite broadcasting receiver system for public hearing.

All. Summary of the Invention The Solution of the Invention:

A tuner and an AFE that selects one repeater from the 1 GHz signal output from the LNB and converts it into a baseband signal, a QPSK demodulator which converts the baseband signal into a digital signal and outputs the result by performing QPSK modulation, and when transmitting a broadcast signal. A channel decoder comprising an FEC for correcting errors, a transfer multiplexer for selecting and outputting one video signal and a related signal from an output of the channel decoder, and decoding and outputting video and audio signals among the output signals of the transfer multiplexer And source decoders comprising an audio / video decoder and an encoder for converting and outputting the decoded video and audio signals into a television broadcast signal.

la. Important use of the invention: can be used in satellite broadcasting reception system.

Description

MULTI-CHANNEL DECIDER OF SATELLITE BROADCASTIN RECELVING SYSTEM FOR A PUBLIC HEARING}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite broadcasting reception system for public hearings, and more particularly, to a multi-channel decoder capable of decoding a plurality of video signals broadcast with one repeater by connecting a plurality of source decoders to one channel decoder.

Satellite broadcasting by broadcast satellite (BS) and communication satellite (communication satellite: CS) means that a broadcast satellite located on an orbit around 35,000 to 36,000 Km of the equator stops broadcasting signals emitted from terrestrial broadcasting stations and re-launches them to the ground. In the form of a parabolic antenna, which is received in each home, there is no blind spot within the radio wave range, and it is possible to watch with clear picture and perfect sound.

BS and CS are satellite broadcasting systems, but there is no intrinsic difference, but BS uses transmission power as large as 100W ~ 200W in order to reduce the cost of receiving system for broadcasting business aimed at receiving radio waves from stationary satellite separately. It is used as a repeater for receivers, and its transmission power is 20W-40W, but the number of repeaters is 15-40. Satellite broadcasting, on the other hand, needs an appropriate receiver to receive the SHF (3G ~ 13G) frequency signal. In addition, since the strength of radio waves on the ground is much weaker than the existing VHF and UHF radio waves, it is affected by rain, cloud effects, buildings, trees, etc., so that high quality antennas, converters, and tuners are required. do.

Figure 1 shows the basic configuration of a conventional satellite broadcasting reception system. The public broadcast satellite reception system includes an antenna 10 for receiving a signal from a satellite, a low noise block-down converter (LNB) 12 for converting and outputting a received signal into a 1 GHz band, and an LNB 12 Distributors (103) for supplying output signals to a plurality of satellite broadcast receivers (16), satellite broadcast receivers (16) for receiving video and audio signals in signals of 1 GHz band respectively inputted through the distributors (103); Upconverters 18 for converting the output signals of the satellite broadcasting receivers 16 into the TV receiving channel frequencies, and mixers 20 for mixing a plurality of TV receiving channel signals.

In the above-described conventional public satellite broadcasting receiver system, a satellite broadcasting signal is received by the antenna 10 and converted into a signal of 1 GHz in the LNB 12. The output of the LNB 12 is then supplied to the multiple satellite receivers via the distributor 14. The distributor 14 is connected to the satellite broadcasting receiver 16 of the number of video channels to receive each video channel. The output of the satellite broadcasting receiver 16 is usually VHF Ch3 or 4 or baseband signal, which is converted via the upconverter 18 to frequencies not used in TV broadcasting, respectively. Then, the frequency raised through the up-converter 18 is synthesized in the mixer 20 and supplied to the TV of each home. In the case of digital satellite broadcasting, there are usually four or more video signals for each repeater, which requires several tens of satellite broadcasting receivers, resulting in duplication of channel receivers (QPSK demodulator). In addition, automatic switching is not easy in case of a satellite broadcast receiver failure, and when a satellite broadcast receiver is used for several decades, there is a problem in that the size of the satellite antenna is increased and an amplifier must be used before distribution.

Accordingly, an object of the present invention is to provide a multi-channel decoder that can increase the cost and reliability by reducing the number of distributors in the satellite broadcasting reception system for public hearing.

The present invention for achieving the above object is a multi-channel decoder of the satellite broadcasting reception system for public hearing,

A tuner that selects one repeater from a 1 GHz signal output from a low noise block-down converter (LNB) and converts the signal into a baseband signal; A QPSK demodulator for converting the baseband signal into a digital signal and outputting QPSK modulation; A channel decoder comprising FEC (Forward Error Correction) for correcting errors occurring when transmitting a broadcast signal,

A transfer multiplexer for selecting and outputting one video signal and a related signal from an output of the channel decoder; An audio / video decoder configured to decode and output a video and audio signal among the output signals of the transfer multiplexer; And a plurality of source decoders comprising an encoder for converting and outputting the decoded video and audio signals into a television broadcast signal.

1 is a basic configuration of a conventional satellite broadcasting receiver system.

2 is a block diagram of a system for receiving satellite broadcasting according to an embodiment of the present invention.

3 is a detailed block diagram of the channel decoder 30 in FIG. 2.

FIG. 4 is a diagram illustrating a connection of source decoders 40a to 40d multi-connected to the channel decoder 30 of FIG. 2.

Hereinafter, an operation according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals refer to like elements throughout the following description and drawings, and detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

FIG. 2 is a block diagram of a system for receiving satellite broadcasting according to an embodiment of the present invention. FIG. 3 is a detailed block diagram of the channel decoder 30 of FIG. 2, and FIG. 4 is a channel of FIG. An illustration of the connection of the source decoders 40a to 40d which are multi-connected to the decoder 30 is shown. The satellite broadcasting reception system for public hearing according to an embodiment of the present invention includes a satellite receiver antenna 10, an LNB 12, a distributor 14, and one channel decoder 30 for receiving satellite signals from one repeater. And a multi-channel decoder 100a composed of five source decoders 40a to 40e and a mixer 20. As shown in FIG. 2, the channel decoder 30 includes a tuner & AFE 32 that selects one repeater from a 1 GHz signal and converts it into a baseband signal, and a QPSK demodulator 34 that performs QPSK demodulation; It consists of a Forward Error Correction (FEC) 36 that corrects errors occurring during satellite signal transmission. On the other hand, the source decoders 40a to 40e connected to the output of the channel decoder 30 are T-MUX (Transfort-Multiplexer) 42 which extracts one video signal and a related signal from the output of the channel decoder 30, respectively. And an A / V (Audio / Video) decoder 44 for decoding and reconstructing the video and audio signals, respectively, and the NTSC encoder 46 for converting and outputting the video and audio signals, respectively. The outputs of the source decoders 40a to 40e are further synthesized into one signal by the mixer 20 and output as TV signals of respective homes.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 3 showing the detailed configuration of the channel decoder 30 and FIG. 4 showing an example of connection of the source decoders 40a to 40d connected to the channel decoder 30. The operation of the multi-channel decoder according to the following description.

After receiving a broadcast signal from the satellite through the antenna 10, the LNB 12 converts the signal into a signal of 1 GHz band. If necessary, the signal amplified by the amplifier is input to each of the multichannel decoders 100a, 100b, and 100c using the divider 14. As a signal input to each of the multi-channel decoders 100a, 100b, and 100c, one repeater signal is selected in tuner A to select a channel of the repeater and noise is removed from the surface acoustic wave filter SA. . The signal from which the noise has been removed by the SAW filter B is demodulated by the primary demodulator C to be a baseband signal of I and Q. The baseband signal is digitally quantized by an analog-to-digital converter (AD) D, demodulated by the QPSK demodulator 34, and the errors generated during transmission by the FEC 36 are corrected. On the other hand, the output of the channel decoder 30 is input to as many source decoders 40a to 40d as the number of image channels as shown in FIG. 4, and the T-MUX 42 of each of the source decoders 40a to 40d corresponds to the corresponding channel. After the signal of the video channel is selected, the A / V decoder 44 restores the audio signal and the video signal. The NTSC encoder 46 then converts and outputs the TV channel frequency to be transmitted, and the outputs of the respective source decoders 40a to 40d are mixed in the mixer 20 and transmitted to the TV.

As described above, according to the present invention, by connecting a plurality of source decoders to one channel decoder, all video signals broadcast to one repeater may be restored to one multichannel decoder and broadcasted at a TV channel frequency.

As described above, the present invention, unlike the conventional method of using a satellite broadcasting receiver for each image channel in a satellite broadcasting reception system for public hearing, implements a multichannel decoder by connecting a plurality of source decoders to a channel decoder, There is an advantage to construct a satellite broadcasting receiver system for public hearing, and if the channel decoder is doubled, it is possible to improve the reliability of the receiver system because the channel decoder can be used without changing the multi-channel decoder even if each part breaks down. There is also an advantage.

Claims (2)

(Correction) In the multi-channel decoder of the satellite broadcasting reception system for public hearing, A tuner which selects one repeater from a signal output from a low noise block-down converter (LNB) and converts it into a baseband signal; A QPSK demodulator for converting the baseband signal into a digital signal and outputting QPSK modulation; A channel decoder comprising FEC (Forward Error Correction) for correcting errors occurring when transmitting a broadcast signal, A transfer multiplexer for selecting and outputting one video signal and a related signal from an output of the channel decoder; An audio / video decoder configured to decode and output a video and audio signal among the output signals of the transfer multiplexer; And a plurality of source decoders comprising an encoder for converting and outputting the decoded video and audio signals into a television broadcast signal. (Correction) The method of claim 1, wherein the source decoders exist by the number of video channels Multi-channel decoders, each connected to an output of a null decoder.

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