JP2009021990A - Optical transmission cooperative receiving system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To arbitrarily set a cooperative receiving signal that can be output for each optical terminal device. <P>SOLUTION: A center device 2 transmits an optical signal modulated by a plurality of cooperative receiving signals in different frequency bands to the optical terminal device 10 via an optical fiber 8. The optical terminal device 10 demodulates the plurality of cooperative receiving signals from the optical signal. The center device 2 modulates an optical signal also, according to a control signal, indicating which cooperative receiving signal is to be output for each optical terminal device 10, and each optical terminal device 10 also demodulates the control signal from the optical signal and outputs a cooperative receiving signal, corresponding to the demodulated control signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a joint reception system, and more particularly to an optical transmission system.

  Conventionally, as an optical transmission joint reception system, for example, there is a system disclosed in Patent Document 1. In the technology disclosed in Patent Document 1, an optical signal is modulated by a terrestrial television broadcast signal of 70 MHz to 770 MHz and a satellite wave television broadcast signal of 1032 MHz to 2150 MHz in the center device, and each optical terminal device In each optical terminal device, the signal is demodulated into the original terrestrial television broadcast signal and the satellite wave television broadcast signal and supplied to the receiver. The receiver is installed with either a television receiver with a terrestrial reception function or a television receiver with both a terrestrial and satellite wave reception function. In the television receiver having the receiver, only the terrestrial wave is received, and in the television receiver having the reception function of both the terrestrial wave and the satellite wave, both the terrestrial wave and the satellite wave are received.

JP 2006-5842 A

  In this optical transmission joint reception system, it is possible to select reception of only terrestrial waves or reception of terrestrial and satellite waves depending on what reception function the television receiver used in each home has. ing. However, since many television receivers sold in recent years have terrestrial and satellite wave reception functions, this optical joint reception system does not require a satellite wave reception service. However, satellite waves can be received. In this case, the operator of the optical transmission joint reception system cannot set the service (including charge) in the terrestrial wave and the satellite wave for each terminal. For example, in a joint reception system using a coaxial cable, there are few systems that can transmit satellite waves as they are, and the frequency is converted to a band that can be transmitted and transmitted, so a set top box is installed in the terminal device of the joint reception system. Since it is connected and frequency-converted to the original satellite wave, the service of the satellite wave can be stopped by disabling the frequency conversion in the set-top box at that time. However, since the above system does not use a set-top box, it is not possible to receive a service with a fine transmission band in each terminal device.

  An object of the present invention is to provide an optical transmission joint reception system capable of arbitrarily setting a joint reception signal that can be output for each optical terminal device.

  An optical transmission joint reception system according to one embodiment of the present invention includes a center device, and the center device transmits an optical signal modulated with a plurality of joint reception signals in different frequency bands via an optical transmission line. The plurality of jointly received signals can be two types of signals such as the terrestrial wave and the satellite wave as described above, and the satellite wave can be further subdivided. In response to the optical signal from the optical transmission path, the plurality of joint reception signals are demodulated by the plurality of optical terminal devices, respectively. The center apparatus also modulates the optical signal with a control signal instructing which shared reception signal is output for each optical terminal apparatus. That is, the optical signal is modulated by a plurality of joint reception signals and control signals. The control signal has a frequency different from that of the plurality of joint reception signals. Each optical terminal apparatus also demodulates the control signal from the optical signal and outputs the joint reception signal corresponding to the demodulated control signal.

  In the optical transmission joint reception system configured as described above, only the desired joint reception signal can be output in each optical terminal device. Therefore, even if the receiver connected to the optical terminal apparatus can receive all the joint reception signals, only a specific joint reception signal can be supplied to the receiver.

  Each optical terminal apparatus is assigned a different address, and each control signal may include an address and information indicating a joint reception signal to be output. If comprised in this way, each optical terminal device which received the control signal from a center apparatus will output according to the information showing the joint reception signal to output included in the control signal with the same address as the address allocated to self Determine the joint reception signal.

  Furthermore, the optical terminal device may have an amplifying unit for each joint reception signal. In this case, the amplifying unit is controlled so as to output the joint reception signal from the amplifying unit corresponding to the supplied information representing the joint reception signal to be output. For example, operating power is supplied to the amplifying means, or the output signal of the amplifying means is supplied to the receiver via a signal blocking means provided on the output side of the amplifying means.

  Further, the information representing the joint reception signal to be output can represent a plurality of joint reception signals. Therefore, any combination of all the joint reception signals can be output, so that the joint reception signal according to the user's request can be supplied to the receiver.

  As described above, according to the present invention, it is possible to arbitrarily set a joint reception signal that can be output for each optical terminal device, and to output only the joint reception signal according to a user's request from the optical terminal device. Therefore, it is possible to receive any service in the transmission band for each terminal device.

  The optical transmission system according to the first embodiment of the present invention has a center device 2 as shown in FIG. The center device 2 is provided with a high frequency head end portion (RFHE portion) 4. The high frequency head end unit 4 outputs a joint reception signal, for example, a television broadcast signal received by an antenna (not shown). In addition to terrestrial television broadcast signals of 70 MHz to 770 MHz, television broadcast signals include satellite broadcast signals or satellite communication signals converted to intermediate frequency signals of 1 GHz band or higher (hereinafter referred to as satellite wave signals). Including. Alternatively, in addition to these, a self-broadcast signal produced by the operator of the joint reception system is also included in the joint reception signal. The independent broadcast signal uses a free frequency band with the television broadcast signal.

  These television broadcast signals are supplied to the optical transmitter 6 where the optical signals are modulated and transmitted to an optical transmission line, for example, the optical fiber 8. The optical fiber 8 is wired to each home in the transmission area of this optical transmission system.

  Each home is provided with an optical terminal device 10. These are connected to the optical fiber 8 and receive the optical signal described above. The optical terminal device 10 demodulates a television broadcast signal from the optical signal, and outputs the television broadcast signal to an output terminal 12 for a television receiver (not shown). The television receiver can receive a terrestrial television broadcast signal and a satellite wave signal. These optical terminal apparatuses 10 are assigned different addresses in advance.

  The center device 2 includes a control signal transmission unit 13 that generates a control signal. The control signal is directed to each optical terminal device 10. The address assigned to each optical terminal device 10 and the optical terminal device 10 output the terrestrial television broadcast signal and the satellite wave signal. A digital signal including instruction information indicating whether the signal is a terrestrial television broadcast signal only, a satellite wave signal only, or no signal received at all, for example, FSK Modulated. The frequency of the carrier wave of this control signal is different from the terrestrial television broadcast signal and the satellite wave signal. The control signal is transmitted to the high-frequency head end unit 4 and transmitted to the optical transmission unit 6 together with the terrestrial television broadcast signal and the satellite wave signal, which modulates the optical signal and is transmitted to each optical terminal device 10 via the optical fiber 8. Is transmitted.

  The optical terminal device 10 has a photoelectric conversion unit 14 as shown in FIG. The photoelectric conversion unit 14 demodulates a terrestrial television broadcast signal, a satellite wave signal, and a control signal from the received optical signal. The demodulated terrestrial television broadcast signal, satellite wave signal, and control signal are supplied to the demultiplexer 18 via the one branching unit 16, where the terrestrial television broadcast signal and satellite wave signal are separated. Waved. The terrestrial television broadcast signal is supplied to the terrestrial wave amplification unit 20, and the satellite wave signal is supplied to the satellite wave amplification unit 22.

  The terrestrial wave amplification unit 20 amplifies and outputs the supplied terrestrial television broadcast signal, and the satellite wave signal amplification unit 22 amplifies and outputs the supplied satellite wave signal. The terrestrial television broadcast signal amplified by the terrestrial wave amplification unit 20 and the satellite wave signal amplified by the satellite wave signal amplification unit 22 are synthesized by the synthesizer 24 and illustrated via the output terminal 26. Not supplied to television receivers.

  The terrestrial amplifying unit 20 amplifies the above-mentioned terrestrial television broadcast signal in a state where the energizing signal is supplied from the control means, for example, the control unit 28, and the satellite wave amplifying unit 22 is also attached from the control unit 28. The satellite wave signal mentioned above is amplified in a state where the force signal is supplied.

  A digital signal is supplied from the FSK demodulator 30 to the controller 28. This digital signal is obtained by demodulating the control signal of the terrestrial television broadcast signal, the satellite wave signal, and the control signal branched by the one branching unit 16 with the FSK demodulating unit 30. Information.

  The control unit 28 includes, for example, a CPU, and determines whether the address in the digital signal matches the address assigned to itself and installed in the address setting unit 32. If they do not match, the control unit 28 does not perform any processing, but if they match, the control unit 28 generates an energizing signal for the terrestrial amplification unit 20 and the satellite wave amplification unit 22 according to the command information. To do.

  For example, when the command information instructs to output both a terrestrial television broadcast signal and a satellite wave signal, an urging signal for both the terrestrial amplifier 20 and the satellite amplifier 22 is generated. To do. As a result, both the terrestrial television broadcast signal and the satellite wave signal are output from the optical terminal device 10 as shown in FIG. By this energizing signal, for example, operating power is supplied to the terrestrial wave amplifying unit 20 and the satellite wave amplifying unit 22, and these start operation.

  When the command information instructs to output only the terrestrial television broadcast signal, an energizing signal for only the terrestrial amplifier 20 is generated. As a result, only the terrestrial television broadcast signal is output from the optical terminal device 10 as shown in FIG.

  When the command information instructs to output only the satellite wave signal, an energizing signal for the satellite wave amplifier 22 is generated. As a result, only the satellite wave signal is output from the optical terminal device 10 as shown in FIG.

  When the command information indicates that both the terrestrial television broadcast signal and the satellite wave signal are not output, no energizing signal is generated. As a result, neither a terrestrial television broadcast signal nor a satellite wave signal is output as shown in FIG. Although not shown, the case where neither the terrestrial television broadcast signal nor the satellite wave signal is output is provided, but an emergency notification signal for notifying the occurrence of an earthquake or the like from the center device 2 to the optical terminal device 10. This is because there may be a user who desires to use the optical terminal device 10 only for receiving the emergency notification signal in the case of the specification transmitted to each optical terminal device.

  Since the signal output in this way can be made different for each optical terminal device 10 in accordance with an instruction from the center device 2, only the signal according to the desire of the user of each optical terminal device 10 is output. Or a state in which no signal is output at all according to the desire of the user. Accordingly, for example, satellite wave signals including paid broadcasting can be easily prevented from being output at homes that do not want to receive them, so that it is possible to provide a viewing service according to the reception request of each home. it can.

  An optical terminal device 10a used in the optical transmission system of the second embodiment of the present invention is shown in FIG. Since the center apparatus 2 and the optical fiber 8 are the same as those of the first embodiment, detailed description thereof is omitted.

  This optical terminal device 10 a also has a photoelectric conversion unit 14. The photoelectric conversion unit 14 demodulates a terrestrial television broadcast signal, a satellite wave signal, and a control signal from the received optical signal. The demodulated terrestrial television broadcast signal, satellite wave signal, and control signal are amplified by the amplification stage 40 and then supplied to a signal blocking means, for example, a level adjusting unit 42, where the level is adjusted. The level-adjusted terrestrial television broadcast signal, satellite wave signal, and control signal are supplied to the terrestrial amplifier 200 and satellite amplifier 220. As the level adjustment unit 42, for example, a variable attenuator using a PIN diode can be used.

  The terrestrial amplifying unit 200 includes a terrestrial television broadcast signal extraction means, for example, a low-pass filter 202, whereby the terrestrial television broadcast signal is extracted and amplified by the amplification stage 204, and then the level adjusting unit 42. The level is adjusted by the same level adjustment unit 206, amplified by the amplification stage 208, and supplied to the low-pass filter 242 similar to the low-pass filter 202 that functions as a part of the synthesizer 240. The level adjustment unit 206 can also use, for example, a variable attenuator using a PIN diode.

  The satellite wave amplifying unit 220 also has satellite broadcast wave extracting means, for example, a high-pass filter 222, whereby a satellite wave signal is extracted and amplified by the amplification stage 224, and then the level adjusting unit 226 similar to the level adjusting unit 42. , And is amplified by the amplification stage 228 and supplied to a high-pass filter 244 similar to the high-pass filter 222 that functions as part of the combiner 240. The level adjustment unit 226 can also use a variable attenuator using a PIN diode, for example.

  The outputs of the low-pass filter 242 and the high-pass filter 244 constituting the synthesizer 240 are combined and supplied to the output terminal 26 via the DC blocking capacitor 44.

  The terrestrial television broadcast signal, the satellite wave signal, and the control signal output from the photoelectric conversion unit 14 are supplied to the FSK demodulation unit 30. The FSK demodulator 30 demodulates a control signal including an address and instruction information as in the first embodiment, and supplies the demodulated signal to the controller 28.

  A DC operating voltage is supplied from the outside to the output terminal 26, supplied to the constant voltage circuit 48 through the high frequency blocking coil 46, and converted into a constant voltage, and the photoelectric conversion unit 14, the FSK demodulating unit 30, the control unit 28, These are supplied to the address setting unit 32 to operate them.

  The voltage of the constant voltage circuit 48 is supplied to the amplification stage 40, the level control unit 42, and the amplification stages 204 and 208 via the switch 50 that is controlled to be opened and closed by the control unit 28. Similarly, the voltage of the constant voltage circuit 48 is supplied to the amplification stage 40, the level control unit 42, and the amplification stages 224 and 228 via the switch 52 that is controlled to be opened and closed by the control unit 28.

  As in the first embodiment, the control unit 28 determines whether the demodulated address matches the address assigned to itself and installed in the address setting unit 32. If they do not match, the control unit 28 does not perform any new processing. If they do match, the control unit 28 controls the switches 50 and 52 according to the command information, and the level adjustment units 42 and 208. 226, voltage supply to the amplification stages 40, 204, 208, 224, and 228, and level control by the level adjusters 42, 208, and 228.

  As the command information, there is information that instructs to output both the terrestrial television broadcast signal and the satellite wave signal, as in the first embodiment. When this command information is demodulated, the control unit 28 closes both the open / close switches 50 and 52, and applies the voltage from the constant voltage circuit 48 to the amplification stage 40, the level adjustment unit 42, and the amplification stages 204, 208, 224 and 228. Supply and operate these. At the same time, a control signal for level adjustment is supplied from the control unit 28 to the level adjustment unit 42 so that the gain at the level adjustment unit 42 becomes appropriate according to the level of the optical signal, and the terrestrial amplification unit 200. The control signal is supplied to both the level adjusting unit 206 and the level adjusting unit 226 of the satellite wave amplifying unit 220 so as to have an appropriate level corresponding to the level of the optical signal. As a result, both the terrestrial television broadcast signal and the satellite wave signal are output from the optical terminal device 10a.

  When the command information instructs to output only the terrestrial television broadcast signal, the control unit 28 closes only the open / close switch 50, and the amplification stage 40, the level adjustment unit 42, the amplification stage 204, The voltage from the constant voltage circuit 48 is supplied to 208 to operate them. At the same time, a control signal for level adjustment is supplied from the control unit 28 to the level adjustment unit 42 so that the level at the level adjustment unit 42 becomes appropriate according to the level of the optical signal, and the terrestrial amplification unit 200. Similarly, the level adjustment unit 206 is also supplied with a control signal for level adjustment. At this time, the voltage from the constant voltage circuit 48 is not supplied to the amplification stages 224 and 228 and the level adjustment unit 226 of the satellite wave amplification unit 220, and these do not operate. As a result, only the terrestrial television broadcast signal is output from the optical terminal device 10a.

  When the command information instructs to output only the satellite wave signal, the control unit 28 closes only the open / close switch 52, and the constant voltage is applied to the amplification stage 40, the level adjustment unit 42, and the amplification stages 224 and 228. The voltage from the circuit 48 is supplied to operate them. At the same time, a control signal for level adjustment is supplied from the control unit 28 to the level adjustment unit 42 so that the level at the level adjustment unit 42 becomes appropriate according to the level of the optical signal, and the satellite wave amplification unit Similarly, the control signal for level adjustment is also supplied to the level adjustment unit 226 of 220. At this time, the voltage from the constant voltage circuit 48 is not supplied to the amplification stages 204 and 208 and the level adjustment unit 206 of the terrestrial amplification unit 200, and these do not operate. Thereby, only the satellite wave signal is output from the optical terminal device 10a.

  When the command information instructs not to output both the terrestrial television broadcast signal and the satellite wave signal, the control unit 28 opens both the open / close switches 50 and 52, and the amplification stage 40 and the level adjustment. The voltage from the constant voltage circuit 48 is not supplied to the unit 42 and the amplification stages 204, 208, 224, 228, and these are not operated. As a result, neither the terrestrial television broadcast signal nor the satellite wave signal is output from the optical terminal device 10a.

  In the first embodiment, the operation power is supplied to the terrestrial amplification unit 20 and the satellite wave amplification unit 22 when the energization signal is supplied. However, the present invention is not limited to this. For example, Operating power is always supplied to the terrestrial amplifier 20 and the satellite amplifier 22, and an open / close switch is provided between the output side of the terrestrial amplifier 20 and the satellite amplifier 22 and the combiner 24, respectively. A corresponding opening / closing switch may be closed when an energizing signal is supplied. Alternatively, an open / close switch may be provided between the input side of the ground wave amplifying unit 20 and the satellite wave amplifying unit 22 and the duplexer 18, and the open / close switch may be closed when an energizing signal is supplied. it can.

  In both the above-described embodiments, the frequency band of whether or not to be output is a terrestrial television broadcast signal and a satellite wave signal, but is not limited to this. For example, a satellite wave signal is further converted to a satellite broadcast signal. Divided into two groups of satellite communication signals, output of only terrestrial television broadcast signals, output of only satellite broadcast signals, output of only satellite communication signals, output of terrestrial television broadcast signals and satellite broadcast signals, Output of terrestrial television broadcast signal and satellite communication signal, output of satellite broadcast signal and satellite communication signal, output of terrestrial television broadcast signal, satellite broadcast signal and satellite communication signal, no output at all it can. The terrestrial television signal can also be divided into a UHF band television broadcast signal and a VHF band television broadcast signal and output in various combinations as described above.

It is a block diagram of the optical transmission joint reception system of a 1st embodiment of the present invention. It is a block diagram of the optical terminal device of the optical transmission joint reception system of FIG. It is a figure which shows the combination of the terrestrial television signal and satellite wave signal which are output from the optical terminal device of FIG. It is a block diagram of the optical terminal device of the optical transmission joint reception system of 2nd Embodiment of this invention.

Explanation of symbols

2 Center equipment 8 Optical fiber (optical transmission line)
10 10a Optical terminal device

Claims (6)

A center device for transmitting an optical signal modulated by a plurality of joint received signals in different frequency bands via an optical transmission line;
A plurality of optical terminal devices that receive the optical signal from the optical transmission line and demodulate the plurality of joint reception signals;
The center apparatus also modulates the optical signal with a control signal instructing which of the common reception signals to output for each of the optical terminal apparatuses, and the control signal has a frequency different from that of each of the common reception signals. Is,
Each optical terminal apparatus also demodulates the control signal from the optical signal, and outputs the joint reception signal according to the demodulated control signal.   2. The optical transmission joint reception system according to claim 1, wherein each optical terminal apparatus is assigned a different address, and each control signal includes an address and information indicating the joint reception signal to be output. Receiving system.   3. The optical transmission joint reception system according to claim 2, wherein the optical terminal apparatus has an amplification unit for each joint reception signal, and outputs the joint reception signal from the amplification unit corresponding to the information representing the joint reception signal to be output. Optical transmission joint reception system.   4. The optical transmission joint reception system according to claim 3, wherein each amplification means is supplied with an operating voltage corresponding to information representing the joint reception signal to be output.   4. The optical transmission joint receiving system according to claim 3, wherein each of the amplifying units has a signal blocking unit, and the signal blocking unit other than the one corresponding to the information representing the joint reception signal to be output blocks the signal. Joint reception system.   3. The optical transmission joint reception system according to claim 2, wherein the information representing the joint reception signal to be output represents a plurality of joint reception signals.

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