KR100621331B1 - Optical Distribution System Having Optical Signal Distributor - Google Patents

Abstract

The present invention relates to a method of configuring an NMS in an optical dispersion system.

The present invention relates to an analog light distribution system having an optical signal splitter used for a satellite digital audio broadcasting (DAB) service and / or a satellite digital multimedia broadcasting (DMB) service, wherein the satellite is satellite-borne. Receives a Time Division Multiplexing (TDM) signal, modulates it into a Code Division Multiplexing (CDM) signal, converts and amplifies the CDM signal into an analog CDM signal, and then converts the analog CDM signal into an all-optical light to generate an analog CDM optical signal. A main donor transmitting through the optical path; An optical signal splitter which receives and branches the analog CDM optical signal transmitted from the main donor; And receiving and photoelectrically converting the analog CDM optical signal branched from the optical signal distributor to generate an RF signal and transmit the RF signal to one or more service receiving terminals located in an area under its control, and a network management system (NMS: Network Management System). It provides an analog light distribution system having an optical signal splitter comprising one or more remote (All) to convert the signal into an optical signal to transmit the optical signal to the main donor through the optical signal splitter.

According to the present invention, in constructing a light distribution system in a propagation shadow area such as a basement, a building interior, a tunnel, etc., an optical signal splitter is connected to one optical transceiver module without having a plurality of optical transceiver modules on the main donor side. In addition, by connecting multiple remotes to the optical signal distributor, it is possible to reduce facility costs, installation costs, and maintenance costs.

Optical dispersion system, optical signal splitter, forward transmission, reverse transmission, LD, PD

Description

Optical Distribution System Having Optical Signal Distributor

Figure 1a is a schematic block diagram showing a conventional analog light distribution system for In-Building (In-Building),

1B is a block diagram schematically illustrating a remote of a conventional digital light distribution system for in-building.

Figure 2a is a schematic block diagram showing a conventional digital light distribution system for in-building,

Figure 2b is a block diagram schematically showing a remote of a conventional digital light distribution system for in-building,

3 is a block diagram schematically showing an analog light distribution system having an optical signal splitter according to a preferred embodiment of the present invention;

4 is a block diagram schematically illustrating a digital light distribution system having an optical signal splitter according to a preferred embodiment of the present invention;

FIG. 5 is a block diagram schematically illustrating an optical transceiver module and a remote optical transceiver module of a main donor interconnected to an optical signal distributor according to a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100, 200, 300, 400: main donors 102, 202, 302, 402: low noise amplifier

104, 204, 304, 404: TDM / CDM converter 106, 206, 306, 406: Tuner

108, 208, 308, 408: TDM demultiplexer 110, 210, 310, 410: CDM modulator

112, 212, 234, 312, 412: DAC

Up Converter: 114, 214, 236, 314, 414

116, 148, 216, 238, 316, 416, 530: Amplifier

118, 150, 218, 240, 318, 418: band pass filter

120, 220, 242, 320, 420: control unit 122, 322: outgoing FSK modem

124, 324: FSK modem for reception

126, 222, 326, 422, 500: optical transceiver module

128, 224: optical transceiver module # 1 130, 226: optical transceiver module # N-1

132, 228: optical transceiver module #N 134, 230, 340, 436: remote

136, 232, 330, 426: Remote # 1 138, 234, 332, 428: Remote # 2

140, 236, 334, 430: Remote # N-1 142, 238, 336, 432: Remote #N

144, 240, 338, 434: Remote # N + 1 146, 232: Remote optical transceiver module

328, 424, 508: optical signal splitter 502: frequency matching section

504, 532: all-optical conversion part 506, 526, 540: WDM part

510, 528: photoelectric conversion unit 512: trans impedance amplifier

514: limiting amplifier 516: remote optical transceiver module # 1

518: Remote Optical Transceiver Module # 2 520: Remote Optical Transceiver Module # N-1

522: Remote Optical Transceiver Module #N 524: Remote Optical Transceiver Module # N + 1

534, 536, 542, 546, 548: LD drive unit

The present invention relates to a light dispersion system having an optical signal distributor. More specifically, the optical signal splitter is provided in the main donor of the optical distribution system used for the satellite digital audio broadcasting service and / or the satellite digital multimedia broadcasting service, thereby reducing the number of optical transceiver modules, and using the optical signal splitter to remotely control the satellites. The present invention relates to an optical dispersion system having an optical signal distributor for transmitting a digital audio broadcast signal and / or a satellite digital multimedia broadcast signal and transmitting an NMS signal to a main donor.

In general, in a mobile communication system, a mobile communication service area is divided into a plurality of cells by using a frequency reuse concept to expand coverage of a mobile communication network, and the mobile communication is located near the center of each cell. A base station (BS) is being installed to handle the service. Here, the radius of the cell is determined according to the traffic amount of the signal or data of the corresponding area. In other words, the cell radius is reduced in urban areas with high traffic volume, and the cell radius is increased in non-city areas with relatively low traffic, so that the traffic generated from each cell is handled by the wireless base station that is responsible for the corresponding mobile communication service. Do not exceed the.

Despite efforts to support better mobile communication services by appropriately adjusting the cell radius according to the frequency reuse concept and traffic volume, radio shadowing areas such as underground, inside buildings, tunnels, etc. are difficult to reach in urban areas. This exists. Installing a number of new wireless base stations to address the radio shadows in these radio shadow areas is not only economically inefficient due to facility costs, installation costs, and maintenance costs, but can also be undesirable in cell design. There will be.

As a solution to this, such a radio shadow area is provided with a mobile communication service using a light distribution system. The optical dispersion system solves the problem of radio wave shading by transmitting a communication channel allocated to a mortgage station to a radio wave shading area through an optical transmission method using a wireless optical repeater. In particular, the use of higher frequencies in 2.5G (2.5G), PCS (PCS), 3G (3G) CDMA2000 series systems, and WCDMA (Wideband CDMA) systems, compared to 2G (2G) mobile communication systems, results in loss of propagation paths. Due to this large size, small diffraction effect, and large building transmission loss, the cell radius is small, and a light scattering optical repeater is almost used.

In general, the optical dispersion type optical repeater includes an analog light distribution system and a digital light distribution system.

FIG. 1A is a block diagram schematically showing a conventional analog light distribution system for in-building, and FIG. 1B is a block diagram schematically showing a remote of a conventional digital light distribution system for in-building.

A conventional analog light distribution system for in-building includes a main donor 100 and a plurality of remotes 134 and the like.

Main-Donor (100) is a satellite digital audio broadcasting (DAB: Digital Audio Broadcasting, hereinafter referred to as 'DAB') and / or satellite digital multimedia broadcasting (DMB: Digital Multimedia Broadcasting, hereinafter referred to as 'DMB') Used in the system, it receives Ku-band satellite time division multiplexing (TDM) signals in the 12.124 to 12.239 GHz band from satellites and receives multiple remote 134 and / or satellites. Equipment for transmitting to a broadcast receiving terminal (not shown). Here, the main donor 100 converts the converted CDM signal into an optical signal and transmits it to the plurality of remotes 134 through the optical path.

The remote 134 transmits an RF signal generated by photoelectric conversion of an optical signal received through the optical path from the main donor 100 to a plurality of satellite broadcasting reception terminals through the S-band. The remote 134 is installed in the basement, the inside of the building, the tunnel, and the like to perform the function of eliminating the shading of radio waves from the satellite DAB service and / or the satellite DMB service.

The internal configuration of the main donor 134 and the remote 134 and the function of each component will be described below. Here, the internal configuration of the remote 134 and the function of each component will be described with reference to FIG. 1B.

First, the forward transmission in which the satellite DAB signal and / or the satellite DMB signal is transmitted from the main donor 100 to the remote 134 or the terminal for satellite broadcasting service is described. A low noise amplifier (LNA) (not shown) is a component that performs a function of amplifying a signal component and transmitting the signal component to the TDM / CDM converter 104 while reducing the noise component mixed with the satellite TDM signal received from the receiver. And the like. The TDM / CDM converter 104 includes a tuner 106, a TDM demultiplexing unit 108, a CDM modulator 110, and a digital to analog converter (DAC). 112). Here, the tuner 106 performs a function of selectively receiving only a radio wave tuned to a radio wave having a preset frequency in the satellite TDM signal received from the low noise amplifier 102.

The TDM demultiplexer 108 demultiplexes the multiplexed satellite TDM signal selected by the tuner 106, separates the satellite TDM signal for each channel, and transmits the satellite TDM signal to the CDM modulator 110. The CDM modulator 110 modulates each satellite signal received from the TDM demultiplexer 108 in a CDM manner to generate a CDM signal, and transmits the CDM signal to the DAC 112, and the DAC 112 transmits the received CDM signal. It is converted into an analog CDM signal and transmitted to the up-converter 114.

The up converter 114 adjusts and outputs the frequency band of the analog CDM signal received from the DAC 112 to the S-band in the 2.630 to 2.655 GHz band in order to transmit it to the remote 134. An amplifier 116 receives an up-adjusted analog CDM signal from the up converter 114, amplifies it to a certain level of intensity for transmission from an antenna, and uses a band pass filter (BPF) 118. To pass). The analog CDM signal transmitted to the band pass filter 118 is filtered by only a signal of a specific frequency band and is transmitted to the satellite broadcasting service terminal through an antenna.

On the other hand, the analog CDM signal to be transmitted to the remote 134 is adjusted to the S-band band in the up converter 114 and then transferred to the optical transceiver module 126, the optical transceiver module 126 receives The analog CDM signal is transmitted to the remote optical transceiver module 146 through the optical path. The analog CDM signal delivered to the remote optical transceiver module 146 is photoelectrically converted and then sent out to the air through the amplifier 148, the band pass filter 150, and the antenna. Of course, the RF signal photoelectrically converted by the remote optical transceiver module 146 is also transmitted to the control unit 154 through the reception frequency shift keying (FSK) modem 152. In addition, a control signal for controlling the remote 134 excluding the satellite DAB signal and / or the satellite DMB signal received through the antenna may be controlled by the control unit 154 through the transmission FSK modem 156. After the conversion to the analog transmission method is transmitted to the optical transceiver module 126.

A reverse transmission process for transmitting an NMS (NMS: NMS) signal from the remote 134 to the main donor 100 will be described later. The NMS signal refers to data generated by the controller 154 of the remote 134 and includes state information of the remote 134. Here, the status information refers to an operation state such as the output of each remote 134, the strength of a signal, and the like, whether it is in normal operation, or a failure information.

The controller 154 generates an NMS signal and transmits the generated NMS signal to the outgoing FSK modem 156. The authenticating FSK modem 156 converts the NMS signal into an analog form and transmits the NMS signal to the remote optical transceiver module 146. The remote optical transceiver module 146 transmits the received analog NMS signal to the optical transceiver module 126 of the main donor 100 through the optical path, and the optical transceiver module 126 receives the analog NMS signal generated by photoelectric conversion. After converting into a digital form of the NMS signal through the credit FSK modem 124 is transmitted to the control unit 120 of the main donor 100.

FIG. 2A is a block diagram schematically showing a conventional digital light distribution system for in-building, and FIG. 2B is a block diagram schematically showing a remote of a conventional digital light distribution system for in-building.

The digital light distribution system for an in-building also has a structure in which the main donor 200 and the plurality of remotes 230 transmit and receive data through wireless communication through an antenna and wired communication through an optical path, similarly to an analog light distribution system. Hereinafter, portions similar to those described in FIGS. 1A and 1B will be omitted, and only different contents will be described for the analog type.

In the case of the forward transmission in which the satellite DAB signal and / or the satellite DMB signal are transmitted from the main donor 200 to the remote 230 through the optical path, the CDM signal modulated by the CDM modulator 210 is transmitted by the optical transceiver module 222. All-optical conversion is transmitted to the remote optical transceiver module 232 through the optical path. Here, the CDM signal transmitted to the optical transceiver module 222 is a digital CDM signal without passing through the DAC 212 and the up converter 214. Accordingly, the remote 230 converts the digital CDM signal received and received photoelectrically through the remote optical transceiver module 232 into an analog CDM signal in the DAC 234, and the S-band frequency band signal in the up converter 236. The frequency band is adjusted upward, and then transmitted to the air through the amplifier 238, the band pass filter 240, and the antenna.

Meanwhile, in the reverse transmission, the control unit 242 of the remote 230 generates an NMS signal and transmits the NMS signal to the remote optical transceiver module 232. In this case, the NMS signal transmitted to the remote optical transceiver module 232 is different from that described in FIGS. 1A and 1B, and thus does not use an outgoing FSK modem because it uses a digital transmission scheme. The remote optical transceiver module 232 converts the received NMS signal to all-optical light and transmits it to the optical transceiver module 222 of the main donor 200 through the optical path.

The analog light dispersion system and the digital light dispersion system described above with reference to FIGS. 1A and 2A, respectively, have the following problems.

In constructing a conventional optical dispersion system, it is common for a plurality of remotes 134 and 230 to be connected one-to-one to the optical transceiver modules 126 and 222 of the main donors 100 and 200. In this configuration, the optical transceiver modules 126 and 222 of the main donors 100 and 200 should be provided as many as the remotes 134 and 230.

Each remote 134, 230 receives a satellite DAB signal and / or a satellite DMB signal from the main donors 100 and 200 through the optical path for forward transmission. On the contrary, in the reverse transmission, the main donors 100 and 200 transmit an NMS signal including an operational state such as the output of each of the remotes 134 and 230, the strength of the signal, the normal operation status, and the generated fault information. To send.

However, when the remotes 134 and 230 are interconnected one-to-one to the optical transceiver modules 126 and 222 of the main donors 100 and 200, as shown in FIGS. 1A and 2A, a plurality of remotes 134 are provided. Since the number of optical transceiver modules 126, 222 must be provided in the main donors 100, 200, the installation cost, the installation cost, and the maintenance cost are high, and the remotes 134, 230 are added in the future. In order to achieve this, there is a difficulty in expanding the optical transceiver modules 126 and 222 to the main donors 100 and 200.

In order to solve the above problems, the present invention, the optical transceiver module of the main donor is provided with an optical signal splitter for distributing the optical signal in a one-to-many connection, connecting a plurality of remote to the optical signal splitter, forward transmission and reverse of the optical signal An object of the present invention is to provide a light distribution system having an optical signal splitter that prevents scattering and interference occurring in transmission.

According to a first object of the present invention, there is provided an analog optical distribution system having an optical signal splitter used for a satellite digital audio broadcasting (DAB) service and / or a satellite digital multimedia broadcasting (DMB) service. And receiving a satellite time division multiplexing (TDM) signal from a satellite, modulating it into a code division multiplexing (CDM) signal, converting and amplifying the CDM signal into an analog CDM signal, and then converting the analog CDM signal into an all-optical analog. A main donor generating a CDM optical signal and transmitting the same through an optical path; An optical signal splitter for receiving and branching the analog CDM optical signal transmitted from the main donor; And receiving and photoelectrically converting the analog CDM optical signal branched from the optical signal distributor to generate an RF signal and transmit the RF signal to one or more service receiving terminals located in an area under its control, and a network management system (NMS: Network Management System). It provides an analog light distribution system having an optical signal splitter comprising one or more remote (All) to convert the signal into an optical signal to transmit the optical signal to the main donor through the optical signal splitter.

In addition, according to a second object of the present invention, in a digital light distribution system having an optical signal distributor for use in a satellite digital audio broadcasting service and / or a satellite digital multimedia broadcasting service, a CDM is received by receiving a satellite TDM signal from an satellite. A main donor which modulates the signal, converts and amplifies the CDM signal into a digital CDM signal, and converts the digital CDM signal into an all-optical light to generate a digital CDM optical signal and transmit it through an optical path; An optical signal splitter which receives and branches the digital CDM optical signal transmitted from the main donor; And receiving and photoelectrically converting the digital CDM optical signal branched from the optical signal splitter to generate an RF signal and to transmit the RF signal to one or more service receiving terminals located in an area under its control, and totally converts the network management system signal. It provides a digital light distribution system having an optical signal distributor comprising one or more remotes for transmitting to the main donor through an optical signal distributor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are designated as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

3 is a block diagram schematically illustrating an analog light distribution system having an optical signal splitter according to a preferred embodiment of the present invention.

An analog light distribution system with an optical signal splitter 328 according to a preferred embodiment of the present invention includes a main donor 300 and a plurality of remotes 340 similar to that shown in FIG. An optical signal splitter 328 is provided between the optical transceiver module 326 and the plurality of remotes 340.

Main-Donor 300 is similar to the main donor 100 of the analog light distribution system shown in FIG. 1A, and is a satellite digital audio broadcasting (DAB) and / or satellite. Used for Digital Multimedia Broadcasting (DMB) system, Ku-band satellite time division multiplexing (TDM) in the 12.124 to 12.239 GHz band transmitted from satellites. It is a device that receives a signal and transmits to a plurality of remote (340) and / or a terminal (not shown) for satellite broadcast reception. Here, the main donor 300 converts the converted analog CDM signal into an optical signal and transmits it to the plurality of remotes 340 through the optical path.

The optical transceiver module 326 of the main donor 300 connects to an optical signal distributor 328 that distributes analog optical signals one-to-many. That is, the analog CDM signal converted to the S-band in the up converter 314 is transmitted to the optical transceiver module 326, the optical transceiver module 326 transmits the analog CDM signal to the optical signal splitter 328 through the optical path. send. The optical signal splitter 328 transfers the received analog CDM signal to the remote optical transceiver module (not shown) through the optical path.

The remote 340 transmits an RF signal generated by photoelectric conversion of an optical signal received through the optical path from the main donor 300 to a plurality of satellite broadcasting reception terminals through the S-band. The remote 340 is installed in a radio shading area where radio waves are difficult to reach, such as underground, inside a building, and in a tunnel, and performs a function of eliminating radio shading in a satellite DAB service or a satellite DMB service. However, in the present invention, as shown in FIGS. 1A and 2A, the plurality of remotes 340 are different from the optical signal splitter 328 unlike the one-to-one connection with the optical transceiver module 126 of the conventional main donor 100. A plurality of remotes 340 are connected to each other through.

A forward transmission in which data is transmitted from the main donor 300 to the remote 340 or the terminal for satellite broadcasting service will be described later.

The low noise amplifier 302 reduces the noise component mixed with the satellite TDM signal received through the antenna, amplifies the signal component, and transmits the signal component to the TDM / CDM converter 304. In the TDM / CDM converter 304, the tuner 306 selectively receives only a radio wave tuned to a radio wave having a preset frequency in the satellite TDM signal received from the low noise amplifier 302, and the TDM demultiplexer 308. Demultiplexes the multiplexed satellite TDM signal selected by the tuner 306 to separate the satellite TDM signal for each channel, and transmits the satellite TDM signal to the CDM modulator 310. The CDM modulator 310 modulates each satellite signal received from the TDM demultiplexer 308 by the CDM method to generate a CDM signal, and delivers the CDM signal to the DAC 312. The DAC 312 transmits the received CDM signal. The signal is converted into an analog CDM signal and transmitted to an up-converter 314.

The up converter 314 adjusts and outputs the frequency band of the analog CDM signal received from the DAC 312 for the S-band in the 2.630 to 2.655 GHz band in order to send it to the remote 340. An amplifier (AMP) 316 receives an up-adjusted analog CDM signal from the up-converter 314 and amplifies it to a certain level of intensity for transmission from an antenna, thereby allowing a band pass filter (BPF) 318. To pass). The analog CDM signal transmitted to the band pass filter 318 is filtered only for signals of a specific frequency band and is transmitted to the terminal for satellite broadcasting service through an antenna. The analog CDM signal to be transmitted to the remote 340 is adjusted to the S-band band in the up converter 314 and then transmitted to the optical transceiver module 326. Up to now, the process of transmitting the analog CDM signal in the conventional analog optical dispersion system shown in FIG.

However, in the present invention, the optical transceiver module 326 transmits the received analog CDM signal to the optical signal splitter 328 through the optical path, and the optical signal splitter 328 is connected to the optical signal splitter 328. 340 transmits the analog CDM signal received through the optical path.

On the other hand, in the case of reverse transmission, the remote 340 of the analog light distribution system of the present invention includes an operation state such as the intensity of each output of the remote 340, the signal intensity, and the like, a normal operation state, and a failure information generated. The NMS signal including the information is generated and transmitted to the main donor 300. The reverse transmission process in which the NMS signal is transmitted from the remote 340 to the main donor 300 will be described in detail with reference to FIG. 5.

4 is a simplified block diagram of a digital light distribution system having an optical signal splitter according to a preferred embodiment of the present invention.

A digital light distribution system having an optical signal splitter 424 in accordance with a preferred embodiment of the present invention includes a main donor 200 and a plurality of remotes 230, similar to that shown in FIG. An optical signal splitter 424 is provided between the optical transceiver module 422 and the plurality of remotes 436. Hereinafter, parts similar to those described in FIG. 3 will be omitted, and only different contents will be described for the analog type.

In the case of the forward transmission in which the satellite DAB signal and / or the satellite DMB signal are transmitted from the main donor 400 to the remote 436 through the optical path, the digital CDM signal modulated by the CDM modulator 410 may be an optical transceiver module 422. All optical conversion is transmitted from to the remote optical transceiver module (not shown) through the optical path. Here, the CDM signal transmitted to the optical transceiver module 422 is a digital CDM signal that does not go through the DAC 412 and the up converter 414.

The digital CDM signal transmitted to the optical transceiver module 422 is transmitted to the optical signal distributor 424, which transmits the aforementioned digital CDM signal to a plurality of remotes 436 connected one-to-many.

Meanwhile, a reverse transmission process in which an NMS signal is transmitted from the remote 436 to the main donor 400 will be described in detail with reference to FIG. 5.

FIG. 5 is a block diagram schematically illustrating an optical transceiver module and a remote optical transceiver module of a main donor interconnected to an optical signal distributor according to a preferred embodiment of the present invention.

The optical transceiver module 500 interconnected to the optical signal splitter 508 according to the preferred embodiment of the present invention is a device for performing photoelectric conversion and all-optical conversion, and includes a frequency matching unit 502, an all-optical conversion unit 504, and a wavelength. The division multiplexer 506, the photoelectric converter 510, the transimpedance amplifier 512, the limiting amplifier 514, and the like are configured. In addition, the remote optical transceiver modules 516 to 524 also perform photoelectric conversion and all-optical conversion, and include a wavelength division multiplexing (WDM) unit 526 and a photoelectric conversion unit 528. ), An amplifier 530, a laser diode (LD) driver 534, an all-optical converter 532, and the like.

First, a forward transmission in which forward signals are transmitted from the optical transceiver module 500 to the remote optical transceiver modules 516 to 524 will be described. Here, the forward signal means an analog CDM signal or a digital CDM signal including a satellite DAB signal and / or a satellite DMB signal. In an analog optical dispersion system, an analog CDM signal is transmitted to an optical signal splitter through a light path and then transmitted to a remote. In a digital optical dispersion system, a digital CDM signal is transmitted through an optical fiber path. In the process to be described later, for the sake of convenience of description, it is referred to as a forward signal.

The frequency matching unit 502 frequency-matches a forward signal in a band of 2630 to 2.655 GHz. In the analog light distribution system, the forward signal refers to an analog CDM signal input from the upconverter of the main donor, and in the digital light distribution system, the forward signal refers to a digital CDM signal that does not go through the main converter's DAC and upconverter. That is, the frequency matching unit 502 performs an optical signal frequency matching for converting the analog CDM signal or the digital CDM signal into the analog CDM optical signal or the digital CDM optical signal by the all-optical conversion unit 504.

The all-optical converting unit 504 converts the analog CDM signal or the digital CDM signal into an analog CDM optical signal or a digital CDM optical signal of the same frequency band according to the frequency matching by the frequency matching unit 502 and transmits the same to the WDM unit 506. The device is composed of LD.

The WDM unit 506 carries a plurality of analog CDM optical signals or digital CDM optical signals received from the all-optical conversion unit 504 on one optical fiber and transmits them to the optical signal distributor 508. In this case, the WDM unit 506 operates as a wavelength division multiplexer that carries signals of several wavelengths in one optical fiber when transmitting signals, and transmits signals of several optical wavelengths in one optical fiber when receiving signals. It acts as a wavelength division demultiplexer, each branching.

The WDM unit 526 of the remote optical transceiver modules 516 to 524 branches and transmits a plurality of analog CDM optical signals or digital CDM optical signals received through one optical fiber to the photoelectric conversion unit 528, and the photoelectric conversion unit In operation 528, an analog CDM optical signal or a digital CDM optical signal is photoelectrically converted to generate an analog CDM signal or a digital CDM signal, which is an RF signal, and transmitted to the amplifier 530. Here, the photoelectric conversion unit 528 is configured to include a photo diode (PD).

The amplifier 530 performs an amplification function of the signal strength to compensate for the strength loss of the signal generated in the conversion process in the photoelectric conversion unit 528 of the remote optical transceiver modules 516 to 524.

Referring to FIGS. 3 and 4 together, reverse transmission in which reverse signals are transmitted from the remote optical transceiver modules 516 to 524 to the optical transceiver module 500 will be described below. In this case, the reverse signal refers to an NMS signal including state information including an operation state such as the output of each of the remotes 340 and 436, the signal intensity, and the like, whether normal operation is performed, and the generated failure information.

The reverse signal applied from the controller (not shown) of the remotes 340 and 436 is input to an LD driver (LD laser driver) 534, and the LD driver 534 adjusts the output power of the input reverse signal. The all-optical converter 532 is driven. That is, the LD driver 534 applies high power to the all-optical converting unit 532 at the high level of the reverse signal, and applies low power to the all-optical converting unit 532 at the low level. .

The all-optical converting unit 532 converts the reverse signal into an optical signal according to the output power applied from the LD driver 534 and transmits it to the WDM unit 526. The WDM unit 526 operates as a wavelength division demultiplexer. The optical signal is transmitted through one optical fiber to the WDM unit 506 of the optical transceiver module 500 through the optical signal distributor 508.

The WDM unit 506 of the optical transceiver module 500 operates as a wavelength division demultiplexer to branch the received optical signal into a plurality of optical signals and transmit the divided optical signals to the photoelectric conversion unit 510. The photoelectric conversion unit converts the optical signal received from the WDM unit 506 into an electrical signal and transfers it to the transimpedance amplifier 512.

A trans-impedance amplifier (TIA) 512 converts a photocurrent component of an electrical signal received from the photoelectric converter 510 into a voltage and transfers it to a limiting amplifier (LA) 514. The limiting amplifier 514 amplifies the voltage component output from the transimpedance amplifier 512 to a degree necessary for a clock operation and a data recovery operation.

In other words, the analog optical distribution system or digital optical distribution system used for the satellite DAB service and / or the satellite DMB service transmits the satellite DAB signal and / or the satellite DMB signal from the forward transmission to the terminal for the remote or satellite broadcasting service. In the reverse transmission, the NMS signal including the state information of the remotes 340 and 436 is transmitted to the main donor.

Next, operations of the remote optical transceiver modules 516 to 524 in the reverse transmission process of transmitting the NMS signal from the remotes 340 and 436 to the main donors 300 and 400 will be described. 3 and 4, the remote # 1 (330, 426), the remote # N-1 (334, 430), and the remote #N (336, 432) are serially connected to the optical signal distributors 328, 424. have. Remote # 2 (332, 428) is serially connected to remote # 1 (330, 426), and remote # N + 1 (338, 434) is serially connected to remote #N (336, 432).

Referring to FIG. 5, the remote # 1 330, 426 is serially connected to the optical signal splitter 508, 328, 424 in FIGS. 3 and 4, and has a dependent remote # 2 332, 428. Doing. In the above-described case, the LD driver 534 of the remote # 1 330, 426 is set to the off state. However, the LD driver 542 of the remote # N-1 334, 430 that is serially connected to the optical signal distributor 508 but does not include the dependent remote is set to the on state. The LD driver 536 of the remote # 2 332, 428 and the LD driver 546 of the remote # N + 1 338, 434 are set to the on state. Here, the on or off setting of the LD driver 536, 542, 546, 548 is controlled by a controller (not shown) of each remote 340, 436.

The remote 340 and 436 transmits the NMS signal backward using a TDM scheme, which is a static allocation scheme, or a polling scheme, which is a dynamic allocation scheme. In this case, the polling method is a method in which remote terminals are used to transmit data to a central host in a multipoint communication system, and all terminals wait until the host sends a data transmission signal.

With the above-described case in mind, it is assumed that the remote # 2 332 and 428 transmit the NMS signal to the main donors 300 and 400 using the TDM scheme. The main donors 300 and 400 generate a control signal including the identification code (ID) and transmission time information of the connected remote # 2 (332, 428), and then the remote # 2 (332, 428) through the optical path. Forward to. In addition, each transmission time set in the identification code is set differently by the TDM method.

The remote # 2 (332, 428) receiving the control signal through the optical path photoelectrically converts the control signal, and analyzes the identification code information included in the converted RF signal to extract information corresponding to its own identification code. The remote # 2 (332, 428) checks the transmission time information assigned to the extracted identification code and transmits the reverse signal, which is an NMS signal, to the main donors (300, 400) through the optical path.

That is, the reverse transmission process in which the remote # 2 (332, 428) transmits the NMS signal to the main donor (300, 400) in more detail as follows. The control unit (not shown) of the remote # 2 (332, 428) receiving the control signal from the main donor (300, 400) generates an NMS signal including the state information of the remote # 2 (332, 428) LD drive unit ( 536). The LD driver 536 controls the output power according to the NMS signal input from the controller to drive the all-optical converter 538. The driven all-optical converting unit 538 converts the NMS signal into all-optical light and transfers it to the WDM unit 540. The WDM unit 540 operates as a wavelength division demultiplexer to transmit an optical signal through a single optical fiber to the remote optical transceiver module #. 1 is transmitted to the WDM unit 526.

The WDM unit 526 of the remote optical transceiver module # 1 516 operates as a wavelength division demultiplexer to transmit the received optical signal to the photoelectric conversion unit 528, and the photoelectric conversion unit 528 transmits the optical signal to the RF signal. After converting to, the amplifier 530 amplifies the signal strength to compensate for the strength loss of the RF signal. The NMS signal amplified by the amplifier 530 is transmitted to the controller (not shown) of the remote # 1 330, 426.

When the control unit of the remote # 1 330, 426 detects the NMS signal converted into the optical signal flowing from the remote # 2 332, 428, the control unit of the remote # 1 330, 426 converts the LD driver 534 set to the off state to the on state. The controller of the remotes # 1 330 and 426 transfers the NMS signal to the optical signal distributor 508 and then converts the LD driver 534 to the off state. In the case of Remote # 1 (330, 426) and Remote #N (336, 432) serially connected to the optical signal splitter 508, the NMS signal is applied only when the LD driver 534, 548 is switched from the off state to the on state. Since it transmits and returns to the off state, when the NMS signals are simultaneously transmitted from the remotes 340 and 436 to the optical signal distributor 328, scattering and interference due to the same optical wavelength can be minimized.

The amplified NMS signal flows into the LD driver 534 and is converted into an optical signal through the all-optical converter 532 and then transferred to the WDM unit 526. The optical signal transmitted to the WDM unit 526 is transmitted to the WDM unit 506 of the main donors 300 and 400 through the optical signal distributor 508. The WDM unit 506 of the main donors 300 and 400 operates as a wavelength division demultiplexer to branch the received optical signal into a plurality of optical signals and transfer them to the photoelectric conversion unit 510, and the photoelectric conversion unit 510 The optical signal is converted into an RF signal and transmitted to the transimpedance amplifier 512. The transimpedance amplifier 512 amplifies the voltage to the extent necessary for the data recovery operation and transfers the NMS signal transmitted from the remote # 2 332 to the controllers 320 and 420 of the main donors 300 and 400.

Meanwhile, a process of transmitting control information using a polling method will be described below. The main donors 300 and 400 query whether there is control information to be transmitted to the remote # 2 332 and 428 according to a preset polling list. The remote # 2 (332, 428) receiving the query signal transmitted from the main donors (300, 400) checks the presence or absence of control information to be transmitted and transmits a response signal, that is, an NMS signal, to the main donors (300, 400).

In the polling method, the process of receiving an NMS signal from the remote # 2 (332, 428) to the main donor (300, 400) is performed by the remote # 2 (332, 428) from the remote # 2 (332, 428) to the main donor (300, 400). It is transmitted through the same process as the method of transmitting the NMS signal.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, in constructing a light distribution system in a propagation shadow area such as a basement, an interior of a building, a tunnel, etc., one optical transceiver module is not provided on the main donor side without a plurality of optical transceiver modules. By connecting optical signal distributors and connecting multiple remotes to optical signal distributors, the cost of installation, installation and maintenance can be reduced.

In addition, there is an advantage in minimizing the scattering and interference of the optical signal generated in the process of transmitting the NMS signal from the plurality of remotes connected to the optical signal distributor in the reverse transmission process to the main donor side.

Claims (24)

In an analog optical distribution system having an optical signal splitter used for a satellite digital audio broadcasting (DAB) service and / or a satellite digital multimedia broadcasting (DMB) service, Receives satellite TDM (Time Division Multiplexing) signals from satellites, modulates them into Code Division Multiplexing (CDM) signals, converts and amplifies the CDM signals into analog CDM signals, and then converts the analog CDM signals by all-optical analog CDM optical signals. A main donor generating a signal and transmitting the signal through an optical path; An optical signal splitter which receives and branches the analog CDM optical signal transmitted from the main donor; And Receives and photoelectrically converts the analog CDM optical signal branched from the optical signal distributor, generates an RF signal, and transmits the RF signal to one or more service receiving terminals located in an area under its control, and a network management system (NMS: Network Management System) At least one remote for converting the signal into an optical signal and transmitting it to the main donor through the optical signal distributor. Analog light distribution system having an optical signal distributor comprising a. The method of claim 1, The second remote group to the N-th remote group characterized in that the remote is connected to the optical signal splitter serially of the remote to the first remote group and the remote connection to the first remote group in a serial manner. An analog light distribution system having an optical signal splitter. The method of claim 2, And the forward transmission state of the first remote group is set to ON, and the reverse transmission state of the first remote group is set to OFF. The method of claim 2, And a forward transmission state of the remote, which is serially connected to the first remote group, is set to on and a reverse transmission state is also set to on. The method of claim 1, The network management system signal includes an optical signal splitter having an optical signal splitter, characterized in that it comprises the strength of each output of the remote, the strength of the signal, the operating state, whether the normal operation, the generated failure information. The method of claim 1, wherein the main donor A low noise amplifier (LNA) for receiving the satellite TDM signal and low noise amplifying the signal; A TDM / CDM converter configured to demultiplex the low noise amplified satellite TDM signal to modulate the CDM signal, and convert the CDM signal into the analog CDM signal; An up-converter for upwardly adjusting the analog CDM signal to a frequency band of an S-band; An amplifier for amplifying the analog CDM signal adjusted up in the up converter; An optical transceiver module for converting the up-adjusted analog CDM signal into the analog CDM optical signal and transmitting it to the optical signal distributor, and receiving the network management system signal transmitted from the optical signal distributor; A control unit for generating remote control information for controlling each of the remote and controlling the main donor; A transmission frequency shift keying (FSK) modem for receiving the remote control information and transmitting the received remote control information to the optical transceiver module in an analog transmission method; A reception frequency shift keying (FSK) modem for receiving a network management system signal transmitted from the remote, converting the signal to an analog transmission method, and transmitting the received signal to the controller; And A band pass filter (BPF) that filters only a specific frequency band signal of the analog CDM signal and transmits the signal to a satellite broadcasting service terminal through an antenna. Analog light distribution system having an optical signal distributor comprising a. The method of claim 1, wherein each said remote is A remote optical transceiver module for receiving the analog CDM optical signal transmitted through the optical signal splitter and performing photoelectric conversion, totally converting the network management system signal and transmitting the optical signal splitter to the main donor through the optical signal splitter; A reception FSK modem which demodulates and transmits the network management system signal, which is optically converted by the remote optical transceiver module, by a digital transmission method; A control unit configured to receive the network management system signal demodulated by the reception FSK modem in a digital transmission scheme and to transmit the network management system signal to the remote optical transceiver module and the main donor; An amplifier for amplifying the intensity of the photoelectrically converted signal from the remote optical transceiver module; And Band pass filter to pass the signal of a specific frequency band of the signal amplified by the amplifier to the RF antenna Analog light distribution system having an optical signal distributor comprising a. 8. The remote optical transceiver module of claim 7, wherein: A wavelength division multiplexing (WDM) unit for multiplexing the analog CDM optical signal or demultiplexing the all-optically converted network management system signal for transmitting to the optical signal distributor; A photoelectric conversion unit for generating an RF signal by photoelectric conversion of the optical signal received by the wavelength division multiplexer; An amplifier for amplifying the signal strength to compensate for the strength loss of the RF signal converted from the photoelectric conversion unit; A laser diode (LD) driver configured to receive the network management system signal generated from the controller and adjust power of an output signal; And An all-optical converting unit for all-optical converting the network management system signal whose output power is adjusted from the LD driver; Analog light distribution system having an optical signal distributor comprising a. The method according to claim 7 or 8, And the control unit controls an on or off state of the LD driving unit. The method of claim 8, And the photoelectric conversion unit includes at least one photo diode (PD), and the all-optical conversion unit includes at least one laser diode (LD). 7. The optical transceiver module of claim 6, A frequency matching unit for frequency matching the analog CDM signal in the 2.630 to 2.655 GhHz band flowing from the up-converter; An all-optical converting unit converting the frequency-matched analog CDM signal into an all-optical CDM optical signal; A wavelength division multiplexer which multiplexes the analog CDM optical signal and transmits the same to the optical signal distributor, and demultiplexes and receives the network management system signal that is totally converted from the optical signal distributor; A photoelectric conversion unit which photoelectrically converts the network management system signal into an RF signal; A trans-impedance amplifier (TIA) for converting a photocurrent component of the network management system signal received from the photoelectric conversion unit into a voltage; And Limiting Amplifer (LA) for amplifying a voltage for restoring data of the network management system signal output from the transimpedance amplifier Analog light distribution system having an optical signal distributor comprising a. The method of claim 11, And the photoelectric converter includes one or more photodiodes, and the all-optical converter includes one or more laser diodes. A digital light distribution system having an optical signal distributor for use in satellite digital audio broadcasting service and / or satellite digital multimedia broadcasting service, Receives satellite TDM signals from satellites, modulates them into CDM signals, converts and amplifies the CDM signals into digital CDM signals, and then converts the digital CDM signals to all-optical light to generate digital CDM optical signals and transmit them through the optical path. donor; An optical signal splitter which receives and branches the digital CDM optical signal transmitted from the main donor; And Receives and photoelectrically converts the digital CDM optical signal branched from the optical signal splitter to generate an RF signal and transmits the RF signal to one or more service receiving terminals located within an area under its control, and totally converts a network management system signal to the optical signal. One or more remotes via a signal splitter to the main donor Digital light distribution system having an optical signal distributor comprising a. The method of claim 13, The second remote group to the N-th remote group characterized in that the remote is connected to the optical signal splitter serially of the remote to the first remote group and the remote connection to the first remote group in a serial manner. Digital light distribution system having an optical signal splitter. The method according to claim 13 or 14, And a forward transmission state of the first remote group is set to on, and a reverse transmission state of the first remote group is set to off. The method according to claim 13 or 14, And a forward transmission state of the remote, which is serially connected to the first remote group, is set to on and a reverse transmission state is also set to on. The method of claim 13, The network management system signal is a digital light distribution system having an optical signal distributor, characterized in that it comprises the strength of each output of the remote, the signal strength, the operating state, whether the normal operation, the generated failure information. The method of claim 13, wherein the main donor A low noise amplifier configured to receive the satellite TDM signal and low noise amplify the signal; A TDM / CDM converter configured to demultiplex the low noise amplified satellite TDM signal to modulate the CDM signal and convert the CDM signal into the digital CDM signal; An up converter for adjusting the CDM signal up to a frequency band of the S-band; An amplifier for amplifying the digital CDM signal up-adjusted in the up converter; An optical transceiver module which converts the digital CDM signal converted by the TDM / CDM conversion unit into the optical CDM optical signal and transmits the digital CDM signal to the optical signal distributor, and receives the network management system signal transmitted by the optical signal distributor; A control unit for generating remote control information for controlling each of the remote and controlling the main donor; And A band pass filter for filtering only a specific frequency band signal of the digital CDM signal and transmitting the signal to a satellite broadcasting service terminal through an antenna. Digital light distribution system having an optical signal distributor comprising a. 14. The system of claim 13, wherein each of said remotes is A remote optical transceiver module for receiving the digital CDM optical signal transmitted through the optical signal splitter and performing photoelectric conversion, totally converting the network management system signal and transmitting the optical CD splitter to the main donor through the optical signal splitter; A control unit controlling the network management system signal to be transmitted to the remote optical transceiver module and the main donor; A digital to analog converter (DAC) for converting an RF signal photoelectrically converted from the remote optical transceiver module into an analog CDM signal; An up converter for adjusting the S-band in the 2.630 to 2.655 GHz band to amplify the analog CDM signal converted from the digital analog converter; An amplifier for amplifying the analog CDM signal adjusted up in the up converter; And Band-pass filter for band-passing the signal of the specific frequency band of the amplified analog CDM signal to the RF antenna Digital light distribution system having an optical signal distributor comprising a. 20. The system of claim 19, wherein the remote optical transceiver module is A wavelength division multiplexing unit for multiplexing the digital CDM optical signal or demultiplexing the all optically converted network management system signal for transmitting to the optical signal distributor; A photoelectric conversion unit for generating an RF signal by photoelectric conversion of the optical signal received by the wavelength division multiplexer; An amplifier for amplifying the signal strength to compensate for the strength loss of the RF signal converted from the photoelectric conversion unit; An LD driver which receives the network management system signal generated from the controller and adjusts power of an output signal; And An all-optical converting unit for all-optical converting the network management system signal whose output power is adjusted from the LD driver; Digital light distribution system having an optical signal distributor comprising a. The method of claim 20, And the controller controls an on or off state of the LD driver. The method of claim 20, And the photoelectric converter includes one or more photodiodes, and the all-optical converter includes one or more laser diodes. 19. The optical transceiver module of claim 18, wherein the optical transceiver module is A frequency matching unit for frequency matching the digital CDM signal flowing from the TDM / CDM conversion unit; An all-optical converting unit configured to all-optical convert the frequency-matched digital CDM signal into the digital CDM optical signal; A wavelength division multiplexing unit which multiplexes and transmits the digital CDM optical signal to the optical signal splitter and demultiplexes and receives the network management system signal which is totally converted from the optical signal splitter; A photoelectric conversion unit which photoelectrically converts the network management system signal into an RF signal; A transimpedance amplifier for converting a photocurrent component of the network management system signal received from the photoelectric conversion unit into a voltage; And Limiting amplifier for amplifying a voltage for data recovery of the network management system signal output from the transimpedance amplifier Digital light distribution system having an optical signal distributor comprising a. The method of claim 23, wherein And the photoelectric converter includes one or more photodiodes, and the all-optical converter includes one or more laser diodes.

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