KR100651690B1 - Apparatus and method for transmitting/receiving broadcasting signal of e-pon network - Google Patents

Abstract

An apparatus and a method for transmitting/receiving broadcasting signals in an E-PON(Ethernet-Passive Optical Network) system are provided to transmit plural signals having the same frequency band even without an additional E/O converter or optical coupler. At least one first broadcasting signal processor receives the first broadcasting signal of RF(Radio Frequency) type, and processes the first broadcasting signal. The second broadcasting signal processor receives the second broadcasting signal of RF type, wherein the second broadcasting signal has a frequency band, which is identical to a portion or the entire portion of a frequency band of the first broadcasting signal. The second broadcasting signal processor converts the second broadcasting signal into a signal having a frequency band, which is not identical to the first broadcasting signal. An RF coupler(330) couples the signals outputted from the first and second broadcasting processors. An optical signal converter(340) converts the output signal of the RF coupler(330) into an optical signal, and outputs the optical signal.

Description

Apparatus and method for transmitting / receiving broadcasting signal of E-PON network

1A and 1B are diagrams respectively illustrating an example of the related art, which is a block diagram of a broadcast signal transmitting apparatus and a receiving apparatus of an E-PON network.

2A and 2B are diagrams illustrating a broadcast signal transmitter and receiver of an E-PON network, respectively, according to another example of the prior art.

3A is a diagram illustrating a broadcast signal transmission apparatus of an E-PON network according to an embodiment of the present invention.

3B is a diagram illustrating a broadcast signal receiving apparatus of an E-PON network in accordance with an embodiment of the present invention.

4A is a flowchart of a method of transmitting a broadcast signal of an E-PON network according to an embodiment of the present invention.

4B is a flowchart illustrating processes of a broadcast signal receiving method of an E-PON network in accordance with an embodiment of the present invention.

The present invention relates to an apparatus and method for transmitting / receiving a broadcast signal of a fiber to the home (FTTH) Ethernet-Passive Optical Network (E-PON) network, and to an overlay video signal transmission method. A signal transmitting and receiving device and method are provided.

The overlay video signal transmission method is a method of transmitting broadcast signals having different wavelengths through an FTTH E-PON network. The FTTH E-PON network, on the other hand, is a network constructed using optical cables. Therefore, a broadcast signal in the form of a radio frequency (RF) signal must be converted into an optical signal to be transmitted through an FTTH E-PON network. That is, the broadcast signal is converted into an optical signal at the transmitting side and then transmitted through the FTTH E-PON network, and is converted back to an RF signal at the receiving side. In addition, in order to transmit a broadcast signal through an FTTH E-PON network, a function of converting an RF signal into an optical signal (E-O (Electric-to-Optical)) and an optical signal into an RF signal (O / E ( There is a need for a broadcast signal transmission apparatus and a broadcast signal reception apparatus having a function of converting optical-to-electricity).

However, in recent years, a plurality of broadcast signals are often provided to one subscriber at the same time. A plurality of broadcast signals provided to one subscriber are transmitted through the FTTH E-PON network after being combined into one signal by the transmitting apparatus. A signal in which a plurality of broadcast signals are combined is separated into original broadcast signals by a receiving device. Hereinafter, transmitting and receiving devices each including a coupling function and a separation function of broadcast signals will be described with reference to the accompanying drawings.

Conventionally, the transmission apparatuses shown in FIGS. 1A, 1B, 2A, and 2B are used for transmitting broadcast signals in an FTTH E-PON network.

1A and 1B are diagrams illustrating an example of the related art, which is a block diagram of a broadcast signal transmitting apparatus and a receiving apparatus of an FTTH E-PON network.

의 파장을 가지는 광신호로 변환하여 출력한다. 한편, 도 1b에 도시된 수신 장치는, 적어도 하나의 방송신호를 포함하는 광신호를 수신하고, 수신한 광신호를 방송신호로 분리해 내어 출력한다.The transmitter shown in FIG. 1A performs RF combining of a satellite broadcast signal and a CATV (Cable Television) broadcast signal.

The light is converted into an optical signal having a wavelength and output. On the other hand, the receiver shown in Fig. 1B receives an optical signal including at least one broadcast signal, separates the received optical signal into a broadcast signal, and outputs it.

That is, FIGS. 1A and 1B illustrate an apparatus for transmitting and receiving a broadcast signal of an FTTH E-PON network that transmits a plurality of broadcast signals using an RF combining scheme. However, the RF coupling method has a problem in that it cannot be used for broadcast signals having the same frequency band. For example, an RF combining method may not be used to transmit a broadcast signal for a MATV (Master Television) and a CATV broadcast signal having the same frequency band.

In order to solve this problem, a light coupling method may be used. The optical coupling method converts a plurality of broadcast signals having the same frequency band into optical signals having different wavelengths and then optically combines them. Meanwhile, in the case of using the optical coupling scheme, broadcast signals having different frequency bands among the broadcast signals to be transmitted may be converted into one optical signal after being combined through RF coupling.

2A and 2B are diagrams illustrating another example of the related art, which is a block diagram of a broadcast signal transmitting apparatus and a receiving apparatus of an E-PON network using an optical coupling scheme.

의 파장을 가지는 광신호로 변환되고, CATV 방송신호가

의 파장을 가지는 광신호로 변환되는 경우를 도시하고 있다. 이들

파장의 광신호 및

파장의 광신호는 광결합되어 출력된다.The transmitter shown in FIG. 2A converts each MATV broadcast signal and CATV broadcast signal into an optical signal, and then optically couples and outputs the two optical signals. In this case, the satellite broadcast signal having a different frequency band from the MATV broadcast signal or the CATV broadcast signal may be RF-combined with the MATV broadcast signal or the CATV broadcast signal. Figure 2a shows that after the satellite broadcast signal and the MATV broadcast signal is RF coupled

Is converted into an optical signal having a wavelength of

The case where the signal is converted into an optical signal having a wavelength is shown. these

Optical signal of wavelength and

The optical signal of the wavelength is optically coupled and output.

The receiving apparatus illustrated in FIG. 2B separates the received optical signal into a plurality of optical signals, and then converts each of the separated optical signals into original broadcast signals.

However, an optical coupler should be used to optically couple the plurality of optical signals or to separate the optical signals. Also, the transmitting apparatus shown in FIG. 2A requires a plurality of E / O converters to convert each of the plurality of broadcast signals into an optical signal. The use of such optocouplers and E / O converters introduces a problem of increased cost. In other words, in order to transmit a broadcast signal in an FTTH E-PON network at a low cost, a broadcast signal transmission / reception apparatus that does not use an E / O converter and an optical coupler is required.

Accordingly, an object of the present invention is to provide an apparatus and method for transmitting and receiving broadcast signals in an FTTH E-PON network for transmitting broadcast signals through an overlay video signal transmission scheme.

Another object of the present invention is to provide an apparatus and method for transmitting and receiving broadcast signals in an FTTH E-PON network that can transmit a plurality of broadcast signals having the same frequency band using an RF combining scheme.

According to the present invention described below, in order to transmit a plurality of broadcast signals using the same frequency band using only the RF combining method, broadcast signals having the same use frequency band have different use frequency bands. Use the change method. Here, having the same use frequency band means that some or all of the use frequency bands coincide.

The apparatus for transmitting broadcast signals of an FTTH (Ethernet-Passive Optical Network) system according to an aspect of the present invention receives a first broadcast signal of RF (Radio Frequency) format, respectively, At least one first broadcast signal processor for performing a predetermined process on the first broadcast signal and outputting the second broadcast signal in RF format having a frequency band corresponding to a part or all of the frequency bands of the first broadcast signal. A second broadcast signal processor, a first broadcast signal processor, and a second broadcast signal processor to output the second broadcast signal by converting the second broadcast signal into a signal having a frequency band that does not match the first broadcast signal. The RF combiner may output an RF coupled unit and an optical signal converter configured to convert the signal output by the RF combiner into an optical signal and output the converted optical signal.

The first broadcast signal may be at least one of a satellite broadcast signal and a CATV (Cable Television) broadcast signal, and the second broadcast signal may be a master antenna television (MATV) broadcast signal.

The RF combiner may RF combine the signals using a filter.

In accordance with another aspect of the present invention, an apparatus for receiving broadcast signals in an FTTH E-PON network includes: an RF converter for converting a received optical signal into an RF signal including at least one broadcast signal, and each broadcast included in the RF signal. A broadcast signal separator for separating a signal, a converter for converting a frequency converted broadcast signal from the separated broadcast signal into an original frequency band, and a switch for selecting and outputting one broadcast signal among the separated broadcast signals; It may include.

The broadcast signal separator may separate each broadcast signal included in the RF signal using a filter.

The switch may select and output a broadcast signal corresponding to the user's selection.

The broadcast signal transmission method of the FTTH E-PON network according to another aspect of the present invention, the first broadcast signal of at least one RF type, and a frequency band that matches part or all of the frequency band of the first broadcast signal When the second broadcast signal having an RF format is input, converting the second broadcast signal so that frequency bands of the broadcast signals do not coincide, and combining the converted second broadcast signal and the first broadcast signal. And converting the combined signal into an optical signal and transmitting the optical signal.

The broadcast signals may be combined using a filter.

In accordance with another aspect of the present invention, a method for receiving a broadcast signal of an FTTH E-PON network includes: receiving an optical signal, converting the optical signal into an RF signal, and using a filter to filter broadcast signals included in the RF signal. The method may include separating the separated broadcast signals, converting a frequency converted broadcast signal among the separated broadcast signals into an original frequency band, and selecting and outputting one broadcast signal from the separated broadcast signals.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In the following, the present invention will be described taking the case of transmitting three broadcast signals of satellite broadcast signal, CATV broadcast signal and MATV broadcast signal as an example.

3A is a diagram illustrating a broadcast signal transmission apparatus of an FTTH E-PON network according to an embodiment of the present invention.

FIG. 3 shows a broadcast of an FTTH E-PON network which converts a used frequency band of a MATV broadcast signal from among a MATV broadcast signal and a CATV broadcast signal having the same use frequency band to another frequency, which does not coincide with a used frequency band of the CATV broadcast signal. A signal transmission device is shown. The MATV broadcast signal must be converted to a frequency different from the frequency used for the satellite broadcast signal. On the other hand, the example of changing the frequency of the MATV broadcast signal other than the CATV broadcast signal is only an example to help the understanding of the present invention. Alternatively, the frequency of the CATV broadcast signal may be converted.

As shown in FIG. 3, a broadcast signal transmitting apparatus (hereinafter, referred to as a "transmitting apparatus") of an FTTH E-PON network according to the present invention includes input broadcast signals, that is, a satellite broadcast signal, a MATV broadcast signal, and the like. Amplifying the EQ & AGC unit 300 (302) 304, the satellite broadcast signal and the CATV broadcast signal, which perform EQ (equalizing) and automatic gain control (AGC), etc., of the CATV broadcast signals, respectively. RF amplification unit 312, 314, RF conversio & amplification unit 320 for changing and amplifying the frequency of the MATV broadcast signal, RF combination for combining the satellite broadcast signal, CATV broadcast signal and the frequency-converted MATV broadcast signal And an E / O LD (Laser Diode) 340 for converting the RF-coupled signal into an optical signal 340. At this time, the MATV broadcasting signal of the RF conversion & amplification unit 320 is included. The frequency conversion may be implemented using an RF mixer, and the RF combiner 330 may broadcast signals in RF form. It can be implemented to include a filter for combining the.

Broadcast signals converted by the E / O LD 340 into optical signals having a single optical wavelength are referred to as broadcast signal receiving devices (hereinafter, referred to as "receiving devices") of the FTTH E-PON network according to the present invention through the FTTH E-PON network. Can be sent). A description of the signal transmission process through the FTTH E-PON network will be omitted. Hereinafter, a broadcast signal receiving apparatus of an FTTH E-PON network according to the present invention will be described with reference to FIG. 3B.

3B is a diagram illustrating a broadcast signal receiving apparatus of an FTTH E-PON network according to an embodiment of the present invention.

As shown in FIG. 3B, a broadcast signal receiving apparatus (hereinafter, referred to as a "receiving apparatus") of an FTTH E-PON network according to the present invention includes an O / E PD (which converts a received optical signal into an RF signal). 350, the broadcast signal separator 354 may separate the broadcast signals from the received optical signal. Here, the broadcast signal separator 354 may separate each broadcast signal using a filter. The broadcast signal separation unit 354 performs frequency conversion for returning to the original frequency band for the MATV broadcast signal, which is a signal frequency-converted by the transmitter, and then outputs the same. Frequency conversion may be performed by an RF mixer.

Meanwhile, the reception apparatus may further include a switch 356 for selecting and outputting only one broadcast signal from various broadcast signals output by the broadcast signal separator 354. The switch 356 selects and outputs a broadcast signal desired by the user in response to the user's input. Broadcast signals that are not selected by the switch, i.e., are not used, are terminated at the filter output stage to prevent signal leakage. By using the switch 356, the receiving device can allow the subscriber to select a desired broadcast while unifying the broadcast path provided to the user.

In addition, the receiving apparatus may further include an RF amplifier 352 (360), MGC (358) for amplifying the signals.

Hereinafter, a broadcast signal transmission / reception method of an FTTH E-PON network according to the present invention will be described with reference to the accompanying drawings. The following description of the present invention will be made through an embodiment of transmitting at least two broadcast signals including a first broadcast signal and a second broadcast signal having the same frequency band. The first broadcast signal and the second broadcast signal may be MATV broadcast signals or CATV broadcast signals having the same frequency band.

FIG. 4A is a flowchart of a broadcast signal transmission method of an FTTH E-PON network according to an embodiment of the present invention.

In operation 400 of FIG. 4A, the transmitting apparatus receives broadcast signals including at least a first broadcast signal and a second broadcast signal. In operation 402, the transmitting apparatus frequency-converts one broadcast signal of the first broadcast signal and the second broadcast signal having a frequency characteristic (for example, a frequency band used). In this case, the frequency after the frequency conversion must be different from the frequencies of other broadcast signals transmitted together with the original use frequencies of the first broadcast signal and the second broadcast signal. In operation 404, the transmitting apparatus RF-combines the frequency-converted broadcast signal and other broadcast signals. In operation 406, the transmitting apparatus converts the combined signal into an optical signal. In operation 408, the transmitting apparatus transmits the optical signal.

The transmitted optical signal is transmitted to the receiving device through the FTTH E-PON network.

4B is a flowchart of a broadcast signal reception method of an FTTH E-PON network according to an embodiment of the present invention.

The receiving device receives the optical signal in operation 450 of FIG. 4B. In step 452, the receiving device converts the received optical signal into an RF signal. In step 452, the receiving device separates and outputs each broadcast signal from the RF-converted signal. At this time, the receiving device performs frequency conversion to return the original frequency to the signal which has been frequency converted. In operation 456, the reception apparatus selects and outputs one broadcast signal corresponding to a user request from among the plurality of broadcast signals output.

As described above, in the present invention, when transmitting a plurality of broadcast signals through the FTTH E-PON network, when broadcast signals having the same use frequency bands are input, the frequency of any broadcast signal among the corresponding broadcast signals, It converts and outputs to another frequency which is not the same as the frequency of broadcast signals transmitted together. As a result, the present invention enables transmission of broadcast signals having the same use frequency band as each other only by RF combining.

On the other hand, the present invention has been described to be applied to the FTTH E-PON network. However, the description of the present invention by taking the specific case as an example is only for aiding the understanding of the present invention, and the present invention is not limited thereto. That is, the present invention may be applied to all E-PON networks using optical cables as well as FTTH. In addition, the present invention may be used in the same manner when not only two broadcast signals but also three or more broadcast signals having the same frequency band.

As described above, in the present invention, when a plurality of broadcast signals having the same frequency band are transmitted, frequency conversion is performed so that the frequency bands of the broadcast signals to be transmitted are not equal to each other, thereby transmitting by using one optical wavelength. . In this way, the present invention enables the transmission of a plurality of broadcast signals having the same frequency band without using a separate E / O converter or an optical coupler. Accordingly, when the present invention is applied, broadcast signals can be transmitted at a low cost.

Claims (9)

In the broadcast signal transmission apparatus of FTTH (Fiber To The Home) E-PON (Ethernet-Passive Optical Network) system, At least one first broadcast signal processor for receiving a first broadcast signal in RF (Radio Frequency) format and performing a predetermined process on the first broadcast signal; Receiving a second broadcast signal in RF format having a frequency band that matches part or all of the frequency band of the first broadcast signal, and a signal having a frequency band in which the second broadcast signal does not match the first broadcast signal. A second broadcast signal processor converting the signal to a second broadcast signal; An RF combiner for RF combining signals output by the first broadcast signal processor and the second broadcast signal processor; And And an optical signal converter for converting the signal output from the RF combiner into an optical signal and outputting the optical signal. The method of claim 1, The first broadcast signal is at least one of a satellite broadcast signal and a CATV (Cable Television) broadcast signal, The second broadcast signal is a broadcast signal transmission apparatus of the FTTH E-PON network which is a master antenna television (MATV) broadcast signal. The method of claim 1, The RF combining unit is a broadcast signal transmitting apparatus of the FTTH E-PON network for RF combining the signals using a filter. In the broadcast signal receiving apparatus of the FTTH E-PON network, An RF converter for converting the received optical signal into an RF signal including at least one broadcast signal; A broadcast signal separator for separating each broadcast signal included in the RF signal; A conversion unit for converting the broadcast signal, which is frequency-converted, from the separated broadcast signal into an original frequency band; And And a switch for selecting and outputting one broadcast signal from the separated broadcast signals. The method of claim 4, wherein And a broadcast signal separating unit for separating each broadcast signal included in the RF signal by using a filter. The method of claim 4, wherein And the switch selects and outputs a broadcast signal corresponding to a user's selection. In the broadcast signal transmission method of the FTTH E-PON network, When a first broadcast signal in at least one RF form and a second broadcast signal in RF format having a frequency band that matches a part or all of the frequency band of the first broadcast signal are input, the frequency bands of the broadcast signals are changed. Converting the second broadcast signal so that it does not match; Combining the converted second broadcast signal and the first broadcast signal; And And converting the combined signal into an optical signal and transmitting the optical signal. The method of claim 7, wherein The combination of the broadcast signal is a broadcast signal transmission method of the FTTH E-PON network using a filter. In the broadcast signal reception method of the FTTH E-PON network, Receiving an optical signal; Converting the optical signal into an RF signal; Separating broadcast signals included in the RF signal using a filter; Converting a frequency converted broadcast signal of the separated broadcast signals into an original frequency band; And The broadcast signal receiving method of the FTTH E-PON network comprising the step of selecting and outputting one broadcast signal of the separated broadcast signals.

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