KR20010044704A - Coupler for noise attenuation - Google Patents

Abstract

PURPOSE: A combining device for attenuating an upper direction noise is provided to attenuate a high frequency noise being created by compounding of a noise and influencing to an upward communication band by attenuating an area being introduced by a large quantity of noise out of frequency areas used in the upward communication. CONSTITUTION: A downward processing unit(10) processes a downward signal transmitted from a head end(30) and transmits the signal to a plurality of member terminals(40). An upward filter unit(21) attenuates a fixed frequency area by attenuating the fixed frequency area having a large quantity of noise at the upward signal transmitted and combined from the members terminal(40) for preventing a communication fault by an interference caused by a compounding of a noise in the head end(30). An upward amplifying unit(22) amplifies an upward signal attenuated in the fixed frequency area and converts into the signal as a proper form for a transmission. An upward processing unit(20) comprises the upward filter unit(21) and the upward amplifying unit(22).

Description

Coupler for noise attenuation

The present invention relates to an uplink noise damping combiner, and more particularly, to an uplink noise damping combiner that attenuates noise of a noisy uplink signal in a CATV network in which communication such as a broadcast transmission network is performed. .

Today, the Internet access service using the cable television network installed for the existing cable broadcasting is in the spotlight.

This is because not only the Internet access service but also various broadcasting programs can be simultaneously viewed, and even when a separate telephone line is not installed, the telephones can also be used simultaneously with the same wiring.

Although the speed will be even higher in the future, it still supports sufficient transmission speeds of 10Mbps downward and 2Mbps upward. Although the wooden structure has slowed down due to a bottleneck when a large number of users are gathered, it is currently providing satisfactory service.

The communication service using the cable television network is focused on receiving information provided by a service provider by asymmetrically allocating frequencies from 5 to 42 MHz in the uplink and 54 to 750 MHz in the downlink.

However, the upstream service is a problem in a communication service using a cable television network because a frequency noise corresponding to 5 to 42 MHz is generated around us and mixed into the signal of the upstream service. This is especially true in the low frequency range of 5 to 13 MHz, which causes service providers to allocate upstream signals to the upstream signal or lack bandwidth in uplink communications without using the 5 to 13 MHz frequency band. Is extended to a part of the downlink service frequency domain and allocated to an uplink signal.

Of course, this approach allows smoother uplink signal transmission, but the noise present at 5 to 13 MHz causes harmonic noise by intermodulation and intermodulation with each other when combining and combining at an aggregation point such as an amplifier or a combiner. It interferes with the higher frequency range, causing problems in uplink communication.

1 is a schematic diagram illustrating a process of generating and synthesizing a noise that is a problem in uplink communication in data transmission and reception using a broadcast transmission network of a dense residential facility and a business facility.

Referring to FIG. 1, noise generated by an electric motor, etc., in each terminal is mixed in an uplink signal and collected by a central amplifier or combiner. A signal in which 5 to 13 MHz noise is mixed is modulated to generate an upward 13 MHz or more signal. It can be seen that noise is also generated in the frequency domain used for communication.

The uplink communication signal generated by mixing the noise is transmitted to the head end through an optical cable, and since the method of decoding the uplink communication signal is difficult at the head end, it is difficult to perform smooth communication.

Figure 2 is a schematic diagram showing the source of the upward noise generated in the data transmission and reception using the broadcast transmission network of dense residential facilities and business facilities.

Referring to the drawings, it can be seen that the most generating noise is an electric motor inserted into a washing machine, a microwave oven, a cleaner, a computer, or the like. In addition, it can be seen that noise is generated by the oscillator, divider, and communication device inside the device.

Figure 3 is a schematic diagram showing the structure of the uplink noise generated in the data transmission and reception using the public network for dense residential facilities and business facilities.

Referring to Figure 3, it can be seen that most of the noise is concentrated around 0 to 10MHz. Therefore, the frequency of this area is not used for communication even though the part allocated to the area of uplink communication, but in the process of synthesizing several noises, harmonic components due to the modulation are generated in the frequency domain of 10MHz or more. It will interfere with the communication.

The present invention was created to improve the above problems, and attenuates a region in which a large amount of noise flows in a frequency region used in uplink communication, and is generated due to the synthesis of the noise to affect uplink communication bands. It is an object to provide an upward noise attenuating combiner that attenuates noise.

1 is a schematic diagram illustrating a process of generating and synthesizing a noise that is a problem in uplink communication in data transmission and reception using a cable television network of a dense residential facility and a business facility;

Figure 2 is a schematic diagram showing the source of the upstream noise generated in data transmission and reception using a cable television network of dense residential facilities and business facilities.

Figure 3 is a schematic diagram showing the structure of the up noise generated in the data transmission and reception using the cable television network of dense residential facilities and business facilities.

4 is a schematic diagram illustrating a process of transmitting an uplink signal in a building in which a broadcasting transmission network using an uplink noise attenuating combiner according to an exemplary embodiment of the present invention is transmitted.

5 is a structural diagram showing an uplink noise attenuating combiner according to a preferred embodiment of the present invention.

6 is a block diagram illustrating an uplink noise damping combiner in accordance with a preferred embodiment of the present invention.

7 is a block diagram illustrating an uplink noise damping combiner in accordance with another embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

10 ....... Down processing part 20 ....... Up processing part

21 ....... Upward Filter Section 22 ....... Upward Amplifier Section

30 ....... Head end 31 ....... Amplifier

Subscriber terminal 61, 67 ...

62 ....... First order high pass filter 63 ....... Down level regulator

64, 74 ... Directional coupler 65 ....... Down output

66 ....... 2nd order high pass filter 68 ....... 1st order bandpass filter

69 ....... Attenuator 72 '...... 2nd-order bandpass filter

75 ....... Upward output 70 ....... Primary amplifier

71 ....... Upward level regulator 73 ....... Secondary amplifier

76 ....... 3rd order bandpass filter

68b, 72, 72'b, 76a ... high pass filter

68a, 76b, 72'a ....... low pass filter

In order to achieve the above object, an uplink noise attenuating combiner includes: a downlink processor for processing downlink signals transmitted from a head end and transmitted to a plurality of subscriber stations; Attenuating the constant frequency region so as to prevent communication disturbance caused by interference due to the synthesis of the noise at the head end by attenuating a certain frequency region with noisy in the combined uplink signal transmitted from the plurality of subscriber stations And an upstream processor including an upstream filter unit configured to amplify an uplink signal attenuated by the predetermined frequency domain and suitable for transmission.

The uplink noise attenuating combiner according to the present invention having such a feature attenuates a frequency region in which a large amount of noise is mixed in an uplink signal by using an uplink filter, and then amplifies and transmits it to the head end by using an amplifier. There is an advantage that smooth communication is possible by suppressing harmonic noise generated by the synthesis of noise.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a schematic diagram illustrating a process of transmitting an uplink signal in a building in which a broadcasting transmission network using an uplink noise attenuating combiner according to an exemplary embodiment of the present invention is transmitted.

Referring to the drawings, the uplink signal in which noise is transmitted from a plurality of subscriber stations is combined in one or several uplink noise attenuating combiners per building, and then a predetermined area is attenuated and transmitted to the final combiner or amplifier. The final combiner or amplifier receiving the uplink signal attenuated by the predetermined frequency domain synthesizes and amplifies the signals from each copper. Since the noise attenuation processing is already performed in the same unit, the noise affecting the uplink communication due to the synthesis is Not generated.

The processed upward signal is transmitted to the head end via the optical cable.

The broadcast transmission network may be a cable television network, and the building in which the broadcast transmission network is constructed may be an apartment complex.

5 is a structural diagram illustrating an uplink noise damping combiner according to an embodiment of the present invention.

Referring to FIG. 5, the uplink noise attenuating combiner includes a downlink processor 10 for processing downlink signals transmitted from the head end 30 and being transmitted to the plurality of subscriber stations 40; By attenuating a certain noisy frequency region in the uplink signal transmitted and coupled from the plurality of subscriber stations 40, the head end 30 may prevent communication failure from occurring due to interference due to the synthesis of the noise. An upstream processor 20 having an uplink filter 21 for attenuating the predetermined frequency region and an uplink amplifier 22 for amplifying an uplink signal attenuated by the predetermined frequency region and being converted to be suitable for transmission. .

In more detail, the downlink processor 10 may receive a downlink signal of approximately 54 to 750 MHz transmitted from the head end 30 to remove noise such as white noise and simultaneously recognize a reception state from the outside. If necessary, the gain is adjusted so that accurate information can be transmitted to the subscriber station 40.

That is, the downlink processor 10 includes a downlink filter unit in which the noise of the downlink signal transmitted from the head end 30 is attenuated, and a downlink output unit indicating an input / output state of the downlink signal. You can also attach a gain regulator or a downlevel regulator.

On the other hand, the upstream processor 20 is a portion for processing the uplink signal of 5 to 42MHz transmitted from the subscriber terminal 40 to the head end 30, even if not used due to the problem of being exposed to severe noise. Nevertheless, when synthesized, the upstream filter unit 21 attenuates a frequency range of 5 to 13 MHz, which may cause noise in an upper frequency band due to intermodulation and intermodulation, and for transmission to the head end 30. The uplink signal is amplified by the uplink amplification unit 22. The upstream output unit for allowing the external signal to be recognized in and out of the upstream signal may be further included.

Here, since the downlink processing unit 10 and the upstream processing unit 20 do not have separate lines but communicate with each other by using only one line in different frequency domains, common terminals of both sides are used to secure safety from lightning. It is desirable to add a lightning protector to the.

In addition, the upstream filter unit 21 preferably attenuates 13 MHz from 5, which is a noisy frequency band, using a band pass filter.

The processed uplink signal is transmitted to the amplifier 31 in the head end 30. Since the noise which is a problem is already attenuated, smooth amplification is performed and smooth communication is possible.

Here, the amplifier 31 may not be the head end 30, but may be a bidirectional amplifier in a broadcast transmission network that is already installed. In the case of the pre-installed bidirectional amplifier, a down amplifier for television broadcasting is provided. There is no possibility of collision with the downstream processing portion of the uplink noise attenuating combiner according to the invention.

6 is a block diagram illustrating an uplink noise damping combiner according to a preferred embodiment of the present invention.

Referring to FIG. 6, the uplink noise attenuating combiner according to the present invention includes a downlink processor for processing a downlink signal as described above; An upstream filter unit attenuating the constant frequency region so as to attenuate the constant frequency region with a large amount of noise in an upstream signal to prevent a communication failure from occurring due to interference due to the synthesis of noise at the head end; It consists of an upstream processor having an uplink amplification unit that is amplified and amplified and amplified to be suitable for transmission.

In more detail, since the downlink processor processes a frequency of 54 to 750MHz, which is a high frequency portion allocated to downlink communication in an Internet service using a cable television network using a frequency of 5 to 750MHz, the head end side First, the first-order high pass filter 62 is positioned to receive a downlink signal and attenuate noise primarily. In order to compensate for the loss caused by the transmission line of the attenuated downlink signal and the self-processing, a downlevel level adjuster 63 is provided, and a second high pass that attenuates noise in the internal processing incorporated into the adjusted signal. The pass filter 66 was disposed.

In addition, it is preferable to use the directional coupler 64 at a predetermined position of the member to display the input / output state of the downlink signal on the downlink output unit 65 so that it can be recognized from the outside.

Here, the downward output unit 65 is preferably at least one of a cathode ray tube, a liquid crystal display, a light emitting diode, and a buzzer.

On the other hand, the upstream processor is a first-order band pass filter 68, the first signal is attenuated a predetermined frequency region by the upstream signal input, and the attenuator 69 is attenuated by the attenuated upstream signal as a whole, and converted to an appropriate amplification input level (69) And a first upstream amplifier 70 in which an uplink signal appropriately converted to the amplification is first amplified, an uplevel adjuster 71 correcting a distortion phenomenon of the uplink signal, and adjusting a level. When amplified, the second band pass filter 72, in which the amplified noise and the predetermined frequency region are attenuated together with the up signal, and the upward signal through the second band pass filter 72 are amplified again to a desired level of signal. A secondary amplifier 73 to be converted, an upstream output unit 75 for displaying an input / output of an upstream signal, a directional coupler 74 for transmitting a proper signal to the upstream output unit 75, and the secondary Upward Signal During Amplification And a third order bandpass filter 76 in which amplified noise and a predetermined frequency region are attenuated.

In more detail, the first band pass filter 68 is a member that attenuates a noisy portion primarily by receiving an uplink signal transmitted from a subscriber station, and internally passes a low pass filter 68a and a high pass. The filter 68b is sequentially passed through.

In addition, the attenuator 69 is a member for converting the upwardly noise-attenuated upward signal into a value suitable for the input of the amplifier.

In addition, the first upstream amplifier 70 is a member for amplifying the upstream signal to be suitable for transmission, and instead of using a large gain amplifier, the first upstream amplifier 70 and the second upstream amplifier 73 to be described later. This is to minimize the distortion of the signal generated when the signal is temporarily amplified.

In addition, as in the attenuator 69, the uplevel regulator 71 is a member for adjusting the output of the upstream signal to be suitable for the input of the amplifier, so that the distortion of the signal can also be improved. The uplevel adjuster 71 may be replaced by a gain adjuster.

The second band pass filter may be a band pass filter or a high pass filter 72, and the second band pass filter may be configured separately from the first band pass filter and the third order band pass to be described later. This is to filter out noise generated during the operation of the amplifier once again. If a band pass filter is used here, the order of the internal high pass filter and the low pass filter does not matter.

In this configuration, it is preferable that each band pass filter has a 4-pole structure, and when the 4-pole band filter is used, the band pass filter can attenuate 40 to 45 dB. By using three four-pole bandpass filters, it is possible to attenuate all the 100dB, the highest output of noise from the subscriber station.

In addition, the secondary amplifier 73 is a member that performs the same role as the primary amplifier described above.

In addition, the directional coupler 74 is a member that is used at a predetermined position to display the input / output state of the upstream signal on the upstream output unit 75 so as to be recognized from the outside.

Here, the upward output unit 75 may be at least one of a cathode ray tube, a liquid crystal display, a light emitting diode, and a buzzer.

In addition, the third-order band pass filter 76 is a member for finally attenuating noise, and specifically, the third-order band pass filter 76 includes a high pass filter 76a and a low pass filter 76b.

In addition, it is preferable to further include an inclination adjuster (not shown) for correcting a high frequency portion having a large loss compared to the low frequency when transmitting to a predetermined portion of the down processing unit and the upstream processing unit, the inclination adjuster is a high frequency portion due to the characteristics of the coaxial cable This is to compensate for the property that the loss increases with the transmission length. The amplification and transmission of the high frequency part in advance allows a member to receive a desired signal.

On the other hand, it is preferable that lightning protection devices 61 and 67 are installed at both ends of the downstream processing unit and the upstream processing unit in order to ensure safety from lightning.

On the other hand, the first band pass filter 68 is installed so that the low pass filter is located first on the uplink signal input side, and the third order band pass filter 76 is located first on the uplink signal output side. This is because the upstream and downstream use the same wiring and receive input by frequency domain.

7 is a block diagram illustrating an uplink noise damping combiner according to another embodiment of the present invention.

Referring to FIG. 7, the structure can be simplified by replacing the filters entering both ends with the duplex filters 80 and 81. FIG.

Also, in the upstream processor, a second pass filter 72 'consisting of a low pass filter 72' and a high pass filter 72'b is used to differ from the high pass filter 72 in the previous embodiment. However, this part can also be configured with a high pass filter only.

Other explanations are the same as described above, and will be omitted.

On the other hand, the present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention. For example, the level adjuster may be located at the output of the secondary amplifier and not after the primary amplifier. In this regard, the level adjuster may be changed to some extent except for the positions of the filter unit and the amplifier unit.

As described above, the uplink noise attenuating combiner according to the present invention attenuates a frequency region in which a large amount of noise is mixed in an uplink signal using an uplink filter, and then amplifies and transmits it to the head end using an amplifier. By suppressing the harmonic noise generated by the synthesis of the noise of the has the advantage that can be smooth communication.

In addition, since a separate signal amplification is not performed in the downlink processor, it is possible to connect to a pre-installed television broadcasting amplifier.

Claims (9)

In the combiner for attenuating the noise contained in the uplink signal located between the head end and the plurality of subscriber stations in the broadcast transmission network, A downlink processor which processes downlink signals transmitted from the head end and is transmitted to the plurality of subscriber stations; Attenuating the constant frequency region so as to prevent communication disturbance caused by interference due to the synthesis of the noise at the head end by attenuating a certain frequency region with noisy in the combined uplink signal transmitted from the plurality of subscriber stations And an upstream processor configured to include an uplink filter unit and an uplink amplifier configured to amplify and convert an uplink signal attenuated by the predetermined frequency domain to be suitable for transmission. The method of claim 1, And said broadcast transmission network is a cable television network. The method of claim 1, And the downstream processor and the upstream processor further include a lightning protector at an input terminal and an output terminal. The method of claim 1, The downlink processor includes a downlink filter unit in which noise of a downlink signal is attenuated; And a downward output unit for indicating an input / output state of the downward signal. The method of claim 1, The upstream processor includes an uplink filter that attenuates a predetermined frequency region including noise in an upstream signal; An up amplifying unit for amplifying the up signal for transmission to the head end; An upstream output unit that displays an input / output state of the upstream signal; And an uplink adjuster for more accurate output of the uplink signal. The method of claim 5, And the upstream filter unit comprises a bandpass filter. The method of claim 5, And said constant frequency range is from 5 to 13 MHz. The method of claim 1, The upstream processor includes a first-order band pass filter in which an uplink signal is input to firstly attenuate a predetermined frequency region; An attenuator in which the attenuated upstream signal is attenuated globally and converted to an appropriate amplification input level; A first upstream amplifier for firstly amplifying an uplink signal appropriately converted to the amplification; An uplevel adjuster for correcting distortion of the uplink signal and adjusting a level; A second-order bandpass filter in which the amplified noise and the predetermined frequency region are attenuated with the uplink signal during the first amplification; A second-order amplifier in which an uplink signal passing through the second-order bandpass filter is amplified again and converted into a signal having a desired level; An upstream output unit for displaying upstream and outgoing signals; A directional coupler for transmitting an appropriate signal to the upstream output unit; With an inclination adjuster to compensate for high frequency parts that have a large loss compared to low frequencies during transmission, And a third-order bandpass filter that attenuates the amplified noise and the predetermined frequency region with the uplink signal during the second amplification. The method of claim 8, The first band pass filter is installed such that a low pass filter is positioned first at the uplink signal input end, and the second pass band filter is installed such that a low pass filter is first located at the uplink signal output end. Noise Attenuator Combiner.