CN102710295B

CN102710295B - Repeater

Info

Publication number: CN102710295B
Application number: CN201210182266.3A
Authority: CN
Inventors: 刘明学; 蔡茂
Original assignee: CHENGDU VAD DIGITAL SYSTEMS TECHNOLOGY Co Ltd
Current assignee: Candice Sichuan Micro Control Technology Co Ltd
Priority date: 2012-06-05
Filing date: 2012-06-05
Publication date: 2014-08-06
Anticipated expiration: 2032-06-05
Also published as: CN102710295A

Abstract

The invention discloses a repeater which comprises a first interface, a first signal separator, a waveform processor, a second interface, a second signal processor, a controller and an electronic switch, wherein the first interface, the first signal separator and the waveform processor are connected with a first cable; the second interface, the second signal separator and the controller are connected with a second cable; the electronic switch is respectively connected with the second interface, the second signal separator and the controller; the first interface is used for acquiring a first mixing signal transmitted in the first cable; the first signal separator is used for separating a first SDI (Serial Digital Interface) signal from the first mixing signal; the waveform processor is used for recovering the separated first SDI signal into a standard SDI signal and transmitting the standard SDI signal to the second interface; the second interface is used for acquiring a second mixing signal transmitted in the second cable; the second signal separator is used for separating a first power signal from the second mixing signal; and the controller is used for controlling the electronic switch to be closed when the condition that a load meeting the preset condition is connected to the first interface is detected, and thus the transmission of the power signal and the SDI signal on one coaxial cable is realized and the use amount of the coaxial cable is reduced.

Description

Repeater

Technical Field

The present application relates to the field of signal transmission, and in particular, to a repeater.

Background

With the development of digitization and high-definition of security monitoring systems, a broadcast-level standard SDI (digital serial Interface) is introduced into the security application field. If, adopt the camera that has the high definition to gather the image in monitoring area, the image encapsulation that will gather sends to supervisory equipment in the SDI signal and shows, and the monitoring personnel of being convenient for look over.

Because the effective transmission distance of the SDI signal is limited, so, when the distance between the camera and the monitoring equipment exceeds the effective transmission distance of the SDI signal, in order to reach the predetermined transmission distance, one or more repeaters need to be adopted to perform relay transmission on the SDI signal, which needs to provide a power signal required by the repeater to work, and because the power signal and the SDI signal are two signals with opposite transmission directions, the power signal and the SDI signal are transmitted on independent coaxial cables respectively at present, so that the layout difficulty of the coaxial cables is increased, the usage amount of the coaxial cables is increased, and the operation cost is further increased.

Disclosure of Invention

The technical problem that this application will be solved provides a repeater to solve power signal and SDI signal and transmit respectively on independent coaxial cable, increaseed coaxial cable's the overall arrangement degree of difficulty, and increased coaxial cable's use amount, and then increased the problem of operation cost.

In order to solve the above problem, the present application discloses a repeater including:

the system comprises a first interface connected with a first cable, a first signal separator, a waveform processor, a second interface connected with a second cable, a second signal separator, a controller and an electronic switch, wherein the electronic switch is respectively connected with the second interface, the second signal separator and the controller; wherein,

the first interface is configured to obtain a first mixed signal transmitted in the first cable, where the first mixed signal includes a first SDI signal and a second power signal;

the first signal separator is configured to separate the first SDI signal from the first mixed signal;

the waveform processor is used for recovering the separated first SDI signal into a standard SDI signal and then sending the standard SDI signal to the second interface;

the second interface is configured to obtain a second mixed signal transmitted in the second cable, where the second mixed signal includes a second SDI signal and a first power signal;

the second signal separator is configured to separate the first power signal from the second mixed signal;

the controller is used for controlling the electronic switch to be closed when detecting that the first interface is connected with a load meeting a preset condition.

Preferably, in the above repeater, the first interface and the second interface are respectively provided with an arrester.

In the repeater, preferably, the waveform processor includes:

an equalizer for performing level amplification and waveform shaping on the separated first SDI signal;

and a clock recoverer for extracting an SDI clock signal from the first SDI signal subjected to the level amplification and the waveform shaping, and recovering the first SDI signal subjected to the level amplification and the waveform shaping into a standard SDI signal with a standard clock signal.

In the repeater, preferably, the load meeting the preset condition is a load in which a difference between an impedance value and a preset impedance value is within a preset range.

In the repeater, preferably, the second mixed signal further includes a first control signal;

correspondingly, the repeater further comprises:

a third signal separator connected to the second interface and separating the control signal;

and the modulator is respectively connected with the third signal separator and the first interface, modulates the frequency of the separated control signal to a preset value and then sends the frequency to the first interface.

A transmission system, comprising:

a repeater as described above;

an HD-SDI camera connected to the repeater through the first cable and transmitting an SDI signal;

the power supply is connected with the repeater through the second cable and provides a power signal required by the repeater;

controller connected with the repeater through the second cable and used for sending control signals

According to the scheme, the relay provided by the embodiment of the application separates the SDI signal from the mixed signal input by the first interface through the first signal separator, shapes the separated SDI signal and sends the shaped SDI signal to the second interface; the power signal is separated from the mixed signal input by the second interface through the second signal separator, when the first interface is detected to be connected with a load meeting the preset condition, the separated power signal is sent to the first interface through the closed electronic switch, the power signal and the SDI signal are transmitted on the same coaxial cable, the layout difficulty of the coaxial cable is reduced, the using amount of the coaxial cable is reduced, and the operation cost is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic structural diagram of a repeater provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of another repeater provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a fourth signal splitter according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Example one

Referring to fig. 1, a schematic structural diagram of a repeater provided in an embodiment of the present application is shown, including:

a first interface 11 connected with a first cable, a first signal separator 12, a waveform processor 13, a second interface 14 connected with a second cable, a second signal separator 15, a controller 16 and an electronic switch 17 respectively connected with the first interface, the second signal separator 15 and the controller 16; wherein,

the first interface 11 is configured to obtain a first mixed signal transmitted in the first cable, where the first mixed signal may include a first SDI signal and a second power signal; preferably, the first interface 11 may be an RJ45 interface

The first signal separator 12 is configured to separate the first SDI signal from the first mixed signal, specifically, since the power signal is a direct current signal and the SDI signal is a high frequency signal relative to the power signal, the first signal separator 12 may be a high pass filter, and the first SDI signal transmitted in the first cable is separated from the first mixed signal by the high pass filter;

the waveform processor 13 is configured to restore the separated first SDI signal to a standard SDI signal, send the standard SDI signal to the second interface 14, and send the standard SDI signal through a second cable connected to the second interface 14;

specifically, the waveform processor 13 may include: an equalizer 131 and a clock restorer 132;

the equalizer 131 is used to perform level amplification and waveform shaping on the separated first SDI signal.

Although the video signal is encoded into a digital data stream, the SDI signal is still analog in nature and still suffers from distortion such as attenuation and phase shift, and the signal is easily lost and phase shifted by a long cable, so that the signal is distorted, and therefore an additional equalizer 131 (which may be a cable equalizer) is added at the receiving end to compensate for the distortion. In cable transmission, the signal may generate distortion such as loss and phase shift due to the frequency response characteristic of the cable, the equalizer 131 may provide compensation for the distorted signal, and may also make an evaluation on the characteristics such as the equalization range and noise performance of the receiving end by adding a longer cable.

The clock recoverer 132 is configured to extract an SDI clock signal from the level-amplified and waveform-shaped first SDI signal, and to level-amplify and waveform-shape the same with a standard clock signal, and recover the SDI clock signal extracted into the standard SDI signal.

Since the equalizer cannot remove the jitter and noise inherent in the signal, in order not to accumulate the jitter of the entire signal chain, a clean SDI signal is regenerated using clock restorer 132, noting that clock restorer requires the equalizer to reconstruct the amplitude of the signal and open the eye before data is regenerated.

The second interface 14 is configured to obtain a second mixed signal transmitted in the second cable, where the second mixed signal may include a second SDI signal and a first power signal; the SDI signal in the second cable is an SDI signal obtained by shaping the separated first SDI signal by the waveform processor 13; preferably, the second interface 14 may also be an RJ45 interface

The second signal separator 15 is configured to separate the first power signal from the second mixed signal, specifically, since the power signal is a dc signal and the SDI signal is a high frequency signal relative to the power signal, the second signal separator 15 may be a low pass filter, and the first power signal is separated from the second mixed signal by the low pass filter.

The controller 16 is configured to control the electronic switch 17 to be turned on when detecting that the first interface is connected with a load meeting a preset condition;

specifically, the electronic switch 17 is in an on state in the initial state, and when the second signal separator 15 separates the first power signal, the controller 16 detects whether a legal device is connected to the first interface, that is, it is detected whether the first interface is connected with a load satisfying a preset condition, and in particular, the controller 16 may determine whether a legal device, preferably, when the controller 16 detects that the difference between the characteristic impedance value of the first interface 11 and a preset characteristic impedance value (the preset characteristic impedance value may be the characteristic impedance value of the repeater provided in the embodiment of the present application) is within a preset range, and considering that the first interface 11 is connected with legal equipment, controlling the electronic switch 17 to be closed, and sending the power signal to the first cable through the first interface 11 for transmission.

Preferably, for the convenience of outdoor use and protection against accidental damage such as lightning strikes, lightning protection designs, such as lightning arresters, are added at both the first interface 11 and the second interface 14.

According to the repeater provided by the embodiment of the application, the SDI signal is separated from the mixed signal input by the first interface through the first signal separator, and the separated SDI signal is sent to the second interface after being shaped; the power signal is separated from the mixed signal input by the second interface through the second signal separator, when the first interface is detected to be connected with a load meeting the preset condition, the separated power signal is sent to the first interface through the closed electronic switch, the power signal and the SDI signal are transmitted on the same coaxial cable, the layout difficulty of the coaxial cable is reduced, the using amount of the coaxial cable is reduced, and the operation cost is reduced.

Example two

Preferably, when the second mixed signal transmitted in the second cable further includes a control signal, another structure of the repeater provided in the embodiment of the present application is as shown in fig. 2, and includes:

a first interface 21 connected with a first cable, a third signal separator 22, a waveform processor 23, a second interface 24 connected with a second cable, a fourth signal separator 25, a controller 26, and an electronic switch 27, a fifth signal separator 28 and a modulator 29 respectively connected with the first interface, the fourth signal separator 25 and the controller 26;

the first interface 21 is configured to obtain a first mixed signal transmitted in the first cable, where the first mixed signal may include a first SDI signal, a second power signal, and a second control signal; preferably, the first interface 21 may be an RJ45 interface.

A third signal separator 22 is configured to separate the first SDI signal from the first mixed signal, preferably, the first signal separator 12 may be a high-pass filter, and specifically, may be a first dc blocking capacitor, where the first dc blocking capacitor only allows the first SDI signal or the second control signal to pass through, and does not allow the second power signal to pass through; the first signal separator may also be a high pass filter circuit.

The waveform processor 23 is configured to shape the separated first SDI signal and send the shaped first SDI signal to the second interface 24, and send the separated first SDI signal through a second cable connected to the second interface 24;

specifically, the waveform processor 23 may include: an equalizer 231 and a clock restorer 232;

the equalizer 231 is configured to perform level amplification and waveform shaping on the separated first SDI signal;

the clock recoverer 232 is configured to extract an SDI clock signal from the first SDI signal subjected to the level amplification and the waveform shaping, and to level-amplify and waveform-shape the first SDI signal with a standard clock signal, and recover the first SDI signal subjected to the SDI clock signal extraction into a standard SDI signal.

The second interface 24 is configured to obtain a second mixed signal transmitted in the second cable, where the second mixed signal may include a second SDI signal, a first power signal, and a first control signal; the SDI signal in the second cable is an SDI signal obtained by shaping the separated first SDI signal by the waveform processor 23; preferably, the second interface 24 may also be an RJ45 interface

A fourth signal separator 25 for separating the first power signal from the second mixed signal;

specifically, the schematic structural diagram of the fourth signal separator 25 is shown in fig. 3, and may include:

and a plurality of series connected inductors (L1, L2, L3) connected to the second interface 24, wherein each inductor has a resistor (L1 connected in parallel with R1, L2 connected in parallel with R2, and L3 connected in parallel with R3) connected in parallel with a capacitor C1 connected in series with the plurality of series connected inductors, and a common terminal of the plurality of series connected inductors and the capacitor is an output terminal of the first power signal.

The controller 26 is configured to control the electronic switch 27 to be closed when detecting that a load meeting a preset condition is connected to the first interface;

specifically, the initial state of the electronic switch 27 is an on state, and when the fourth signal splitter 25 splits the first power signal, the controller 26 detects whether a legal device is connected to the first interface, that is, whether the first interface is connected with a load satisfying a preset condition, in particular, the controller 26 may determine whether a legal device, preferably, when the controller 26 detects that the difference between the characteristic impedance value of the first interface 21 and a preset characteristic impedance value (the preset characteristic impedance value may be the characteristic impedance value of the repeater provided in the embodiment of the present application) is within a preset range, and considering that the first interface 21 is connected with legal equipment, controlling the electronic switch 27 to be closed, and sending the power signal to the first cable through the first interface 21 for transmission.

A fifth signal separator 28 for separating the control signal from the second mixed signal; the specific fifth signal separator 28 may include: the second DC blocking capacitor is connected with the second cable and used for filtering the power signal in the second mixed signal, and the RC low-pass filter is connected with the second DC blocking capacitor.

The modulator 29 is configured to modulate the frequency of the separated control signal to a preset value, and then send the modulated control signal to the first interface 21, where the control signal is transmitted through the first cable.

The present application also provides a transmission system, comprising:

a repeater as described above;

a power source connected to the repeater through the second cable, the power signal passing through the repeater;

and the controller is connected with the repeater through the second cable and used for sending a control signal for controlling the work of the HD-SDI camera.

It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other. For the device-like embodiment, since it is basically similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

For convenience of description, the above devices are described as being divided into various units by function, and are described separately. Of course, the functionality of the units may be implemented in one or more software and/or hardware when implementing the present application.

From the above description of the embodiments, it is clear to those skilled in the art that the present application can be implemented by software plus necessary general hardware platform. Based on such understanding, the technical solutions of the present application may be essentially or partially implemented in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method according to the embodiments or some parts of the embodiments of the present application.

The above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core ideas; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A repeater, comprising:

the controller is used for controlling the electronic switch to be closed when the first interface is detected to be connected with a load meeting a preset condition;

wherein the waveform processor comprises: an equalizer for performing level amplification and waveform shaping on the separated first SDI signal; and a clock recoverer for extracting an SDI clock signal from the first SDI signal subjected to the level amplification and the waveform shaping, and recovering the first SDI signal subjected to the level amplification and the waveform shaping into a standard SDI signal with a standard clock signal.

2. The repeater according to claim 1, wherein a lightning arrester is provided at each of the first and second interfaces.

3. The repeater according to claim 1, wherein the load satisfying the predetermined condition is a load having an impedance value within a predetermined range from a predetermined impedance value.

4. The repeater according to claim 1, wherein the second mixed signal further comprises a first control signal;

correspondingly, the repeater further comprises:

5. A transmission system, comprising:

the repeater of any one of claims 1-4;

and the controller is connected with the repeater through the second cable and sends a control signal.