CN2872771Y - Radio-frequency multi-path loop selecting circuit for two-way HFC network - Google Patents
Radio-frequency multi-path loop selecting circuit for two-way HFC network Download PDFInfo
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- CN2872771Y CN2872771Y CN 200620069833 CN200620069833U CN2872771Y CN 2872771 Y CN2872771 Y CN 2872771Y CN 200620069833 CN200620069833 CN 200620069833 CN 200620069833 U CN200620069833 U CN 200620069833U CN 2872771 Y CN2872771 Y CN 2872771Y
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Abstract
The utility model discloses a feedback radio frequency multi-channel selector circuit applied to bi-directional HFC network. The circuit is mainly used for remote selection of any one feedback channel in cable TV bi-directional optical fiber coaxial mixed transmission network, so as to remotely acquire feedback frequency spectrum of any one optical node. The circuit comprises a power supply module, an IP communication interface, a main control circuit, a gate circuit, a multi-channel analogue radio frequency gate circuit, and a signal mixing amplifying circuit. The inventive multi-channel selector circuit can be connected into multi-channel radio frequency feedback monitoring signal remote gate system of cable TV bi-directional HFC network to remotely select any one feedback channel at low cost, so as to acquire feedback frequency spectrum of any one optical node. Therefore, design and maintenance personnel can acquire desired real-time feedback signal frequency spectrum in central apparatus room to make analysis and monitoring.
Description
Technical field
The utility model relates to a kind of passback radio frequency multiplexer circuit that is applied to two-way hfc plant, this circuit is mainly used in the coaxial hybrid network transmission network of cable TV bidirectional optical fiber (being two-way HFC net) medium-long range and selects arbitrary return path, obtains the inverse frequency spectrum signal of arbitrary optical node and this signal is sent back the multi-route radio frequency remote back transmission signal monitoring system (this system is specifically designed to the spectrum monitoring of the two-way HFC transmission network of cable TV backward channel) that cable TV station's front end is monitored.
Background technology
Current society, cable TV network has been broken away from all the time the network condition as one-way transmission broadcast television signal a kind of like this function singleness, the construction of cable TV two-way network and transformation have solved cable TV network transmitted in both directions function, thereby make cable TV network that interactive service can be provided, promptly unidirectional radio and television transport service and two-way cable TV interactive service.
When two-way cable TV interactive service is described, we generally represent signal from interactive service front end (catv center) equipment to terminal (terminal use) equipment with downstream signal, represent signal from terminal equipment to the interactive service headend equipment with return path signal.Hereinafter we will represent sense between interactive service headend equipment and the terminal equipment with downstream signal and return path signal, and be used to transmit the passage of return path signal, and we are referred to as return path.
The construction and the transformation of two-way HFC net, make cable TV network transmit network development and become the two-way transmission network that to run interactive service by previous unidirectional broadcasting, but the frequency spectrum situation of return path can greatly influence the delivery quality of cable TV back transmission signal in the network, exceedingly odious return path noise spectrum signal even can interrupt interactive service, the return path signal that therefore obtains two-way HFC net in time, expediently has very important meaning for the construction and the maintenance of network.
Existing two-way hfc plant structure exists many problems in actual construction with when safeguarding bilateral network, such as the commissioning staff when the network of the different optical nodes of debugging or during the network of affiliated different branch centers, must constantly between debugging section and branch center, hurry back and forth, so that the front end commissioning device and the up-downgoing passage of the section of transferring are mated, thereby reduced the efficient of work by adjustment; And when two-way services were interrupted, we at first suspected the deterioration of network condition usually, so RF engineer must hurry to the branch center, judged the quality of the network operation to obtain inverse frequency spectrum, thereby had prolonged the time of failure judgement; Such as under existing service mode, the operation conditions that can't observe whole network in real time expediently provides reliable data for we safeguard and build bilateral network again.
At present, the method of obtaining return path signal mainly as shown in Figure 1, among Fig. 1, the return path signal of two-way HFC net inserts passback spectrum monitoring equipment in the branch center, one or more passback spectrum monitoring equipment is installed in each branch center just can reach monitoring (because radio frequency mouth limited amount that the inverse frequency spectrum monitoring equipment provides to all return paths, according to the quantity of the reverse channel transmission of each branch center, we must provide the enough equipment of quantity could satisfy all needs of monitoring).The major defect of this mode is:
1. costing an arm and a leg of a passback spectrum measurement equipment reaches hundreds of thousands unit usually, is very expensive for cable television operators that have a plurality of branch centers.
2. utilization rate of equipment and installations is low.Operator realizes the whole network monitoring if desired, then needs to purchase many passback spectrum measurement equipment, and the monitoring range of every equipment is very limited.
Summary of the invention
The purpose of this utility model is the deficiency that exists in the above-mentioned cable TV two-way network management maintenance in order to overcome, provide a kind of and can be issued to the arbitrary return path of Remote Selection in the relatively low situation of cost, obtain the passback spectrum signal of arbitrary optical node and this signal is sent back the return path signal frequency spectrum selection circuit that cable TV station's front end is monitored, promptly be applied to the passback radio frequency multiplexer circuit of two-way hfc plant.
The technical scheme that realizes the utility model purpose is such:
A kind of passback radio frequency multiplexer circuit that is applied to two-way hfc plant, this circuit is mainly used in the coaxial hybrid network transmission network of cable TV bidirectional optical fiber medium-long range and selects arbitrary return path, so that the inverse frequency spectrum of the arbitrary optical node of long-range acquisition is characterized in that: described circuit comprises:
Power module is used for providing power supply to the equipment each several part;
The IP communication interface, the one end is connected to public IP network, and the other end connects governor circuit, is used for the online IP packet of common data is converted to equipment identifiable information frame;
Governor circuit, its input links to each other with described IP communication interface, and output is connected to gating circuit;
Gating circuit, its input links to each other with described governor circuit, and output is connected to multi-channel analog radio frequency gating circuit, is used to carry out the control command that governor circuit sends;
Multi-channel analog radio frequency gating circuit, its input connects and links to each other with described gating circuit, and output is connected to signal mixing amplifying circuit, is used for according to described gating circuit control signal gating one road back transmission signal monitoring passage;
Signal mixing amplifying circuit, its input links to each other with described multi-channel analog radio frequency gating circuit, output is connected to two-way hfc plant light return path, is used for selected signal is carried out certain level adjustment, to satisfy the requirement of radio frequency light return path for input signal.
Described IP communication interface mainly is made up of IP/ serial conversion module and serial level converter two parts, the IP port of IP/ serial conversion module is connected with the external IP public data network, and the TX of serial data by IP/ serial conversion module is connected with T10 with the R1I of serial level converter respectively with the RX interface, the signal of reception and transmission ± 12V, R10 is connected with TX with the RX of described governor circuit with T1I, the signal of reception and transmission ± 5V.
As core devices, described CPU control chip is 8051 singlechip chips to described governor circuit by the CPU control chip, and its RX is connected with T1I with the R10 of TX pin with the serial level converter of communication interface circuit, receives and send serial data; P0.0～P0.7 data wire is connected with the D0～D7 mouth of described gating circuit latch, be used to send the gating director data, P2.0～P2.7 data wire is connected with the interface that latchs of latch in the described gating circuit respectively, is used with P0.0～P0.7 interface to reach the gating purpose.
The Q0 of described gating circuit latch～Q7 mouth is connected to the control interface of described multi-channel analog radio frequency gating circuit, and the gating instruction is delivered to described multi-channel analog radio frequency gating circuit by these oral instructions, so that control the state of each radio-frequency (RF) switch.
Described multi-channel analog radio frequency gating circuit is provided with three kinds of external interfaces, a kind of is the RFIN interface, the return path signal of the hfc plant in the system just inserts these interfaces, another kind is the RFOUT interface, export described signal mixing amplifying circuit by the selecteed return path signal of control signal to by this interface, also have a kind of S0 of being～S3 interface, this interface is connected with the Q0～Q7 of described gating circuit latch, receives the selection signal of sending here from described gating circuit.The core devices of multi-channel analog radio frequency gating circuit is the radio frequency multidiameter option switch, and the bandwidth of this radio frequency multidiameter option switch should be not less than 100MHz.
Described signal mixing amplifying circuit mixes access passback amplification module with the RFOUT mouth of described multi-channel analog radio frequency gating circuit, the passback amplification module is amplified to signal and satisfies radio frequency light return path signal input requirement, exports radio frequency light return path to from the RFOUT mouth then.
The passback radio frequency multiplexer circuit (hereinafter to be referred as multiplexer circuit) that is applied to two-way hfc plant of the present utility model is inserted the two-way hfc plant multi-route radio frequency remote back transmission signal monitoring system of cable TV, by the front-end control facilities that is arranged on cable TV station center (front end) send that poll, specific return path are chosen, shutoff and long-rangely the instruction instruction such as restart, cooperate ripe relatively reverse passback optical transport technology simultaneously, reached can be under lower-cost situation the arbitrary return path of Remote Selection, obtain the purpose of the passback frequency spectrum of arbitrary optical node.The communication channel that provides by public IP network between front-end control device and the multiplexer circuit of the present utility model instructs transmission, multiplexer circuit is reduced into its discernible serial data by the IP communication interface with the IP packet, CPU in the multiplexer circuit is converted to data discernible instruction and is sent to gating circuit, control multi-channel analog radio frequency gating circuit to reach the purpose of choosing one road back transmission signal monitoring and turn-offing other back transmission signal monitoring by gating circuit, and the result that will carry out sends front-end control facilities in the same way to, the return path signal frequency spectrum that makes design and attendant oneself need can obtain in real time in the platform central machine room is analyzed, monitoring, multiplexer circuit of the present utility model can guarantee to have only in single multiplexer circuit one road back transmission signal monitoring selected.
Description of drawings
Fig. 1 is present two-way hfc plant return path signal obtain manner theory diagram;
Fig. 2 is a multiplexer circuit theory diagram of the present utility model;
Fig. 3 is multiplexer circuit of the present utility model ± 5V power circuit principle figure;
Fig. 4 is multiplexer circuit of the present utility model+24V power circuit principle figure;
Fig. 5 is a multiplexer circuit IP communication interface circuit schematic diagram of the present utility model;
Fig. 6 is a multiplexer circuit governor circuit schematic diagram of the present utility model;
Fig. 7 is a multiplexer circuit gating circuit schematic diagram of the present utility model;
Fig. 8 is a multiplexer circuit multi-channel analog radio frequency gating circuit schematic diagram of the present utility model;
Fig. 9 is a multiplexer circuit signal mixing amplifying circuit schematic diagram of the present utility model;
Figure 10 is the complete circuit theory diagrams of multiplexer circuit of the present utility model.
Embodiment
For making your auditor and the public can further understand multiplexer circuit architectural feature of the present utility model and beneficial effect thereof, the spy reaches embodiment in conjunction with the accompanying drawings embodiment of the present utility model is described in detail as follows:
What multiplexer circuit mainly solved is the problem that can select one road signal output (OUT) from multichannel input signal (IN) artificially arbitrarily, in order to solve this key problem of the arbitrary return path of Remote Selection, cooperate ripe relatively reverse passback optical transport technology simultaneously, reach can the arbitrary optical node inverse frequency spectrum of long-range acquisition purpose.Fig. 2 is the multiplexer circuit theory diagram, it comprises: power module, IP communication interface, governor circuit, gating circuit, multi-channel analog radio frequency gating circuit, signal mixing amplifying circuit, wherein governor circuit is the core part of multiplexer circuit of the present utility model.
Wherein power module adopts the multiple power source circuit, the equipment of being respectively provides ± 5V and+the 24V DC power supply, its circuit theory is respectively as shown in Figure 3 and Figure 4.
One end of IP communication interface is connected to the system communication passage, the other end connects governor circuit, be used for the online IP packet of common data is converted to equipment identifiable information frame, Fig. 5 shows the circuit theory of this IP communication interface, and communication interface circuit mainly is made up of IP/ serial conversion module and serial level converter two parts:
A) IP/ serial conversion module mainly realizes the mutual conversion of data format between IP packet and the serial data, wherein the IP packet is connected with the external IP public data network by the IP port of modular converter, and serial data is connected with T10 with the R1I of serial level converter respectively with the RX interface by modular converter TX, and IP/ serial conversion module generally can be made of the protocol converter of special-purpose RS232-TCP/IP;
B) owing to the standard serial data voltage be ± 12V, and governor circuit receives and send voltage be ± 5V, so used the serial level converter to carry out the correspondent voltage conversion, the R1I of serial level converter is connected with IP/ serial conversion module with TI0, the signal of reception and transmission ± 12V, R10 is connected with TX with the RX of governor circuit with T1I, the signal of reception and transmission ± 5V, and we have used the MAX232 chip serial level converter.
The circuit theory of governor circuit as shown in Figure 6, it is connected to described IP communication interface and gating circuit respectively, by the CPU control chip as core devices, form control circuit, wherein, described CPU is programmed, and CPU carries out verification, analysis, judgement and reorganization to the information frame that is sended over by front-end control device, forms control command and exports gating circuit to; We have used 8051 comparatively common singlechip chips, and its RX is connected with T1I with the R10 of TX pin with the serial level converter of communication interface circuit, receive and send serial data; P0.0～P0.7 data wire is connected with the D0～D7 mouth of gating circuit latch, is used to send the gating director data, and P2.0～P2.7 data wire is connected with the interface that latchs of latch in the gating circuit respectively, is used with P0.0～P0.7 interface to reach the gating purpose.Before use, we must write corresponding software kit in the single-chip microcomputer, make single-chip microcomputer carry out verification, analysis, judgement and reorganization to the information frame that sends over by the PC front-end control device, form the instruction of control peripheral circuit gating module, by P0.0～0.7 and P2.0～2.7 data port gating circuit is delivered in instruction then.
The circuit theory of gating circuit as shown in Figure 7, it is connected to described governor circuit and multi-channel analog radio frequency gating circuit respectively, it mainly acts on is the instruction of carrying out governor circuit, and is that the particular level of special pin is sent to multi-channel analog radio frequency gating circuit with instruction transformation.We have designed 8 gating circuits in the multiplexer circuit of present embodiment, the D0 of all gating circuits～D7 mouth all is connected to the P0.0～P0.7 mouth of governor circuit, the mouth that latchs of 8 gating circuits then is connected with the P2.0～P2.7 pin of governor circuit respectively, we at first select No. one gating circuit by P2.0～P2.7 data port like this, and then send gating instruction by selecteed gating circuit to multi-channel analog radio frequency gating circuit by P0.0～P0.7 mouth; The Q0 of gating circuit～Q7 mouth is connected to the control interface of multi-channel analog radio frequency gating circuit, and the gating instruction is delivered to multi-channel analog radio frequency gating circuit by these oral instructions, so that control the state of each radio-frequency (RF) switch.This circuit cooperates with governor circuit and has only one the tunnel to be exported by gating in the return path that can guarantee all inputs, has satisfied the selection of system for the single channel return path signal.We have used the HC373 chip latch.
Fig. 8 is the circuit theory of multi-channel analog radio frequency gating circuit, and it is connected to described gating circuit and signal mixing amplifying circuit respectively, is used for according to described gating circuit control signal gating one road back transmission signal monitoring passage.Multi-channel analog radio frequency gating circuit is a vitals realizing the RF channel selecting, the radio frequency multidiameter option switch then is the core devices of analog radio frequency gating matrix circuit, it can guarantee under the situation that the input of multichannel RF signal is arranged, have and only have one road RF signal output, and the output signal of selecteed return path and input signal are in full accord.Not only need to consider the volume, voltage of device etc. when selecting radio frequency multidiameter option switch device, the more important thing is the bandwidth that needs to consider selector switch, in conjunction with the characteristics of HFC inverse frequency spectrum, the bandwidth that needs switching device at least is more than 100MHz.One has 8 multi-channel analog radio frequency gating circuits in the multiplexer circuit of present embodiment, each multi-channel analog radio frequency gating circuit has three kinds of external interfaces, a kind of is the RFIN interface, the return path signal of the hfc plant in the system just inserts these interfaces, another kind is the RFOUT interface, export signal mixing amplifying circuit by the selecteed return path signal of control signal to by this interface, also has a kind of S0 of being～S3 interface, we are called control interface, this interface is connected with the Q0～Q7 of gating circuit, receives the selection signal of sending here from gating circuit.Here we have selected video buffer switch MAX4221 chip as the radio frequency multidiameter option switch, the reason of selecting for use is that this chip belt wide region reaches 300MHz, satisfy the requirement of our 100MHz bandwidth range, flatness in frequency range has reached ± 0.5dB simultaneously, and decay also has only 0.5dB in the frequency range, can reach the requirement of system of the present invention.
Fig. 9 is the circuit theory of signal mixing amplifying circuit, it is connected to described multi-channel analog radio frequency gating circuit and described system radio frequency light return path respectively, be used for selected signal is carried out certain level adjustment, to satisfy of the requirement of radio frequency light return path for input signal.Signal mixing amplifying circuit mixes access passback amplification module with the RFOUT mouth of 8 multi-channel analog radio frequency gating circuits, the passback amplification module is amplified to signal and satisfies radio frequency light return path signal input requirement, exports radio frequency light return path to from the RFOUT mouth then.Here mixing module can use blender special-purpose in the two-way hfc plant of cable TV, and the passback amplification module can use passback amplification module special-purpose in the two-way hfc plant of cable TV.
Figure 10 is the complete circuit theory diagrams of multiplexer circuit, wherein 1 is the circuit theory of multiplexer circuit main control circuit part, the 2nd, multiplexer circuit IP communication interface partial circuit principle, the 3rd, multiplexer circuit gating circuit partial circuit principle, the 4th, multiplexer circuit multi-channel analog radio frequency gating circuit partial circuit principle, the 5th, the multiplexer circuit signal mixes the amplification circuits circuit theory, the 6th, multiplexer circuit ± 5V power circuit principle, the 7th, multiplexer circuit+24V power circuit principle.
Claims (7)
1. passback radio frequency multiplexer circuit that is applied to two-way hfc plant, this circuit is mainly used in the coaxial hybrid network transmission network of cable TV bidirectional optical fiber medium-long range and selects arbitrary return path, so that the inverse frequency spectrum of the arbitrary optical node of long-range acquisition is characterized in that: described circuit comprises:
Power module is used for providing power supply to the equipment each several part;
The IP communication interface, the one end is connected to public IP network, and the other end connects governor circuit, is used for the online IP packet of common data is converted to equipment identifiable information frame;
Governor circuit, its input links to each other with described IP communication interface, and output is connected to gating circuit;
Gating circuit, its input links to each other with described governor circuit, and output is connected to multi-channel analog radio frequency gating circuit, is used to carry out the control command that governor circuit sends;
Multi-channel analog radio frequency gating circuit, its input links to each other with described gating circuit, and output is connected to signal mixing amplifying circuit, is used for according to described gating circuit control signal gating one road back transmission signal monitoring passage;
Signal mixing amplifying circuit, its input links to each other with described multi-channel analog radio frequency gating circuit, output is connected to two-way hfc plant light return path, is used for selected signal is carried out certain level adjustment, to satisfy the requirement of radio frequency light return path for input signal.
2. multiplexer circuit according to claim 1, it is characterized in that: described IP communication interface mainly is made up of IP/ serial conversion module and serial level converter two parts, the IP port of IP/ serial conversion module is connected with the external IP public data network, and the TX of serial data by IP/ serial conversion module is connected with T10 with the R1I of serial level converter respectively with the RX interface, the signal of reception and transmission ± 12V, R10 is connected with TX with the RX of described governor circuit with T1I, the signal of reception and transmission ± 5V.
3. multiplexer circuit according to claim 1, it is characterized in that: described governor circuit by the CPU control chip as core devices, described CPU control chip is 8051 singlechip chips, its RX is connected with T1I with the R10 of TX pin with the serial level converter of communication interface circuit, receives and send serial data; P0.0～P0.7 data wire is connected with the D0～D7 mouth of described gating circuit latch, be used to send the gating director data, P2.0～P2.7 data wire is connected with the interface that latchs of latch in the described gating circuit respectively, is used with P0.0～P0.7 interface to reach the gating purpose.
4. multiplexer circuit according to claim 1, it is characterized in that: the Q0 of described gating circuit latch～Q7 mouth is connected to the control interface of described multi-channel analog radio frequency gating circuit, the gating instruction is delivered to described multi-channel analog radio frequency gating circuit by these oral instructions, so that control the state of each radio-frequency (RF) switch.
5. multiplexer circuit according to claim 1, it is characterized in that: described multi-channel analog radio frequency gating circuit is provided with three kinds of external interfaces, a kind of is the RFIN interface, the return path signal of the hfc plant in the system just inserts these interfaces, another kind is the RFOUT interface, export described signal mixing amplifying circuit by the selecteed return path signal of control signal to by this interface, also has a kind of S0 of being～S3 interface, this interface is connected with the Q0～Q7 of described gating circuit latch, receives the selection signal of sending here from described gating circuit.
6. multiplexer circuit according to claim 1 is characterized in that: described multi-channel analog radio frequency gating circuit is provided with the radio frequency multidiameter option switch, and the bandwidth of this radio frequency multidiameter option switch should be not less than 100MHz.
7. multiplexer circuit according to claim 1, it is characterized in that: described signal mixing amplifying circuit mixes access passback amplification module with the RFOUT mouth of described multi-channel analog radio frequency gating circuit, the passback amplification module is amplified to signal and satisfies radio frequency light return path signal input requirement, exports radio frequency light return path to from the RFOUT mouth then.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620069833 CN2872771Y (en) | 2006-03-02 | 2006-03-02 | Radio-frequency multi-path loop selecting circuit for two-way HFC network |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200620069833 CN2872771Y (en) | 2006-03-02 | 2006-03-02 | Radio-frequency multi-path loop selecting circuit for two-way HFC network |
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| CN2872771Y true CN2872771Y (en) | 2007-02-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200620069833 Expired - Fee Related CN2872771Y (en) | 2006-03-02 | 2006-03-02 | Radio-frequency multi-path loop selecting circuit for two-way HFC network |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101282443B (en) * | 2007-04-05 | 2010-09-29 | 青岛海信电器股份有限公司 | Automatic strobe circuit for multipath signal source interface |
-
2006
- 2006-03-02 CN CN 200620069833 patent/CN2872771Y/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101282443B (en) * | 2007-04-05 | 2010-09-29 | 青岛海信电器股份有限公司 | Automatic strobe circuit for multipath signal source interface |
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Granted publication date: 20070221 Termination date: 20110302 |