CN208782838U - Filtration system based on RDS and SCA broadcasting RF signals - Google Patents
Filtration system based on RDS and SCA broadcasting RF signals Download PDFInfo
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- CN208782838U CN208782838U CN201821610837.8U CN201821610837U CN208782838U CN 208782838 U CN208782838 U CN 208782838U CN 201821610837 U CN201821610837 U CN 201821610837U CN 208782838 U CN208782838 U CN 208782838U
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Abstract
The utility model discloses a kind of filtration systems based on RDS and SCA broadcasting RF signals, including main control chip；Main control chip is electrically connected with RDS demodulation module and SCA demodulation module respectively；The RDS demodulation module is electrically connected with RDS audio low-pass filter and 57K high-pass filter respectively；SCA demodulation module is electrically connected with 67K high-pass filter and SCA audio low-pass filter respectively.The problem of the utility model can efficiently solve RDS and SCA broadcasting RF signals in demodulation transmission process, the influence of the intersymbol interference vulnerable to the transmission of high fdrequency component, low frequency component and data, has stronger practicability and generalization.
Description
Technical field
The utility model belongs to the technical field of electronics and information, and in particular to one kind is based on RDS and SCA broadcasting RF signals
Filtration system.
Background technique
With the construction of national emergent broadcast system in recent years and perfect, the problem of frequency resource, is also increasingly closed
Note.Emergency broadcase system is in existing broadcast television technique system-based, and by being transformed, upgrading, formation can be received, be audited
Emergent broadcast information, emergent broadcast instruction are broadcast by production, the links such as scheduling controlling, news release generate emergent broadcast and disappear
Breath, emergent broadcast program and emergent broadcast signature, and message reception facility is sent to by the dedicated emergency sending device that broadcasts the message
Technological system.It generally comprises: emergent broadcast center and emergent broadcast transmission nerve of a covering two parts.This development project achievement can be with
It is widely used in domestic emergency broadcase system construction, village, emergent broadcast village rings construction, public address system is built, campus broadcasting is built
If waiting the fields such as public services, emergency service.
Emergency broadcase system is built at present, and various regions countryside broadcast village village's acoustic system is all made of different transmission modes and is covered
Lid, system is also different using equipment, has frequency modulation additional channel (SCA) broadcast, frequency-modulated analog broadcast etc., each businessman is in order to win
Market development is obtained, front end, terminal device insert secret agreement when transmitting broadcast singal.Sichuan Province is proposed system within 2015
As soon as emergency broadcase system construction scheme, office, province the old and new's system equipment compatibling problem, the problem of lacking of capital, frequency resource compared with
The problems such as good utilisation, is currently without specific solution.
Single RDS emergent broadcast equipment, SCA, which broadcast village, village and ring equipment, has been successfully applied to more ground Radio, Film and Television Administration, and various regions are wide
Electric office also expects that can purchase a can receive at present parses RDS/SCA broadcast singal but also transmitted with same broadcasting frequency in a hurry
The equipment of RDS/SCA broadcast singal has solved current terminal device and has freely replaced and repair, avoid system equipment repeated construction and
Waste.
Except this, existing RDS and SCA broadcasting RF signals are in demodulation transmission process, vulnerable to high fdrequency component, low frequency component
With the influence of the intersymbol interference of data transmission, the combining of transmission and later period to signal has large effect.
Utility model content
The purpose of this utility model is that being directed to above-mentioned deficiency in the prior art, provide a kind of based on RDS and SCA broadcast
The filtration system of RF signal, to solve RDS and SCA broadcasting RF signals in demodulation transmission process, vulnerable to high fdrequency component, low
The problem of influence of the intersymbol interference of frequency component and data transmission.
In order to achieve the above objectives, the technical scheme adopted by the utility model is that:
A kind of filtration system based on RDS and SCA broadcasting RF signals comprising main control chip；Main control chip respectively with RDS
Demodulation module and the electrical connection of SCA demodulation module；The RDS demodulation module is filtered with RDS audio low-pass filter and 57K high pass respectively
The electrical connection of wave device；SCA demodulation module is electrically connected with 67K high-pass filter and SCA audio low-pass filter respectively；
SCA audio low-pass filter includes 4 rank Qie Bixue of R6, R7, C6, C8, R8, R9, C9, C10, U1A, U1B composition
Husband's type low-pass filter；67K high-pass filter include C5, C20, R14, R15, C21, C22, R16, R17, C23, C24, R18,
6 rank Chebyshev type 67K high pass bandpass filters of R19, U3A, U3B, U4A composition；6 rank Chebyshev type 67K high pass pass filters
RLC band logical of the device successively with the 67K band logical amplifilter of R20, R21, C25, L1, U4B composition and R21, C25, L1 composition is filtered
The connection of wave device；
RDS audio low-pass filter includes DR4, DR5, DC4, DC6, DR6, DR7, DR8, DC7, DC8, IC1A, IC1B group
At 4 rank Chebyshev type low-pass filters；57K high-pass filter include GC3, GC4, GR6, GR7, GC5, GR8, GC6,
4 rank Chebyshev type 57K high pass bandpass filters of GR39, GC7, GR10, GR11, GC8, IC3B, IC4B composition；4 rank Qie Bixue
The input terminal of husband's type 57K high pass bandpass filter is connect with the 57K baseband signal amplifying circuit that GR3, GR4, GC2, IC3A are formed,
Output end is connect with GR12, GR13, GC10, IC4A baseband amplification circuit formed.
Preferably, the input terminal of RDS demodulation module and SCA demodulation module is connect with distributor.
Preferably, RDS demodulation module and SCA demodulation module include the TDA5767 being electrically connected by I2C with main control chip
Demodulation module.
Filtration system provided by the utility model based on RDS and SCA broadcasting RF signals, has the advantages that
The 4 rank Chebyshev type low-pass filters of the utility model can filter out the high frequency division of the 15K or more in SCA audio
Amount, 6 rank Chebyshev type 67K high pass bandpass filters can filter out in 67K baseband signal unnecessary low frequency in 20K following signals
The high fdrequency component of ingredient and low-frequency disturbance and 100K or more；Meanwhile 4 rank Chebyshev type low pass filtereds in 57K high-pass filter
Wave device can filter out the high fdrequency component of 15K or more in RDS audio, to improve audio signal-to-noise ratio；Its 57K high pass bandpass filter, can filter
Except in 57K baseband signal in 20K following signals unnecessary low-frequency component and low-frequency disturbance and 100K or more high fdrequency component.
Except this improves base band signal transmission signal-to-noise ratio, passes through signal by signal by baseband signal amplifying circuit and baseband amplification circuit
Amplification can efficiently solve RDS and SCA broadcast RF to improve 57K and 67K baseband level to subtract the intersymbol interference of small data transmission
Signal in demodulation transmission process, ask by the influence of the intersymbol interference vulnerable to the transmission of high fdrequency component, low frequency component and data
Topic.
Detailed description of the invention
Fig. 1 is the topological diagram of the filtration system based on RDS and SCA broadcasting RF signals.
Fig. 2 is that filtration system 67K base-band data signal and audio signal based on RDS and SCA broadcasting RF signals demodulate electricity
Lu Tu.
Fig. 3 is filtration system 67K base-band data signal and audio signal filtered electrical based on RDS and SCA broadcasting RF signals
Lu Tu.
Fig. 4 is that filtration system 57K base-band data signal and audio signal based on RDS and SCA broadcasting RF signals demodulate electricity
Lu Tu.
Fig. 5 is filtration system 57K base-band data signal and audio signal filtered electrical based on RDS and SCA broadcasting RF signals
Lu Tu.
Fig. 6 is filtration system 57K/67K baseband signal, audio signal switching circuit based on RDS and SCA broadcasting RF signals
Figure.
Fig. 7 is that the combining of filtration system 57K/67K baseband signal, audio signal based on RDS and SCA broadcasting RF signals is electric
Lu Tu.
Specific embodiment
Specific embodiment of the present utility model is described below, in order to facilitate understanding by those skilled in the art
The utility model, it should be apparent that the utility model is not limited to the range of specific embodiment, to the common skill of the art
For art personnel, if various change the attached claims limit and determine the utility model spirit and scope in,
These variations are it will be apparent that all are created using the utility model of the utility model design in the column of protection.
According to one embodiment of the application, with reference to Fig. 1, the filtering system based on RDS and SCA broadcasting RF signals of this programme
System, including main control chip, main control chip are electrically connected with RDS demodulation module and SCA demodulation module respectively, RDS demodulation module difference
Be electrically connected with RDS audio low-pass filter and 57K high-pass filter, SCA demodulation module respectively with 67K high-pass filter and SCA
Audio low-pass filter electrical connection.
Wherein, the input terminal of RDS demodulation module and SCA demodulation module is connect with distributor, and distributor is used for will simultaneously
The higher level's RDS/SCA broadcasting RF signals received, distribute to RDS demodulation module and SCA demodulation module, and complete the solution of signal
It adjusts.
Signal enters RDS demodulation module and SCA demodulation module, demodulates 57K base-band data signal and audio signal respectively
And 67K base-band data signal and audio signal.It is cut by main control chip, high-pass and low-pass filter, baseband switching module and audio
The cooperation of block is changed the mold, wherein output (when usually single frequency modulation broadcasting inputs, passes through the control of main control chip all the way for two-way audio choosing
Directly export；When RDS/SCA broadcast singal simultaneously input when, pass through main control chip control RDS broadcast audio output) and with parsing
57K, 67K base-band data signal of output are modulated to equipment output after combiner is combined by the way of direct frequency modulation
In broadcasting frequency, the twin subcarrier modulation technique that RDS/SCA is combined is realized, complete the forwarding capability of system broadcasts signal.
When equipment carries out spot broadcasting, believed by the data base call of main control chip, transmission, 57K, 67K base band data
Number control switching, audio frequency control switching after combiner is combined, be modulated to by the way of direct frequency modulation the equipment output it is wide
It broadcasts in frequency, realizes the twin subcarrier modulation technique that local RDS/SCA is combined, that completes local broadcast signal broadcasts function.
With reference to Fig. 2, distributor distributes RDS/SCA broadcasting RF signals, and signal enters SCA demodulation module and demodulated.Demodulation
Module TDA5767 and main control chip communicates by I2C (SDA/SCL), realization demodulation module frequency phase lock, according to user demand into
Row equipment receives frequency (87-108MHz) setting.Wherein, main control chip is STM32F429IGT chip.
And the audio (L-out/R-out) that demodulation module demodulates is put with composite signal (MPX) through 9018Q1 triode
Output, send to 67K high pass, audio low-pass wave circuit after big.
With reference to Fig. 3, signal respectively enters 67K high-pass filter and SCA audio low-pass filter after SCA demodulation module
In.After triode Q3 amplification, collector is exported through C4 to low-pass filter for 67K baseband signal and audio signal；Emitter is defeated
Out through C5 to high-pass filter.
SCA audio low-pass filter includes R6 (2K), R7 (3.6K), C6 (18000P), C8 (470P), R8 (15K), R9
The 4 rank Chebyshev type low-pass filters that (24K), C9 (1000P), C10 (470P), U1A, U1B (BC4558) are formed, for filtering
Except the high fdrequency component of 15K or more, to improve audio signal-to-noise ratio.
67K high-pass filter include C5 (4700P), C20 (2200P), R14 (820 Ω), R15 (1k), C21 (6800P),
C22(3300P)、R16(430Ω)、R17(910Ω)、C23(2200P)、C24(1000P)、R18(470Ω)、R19(8.2k)、
U3A, U3B, U4A (BC4558) (1,2,3 foot) composition 6 rank Chebyshev type 67K high pass bandpass filters, for filter out 20K with
The high fdrequency component of unnecessary low-frequency component and low-frequency disturbance and 100K or more in lower signal.
6 rank Chebyshev type 67K high pass bandpass filters successively with R20 (75 Ω), R21 (2k), C25 (6800P), L1
The 67K band logical amplifilter and R21 (2k), C25 (6800P), L1 (1mH) of (1mH), U4B (5,6,7 foot) (BC4558) composition
(BC4558) the RLC bandpass filter connection formed.For to bandpass filtering again after high pass filter filters, and pass through
Band logical is amplified to improve 67K baseband level to subtract the intersymbol interference of small data transmission.
With reference to Fig. 4, distributor distributes RDS/SCA broadcasting RF signals, and signal enters RDS demodulation module and demodulated.Demodulation
Module TDA5767 and main control chip communicates by I2C (SDA/SCL), realization demodulation module frequency phase lock, according to user demand into
Row equipment receives frequency (87-108MHz) setting.
Meanwhile the audio (L-out/R-out) that demodulation module demodulates is amplified with composite signal (MPX) through XQ1 triode
After export, send to 57K high pass, audio low-pass wave circuit.
With reference to Fig. 5, signal respectively enters 57K high-pass filter and RDS audio low-pass filter after RDS demodulation module
In.57K baseband signal and audio signal are after triode DGQ3 amplification, and collector output is through DC10 to low-pass filter, transmitting
Pole is exported through DC1 to high-pass filter.
RDS audio low-pass filter includes DR4 (2K), DR5 (3.6K), DC4 (18000P), DC6 (470P), DR6
4 ranks that (15K), DR7 (1.5K), DR8 (24K), DC7 (1000P), DC8 (470P), IC1A, IC1B (MC33078) are formed cut ratio
Husband's type low-pass filter is avenged, for filtering out the high fdrequency component of 15K or more, to improve audio signal-to-noise ratio.
57K high-pass filter includes GC3 (1500P), GC4 (2700P), GR6 (830 Ω), GR7 (3.16K), GC5
(1500P)、GR8(1K)、GC6(3900P)、GR9(120Ω)、GC7(6800P)、GR10(3.16K)、GR11(1K)、GC8
The 4 rank Chebyshev type 57K high pass pass filters of (3900P), IC3B (MC33078) (5,6,7 foot), IC4B (5,6,7 foot) composition
Device, for filtering out the high fdrequency component of unnecessary low-frequency component and low-frequency disturbance and 100K or more in 20K following signals.
Except this, GR3 (47K), GR4 (150K), GC2 (10P), IC3A (1,2,3 foot) (MC33078) constitute a 57K
Baseband signal amplifying circuit, to improve base band signal transmission signal-to-noise ratio；；GR12(4.7K),GR13(51K),GC10(10P),
IC4A (MC33078) (1,2,3 foot) constitutes a filtered baseband amplification circuit, by amplifying to improve 57K base band electricity
The flat intersymbol interference to subtract small data transmission.
With reference to Fig. 6, baseband switching module exports 57K/67K high-pass and low-pass filter, 57K/67K baseband signal module
57K/67K baseband signal passes through capacitor C100 (10uF), C101 (10uF), C102 (10uF), C103 (10uF) (CD4052BM)
Coupling is sent to switching module IC101, and 9 feet and 10 feet of switching module IC101 are controlled by main control chip, realizes forwarding higher level
57K/67K baseband signal and the switching output of local 57K/67K baseband signal.
With reference to Fig. 6, Audio conversion module, the audio signal that RDS/SCA low-pass filter is exported and local audio signal
It is sent to switching module IC102 by capacitor C300 (10uF), C301 (10uF), C302 (10uF) coupling, passes through main control chip control
9 feet and 10 feet of switching module IC102 (CD4052BM) processed realize the audio of forwarding higher level RDS, SCA low-pass filter output
Signal and local audio signal switching output.
With reference to Fig. 7, baseband switching module and Audio conversion module are connect with combiner, wherein 57K/67K base band letter
Number, audio signal Combining Circuit is by C200 (10uF), R204 (1M), R200 (51K), C201 (10uF), R205 (1M), R201
(51K), C202 (10uF), R206 (10K), R202 (470K), C203 (10uF), R203 (1K) composition.
It is no more than the mentality of designing of 7.5K, the base of 57K to main carrier modulation maximum frequency deviation according to RDS or SCA baseband signal
Band signal divides after R204, R200 partial pressure are coupled with the baseband signal of 67K by C201 through R205, R201 after being coupled by C200
Pressure and audio signal modulate its to main carrier after R203 is combined through R206, R202 partial pressure after coupling by C202 and export maximum frequency
It is designed partially for 75kHz.
Design requirement is transmitted according to national broadcast television, and meets system terminal equipment reliable reception, the utility model
57K/67K baseband signal is all made of the same level and is combined modulation.
I.e. when being not inserted into 67K baseband signal and audio signal, capacitor C203 of the base band signal of 57K after combining
Place's detection Xin electricity Ping≤7.5K, similarly when being not inserted into 57K baseband signal and audio signal, the base band signal of 67K exists
Xin electricity Ping≤7.5K is detected at capacitor C203 after combining.Although total Pin Pian≤15K after the combining of 57K/67K baseband signal,
The 10% of the total frequency deviation of stereophonic broadcasting frequency modulation broadcasting slightly above required, but modulated after summation tone frequency total frequency deviation be 75K when, after modulation
Audio signal-to-noise ratio >=70dB, meet national frequency modulation broadcasting transmission requirement.
With reference to he 7, radio-frequency modulations through capacitor C203 are coupled to by 57K/67K baseband signal, the audio signal after combining
Module audio input port completes 57K/67K base-band data signal in same broadcasting frequency by way of direct frequency modulation
Mentality of designing is transmitted, is realized based on RDS/SCA with the application for broadcasting f-m multiplex technology.
The 4 rank Chebyshev type low-pass filters of the utility model can filter out the high frequency division of the 15K or more in SCA audio
Amount, 6 rank Chebyshev type 67K high pass bandpass filters can filter out in 67K baseband signal unnecessary low frequency in 20K following signals
The high fdrequency component of ingredient and low-frequency disturbance and 100K or more；Meanwhile 4 rank Chebyshev type low pass filtereds in 57K high-pass filter
Wave device can filter out the high fdrequency component of 15K or more in RDS audio, to improve audio signal-to-noise ratio；Its 57K high pass bandpass filter, can filter
Except in 57K baseband signal in 20K following signals unnecessary low-frequency component and low-frequency disturbance and 100K or more high fdrequency component.
Except this improves base band signal transmission signal-to-noise ratio, passes through signal by signal by baseband signal amplifying circuit and baseband amplification circuit
Amplification can efficiently solve RDS and SCA broadcast RF to improve 57K and 67K baseband level to subtract the intersymbol interference of small data transmission
Signal in demodulation transmission process, ask by the influence of the intersymbol interference vulnerable to the transmission of high fdrequency component, low frequency component and data
Topic.
Although being described in detail in conjunction with specific embodiment of the attached drawing to utility model, should not be construed as to this
The restriction of the protection scope of patent.In range described by claims, those skilled in the art are without creative work
The various modifications and deformation that can make still belong to the protection scope of this patent.
Claims (3)
1. a kind of filtration system based on RDS and SCA broadcasting RF signals, it is characterised in that: including main control chip；The master control core
Piece is electrically connected with RDS demodulation module and SCA demodulation module respectively；The RDS demodulation module respectively with RDS audio low-pass filter
It is electrically connected with 57K high-pass filter；The SCA demodulation module is electric with 67K high-pass filter and SCA audio low-pass filter respectively
Connection；
The SCA audio low-pass filter includes 4 rank Qie Bixue of R6, R7, C6, C8, R8, R9, C9, C10, U1A, U1B composition
Husband's type low-pass filter；The 67K high-pass filter include C5, C20, R14, R15, C21, C22, R16, R17, C23, C24,
6 rank Chebyshev type 67K high pass bandpass filters of R18, R19, U3A, U3B, U4A composition；The 6 rank Chebyshev type 67K high
Filter is successively formed with the 67K band logical amplifilter of R20, R21, C25, L1, U4B composition and R21, C25, L1 all
The connection of RLC bandpass filter；
The RDS audio low-pass filter includes DR4, DR5, DC4, DC6, DR6, DR7, DR8, DC7, DC8, IC1A, IC1B group
At 4 rank Chebyshev type low-pass filters；The 57K high-pass filter include GC3, GC4, GR6, GR7, GC5, GR8, GC6,
4 rank Chebyshev type 57K high pass bandpass filters of GR39, GC7, GR10, GR11, GC8, IC3B, IC4B composition；4 rank is cut
57K baseband signal amplifying circuit than the input terminal and GR3, GR4, GC2, IC3A composition of avenging husband's type 57K high pass bandpass filter connects
It connects, output end is connect with GR12, GR13, GC10, IC4A baseband amplification circuit formed.
2. the filtration system according to claim 1 based on RDS and SCA broadcasting RF signals, it is characterised in that: the RDS
The input terminal of demodulation module and SCA demodulation module is connect with distributor.
3. the filtration system according to claim 1 based on RDS and SCA broadcasting RF signals, it is characterised in that: the RDS
Demodulation module and SCA demodulation module include the TDA5767 demodulation module being electrically connected by I2C with main control chip.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201821610837.8U CN208782838U (en) | 2018-09-29 | 2018-09-29 | Filtration system based on RDS and SCA broadcasting RF signals |
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| CN201821610837.8U CN208782838U (en) | 2018-09-29 | 2018-09-29 | Filtration system based on RDS and SCA broadcasting RF signals |
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| CN208782838U true CN208782838U (en) | 2019-04-23 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112134638A (en) * | 2020-09-24 | 2020-12-25 | 四川省广播电视科学技术研究所 | Synchronous deployment system and method for Internet of things and emergency broadcast |
-
2018
- 2018-09-29 CN CN201821610837.8U patent/CN208782838U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112134638A (en) * | 2020-09-24 | 2020-12-25 | 四川省广播电视科学技术研究所 | Synchronous deployment system and method for Internet of things and emergency broadcast |
| CN112134638B (en) * | 2020-09-24 | 2023-04-18 | 四川省广播电视科学技术研究所 | Synchronous deployment system and method for Internet of things and emergency broadcast |
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