CN105791204A - Full-digital envelope detection demodulation method of alternating current IRIG-B code and apparatus thereof - Google Patents
Full-digital envelope detection demodulation method of alternating current IRIG-B code and apparatus thereof Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
- H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
- H04L27/38—Demodulator circuits; Receiver circuits
- H04L27/3845—Demodulator circuits; Receiver circuits using non - coherent demodulation, i.e. not using a phase synchronous carrier
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/02—Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
- H04L27/04—Modulator circuits; Transmitter circuits
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
- H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
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Abstract
A full-digital envelope detection demodulation method of an alternating current IRIG-B code and an apparatus thereof are disclosed. The alternating current IRIG-B code is converted into a digital signal via an A/D sampling module. An orthogonal digital mixer module multiplies an input digital signal with a sine carrier signal and a cosine carrier wave generated by a digital oscillator NCO respectively and carries out frequency mixing. The two paths of signals after the frequency mixing carry out filtering via one low-pass filtering module respectively. The two low-pass filtering modules filter high frequency components so as to acquire low frequency components, and two paths of low frequency signals are input into a quadratic sum processing module. The quadratic sum processing module carries out square on the two branches of low frequency signals respectively and then carries out summation, and alternating current portions in the low frequency components are eliminated so as to acquire an envelope signal of a direct current IRIG-B code. The envelope signal of the direct current IRIG-B code output by the quadratic sum processing module passes through a smoothness and threshold setting module so that the accurate direct current IRIG-B code is acquired. Finally, a direct current B code demodulation module demodulates time information so as to complete full-digital demodulation of the alternating current B code. The structure is simple, an algorithm complexity is low and circuit realization is easy.
Description
Technical field
The present invention relates to measurement and control in time and frequency field, particularly relate to the Service of Timing of IRIG-B code in measurement and control in time and frequency field, specifically
For a kind of digital envelope detection demodulation method exchanging IRIG-B code and device.
Background technology
IRIG code is by the subordinate of target range commandant committee of the U.S. (Range Commanders Council, abridge RCC)
The one that mechanism Inter-range Instrumentation Group (range time instrument group) designed the earliest in nineteen fifty-nine
BCD serial time modulation code.The coded format of IRIG has " A, B, D, E, G, H " six kinds of forms, and wherein IRIG-B (being called for short B code) makees
One for temporal information transmission commonly uses form, is widely applied in temporal information transmission.IRIG-B code time service skill
Art has had extensively in scientific research, power system, satellite navigation, guided missile, aerospace launching test, weapon test and daily life
General application.
In actual applications, according to distance and the requirement of different time precision, the IRIG-B of distance IRIG-B code generator
Code have employed two kinds of pattern AC codes (alternating current code) and DC code (direct current code) in actual transmissions.DC is used when transmission range is near
Code, B (DC) code is the timing code of one frame per second, is mainly made up of the rectangular pulse that some width are different；When transmission range ratio
Using AC code time farther out, IRIG-B (AC) code is the letter that 1kHz sine wave is made amplitude modulation(PAM) by a kind of pulse width modulation code again
Number, there are three kinds of different modulating pulse widths, second signal reference symbols sn and location recognition to be masked as 8ms, code word " 1 " is 5ms, code
Word " 0 " and index marker are 2ms.The comparison of wave shape of IRIG-B (AC) code and IRIG-B (DC) is as shown in Figure 1.
The decoding technique of IRIG-B code is the major reason affecting final timing system precision, at present, both at home and abroad
The demodulation mode of direct current IRIG-B code is mainly used the method that pulsewidth counts；Demodulation to exchange IRIG-B code divides from method
Class has two kinds: coherent demodulation mode and non-coherent demodulation mode.
Coherent demodulation mode it is crucial that receiving terminal to provide one and receive signal carrier stringent synchronization coherent carrier,
Recover the quality of carrier performance, be directly connected to the quality of IRIG-B code demodulation performance.And in actual practice, no matter which kind of is used
The carrier phase that method is extracted is constantly present certain error, has a significant impact carrier synchronization performance；Owing to needs recover to carry
It is complex that ripple makes equipment realize, and be difficult to dock at short notice the coherent carrier collected mail number estimate accurately and
Follow the tracks of.
Summary of the invention
Based on the deficiency of exchange IRIG-B code demodulation method in prior art, the present invention proposes a kind of exchange IRIG-B code
Digital envelope detection demodulation method and device.The method is a kind of non-coherent demodulation mode, and envelope detection only need to be extracted directly
The envelope of stream IRIG-B code, without recovering carrier wave, so to coherent carrier without accurately estimating and following the tracks of, and then the method
Simple in construction, algorithm complex is low, it is easy to circuit realiration, can be widely applied to need exchange IRIG-B code is decoded time service
Equipment in.
The technical scheme is that
A kind of digital envelope detection demodulation method exchanging IRIG-B code, comprises the following steps:
S1: analog AC IRIG-B code is converted into digital signal by A/D modular converter；
S2: with sinusoidal carrier, digital signal is replicated signal sin respectively, and ((w+ Δ w) t+ θ) and cosine carrier replicate signal
Cos ((w+ Δ w) t+ θ) multiplicative mixing, it is achieved carrier wave two harmonic separates with low frequency component, wherein digital signal y (t) with
Sinusoidal carrier replicates that branch road of signal mixing and is referred to as in-phase branch, and digital signal y (t) and cosine carrier replicate signal mixing
Another branch road be referred to as quadrature branch；Digital signal y (t) and sinusoidal carrier obtain y after replicating signal mixingI(t), numeral letter
Number y (t) and cosine carrier obtain y after replicating signal mixingQ(t):
Wherein: Δ w is the frequency difference that sinusoidal carrier replicates signal or cosine carrier duplication signal and digital signal y (t), and θ is
Sinusoidal carrier replicates signal or the initial phase of cosine carrier duplication signal；
S3: two mixed frequency signals in in-phase branch and quadrature branch are demodulated respectively filtering, pass through low pass filter
Filter two harmonics of carrier signal, obtain low frequency signal；
S4: filtered two-way low frequency signal carries out quadratic sum process, eliminates the AC portion cos in low frequency signal
(Δ wt-θ) and sin (Δ wt-θ), extract the envelope signal of direct current IRIG-B code
S5: arranged by smoothing processing and thresholding, obtain direct current IRIG-B code accurately；
S6: the direct current IRIG-B code obtained in step S5 is demodulated, final output time information.
Further, in order to improve transmission quality, it is simple to signal processing and system integrated, will be logical after signal sampling
Cross Digital Way and realize demodulation.Orthogonal digital frequency mixer is utilized to realize two frequencys multiplication and the low frequency component of the i.e. carrier signal of high frequency
Separate, then utilize the FIR low pass filter that can keep linear phase to realize filtering, filter high fdrequency component, stay required
Low frequency component.
Further, smoothing processing and thresholding are arranged, in order to reduce the noise shadow such as sampling, circuit board low-frequency disturbance
Ringing, the present invention takes the processing method of a kind of simplicity, and first signal envelope is taked the method for moving average carry out data smoothing,
Then the intermediate value (maximum and the intermediate value of minima) of signal amplitude is taken as threshold value.Code element is differentiated according to thresholding,
Just can demodulate direct current IRIG-B code.Finally, utilizing DC B code demodulation module to demodulate direct current IRIG-B code, output is corresponding
Temporal information.
The present invention provides a kind of digital envelope detection demodulating equipment exchanging IRIG-B code, including A/D modular converter, just
Intersection number word mixer module, digital oscillator NCO, low-pass filtering module, quadratic sum processing module, smooth and thresholding arrange mould
Block, DC B code demodulation module, exchange IRIG-B code is input to orthogonal digital after A/D modular converter is converted into digital signal
Mixer module, digital oscillator NCO produces the i.e. sinusoidal carrier of two-way orthogonal signalling and replicates signal and cosine carrier duplication signal,
Orthogonal digital mixer module by input digital signal respectively with digital oscillator NCO produce sinusoidal carrier replicate signal and
Cosine carrier signal multiplication is mixed, and it is that homophase props up that the digital signal of input and sinusoidal carrier replicate that branch road of signal mixing
Road, it is quadrature branch that the digital signal of input and cosine carrier replicate another branch road of signal mixing, the two-way after mixing
Signal obtains low frequency component respectively through a low-pass filtering module, the high fdrequency component filtering in-phase branch and quadrature branch respectively,
The two-way AC signal of two low-pass filtering module outputs all inputs quadratic sum processing module, and quadratic sum processing module is by in-phase branch
Square then sue for peace respectively with the low frequency signal of quadrature branch, eliminate the AC portion in low frequency component, obtain direct current IRIG-B
The envelope signal of code；The envelope signal of the direct current IRIG-B code of quadratic sum processing module output arranges mould through smooth and thresholding
Block, obtains direct current IRIG-B code accurately, is finally demodulated temporal information by DC B code demodulation module, complete the complete of alternating-current B code
Digital demodulation.
The invention has the beneficial effects as follows:
Envelope detection of the present invention only need to extract the envelope of direct current IRIG-B code, it is not necessary to carrier wave is carried out relevant estimate and with
Track, the method simple in construction, algorithm complex is low, it is easy to circuit realiration, can be widely applied to need to enter exchange IRIG-B code
In the equipment of row decoding time service.
Accompanying drawing explanation
Fig. 1 graphic extension IRIG-B code waveform diagram；
Fig. 2 graphic extension present invention realizes schematic diagram；
Fig. 3 graphic extension exchange IRIG-B code all-digital demodulation flow chart；
Fig. 4 graphic extension exchange IRIG-B code all-digital demodulation structure drawing of device；
Fig. 5 graphic extension I tributary signal and filtered oscillogram；
Fig. 6 graphic extension Q tributary signal and filtered oscillogram；
Notional result and actual result oscillogram after Fig. 7 graphic extension low-pass filtering；
Fig. 8 graphic extension envelope oscillogram before and after smooth；
Fig. 9 graphic extension exchange IRIG-B code demodulation result.
Detailed description of the invention
The solution in frequency domain method provided the present invention below in conjunction with the accompanying drawings is described in detail.
The present invention realize schematic diagram as in figure 2 it is shown, use envelope detection method.Exchange IRIG-B code y (t) is by directly
Stream IRIG-B code x (t) carries out amplitude modulation(PAM) to 1kHz sinusoidal signal and obtains, and the envelope of brewed exchange IRIG-B code is direct current
IRIG-B code, it contains corresponding temporal information, as shown in Figure 1.In practical situations both, the local carrier of receiving terminal cannot be with
Modulated signal strictly with frequency homophase, at receiving terminal, is produced two-way orthogonal signalling, i.e. sinusoidal carrier by digital oscillator NCO multiple
((w+ Δ w) t+ θ) and cosine carrier replicate signal cos ((w+ Δ w) t+ θ), pairwise orthogonal signal and modulated signal to signal sin processed
Frequency have slight frequency difference Δ w, its initial phase is θ.Input signal y (t) and sinusoidal carrier are replicated that of signal mixing
Branch road is referred to as in-phase branch (being called for short I branch road), and another branch road being mixed with cosine carrier duplication signal is referred to as quadrature branch
(being called for short Q branch road).
Input signal y (t) obtains y with I branch road and Q branch road two paths of signals after mixing respectivelyI(t) and yQ(t):
By mixing expression formula (1) and (2) it can be seen that I branch road and Q tributary signal are all separated into high and low frequency divides
The combination of amount, its low frequency components is the envelope product with approximate DC signal of direct current IRIG-B code, through low pass filter
Can be obtained by this part low frequency component after high fdrequency component being filtered, time-domain representation formula is:
Due to the existence of receiving terminal carrier beat Δ w, still with the presence of AC signal after low-pass filtering, in order to demodulate
The envelope signal of direct current IRIG-B code, according to the characteristic of this AC signal, by two-way filter result yFIAnd yFQCarry out a square summation
After can obtainIts expression formula is as follows:
This signal maintains the envelope of direct current IRIG-B code, but is not strict square wave, need to be by arranging THRESHOLD ESTIMATION
Go out pulsewidth and amplitude, and then obtain the accurate envelope of direct current IRIG-B code, then just the time can be believed by the demodulation of DC B code
Breath demodulates out.
A kind of digital its flowchart of envelope detection demodulation method exchanging IRIG-B code of the present invention as it is shown on figure 3,
Comprise the following steps:
S1: analog AC IRIG-B code is converted into digital signal through A/D modular converter；
S2: digital signal is mixed with sinusoidal carrier signal and cosine carrier signal multiplication respectively, it is achieved carrier wave two frequency multiplication
Component separates with low frequency component, and digital signal and sinusoidal carrier replicate signal sin, and ((w+ Δ w) t+ θ) is mixed to obtain mixing letter
Number yIThe derivation result of (t) such as formula (1)；Digital signal and cosine carrier are replicated signal cos, and ((w+ Δ w) t+ θ) is mixed mixed
Frequently signal yQT the derivation result of () such as formula (2), the mixed frequency signal of I branch road and Q branch road all becomes by high frequency i.e. the two of carrier signal
Harmonic and the low frequency i.e. envelope of direct current IRIG-B code and the combination of approximate DC signal.
S3: the orthogonal digital through S2 step is mixed, in order to obtain the envelope signal of direct current IRIG-B code, to two mixing letters
Number it is demodulated filtering respectively, is filtered two harmonics of carrier signal by low pass filter, obtain low frequency component: direct current
The envelope of IRIG-B code and AC signal such as formula (3) and formula (4) are shown；
S4: filtered two-way low frequency signal carries out quadratic sum process, eliminates the AC portion cos in low frequency signal
(Δ wt-θ) and sin (Δ wt-θ), extract the envelope signal of direct current IRIG-B code
S5: arranged by smoothing processing and thresholding, eliminate the signal jitter brought because of noise etc., obtain direct current accurately
IRIG-B code；
S6: the direct current IRIG-B code obtained in step S5 is demodulated, final output time information.
Fig. 4 is the schematic diagram of a kind of digital envelope detection demodulating equipment exchanging IRIG-B code of the present invention, this device bag
Include A/D modular converter 110, orthogonal digital mixer module 120,1# low-pass filtering module 131 and 2# low-pass filtering module 132,
Quadratic sum processing module 140, smooth and thresholding arrange module 150, DC B code demodulation module 160.The exchange of outside input
IRIG-B code is input to orthogonal digital mixer module 120 after A/D modular converter 110 is converted into digital signal, and numeral is shaken
Swing device NCO and produce two-way orthogonal signalling i.e. sinusoidal carrier duplication signal and cosine carrier duplication signal, orthogonal digital frequency mixer mould
The sinusoidal carrier that the digital signal of input produces with digital oscillator NCO respectively is replicated signal and cosine carrier signal by block 120
Multiplicative mixing, it is in-phase branch i.e. I branch road that the digital signal of input and sinusoidal carrier replicate that branch road of signal mixing, input
Digital signal and cosine carrier to replicate another branch road of signal mixing be quadrature branch i.e. Q branch road, I branch road and Q branch road
Two-way mixed frequency signal is respectively through 1# low-pass filtering module 130 and 2# low-pass filtering module 131,1# low-pass filtering module 130 He
2# low-pass filtering module 131 filters the high fdrequency component of I branch road and Q branch road respectively and obtains low frequency component, according to I branch road and Q branch road
The characteristic of this two-way AC signal, by quadratic sum processing module 140, allow I branch road and Q branch road low frequency signal respectively square
Then sue for peace, eliminate the AC portion in low frequency component, obtain the envelope signal of direct current IRIG-B code；Set through smooth and thresholding
Put module 150, obtain direct current IRIG-B code accurately, finally demodulated temporal information by DC B code demodulation module 160, complete
The all-digital demodulation of alternating-current B code.
The present invention its operation principle of this device can be summarized as:
Outside input AC IRIG-B code is converted into digital signal through A/D modular converter 110；Orthogonal digital frequency mixer mould
Block 120 is to separate with DC component to realize carrier wave, uses carrier wave NCO, its merit in orthogonal digital mixer module 120
Can be to produce orthogonal sinusoidal carrier to replicate signal and cosine carrier duplication signal, it is achieved orthogonal digital is mixed.Use on I branch road
Sinusoidal carrier replicate the cosine carrier on signal and Q branch road and replicate signal, respectively with to exchange IRIG-B code-phase multiplied to I branch road
Signal and Q tributary signal, it is achieved that high fdrequency component separates with low frequency component, high-frequency signal is two harmonics of carrier wave, low
Frequently signal includes envelope and the AC signal of direct current IRIG-B code to be demodulated, and needs by low pass filtered to obtain low frequency component
Ripple device filters two harmonics；
The effect of low pass filter blocks 130 is contemplated to filter high fdrequency component, leaves useful low frequency component；In order to disappear
Except due to the impact of modulated signal Yu local carrier frequency difference, according to the characteristic of AC signal in low frequency component, at quadratic sum
Reason module 140, eliminates AC signal and obtains the initial envelope of direct current IRIG-B code；Then arrange module 150 by thresholding to carry out
Thresholding is arranged, and envelope becomes strict square wave, DC B code the most accurately.Finally, by direct current IRIG-B code demodulation module
160, by temporal information demodulation output.
Specifically, the analog AC IRIG-B code of input is converted into digital signal by A/D modular converter 110, and A/D changes
Module the present embodiment have employed a high-performance of AD company of the U.S., low-power consumption, wieldy modulus conversion chip.
Specifically, orthogonal digital mixer module 120 realizes orthogonal digital mixing, is separated by high and low frequency component.
Orthogonal digital mixer module 120 utilizes carrier wave NCO to realize in FPGA, and its core component is phase accumulator and phase amplitude
Changer, searches phase amplitude look-up table according to accumulated phase, is converted into signal amplitude, obtains orthogonal sinusoidal signal and cosine
Signal.Two paths of signals respectively with numeral modulated signal multiplicative mixing, it is achieved orthogonal digital be mixed.
Specifically, in order to avoid wave filter produces nonlinear phase delay, need utilization can keep linear phase
Low pass filter is filtered.In order to simplify hardware designs, the present embodiment such as have employed at the low pass filter of ripple, the sample frequency
For 100KHz, passband frequency domain is [0～0.1] KHz, intermediate zone frequency domain [0.1～1.9] KHz, and stopband frequency domain is f >=1.9KHz, for
Reduction exponent number, design stopband attenuation Astop is 20dB, and filter order is 48 rank.I branch road and Q branch road two paths of signals are respectively
After wave digital lowpass filter by design, the signal envelope before filtered envelope and filtering is the most identical, and actual filtering is tied
Fruit has a fixing delay as shown in Figure 5 and Figure 6 compared with theoretical filter result.In Fig. 5, first figure is I branch road before filtering
Signal after mixing, second figure is the I branch road mixed frequency signal result through low pass filter, and it includes and before filtering
The envelope of mixed frequency signal is the most identical, and the 3rd figure is filtered result in theoretical derivation, result filtered with reality
Simply there is a fixing delay, this causes due to hardware resource, belongs to normal outcome；Same Fig. 6 refers to Q branch road and mixes
Frequently the result before and after signal filtering is consistent with I branch road result.It should be noted that median filter parameter of the present invention is arranged simply
For existing hardware resource, other equipment can arrange different parameters according to practical situation, and filter parameter can
To be adjusted according to system practical situation, its principle followed is on the premise of obtaining the filter result meeting index, to the greatest extent
Amount saves hardware resource.The design parameter of wave filter arranges and does not constitute the restriction to the present embodiment.
Specifically, quadratic sum processing module 140 is exactly by right for first square of the two paths of signals of two low-pass filtering module outputs
Rear summation, eliminates the frequency difference and the impact of phase contrast existed due to modulated signal with local carrier.Then by defeated for quadratic sum signal
Deliver to smooth and module 150 is set with thresholding.
Specifically, although the signal results processed through low-pass filtering and quadratic sum maintains direct current IRIG-B code waveform
Envelope, but due to the impact of the factor such as sampling, circuit noise interference, the shake of filtered signal envelope is relatively big, such as Fig. 7 institute
Show, be likely to generation burr cause error code if directly compared with thresholding.In order to arrange suitable threshold value, the present embodiment
Signal is smoothed by the method initially with moving average, eliminates bigger shake, then takes the intermediate value of signal amplitude (
Big value and the intermediate value of minima) as threshold value.As shown in Figure 8, curve 1 refers to the signal waveform before smoothing, and curve 2 refers to smooth
After signal waveform, it can be seen that the choosing and arranging of the more conducively threshold value of the signal waveform after smoothing processing.
Further, after setting completed, when the signal data value after smoothing processing is more than threshold value, then output is straight for thresholding
The high value of stream IRIG-B code, when the data value after smoothing processing is less than threshold value, then output direct current IRIG-B code is low
Level value, then the waveform of final output signal is exactly direct current IRIG-B code, and the decoding precision of statistics the present embodiment can reach
6us, as it is shown in figure 9, the requirement (IRIG-B that disclosure satisfy that in national military standard GJB2991A-2008 " B time code interface terminal " specification
(AC) synchronous error should < 10us).
Specifically, the decoding concrete grammar of direct current IRIG-B code is as follows: measured the width of code element, profit by counting mode
With 10MHz as clock signal, when IRIG-B code rising edge being detected, start counting up, after trailing edge being detected, terminate meter
Number, judges count value simultaneously, exports, according to the result of count value, the numerical value that current symbol is corresponding: consider Redundancy Design,
If count value is between 75000～85000, this code element is 8ms pulsewidth code element, represents flag bit；If count value 45000～
Between 55000, this code element is 5ms pulsewidth code element, represents 1；If count value is between 25000～35000, this code element is 2ms arteries and veins
Wide code element, represents 0.The reference mark of time frame is made up of a location recognition mark and adjacent reference symbols sn, and its width is
8ms, i.e. two continuous print 8ms.Therefore, first it is detected that the frame head of a frame signal, then according to the form of DC B code can be just
Really demodulate the second, point, time, sky information.
In sum, although the present invention is disclosed above with preferred embodiment, so it is not limited to the present invention, any
Those of ordinary skill in the art, without departing from the spirit and scope of the present invention, when various change and retouching can be made, therefore this
Bright protection domain is when defining in the range of standard depending on claims.
Claims (5)
1. the digital envelope detection demodulation method exchanging IRIG-B code, it is characterised in that comprise the following steps:
S1: analog AC IRIG-B code is converted into digital signal by A/D modular converter；
S2: with sinusoidal carrier, digital signal is replicated signal sin respectively, and ((w+ Δ w) t+ θ) and cosine carrier replicate signal cos
((w+ Δ w) t+ θ) multiplicative mixing, it is achieved carrier wave two harmonic separates with low frequency component, wherein digital signal y (t) with just
String carrier wave replicates that branch road of signal mixing and is referred to as in-phase branch, and digital signal y (t) and cosine carrier replicate signal mixing
Another branch road is referred to as quadrature branch；Digital signal y (t) and sinusoidal carrier obtain y after replicating signal mixingI(t), digital signal
Y (t) and cosine carrier obtain y after replicating signal mixingQ(t):
Wherein: Δ w is the frequency difference that sinusoidal carrier replicates signal or cosine carrier duplication signal and digital signal y (t), and θ is sinusoidal
Carrier wave replicates signal or the initial phase of cosine carrier duplication signal；
S3: two mixed frequency signals in in-phase branch and quadrature branch are demodulated respectively filtering, are filtered by low pass filter
Two harmonics of carrier signal, obtain low frequency signal；
S4: filtered two-way low frequency signal carries out quadratic sum process, eliminates AC portion cos (the Δ wt-in low frequency signal
θ) with sin (Δ wt-θ), extract the envelope signal of direct current IRIG-B code
S5: arranged by smoothing processing and thresholding, obtain direct current IRIG-B code accurately；
S6: the direct current IRIG-B code obtained in step S5 is demodulated, final output time information.
The digital envelope detection demodulation method of exchange IRIG-B code the most according to claim 1, it is characterised in that S1
In, analog AC IRIG-B code is by direct current IRIG-B code, 1kHz sinusoidal signal to be carried out amplitude modulation(PAM) and obtain.
The digital envelope detection demodulation method of exchange IRIG-B code the most according to claim 1, it is characterised in that in S3
Employing can keep the FIR low pass filter of linear phase to realize filtering.
The digital envelope detection demodulation method of exchange IRIG-B code the most according to claim 1, it is characterised in that S5
In, first envelope signal is taked the method for moving average carry out data smoothing, then takes the intermediate value of signal amplitude as door
Limit value, threshold value after setting completed, when the signal data value after smoothing processing is more than threshold value, then exports direct current IRIG-B code
High value, when the signal data value after smoothing processing less than threshold value time, then export direct current IRIG-B code low level value,
Then the waveform of final output signal is exactly direct current IRIG-B code.
5. the digital envelope detection demodulating equipment exchanging IRIG-B code, it is characterised in that include A/D modular converter, just
Intersection number word mixer module, digital oscillator NCO, low-pass filtering module, quadratic sum processing module, smooth and thresholding arrange mould
Block, DC B code demodulation module, exchange IRIG-B code is input to orthogonal digital after A/D modular converter is converted into digital signal
Mixer module, digital oscillator NCO produces the i.e. sinusoidal carrier of two-way orthogonal signalling and replicates signal and cosine carrier duplication signal,
Orthogonal digital mixer module by input digital signal respectively with digital oscillator NCO produce sinusoidal carrier replicate signal and
Cosine carrier signal multiplication is mixed, and it is that homophase props up that the digital signal of input and sinusoidal carrier replicate that branch road of signal mixing
Road, it is quadrature branch that the digital signal of input and cosine carrier replicate another branch road of signal mixing, the two-way after mixing
Signal obtains low frequency component respectively through a low-pass filtering module, the high fdrequency component filtering in-phase branch and quadrature branch respectively,
The two-way AC signal of two low-pass filtering module outputs all inputs quadratic sum processing module, and quadratic sum processing module is by in-phase branch
Square then sue for peace respectively with the low frequency signal of quadrature branch, eliminate the AC portion in low frequency component, obtain direct current IRIG-B
The envelope signal of code；The envelope signal of the direct current IRIG-B code of quadratic sum processing module output arranges mould through smooth and thresholding
Block, obtains direct current IRIG-B code accurately, is finally demodulated temporal information by DC B code demodulation module, complete the complete of alternating-current B code
Digital demodulation.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106559377A (en) * | 2016-10-26 | 2017-04-05 | 上海华虹集成电路有限责任公司 | Send carrier generating circuit |
| CN108088801A (en) * | 2017-12-07 | 2018-05-29 | 电子科技大学 | Laser NDT device based on 90 ° of optical mixer units |
| CN108712358A (en) * | 2018-04-11 | 2018-10-26 | 北京航天长征飞行器研究所 | A kind of general QAM and APSK demodulators and demodulation method |
| CN109270831A (en) * | 2018-11-21 | 2019-01-25 | 中国科学院国家授时中心 | BPM shortwave multifrequency point timing system |
| CN111650480A (en) * | 2020-04-28 | 2020-09-11 | 西安远测电力科技有限公司 | Realization of ultrahigh frequency partial discharge detection technology based on correlation |
| CN114517749A (en) * | 2021-12-29 | 2022-05-20 | 中国航天***科学与工程研究院 | Carrier rocket automatic ignition control system |
| CN115001592A (en) * | 2022-05-26 | 2022-09-02 | 江苏科大亨芯半导体技术有限公司 | Demodulation method and system for multi-carrier frequency top modulation |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101034904A (en) * | 2007-04-10 | 2007-09-12 | 鼎芯通讯（上海）有限公司 | Device and method for the FM radio to accurately search broadcasting station |
| CN101398481A (en) * | 2008-11-13 | 2009-04-01 | 上海交通大学 | Digital high precision dynamic cymoscope |
| CN103616566A (en) * | 2013-11-15 | 2014-03-05 | 中国电子科技集团公司第四十一研究所 | Linear average value detector realizing method based on software defined radio |
| US20140177489A1 (en) * | 2012-05-09 | 2014-06-26 | Huawei Technologies Co., Ltd. | Carrier Synchronization Method, Circuit, and System |
-
2016
- 2016-04-29 CN CN201610279246.6A patent/CN105791204A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101034904A (en) * | 2007-04-10 | 2007-09-12 | 鼎芯通讯（上海）有限公司 | Device and method for the FM radio to accurately search broadcasting station |
| CN101398481A (en) * | 2008-11-13 | 2009-04-01 | 上海交通大学 | Digital high precision dynamic cymoscope |
| US20140177489A1 (en) * | 2012-05-09 | 2014-06-26 | Huawei Technologies Co., Ltd. | Carrier Synchronization Method, Circuit, and System |
| CN103616566A (en) * | 2013-11-15 | 2014-03-05 | 中国电子科技集团公司第四十一研究所 | Linear average value detector realizing method based on software defined radio |
Non-Patent Citations (3)
| Title |
|---|
| 任永良: "一种新型数据传输***设计与实现", 《中国优秀硕士学位论文全文数据库 信息科技辑（月刊）》 * |
| 储飞黄等: "滑动相关法伪码捕获的FPGA实现", 《世界电子元器件》 * |
| 王丽敏: "全数字IRIG_B码解调方法的研究", 《中国优秀硕士学位论文全文数据库 信息科技辑（月刊）》 * |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106559377A (en) * | 2016-10-26 | 2017-04-05 | 上海华虹集成电路有限责任公司 | Send carrier generating circuit |
| CN108088801A (en) * | 2017-12-07 | 2018-05-29 | 电子科技大学 | Laser NDT device based on 90 ° of optical mixer units |
| CN108712358A (en) * | 2018-04-11 | 2018-10-26 | 北京航天长征飞行器研究所 | A kind of general QAM and APSK demodulators and demodulation method |
| CN109270831A (en) * | 2018-11-21 | 2019-01-25 | 中国科学院国家授时中心 | BPM shortwave multifrequency point timing system |
| CN109270831B (en) * | 2018-11-21 | 2020-09-22 | 中国科学院国家授时中心 | BPM short wave multi-frequency point timing system |
| CN111650480A (en) * | 2020-04-28 | 2020-09-11 | 西安远测电力科技有限公司 | Realization of ultrahigh frequency partial discharge detection technology based on correlation |
| CN111650480B (en) * | 2020-04-28 | 2022-10-28 | 西安远测电力科技有限公司 | Realization of ultrahigh frequency partial discharge detection technology based on correlation |
| CN114517749A (en) * | 2021-12-29 | 2022-05-20 | 中国航天***科学与工程研究院 | Carrier rocket automatic ignition control system |
| CN114517749B (en) * | 2021-12-29 | 2023-12-12 | 中国航天***科学与工程研究院 | Automatic ignition control system of carrier rocket |
| CN115001592A (en) * | 2022-05-26 | 2022-09-02 | 江苏科大亨芯半导体技术有限公司 | Demodulation method and system for multi-carrier frequency top modulation |
| CN115001592B (en) * | 2022-05-26 | 2024-01-30 | 江苏科大亨芯半导体技术有限公司 | Demodulation method and system for multi-carrier frequency modulation |
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