CN109327413A - It is a kind of to simulate the demodulating system combined with number and demodulation method - Google Patents
It is a kind of to simulate the demodulating system combined with number and demodulation method Download PDFInfo
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- CN109327413A CN109327413A CN201811069186.0A CN201811069186A CN109327413A CN 109327413 A CN109327413 A CN 109327413A CN 201811069186 A CN201811069186 A CN 201811069186A CN 109327413 A CN109327413 A CN 109327413A
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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
- H04L27/3854—Demodulator circuits; Receiver circuits using non - coherent demodulation, i.e. not using a phase synchronous carrier using a non - coherent carrier, including systems with baseband correction for phase or frequency offset
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/54—Systems for transmission via power distribution lines
- H04B3/542—Systems for transmission via power distribution lines the information being in digital form
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Abstract
The present invention provides a kind of demodulating systems and method that simulation is combined with number, analog demodulation circuit is combined with digital demodulating block, wherein, analog demodulation circuit is filtered to the signal received and preliminary phase demodulation, obtain comprising base-band information and the two paths of signals envelope there may be phase difference, and obtain signal envelope peak value and digital signal corresponding with signal envelope.Digital demodulating block is connected with analog demodulation circuit, based on the peak value of two paths of signals envelope, determines target acquistion signal, and carry out digital demodulation calculating to target acquistion signal, is finally completed the reduction of baseband signal.This programme is filtered by analog demodulation circuit to the signal received and preliminary phase demodulation processing, greatly reduce the sample frequency and calculation amount of pure digi-tal demodulation, and the reduction that further demodulation calculating is finally completed baseband signal is carried out to preliminary identified result by digital demodulating block, without restoring local carrier, demodulation difficulty is thereby reduced, cost has been saved.
Description
Technical field
The present invention relates to power-line carrier communication fields, and in particular to a kind of demodulating system that simulation is combined with number
And demodulation method.
Background technique
DPSK (differential phase keying (DPSK), Differential Phase Shift Keying) is using before and after modulated signal
The relative phase of carrier wave changes to transmit information between symbol, is a kind of tune of common electric line carrier communication single carrier frequency point
Modulation demodulation system.
Existing DPSK system is mostly the demodulation mode of pure digi-tal demodulation modes or pure simulation, wherein digital demodulation side
The noiseproof feature of formula is higher, the bit error rate is lower, but it needs to carry out signal real-time sampling and pass through largely to calculate, final to go back
Original goes out digital baseband signal, completes demodulation.And the demodulation mode of pure simulation is that the signal received is realized to carrier restoring, then
Carrier wave after reduction is multiplied with original signal, to complete to demodulate.
Inventors have found that pure digi-tal demodulation mode wants sample frequency and calculation amount with the raising of carrier frequency
Asking also can be higher and higher, and also can be relatively large by sampling and calculating bring communication time-delay, it is difficult to for requirement of real-time
Higher occasion.For pure analog demodulation mode type by pure hardware realization, communication time-delay is smaller, but hardware circuit is relative complex, cost compared with
Height, and with the raising of carrier frequency, the phase error for going back primary carrier is difficult to control, so that it is higher to will lead to the bit error rate, communication
Reliability is difficult to ensure.
Therefore, how a kind of demodulating system is provided, can reduce communication and be delayed and reduce the bit error rate, be those skilled in the art
Member's big technical problem urgently to be resolved.
Summary of the invention
In view of this, can reduce communication the embodiment of the invention provides demodulating system and be delayed and reduce the bit error rate.
To achieve the above object, the embodiment of the present invention provides the following technical solutions:
A kind of demodulating system that simulation is combined with number, comprising: analog demodulation circuit and digital demodulating block；
The analog demodulation circuit is filtered to the signal received and preliminary phase demodulation, obtains comprising base-band information
Two paths of signals envelope, and obtain the signal envelope peak value and digital signal corresponding with the signal envelope；
The digital demodulating block is connected with the analog demodulation circuit, based on the peak value of signal envelope described in two-way, really
Target acquistion signal is made, and digital demodulation calculating is carried out to the target acquistion signal, restores baseband signal.
Preferably, the analog demodulation circuit include the mutually orthogonal analog switch phase discriminator of bandpass filter, two-way with
And the non-sampled type analog-to-digital converter of two-way；
The bandpass filter is for being filtered the signal received；
The input terminal of the analog switch phase discriminator is connected with the output end of the bandpass filter, mould described in the first via
The first pwm signal that quasi- switch phase discriminator is exported based on the digital demodulating block, carries out preliminary phase demodulation to filtered signal
The signal envelope that the first via includes base-band information is obtained, analog switch phase discriminator described in the second tunnel is based on the digital demodulating block
Second pwm signal of output carries out preliminary phase demodulation to filtered signal and obtains the signal envelope that the second tunnel includes base-band information；
The input terminal of the non-sampled type analog-to-digital converter is connected with the output end of the analog switch phase discriminator, obtains institute
It states corresponding to signal envelope described in the peak value of first via signal envelope and the peak value and two-way of the second road signal envelope
Digital signal.
Preferably, first pwm signal and second pwm signal are that identical and duty ratio is 50% with carrier frequency
Mutually orthogonal signal.
Preferably, the bandpass filter is passive filter or active filter.
Preferably, the analog switch phase discriminator includes resistance network circuit, analog switch and low-pass filter, described
Resistance network circuit includes first resistor and second resistance；
The analog switch, the second resistance and the low-pass filter are parallel with one another, the analog switch it is defeated
The input terminal of the low-pass filter is terminated out；
The output end of the first end of the first resistor and the analog switch is as the analog switch phase discriminator
Two input terminals；
The second end of the first resistor is connected with the input terminal of the analog switch, the control termination of the analog switch
First pwm signal or second pwm signal.
Preferably, the non-sampled type analog-to-digital converter includes comparator and peak detection circuit；
The first input end of the comparator is connected with the input terminal of the peak detection circuit, and as described non-sampled
The input terminal of type analog-to-digital converter, the second input termination reference voltage of the comparator, the output end conduct of the comparator
First output end of the non-sampled type analog-to-digital converter is used for the first via signal envelope and the reference voltage,
The first digital signal is obtained, or, the second road signal envelope and the reference voltage, obtain the second digital signal；
Second output terminal of the output end of the peak detection circuit as the analog-digital converter, for obtaining described
The peak value of the peak value of signal envelope and the second road signal envelope all the way.
Preferably, the digital demodulating block includes that capture selection control module, operation demodulation module and two-way are orthogonal
PWM output module；
The PWM output module exports first pwm signal all the way, described in the output of PWM output module described in another way
Second pwm signal；
The capture selects peak value and the second road signal packet of the control module based on the first via signal envelope
The peak value of network, determines first digital signal or second digital signal is the target acquistion signal；
The operation demodulation module is connected with the first output end of the non-sampled type analog-to-digital converter, catches to the target
It obtains signal and carries out digital demodulation calculating, restore baseband signal.
Preferably, the operation demodulation module includes adder Module and two-way delay multiplication module；
The input terminal of the delay multiplication module is connected with the first output end of the non-sampled type analog-to-digital converter, right
First digital signal and second digital signal delay, obtain the first delayed digital signal and the second delayed digital
Signal, and be calculated first digital signal and the first delayed digital signal the first product and it is described second number
Second product of word signal and the second delayed digital signal；
The input terminal of the adder Module is connected with the output end for the multiplier that is delayed described in two-way, determines that described first multiplies
Long-pending and described second product and be the base band recovering signal.
A kind of demodulation method, the demodulating system above-mentioned applied to any one, the demodulation method include:
The signal received is filtered and preliminary phase demodulation, obtains the two paths of signals envelope comprising base-band information；
Obtain the signal envelope peak value and digital signal corresponding with the signal envelope；
Based on the peak value of signal envelope described in two-way, determine target acquistion signal, and to the target acquistion signal into
Row digital demodulation calculates, and restores baseband signal.
Preferably, the peak value based on signal envelope described in two-way, determines target acquistion signal, comprising:
Judge first digital signal and second digital signal whether be simultaneously be useful signal, if so,
Determine the corresponding number of the larger value in the peak value of the first via signal envelope and the peak value of the second road signal envelope
Signal is the target acquistion signal, if the peak value of the peak value of the first via signal envelope and the second road signal envelope
It is equal, it is determined that first digital signal is the target acquistion signal, if not, determining that the effective digital signal of data is
The target acquistion signal.
Based on the above-mentioned technical proposal, the present invention provides a kind of demodulating systems and method that simulation is combined with number, by mould
Quasi- demodulator circuit is combined with digital demodulating block, wherein analog demodulation circuit is filtered the signal received and just
Walk phase demodulation, obtain comprising base-band information and the two paths of signals envelope there may be phase difference, and obtain the peak value of signal envelope with
And digital signal corresponding with signal envelope.Digital demodulating block is connected with analog demodulation circuit, based on two paths of signals envelope
Peak value determines target acquistion signal, and carries out digital demodulation calculating to target acquistion signal, is finally completed going back for baseband signal
It is former.This programme is filtered by analog demodulation circuit to the signal received and preliminary phase demodulation processing, greatly reduces pure
The sample frequency and calculation amount of digital demodulation, and further demodulation is carried out to preliminary identified result by digital demodulating block and is calculated
It is finally completed the reduction of baseband signal, without restoring local carrier, demodulation difficulty is thereby reduced, has saved cost.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
The embodiment of invention for those of ordinary skill in the art without creative efforts, can also basis
The attached drawing of offer obtains other attached drawings.
Fig. 1 is the structural schematic diagram for the demodulating system that a kind of simulation provided in an embodiment of the present invention is combined with number；
Fig. 2 is the another structural schematic diagram for the demodulating system that a kind of simulation provided in an embodiment of the present invention is combined with number；
Fig. 3 is the another structural schematic diagram for the demodulating system that a kind of simulation provided in an embodiment of the present invention is combined with number；
Fig. 4 is the another structural schematic diagram for the demodulating system that a kind of simulation provided in an embodiment of the present invention is combined with number；
Fig. 5 is the another structural schematic diagram for the demodulating system that a kind of simulation provided in an embodiment of the present invention is combined with number；
Fig. 6 is the comparison diagram of the sample frequency of the embodiment of the present invention and the sample frequency of pure digi-tal debugging；
Fig. 7 is a kind of flow diagram of demodulation method provided in an embodiment of the present invention；
Fig. 8 is the flow diagram of another demodulation method provided in an embodiment of the present invention.
Specific embodiment
In conjunction with background technique it is found that requirement meeting of the pure digi-tal demodulation mode to sample frequency and calculation amount in the prior art
It is higher and higher.For pure analog demodulation mode type by pure hardware realization, communication time-delay is smaller, but hardware circuit is relative complex, higher cost.
Specifically, pure digi-tal demodulation mode is divided into following two step:
Step 1: sampling to the signal received, sampling rate meets nyquist sampling theorem, i.e. sample frequency
Greater than 2 times (i.e. 2 times of carrier frequency) of signal frequency, when actual demodulation, in order to preferably realize that demodulation reduces the bit error rate, one
As can choose higher sample frequency, high-speed communication in the case where, it is higher to the performance requirement of MCU, and holding time and
Software resource is also more.
Step 2: calculate, due to being sampled when sampling to analog signal, so the data sampled at this time are floating type
Data.No matter this Fourier transformation of FFT/DFT is used to seek the algorithm of phase, or local carrier is restored by digital phase-locked loop
The algorithm of coherent demodulation is required to carry out a large amount of floating type operation, needs to expend a large amount of software resource and time, to MCU
Requirement it is also relatively high.This has resulted in pure digi-tal and has realized that time delay is big, software work amount is big, big to the dependence of MCU performance.
Pure analog demodulation mode type is generally divided into the following two kinds:
One, coherent demodulation restores local carrier by analog phase-locked look, then passes through simulation with local carrier and reception signal
Multiplier is multiplied, and obtains baseband envelope, then be sampled judgement and bit synchronization to baseband envelope, is finally completed demodulation.
This mode needs to use analog phase-locked look and analog multiplier, but both device costs are higher, and analog phase-locked look
Locking phase precision and response speed are larger to the Control of Bit Error Rate of demodulation.
Two, non-coherent demodulation is delayed to signal is received, is then multiplied with original signal, and delay time is a base band
The time of a data of signal.How to realize that the delay of this data time is more crucial.First, the time is relatively
It is long；Secondly, it is desirable that time delay module does not influence the amplitude of signal, frequency and entrained base-band information, but pure hardware realization
Get up relatively difficult.
Based on this, referring to Fig. 1, Fig. 1 is the demodulating system that a kind of simulation provided in an embodiment of the present invention is combined with number
Frame construction drawing, which includes: analog demodulation circuit 10 and digital demodulating block 20.
Wherein, the analog demodulation circuit 10 is filtered the signal received and preliminary phase demodulation, obtains comprising base
Information and two paths of signals envelope there may be phase difference, and obtain the signal envelope peak value and with the signal packet
The corresponding digital signal of network.
The digital demodulating block 20 is connected with the analog demodulation circuit 10, the peak based on signal envelope described in two-way
Value, determines target acquistion signal, and carry out demodulation calculating to the target acquistion signal, is finally completed going back for baseband signal
It is former.
As it can be seen that this programme carries out preliminary phase demodulation processing and non-sampled pattern to the signal received by analog demodulation circuit
Number conversion, so that digital demodulating block is not necessarily to carry out high-speed sampling to reception signal and calculate, it is only necessary to be carried out to the peak value of signal
It samples, greatly reduces sample frequency, while demodulating calculating only to need at digital signal corresponding to preliminary identified result
Reason avoids a large amount of floating type and calculates, and greatly reduces sample frequency and calculation amount relative to pure digi-tal demodulation, reduces pair
The occupancy of software resource；Simultaneously because later period demodulation introduces digital demodulation, the load of complexity needed for avoiding pure analog demodulator
Wave synchronous circuit and bit synchronization circuit greatly reduce the complexity of hardware circuit, have saved cost, improve demodulation
Reliability.
Specifically, as shown in Fig. 2, present embodiments providing a kind of specific implementation structure of analog demodulation circuit, the simulation
Demodulator circuit 10 includes bandpass filter 101, two path analoging switch phase discriminators 102 and the non-sampled type analog-to-digital converter of two-way
103。
Wherein, the connection relationship of each device is as follows:
The bandpass filter 101 is for being filtered the signal received；
The input terminal of the analog switch phase discriminator 102 is connected with the output end of the bandpass filter 101, the first via
The first pwm signal that the analog switch phase discriminator is exported based on the digital demodulating block carries out just filtered signal
Phase demodulation is walked, obtaining the first via includes base-band information but the signal envelope there may be phase difference, the mirror of analog switch described in the second tunnel
The second pwm signal that phase device is exported based on the digital demodulating block carries out preliminary phase demodulation to filtered signal, obtains second
Road includes base-band information but the signal envelope there may be phase difference；
The input terminal of the non-sampled type analog-to-digital converter 103 is connected with the output end of the analog switch phase discriminator 102,
It obtains the peak value of the first via signal envelope and the peak value of the second road signal envelope and two paths of signals envelope institute is right
The digital signal answered.
It should be noted that in the present embodiment, first pwm signal and second pwm signal can be and load
The mutually orthogonal signal that wave frequency rate is identical and duty ratio is 50%.The centre frequency of the bandpass filter can be carrier frequency
The bandwidth of the corresponding frequency of point, the bandpass filter can be the bandwidth of twice of baseband signal for needing to restore.
Except this, the present embodiment additionally provides a kind of specific implementation structure of analog switch phase discriminator, as shown in figure 3, described
Analog switch phase discriminator 102 includes resistance network circuit 1021, analog switch 1022 and low-pass filter 1023, the resistance
Lattice network 1021 includes first resistor and second resistance.
Wherein, the connection relationship of each device is as follows:
The analog switch, the second resistance and the low-pass filter are parallel with one another, the analog switch it is defeated
The input terminal of the low-pass filter is terminated out；
The output end of the first end of the first resistor and the analog switch is as the analog switch phase discriminator
Two input terminals；
The second end of the first resistor is connected with the input terminal of the analog switch, the control termination of the analog switch
First pwm signal or second pwm signal.
Except this, the present embodiment additionally provides a kind of specific implementation structure of non-sampled type analog-to-digital converter, as shown in figure 3,
The non-sampled type analog-to-digital converter 103 includes comparator 1031 and peak detection circuit 1032.
Wherein, the connection relationship of each device is as follows:
The first input end of the comparator is connected with the input terminal of the peak detection circuit, and as described non-sampled
The input terminal of type analog-to-digital converter, the second input termination reference voltage of the comparator, the output end conduct of the comparator
First output end of the non-sampled type analog-to-digital converter is used for the first via signal envelope and the reference voltage,
First digital signal is obtained, or, the second road signal envelope and the reference voltage, obtain second number
Signal；
Second output terminal of the output end of the peak detection circuit as the analog-digital converter, for obtaining described
The peak value of the peak value of signal envelope and the second road signal envelope all the way.
Except this, the present embodiment additionally provides a kind of specific implementation structure of digital demodulating block, as shown in figure 4, the number
Demodulation module 20 includes capture selection control module 201, operation demodulation module 202 and the orthogonal PWM output module of two-way
203。
Wherein, the logical relation of each module is as follows:
The PWM output module exports first pwm signal all the way, described in the output of PWM output module described in another way
Second pwm signal；
The capture selects peak value and the second road signal packet of the control module based on the first via signal envelope
The peak value of network, determines first digital signal or second digital signal is the target acquistion signal；
The operation demodulation module is connected with the first output end of the non-sampled type analog-to-digital converter, catches to the target
It obtains signal and carries out demodulation calculating, restore baseband signal.
Except this, the present embodiment additionally provides a kind of specific implementation structure of operation demodulation module, as shown in figure 5, the fortune
Calculating demodulation module 202 includes adder Module 2021 and two-way delay multiplication module 2022.
Wherein, the logical relation of each module is as follows:
The input terminal of the delay multiplication module is connected with the first output end of the non-sampled type analog-to-digital converter, right
First digital signal and second digital signal delay, obtain the first delayed digital signal and the second delayed digital
Signal, and be calculated first digital signal and the first delayed digital signal the first product and it is described second number
Second product of word signal and the second delayed digital signal；
The input terminal of the adder Module is connected with the output end for the multiplier that is delayed described in two-way, determines that described first multiplies
Long-pending and described second product and be the base band recovering signal.
Schematically, in conjunction with above-mentioned Fig. 1-Fig. 5, a specific example in demodulating system provided in this embodiment is said
Bright, demodulating system provided in this embodiment includes analog demodulator part and digital demodulation part, wherein analog demodulator part is
Analog demodulation circuit 10 is reflected by the mutually orthogonal upper path analoging switch phase discriminator of bandpass filter, two-way and lower path analoging switch
The non-sampled type analog-to-digital converter composition of phase device and the independent upper non-sampled type analog-to-digital converter in road of two-way and lower road.
Bandpass filter is for handling the signal received, and centre frequency is arranged at carrier frequency point, band
Width is 2 times of baseband signal bandwidth, which can be passive filter and be also possible to active filter.
Upper path analoging switch phase discriminator is identical with the hardware of lower path analoging switch phase discriminator, by resistor network, mould
Quasi- switch and low-pass filter composition, wherein resistor network is two resistance series connection, one terminal strip bandpass filter, the other end
It is directly grounded.The switch ends one of analog switch terminate the common point of two series resistances, other end ground connection, control termination number
The pwm signal of word demodulation part output.And that resistance being grounded then low-pass filter in parallel, eventually by the low pass filtered
The output of wave device realization analog switch phase discriminator.
Upper and lower two path analoging switch phase discriminator of road is the difference is that it controls signal, upper and lower two path analoging switch of road mirror
Phase device is controlled by the mutually orthogonal pwm signal of two-way respectively, the PWM letter of so-called mutually orthogonal i.e. two-way control analog switch movement
Number for mutually orthogonal signal (the i.e. phase difference of two signals of two-way )。
When work, the two-way frequency exported by digital demodulation part is identical as carrier frequency, duty ratio be 50% it is mutual
Orthogonal two-way PWM wave carrys out drive analog switch movement, receives to coupling circuit and the letter after band-pass filter
Number carry out keying, that is, be equivalent to be gone to be multiplied with the signal received with the square-wave signal of same frequency, due to there was only square-wave signal
In fundametal compoment and the signal multiplication that receives can obtain a DC quantity, however high frequency all after low-pass filter
Ingredient is attenuated, and is only remained the Partial DC and is measured by get containing base-band information to two-way but there are phase offsets
Signal envelope.
The upper non-sampled type analog-to-digital converter in road is identical with the non-sampled type analog-to-digital converter hardware in lower road, by comparator
It is formed with peak detection circuit, the input terminal of comparator and peak detection circuit in the upper non-sampled type analog-to-digital converter in road simultaneously connects
In the output end of upper path analoging switch phase discriminator, wherein the output termination capture selection road the control module Zhong Shang input of comparator
The port Cap/IO, peak detection circuit connect capture selection the road control module Zhong Shang AD conversion port；The lower non-sampled pattern in road
The input terminal of comparator and peak detection circuit in number converter is attempted by the output end of lower path analoging switch phase discriminator, wherein
The port Cap/IO of the output termination capture selection road the control module Zhong Xia input of comparator, peak detection circuit connect capture choosing
Select the road control module Zhong Xia AD conversion port.
When work, comparator circuit in the upper and lower non-sampled type analog-to-digital converter of road two-way for will containing base-band information but
The digital signal being converted into there are phase offset is compared with decision level there are the signal envelope of phase offset, and upper and lower road
Peak detection circuit in the non-sampled type analog-to-digital converter of two-way is then used to extract two path analoging switch phase discriminators output letter up and down
The peak value of number envelope, for upper and lower two-way envelope is carried out for digital demodulation part the digital signal validity after analog-to-digital conversion with
And the selection in capture channel provides the foundation of judgement.
Digital demodulation portion is divided into digital demodulating block, specifically mutual by two-way mainly by MCU and its relevant software realization
Orthogonal PWM output module, capture selection control module and operation demodulation module composition.
The mutually orthogonal PWM output module of two-way is arranged by software by the PWM module of MCU and is realized, for providing two-way
Mutually orthogonal, frequency is identical as carrier frequency, and the PWM wave that duty ratio is 50% is come the control of realizing analog switch.
Capture selection control module is realized by the independent AD conversion interface of the two-way up and down of MCU by related software, two-way
AD conversion port acquires peak detection circuit output in the non-sampled type analog-to-digital converter of analog demodulator part or more road two-way respectively
The envelope of two-way up and down peak value, judged by detecting the peak value that two path analoging switch phase discriminators export envelope up and down to that
Signal after the digitlization of road envelope is captured.
When work, the data sampled and a lowest decision thresholding are first compared i.e. data by the port upper and lower two-way AD
Effective judgement is less than this threshold value, then represent comparator in non-sampled type analog-to-digital converter can not reliable recognition, so
Cast out the data in the channel, and the data in the channel are all assigned zero.At this point, if the peak value of two paths is not above up and down
The threshold value, then it is assumed that do not receive any data；If the peak value of only upper paths is more than the threshold value, the input of the road Ze Jiangshang
The port Cap/IO be set as acquisition mode, obtained data are denoted as WK(K represents data bit digit), then data are whole on lower road
Assign zero.
If the peak value of only lower paths is more than the threshold value, the port Cap/IO of the road Ze Jiangxia input is set as capture mould
Formula, obtained data are denoted as ZK(K represents data bit digit), then data all assign zero on lower road；If the peak value of upper and lower two paths
It is more than the threshold value, then the peak value of two paths is compared, the biggish Cap/IO that is then inputted all the way of peak value
Port is set as acquisition mode, and another port is then set as the input pattern of IO, takes triggering defeated by that port of acquisition mode
The reading data of inbound port, so that the data for reaching two road ports are read in.
If the peak value of two paths is equal, the road Ze Jiangshang input port is set as acquisition mode, and lower road port is set as the defeated of IO
Enter mode, the reading data of triggering input port is taken by that port of acquisition mode, so that the data for reaching two road ports are read
Enter.
By the independent delay multiplication device module of upper and lower two-way and all the way, adder Module forms operation demodulation module, and upper road is only
Vertical delay multiplication module connects the port Cap/IO of road input, so that the data (0 or 1) for obtaining every bit are denoted as WK,
Again by WKThe delay for carrying out 1bit obtains WK-1, by WKWith WK-1It is multiplied；The lower independent delay road the multiplication module Jie Xia input in road
The port Cap/IO, so that the data (0 or 1) for obtaining every bit are denoted as ZK, then by ZKThe delay for carrying out 1bit obtains ZK-1, will
ZKWith ZK-1It is multiplied.
The two-way input of adder Module connects the independent delay multiplication device module of operation demodulation module or more two-way respectively
Output, is added i.e. W for the result of the independent delay multiplication device module of upper and lower two-wayK×WK-1+ZK×ZK-1It is finally completed base band
The reduction of signal.
It is noted that the mode of pure digi-tal demodulation and pure analog demodulator in compared with the prior art, the present invention
The demodulating system that a kind of simulation that embodiment provides is combined with number passes through analog switch phase discriminator first and realizes baseband signal
Preliminary reduction, by the orthogonal signal keying of two-way, has obtained two-way and has contained base-band information it is likely that there are the numbers of phase shift
Signal, the process realize that delay can be ignored, and the cost of device by analog switch, comparator and peak detection circuit
It is lower.
Then the digital quantity after preliminary phase demodulation is mainly handled by numerical portion, i.e., 0,1 amount are soft without real-coded GA
Part calculation amount is small, and the sampling of another numerical portion only samples the envelope peak of peak detection circuit output, and sample frequency can
It is very low to drop to.So calculation amount is small, sample frequency is low, just will be greatly reduced to the performance dependence of MCU.
From Fig. 6, it is apparent that being equally that a cycle samples 4 times, the sample frequency that digital simulation combines will be much
Less than the sample frequency of pure digi-tal demodulation.
Except this, the present embodiment additionally provides a kind of demodulation method, the demodulating system above-mentioned applied to any one, such as Fig. 7
Shown, which includes:
S71, the signal received is filtered and preliminary phase demodulation, obtains the two paths of signals packet comprising base-band information
Network；
S72, the peak value for obtaining the signal envelope and digital signal corresponding with the signal envelope；
S73, the peak value based on signal envelope described in two-way determine target acquistion signal, and believe the target acquistion
Number carry out digital demodulation calculating, restore baseband signal.
The realization of this method can be realized based on above-mentioned demodulating system.On the basis of the above embodiments, this implementation
Example additionally provides a kind of peak value based on signal envelope described in two-way, determines the specific implementation step of target acquistion signal, such as
It is as follows shown in Fig. 8:
Whether the capture selects control module to judge first digital signal and second digital signal to be same
When be useful signal, if so, determining the peak value of the first via signal envelope and the peak value of the second road signal envelope
In the corresponding digital signal of the larger value be the target acquistion signal, take the first number if two paths of signals envelope peak is equal
Word signal is the target acquistion signal, if not, determining that the effective digital signal of data is the target acquistion signal.
In conclusion the present invention provides a kind of demodulating system and method that simulation is combined with number, by analog demodulator electricity
Road is combined with digital demodulating block, wherein analog demodulation circuit is filtered to the signal received and preliminary phase demodulation, obtains
To comprising base-band information and there may be the two paths of signals envelopes of phase difference, and obtain signal envelope peak value and with signal packet
The corresponding digital signal of network.Digital demodulating block is connected with analog demodulation circuit, based on the peak value of two paths of signals envelope, determines
Target acquistion signal, and digital demodulation calculating is carried out to target acquistion signal, it is finally completed the reduction of baseband signal.This programme is logical
It crosses analog demodulation circuit to be filtered the signal received and the processing of preliminary phase demodulation, greatly reduces adopting for pure digi-tal demodulation
Sample frequency and calculation amount, and further demodulation calculating is carried out to preliminary identified result by digital demodulating block and is finally completed base band
The reduction of signal thereby reduces demodulation difficulty, has saved cost without restoring local carrier.
Each embodiment in this specification is described in a progressive manner, the highlights of each of the examples are with other
The difference of embodiment, the same or similar parts in each embodiment may refer to each other.For device disclosed in embodiment
For, since it is corresponded to the methods disclosed in the examples, so being described relatively simple, related place is said referring to method part
It is bright.
Professional further appreciates that, unit described in conjunction with the examples disclosed in the embodiments of the present disclosure
And algorithm steps, can be realized with electronic hardware, computer software, or a combination of the two, in order to clearly demonstrate hardware and
The interchangeability of software generally describes each exemplary composition and step according to function in the above description.These
Function is implemented in hardware or software actually, the specific application and design constraint depending on technical solution.Profession
Technical staff can use different methods to achieve the described function each specific application, but this realization is not answered
Think beyond the scope of this invention.
The step of method described in conjunction with the examples disclosed in this document or algorithm, can directly be held with hardware, processor
The combination of capable software module or the two is implemented.Software module can be placed in random access memory (RAM), memory, read-only deposit
Reservoir (ROM), electrically programmable ROM, electrically erasable ROM, register, hard disk, moveable magnetic disc, CD-ROM or technology
In any other form of storage medium well known in field.
The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention.
Various modifications to these embodiments will be readily apparent to those skilled in the art, as defined herein
General Principle can be realized in other embodiments without departing from the spirit or scope of the present invention.Therefore, of the invention
It is not intended to be limited to the embodiments shown herein, and is to fit to and the principles and novel features disclosed herein phase one
The widest scope of cause.
Claims (10)
1. a kind of demodulating system that simulation is combined with number characterized by comprising analog demodulation circuit and digital solution mode transfer
Block；
The analog demodulation circuit is filtered to the signal received and preliminary phase demodulation, obtains the two-way comprising base-band information
Signal envelope, and obtain the signal envelope peak value and digital signal corresponding with the signal envelope；
The digital demodulating block is connected with the analog demodulation circuit, based on the peak value of signal envelope described in two-way, determines
Target acquistion signal, and digital demodulation calculating is carried out to the target acquistion signal, restore baseband signal.
2. demodulating system according to claim 1, which is characterized in that the analog demodulation circuit include bandpass filter,
The mutually orthogonal analog switch phase discriminator of two-way and the non-sampled type analog-to-digital converter of two-way；
The bandpass filter is for being filtered the signal received；
The input terminal of the analog switch phase discriminator is connected with the output end of the bandpass filter, and simulation described in the first via is opened
The first pwm signal that phase discriminator is exported based on the digital demodulating block is closed, preliminary phase demodulation is carried out to filtered signal and is obtained
The first via includes the signal envelope of base-band information, and analog switch phase discriminator described in the second tunnel is exported based on the digital demodulating block
The second pwm signal, to filtered signal carry out preliminary phase demodulation obtain the second tunnel include base-band information signal envelope；
The input terminal of the non-sampled type analog-to-digital converter is connected with the output end of the analog switch phase discriminator, obtains described the
Number corresponding to signal envelope described in the peak value and two-way of the peak value of signal envelope and the second road signal envelope all the way
Word signal.
3. demodulating system according to claim 2, which is characterized in that first pwm signal and second pwm signal
The mutually orthogonal signal for being 50% for the identical and duty ratio with carrier frequency.
4. demodulating system according to claim 2, which is characterized in that the bandpass filter is passive filter or active
Filter.
5. demodulating system according to claim 2, which is characterized in that the analog switch phase discriminator includes resistor network electricity
Road, analog switch and low-pass filter, the resistance network circuit include first resistor and second resistance；
The analog switch, the second resistance and the low-pass filter are parallel with one another, the output end of the analog switch
Connect the input terminal of the low-pass filter；
Two as the analog switch phase discriminator of the output end of the first end of the first resistor and the analog switch
Input terminal；
The second end of the first resistor is connected with the input terminal of the analog switch, described in the control termination of the analog switch
First pwm signal or second pwm signal.
6. demodulating system according to claim 2, which is characterized in that the non-sampled type analog-to-digital converter includes comparator
And peak detection circuit；
The first input end of the comparator is connected with the input terminal of the peak detection circuit, and as the non-sampled pattern
The input terminal of number converter, the second of the comparator, which inputs, terminates reference voltage, described in the output end conduct of the comparator
First output end of non-sampled type analog-to-digital converter is obtained for the first via signal envelope and the reference voltage
First digital signal, or, the second road signal envelope and the reference voltage, obtain the second digital signal；
Second output terminal of the output end of the peak detection circuit as the analog-digital converter, for obtaining the first via
The peak value of the peak value of signal envelope and the second road signal envelope.
7. demodulating system according to claim 2, which is characterized in that the digital demodulating block includes capture selection control
Module, operation demodulation module and the orthogonal PWM output module of two-way；
The PWM output module exports first pwm signal, the output of PWM output module described in another way described second all the way
Pwm signal；
Capture the selection peak value and the second road signal envelope of the control module based on the first via signal envelope
Peak value, determines first digital signal or second digital signal is the target acquistion signal；
The operation demodulation module is connected with the first output end of the non-sampled type analog-to-digital converter, believes the target acquistion
Number carry out digital demodulation calculating, restore baseband signal.
8. demodulating system according to claim 7, which is characterized in that the operation demodulation module include adder Module with
And two-way delay multiplication module；
The input terminal of the delay multiplication module is connected with the first output end of the non-sampled type analog-to-digital converter, to described
First digital signal and second digital signal delay obtain the first delayed digital signal and the second delayed digital letter
Number, and the first product and second number of first digital signal and the first delayed digital signal is calculated
Second product of signal and the second delayed digital signal；
The input terminal of the adder Module with described in two-way be delayed multiplier output end be connected, determine first product with
And second product and be the base band recovering signal.
9. a kind of demodulation method, which is characterized in that, should applied to the demodulating system as described in any one of claim 1-8
Demodulation method includes:
The signal received is filtered and preliminary phase demodulation, obtains the two paths of signals envelope comprising base-band information；
Obtain the signal envelope peak value and digital signal corresponding with the signal envelope；
Based on the peak value of signal envelope described in two-way, target acquistion signal is determined, and the target acquistion signal is counted
Word demodulation calculates, and restores baseband signal.
10. demodulation method according to claim 9, which is characterized in that the peak value based on signal envelope described in two-way,
Determine target acquistion signal, comprising:
Judge first digital signal and second digital signal whether be simultaneously be useful signal, if so, determining
The corresponding digital signal of the larger value in the peak value of the peak value of the first via signal envelope and the second road signal envelope
For the target acquistion signal, if the peak value phase of the peak value of the first via signal envelope and the second road signal envelope
Deng, it is determined that first digital signal is the target acquistion signal, if not, determining that the effective digital signal of data is institute
State target acquistion signal.
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