CN106453177A - FSK (Frequency Shift Keying) signal demodulation method and system for narrowband direct printing telegraph equipment - Google Patents
FSK (Frequency Shift Keying) signal demodulation method and system for narrowband direct printing telegraph equipment Download PDFInfo
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- CN106453177A CN106453177A CN201610856292.8A CN201610856292A CN106453177A CN 106453177 A CN106453177 A CN 106453177A CN 201610856292 A CN201610856292 A CN 201610856292A CN 106453177 A CN106453177 A CN 106453177A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/14—Demodulator circuits; Receiver 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
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/103—Chirp modulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/106—M-ary FSK
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
- H04L27/14—Demodulator circuits; Receiver circuits
- H04L27/144—Demodulator circuits; Receiver circuits with demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements
- H04L27/148—Demodulator circuits; Receiver circuits with demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements using filters, including PLL-type filters
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Abstract
The invention discloses an FSK (Frequency Shift Keying) signal demodulation method and system for narrowband direct printing telegraph equipment. The FSK signal demodulation method and system are simple in design, use a calling code field with uniqueness in a narrowband direct printing telegraph ARQ communication mode as a synchronous signal required for FSK signal demodulation, and meanwhile, implements synchronous locking on a narrowband direct printing telegraph signal according to a signal emission period (450ms) and an automatic repeat mechanism of the ARQ communication mode so as to implement narrowband direct printing telegraph signal demodulation and facilitate popularization and application on the pipeline operation in integrated circuits, such as an FPGA, a DSP and the like. The method and the system which are disclosed by the invention can implement demodulation of a non-synchronous sequence short burst FSK signal, and can be applied to non-synchronous sequence short burst communication products based on modulation modes of FSK, MSK (Minimum Shift Keying), GMSK (Gaussian Minimum Shift Keying) and the like.
Description
Technical field
The invention belongs to digital communication technology field is and in particular to a kind of FSK for narrow band direct printing telegraph equipment
Signal demodulating method.
Background technology
At sea in mobile communication business, short wave communication all plays key player all the time.Wherein arrowband directly prints
Word telegram (NBDP) equipment is even more one of important component part of Global Maritime Distress and Safety Syst (GMDSS).
The direct printing telegraph in arrowband has two kinds of communication modes：Unit 7 (one character of the 4B3Y representation of a 7bits, B
=0, Y=1) selective communication mode (ARQ) and 7 cell broadcast communication modes (FEC).Using FSK modulation, modulation rate is
100 bauds, frequency displacement is 170Hz it is adaptable to the mid frequency of the audible spectrum of sender should be 1700Hz.
One ARQ calling cycle is 450ms, wherein comprises：Main page station 210ms information word group launch time, (3 characters were altogether
The information of 21bit), by page station 70ms control signal launch time (information of the common 7bit of 1 character), signal space transmission time
T1 and equipment time delay t2 etc..Wherein, there are not redundant signals in 21bits information word group and 7bits control signal.One ARQ exhales
Make cycle basic sequential as shown in Figure 1.
In the ARQ communication mode of the direct printing telegraph in arrowband, communicating pair sets up communication needs there is exhaling of uniqueness
Be code field, this calling code field calls word groups by 3 groups of 21bits and constitutes, the respectively first calling word group, the second calling word group,
3rd calling word group.And in ARQ communication process, communicating pair must strictly keep the calling cycle of 450ms.Detailed content is joined
Examine ITU-R M.625-4 recommendation《Using the direct printing telegraph apparatus of automatic identification in maritime mobile service》.
As can be seen that in selective communication, the direct printing telegraph in arrowband uses a kind of burst of irredundant sequence
Communication mode, due to not comprising to determine facies-suite in this burst, the common synchronous method here based on theory of PLL is not
It is suitable for.
Content of the invention
The technical problem to be solved is, for the deficiencies in the prior art, provides one kind directly to print for arrowband
The fsk signal demodulation method of word telegraphic instrument and system, are capable of no synchronizing sequence short-term burst fsk signal demodulation, can answer
For the nothing based on modulation systems such as frequency shift keying (FSK), minimum shift keying (MSK), Guassian Minimum Shift Keying GMSKs (GMSK)
Synchronizing sequence short-term burst communication product.
The present invention solves the technical scheme that adopted of above-mentioned technical problem：For narrow band direct printing telegraph equipment
Fsk signal demodulation method, the ARQ communication mode of this narrow band direct printing telegraph equipment is set up has exhaling of uniqueness needed for communication
Make code field call word group by 3 groups of 21bits to constitute, i.e. the first calling word group, the second calling word group and the 3rd calling word group, should
Fsk signal demodulation method comprises the following steps：
(1) FSK radiofrequency signal narrow band direct printing telegraph equipment being sent carries out quantization sampling and obtains radio frequency sampling number
According to, then radio frequency sampled data is filtered with extraction process, obtain quadrature base band data IQ that sample rate is Fs=2400Hz；
(2) calculate the corresponding instantaneous frequency values of quadrature base band data IQ, and the instantaneous frequency values that will be greater than equal to 0 be classified as 1,
Instantaneous frequency values less than 0 are classified as -1, obtain returning 1 or return the data after -1；
(3) 1 will be returned or return the data after -1, be stored in, every K=24 point, the FIFO that depth is at 21 points, obtain K simultaneously
Row branch road；
(4) respectively K parallel branch is carried out correlation computations with the described first calling word group, when in K parallel branch
Continuous L branch road (L>=5), when correlation peak is more than or equal to correlation threshold, extracts in continuous L branch road and be in center
The branch road of position is as optimum branch road P；
(5), after optimum branch road P delay buffer 450ms, first optimum branch road P is slided with the described second calling word group
Dynamic correlation computations；
If correlation peak is less than correlation threshold, repeat step (4), redefine optimum branch road；
If correlation peak is more than correlation threshold, after optimum branch road P continues delay buffer 450ms, with the described the 3rd
Calling word group enters line slip correlation computations, if correlation peak is less than correlation threshold, repeat step (4), redefines optimum
Branch road, if correlation peak is more than correlation threshold, the optimum branch road P of locking is synchronous branch road, and makees demodulation output.
Preferably, the determination process of optimum branch road P is as follows in step (4)：
Step 1：Meet quantity L that correlation peak is equal to the branch road of correlation threshold by counter records, Ln represents out
The L of beginning correlation value calculationnIndividual branch road, during original state, L=0, n=1；
Step 2：Take LnThe data of individual branch road caching；
Step 3：LnThe data of individual branch road caching carries out correlation computations with the described first calling word group；
Step 4：Judge whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execute step
Rapid 5, otherwise execution step 6；
Step 5：As the L=L+1 of counter records, execution step 2, take Ln+1Individual branch road data cached and described
First calling word group continue correlation computations；
Step 6：Judge whether L is more than or equal to 5, if L>=5, execution step 7, otherwise execution step 8；
Step 7：If n+ [L/2]>24, then take optimum branch road P=n+ [L/2] -24, otherwise take optimum branch road P=n+ [L/
2], wherein [L/2] represents downward rounding operation；
Step 8：Counter O reset, L=0, then execute to step 2, take Ln+1The data of individual branch road caching with described
The first calling word group carry out correlation computations, repeat step 2～step 6, until optimum branch road P is determined.
Preferably, the determination process of synchronous branch road is as follows in step (5)：
Step a：After optimum branch road P first time delay buffer 450ms, take data cached sequence P1；
Step b：Data cached sequence P1Carry out correlation computations with the second described calling word group；
Step c：Judge whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execute step
Rapid d, otherwise repeat step (4), redefine optimum branch road；
Step d：After optimum second delay buffer 450ms of branch road P, take data cached sequence P2；
Step e：Data cached sequence P2Carry out correlation computations with the second described calling word group；
Step f：Judge whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execute step
Rapid g, otherwise repeat step (4), redefine optimum branch road；
Step g：The optimum branch road P of locking is synchronous branch road.
For the fsk signal demodulating system of narrow band direct printing telegraph equipment, including the AD sampling unit being sequentially connected, number
Word down-converter unit, instantaneous frequency unit, serioparallel exchange unit line slip correlation unit and delay locked unit；
The described outfan of AD sampling unit is connected with the input of described Digital Down Convert unit, and described AD adopts
The FSK radiofrequency signal that sample unit is used for that narrow band direct printing telegraph equipment is sent carries out quantization sampling and obtains radio frequency sampling number
According to, and provide radio frequency sampled data to described Digital Down Convert unit；
The described outfan of Digital Down Convert unit is connected with the input of described instantaneous frequency unit, described number
Word down-converter unit is used for radio frequency sampled data is filtered with extraction process, obtains the orthogonal basiss that sample rate is Fs=2400Hz
Band data IQ, and provide quadrature base band data IQ to described instantaneous frequency unit；
The described outfan of instantaneous frequency unit is connected with the input of described serioparallel exchange unit, and described is instantaneous
Frequency cells are used for calculating the corresponding instantaneous frequency values of quadrature base band data IQ, and the instantaneous frequency values that will be greater than equal to 0 are classified as
1, the instantaneous frequency values less than 0 are classified as -1, obtain returning 1 or return the data after -1, and provide to described serioparallel exchange unit
Return 1 or return the data after -1；
The outfan of described serioparallel exchange unit is connected with described and line slip correlation unit input, described
Serioparallel exchange unit is used for return 1 or returning the data after -1, is stored in, every K=24 point, the FIFO that depth is at 21 points, obtains K
Individual parallel branch；
Described and line slip correlation unit outfan is connected with the input of described delay locked unit, described
And line slip correlation unit is used for respectively with the described first calling word group, K parallel branch being carried out correlation computations, when K is individual simultaneously
Continuous L branch road (L in row branch road>=5), when correlation peak is more than or equal to correlation threshold, extract in continuous L branch road
The branch road being in center is as optimum branch road P；
Described delay locked unit is used for after optimum branch road P delay buffer 450ms, by by optimum branch road P and institute
The the second calling word group stated, the 3rd calling word group enter line slip correlation computations, and locking synchronization branch road simultaneously makees demodulation output.
Preferably, described Digital Down Convert unit includes the first multiplier, a CIC decimation filter, a FIR
Decimation filter, digital controlled oscillator, the second multiplier, the 2nd CIC decimation filter and the 2nd FIR decimation filter, described
AD sampling unit, the first multiplier, a CIC decimation filter and a FIR decimation filter are sequentially connected, and described first
FIR decimation filter is used for output orthogonal signal data I；Described AD sampling unit, the second multiplier, the 2nd CIC extract filter
Ripple device and the 2nd FIR decimation filter are sequentially connected, and the 2nd described FIR decimation filter is used for exporting in-phase signal data Q；
Described digital controlled oscillator is connected with the first described multiplier and the second multiplier respectively.
Preferably, described instantaneous frequency unit includes the first delay unit, the second delay unit, the 3rd time delay list
Unit, the 4th delay unit, the 3rd multiplier, the 4th multiplier, the 5th multiplier, the 6th multiplier, subtractor, adder, remove
Musical instruments used in a Buddhist or Taoist mass and normalization unit, the input of the first described delay unit and the second described delay unit is respectively with described
The outfan of one FIR decimation filter is connected, and described orthogonal signalling data I is divided into four tunnels, that is, first via orthogonal signalling data,
Second tunnel orthogonal signalling data, the 3rd tunnel orthogonal signalling data and the 4th tunnel orthogonal signalling data, the orthogonal letter of the described first via
Number is sent directly into the 3rd described multiplier, and the second described tunnel orthogonal signalling data is prolonged through the first described delay unit
When one caching period after send into the 5th described multiplier, the 3rd described tunnel orthogonal signalling data is sent directly into described the
Four multipliers, the 4th described tunnel orthogonal signalling data sends into institute after described one caching period of the second delay unit time delay
The 4th multiplier stated；The input of the 3rd described delay unit and the 4th described delay unit is respectively with described second
The outfan of FIR decimation filter is connected, and described in-phase signal data Q is divided into four tunnels, that is, first via in-phase signal data, the
Two tunnel in-phase signal data, the 3rd tunnel in-phase signal data and the 4th tunnel in-phase signal data, described first via in-phase signal
Data sends into the 3rd described multiplier after described one caching period of the 3rd delay unit time delay, and the second described tunnel is same
Believe that number is sent directly into the 5th described multiplier, the 3rd described tunnel in-phase signal data is through the 4th described time delay list
The 6th described multiplier is sent into, the 4th described tunnel in-phase signal data is sent directly into described after one caching period of first time delay
The 6th multiplier；The outfan of the 3rd described multiplier and the 5th described multiplier is defeated with described subtractor respectively
Enter end to be connected, the outfan input with described adder respectively of the 4th described multiplier and the 6th described multiplier
It is connected, the outfan input phase with described divider respectively of the described outfan of subtractor and described adder
Even, the described outfan of divider is connected with the input of described normalization unit, returns 1 or returns the data after -1 through described
Normalization unit outfan output.
Compared with prior art, it is an advantage of the current invention that：Disclosed by the invention for narrow band direct printing telegraph equipment
Fsk signal demodulation method and system, design is simple, and it is unique using having in arrowband direct printing telegraph ARQ communication mode
Property calling code field as the required synchronizing signal of fsk signal demodulation, the signal transmit cycle according to ARQ communication mode simultaneously
(450ms) and automatic retransmission mechanism, realize the genlocing to arrowband direct printing telegraph signal, thus realize arrowband directly printing
Word telegraphic signal demodulates, and is easy to popularization and application in the pile line operation in the integrated circuits such as FPGA and DSP.The inventive method and
System is capable of no synchronizing sequence short-term burst fsk signal demodulation, can be applicable to based on frequency shift keying (FSK), minimum shift frequency
The no synchronizing sequence short-term burst communication product of the modulation systems such as keying (MSK), Guassian Minimum Shift Keying GMSK (GMSK).
Brief description
Fig. 1 is the basic sequential in an ARQ calling cycle of narrow band direct printing telegraph equipment；
Fig. 2 is the structure connection diagram of demodulating system of the present invention；
Fig. 3 is the structural representation of Digital Down Convert unit in demodulating system of the present invention；
Fig. 4 is the structural representation of instantaneous frequency unit in demodulating system of the present invention；
Fig. 5 is the data conversion schematic diagram of serioparallel exchange unit in demodulating system of the present invention；
Fig. 6 is the flow chart of optimum branch road P determination process in demodulation method of the present invention, i.e. the signal stream of parallel sliding unit
Cheng Tu；
Fig. 7 is the flow chart of synchronous branch road determination process in demodulation method of the present invention, i.e. the signal stream of delay locked unit
Cheng Tu.
Specific embodiment
Below in conjunction with accompanying drawing embodiment, the present invention is described in further detail.
The fsk signal demodulation method for narrow band direct printing telegraph equipment of embodiment, the direct printing telegraph in this arrowband
The calling code field needed for the ARQ communication mode foundation communication of equipment with uniqueness is made up of 3 groups of 21bits calling word groups, that is,
First calling word group, the second calling word group and the 3rd calling word group, this fsk signal demodulation method comprises the following steps：
(1) FSK radiofrequency signal narrow band direct printing telegraph equipment being sent carries out quantization sampling and obtains radio frequency sampling number
According to, then radio frequency sampled data is filtered with extraction process, obtain quadrature base band data IQ that sample rate is Fs=2400Hz；
(2) calculate the corresponding instantaneous frequency values of quadrature base band data IQ, and the instantaneous frequency values that will be greater than equal to 0 be classified as 1,
Instantaneous frequency values less than 0 are classified as -1, obtain returning 1 or return the data after -1；
(3) 1 will be returned or return the data after -1, be stored in, every K=24 point, the FIFO that depth is at 21 points, obtain K simultaneously
Row branch road；
(4) respectively K parallel branch is carried out correlation computations with the described first calling word group, when in K parallel branch
Continuous L branch road (L>=5), when correlation peak is more than or equal to correlation threshold, extracts in continuous L branch road and be in center
The branch road of position is as optimum branch road P, as shown in fig. 6, concrete determination process is as follows：
Step 1：Meet quantity L that correlation peak is equal to the branch road of correlation threshold by counter records, Ln represents out
The L of beginning correlation value calculationnIndividual branch road, during original state, L=0, n=1；
Step 2：Take LnThe data of individual branch road caching；
Step 3：LnThe data of individual branch road caching carries out correlation computations with the described first calling word group；
Step 4：Judge whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execute step
Rapid 5, otherwise execution step 6；
Step 5：As the L=L+1 of counter records, execution step 2, take Ln+1Individual branch road data cached and described
First calling word group continue correlation computations；
Step 6：Judge whether L is more than or equal to 5, if L>=5, execution step 7, otherwise execution step 8；
Step 7：If n+ [L/2]>24, then take optimum branch road P=n+ [L/2] -24, otherwise take optimum branch road P=n+ [L/
2], wherein [L/2] represents downward rounding operation；
Step 8：Counter O reset, L=0, then execute to step 2, take Ln+1The data of individual branch road caching with described
The first calling word group carry out correlation computations, repeat step 2～step 6, until optimum branch road P is determined；
(5), after optimum branch road P delay buffer 450ms, first optimum branch road P is slided with the described second calling word group
Dynamic correlation computations；
If correlation peak is less than correlation threshold, repeat step (4), redefine optimum branch road；
If correlation peak is more than correlation threshold, after optimum branch road P continues delay buffer 450ms, with the described the 3rd
Calling word group enters line slip correlation computations, if correlation peak is less than correlation threshold, repeat step (4), redefines optimum
Branch road, if correlation peak is more than correlation threshold, the optimum branch road P of locking is synchronous branch road, and makees demodulation output, wherein, such as
Shown in Fig. 7, the determination process of synchronous branch road is as follows：
Step a：After optimum branch road P first time delay buffer 450ms, take data cached sequence P1；
Step b：Data cached sequence P1Carry out correlation computations with the second described calling word group；
Step c：Judge whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execute step
Rapid d, otherwise repeat step (4), redefine optimum branch road；
Step d：After optimum second delay buffer 450ms of branch road P, take data cached sequence P2；
Step e：Data cached sequence P2Carry out correlation computations with the second described calling word group；
Step f：Judge whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execute step
Rapid g, otherwise repeat step (4), redefine optimum branch road；
Step g：The optimum branch road P of locking is synchronous branch road.
For the fsk signal demodulating system of narrow band direct printing telegraph equipment, can achieve above-mentioned fsk signal demodulation method,
As shown in Fig. 2 this fsk signal demodulating system include being sequentially connected AD sampling unit 1, Digital Down Convert unit 2, instantaneous frequency
Unit 3, serioparallel exchange unit 4 line slip correlation unit 5 and delay locked unit 6.
The outfan of AD sampling unit 1 is connected with the input of Digital Down Convert unit 2, and AD sampling unit 1 is used for narrow
Carry out quantization sampling with the FSK radiofrequency signal that direct printing telegraph apparatus sends and obtain radio frequency sampled data, and become under numeral
Frequency unit 2 provides radio frequency sampled data.
The outfan of Digital Down Convert unit 2 is connected with the input of instantaneous frequency unit 3, and Digital Down Convert unit 2 is used
Process in radio frequency sampled data is filtered with extraction, obtain quadrature base band data IQ that sample rate is Fs=2400Hz, and to
Instantaneous frequency unit provides quadrature base band data IQ.As shown in figure 3, Digital Down Convert unit 2 includes the first multiplier 21, first
CIC decimation filter 22, a FIR decimation filter 23, digital controlled oscillator 24, the second multiplier 25, the 2nd CIC filtering extraction
Device 26 and the 2nd FIR decimation filter 27, AD sampling unit 1, the first multiplier 21, a CIC decimation filter 22 and first
FIR decimation filter 23 is sequentially connected, and a FIR decimation filter 23 is used for output orthogonal signal data I；AD sampling unit 1,
Second multiplier 25, the 2nd CIC decimation filter 26 and the 2nd FIR decimation filter 27 are sequentially connected, the 2nd FIR filtering extraction
Device 27 is used for exporting in-phase signal data Q；Digital controlled oscillator 24 is connected with the first multiplier 21 and the second multiplier 25 respectively.AD
After being multiplied using the cosine of data and digital controlled oscillator 24 and sinusoidal signal, obtain orthogonal signalling data I and in-phase signal data
Q, data I extracts through the 2nd CIC through a CIC decimation filter 22 and a FIR decimation filter 23 filtering extraction, data Q
Wave filter 26 and the 2nd FIR decimation filter 27 filtering extraction, obtain using the baseband I circuit-switched data for Fs=2400Hz for the frequency and
Base band Q circuit-switched data, i.e. quadrature base band data IQ.
The outfan of instantaneous frequency unit 3 is connected with the input of serioparallel exchange unit 4, instantaneous frequency unit 3 by based on
Calculate the corresponding instantaneous frequency values of quadrature base band data IQ, and the instantaneous frequency values that will be greater than equal to 0 are classified as 1, will be instantaneous less than 0
Frequency values are classified as -1, obtain returning 1 or return the data after -1, and return 1 or return the data after -1 to serioparallel exchange unit 4 offer.As
Shown in Fig. 4, instantaneous frequency unit 3 includes the first delay unit 31, the second delay unit 32, the 3rd delay unit the 33, the 4th prolong
Shi Danyuan 34, the 3rd multiplier 35, the 4th multiplier 36, the 5th multiplier 37, the 6th multiplier 38, subtractor 71, adder
72nd, divider 73 and normalization unit 74, the input of the first delay unit 31 and the second delay unit 32 respectively with a FIR
The outfan of decimation filter 23 is connected, and orthogonal signalling data I is divided into four tunnels, and that is, first via orthogonal signalling data, the second tunnel be just
Hand over signal data, the 3rd tunnel orthogonal signalling data and the 4th tunnel orthogonal signalling data, first via orthogonal signalling data is sent directly into
3rd multiplier 35, the second tunnel orthogonal signalling data obtains I after one caching period of the first delay unit 31 time delay1Data,
Send into the 5th multiplier 37, the 3rd tunnel orthogonal signalling data is sent directly into the 4th multiplier 36, the 4th tunnel orthogonal signalling data warp
I is obtained after one caching period of second delay unit, 32 time delay1Data, sends into the 4th multiplier 36；3rd delay unit 33 He
The input of the 4th delay unit 34 is connected with the outfan of the 2nd FIR decimation filter 27 respectively, and in-phase signal data Q is divided into
Four tunnels, that is, first via in-phase signal data, the second tunnel in-phase signal data, the 3rd tunnel in-phase signal data and the 4th tunnel are same believes
Number, first via in-phase signal data obtains Q after one caching period of the 3rd delay unit 33 time delay1Data, sends into the
Three multipliers 35, the second tunnel in-phase signal data is sent directly into the 5th multiplier 37, and the 3rd tunnel in-phase signal data is prolonged through the 4th
Q is obtained after one caching period of Shi Danyuan 34 time delay1Data, sends into the 6th multiplier 38, and the 4th tunnel in-phase signal data is direct
Send into the 6th multiplier 38；The outfan of the 3rd multiplier 35 and the 5th multiplier 37 input phase with subtractor 71 respectively
Even, the 4th multiplier 36 is connected with the input of adder 72 respectively with the outfan of the 6th multiplier 38, subtractor 71 defeated
Go out end to be connected with the input of divider 73 respectively with the outfan of adder 72, the outfan of divider 73 and normalization unit
74 input is connected, and returns 1 or returns the outfan through normalization unit 74 for the data after -1 to export.As shown in figure 4, the 3rd multiplication
Device 35 exports I*Q1Data, the 5th multiplier 37 exports Q*I1Data, I*Q1Data and Q*I1Data sends into subtractor 71；4th
Multiplier 36 exports I*I1Data, the 6th multiplier 38 exports Q*Q1Data, I*I1Data and Q*Q1Data sends into adder 72；
Subtractor 71 exports I*Q1-Q*I1Data, adder 72 exports I*I1+Q*Q1Data；I*Q1-Q*I1Data and I*I1+Q*Q1Data
Send into divider 73, divider 73 output is sent into normalization unit 74, obtained returning 1 or return the data after -1.
The outfan of serioparallel exchange unit 4 is connected with the input of simultaneously line slip correlation unit 5, and serioparallel exchange unit 4 is used
In 1 will be returned or returns the data after -1, it is stored in, every K=24 point, the FIFO that depth is at 21 points, obtains K parallel branch.String
And the data conversion schematic diagram of converting unit 4 is as shown in Figure 5.
And the outfan of line slip correlation unit 5 is connected with the input of delay locked unit 6, and line slip correlation unit
5 are used for respectively K parallel branch and the first calling word group being carried out correlation computations, when the continuous L branch road in K parallel branch
(L>=5), when correlation peak is more than or equal to correlation threshold, extract the branch road conduct being in center in continuous L branch road
Optimum branch road P.The signal flow graph of parallel sliding unit 5 is as shown in Figure 6.
Delay locked unit 6 is used for after optimum branch road P delay buffer 450ms, by calling optimum branch road P and second
Word group, the 3rd calling word group enter line slip correlation computations, and locking synchronization branch road simultaneously makees demodulation output.The letter of delay locked unit 6
Number flow chart is as shown in Figure 7.
Claims (6)
1. it is used for the fsk signal demodulation method of narrow band direct printing telegraph equipment, the ARQ of this narrow band direct printing telegraph equipment leads to
Letter mode is set up to have the calling code field of uniqueness needed for communication and call word groups by 3 groups of 21bits and is constituted, i.e. the first calling word
Group, the second calling word group and the 3rd calling word group are it is characterised in that this fsk signal demodulation method comprises the following steps：
(1) FSK radiofrequency signal narrow band direct printing telegraph equipment being sent carries out quantization sampling and obtains radio frequency sampled data, then
Radio frequency sampled data is filtered with extraction process, obtains quadrature base band data IQ that sample rate is Fs=2400Hz；
(2) calculate the corresponding instantaneous frequency values of quadrature base band data IQ, and the instantaneous frequency values that will be greater than equal to 0 are classified as 1, will be little
Instantaneous frequency values in 0 are classified as -1, obtain returning 1 or return the data after -1；
(3) 1 will be returned or return the data after -1, be stored in, every K=24 point, the FIFO that depth is at 21 points, obtain K parallel
Road；
(4) respectively K parallel branch is carried out correlation computations with the described first calling word group, when the company in K parallel branch
Continuous L branch road (L>=5), when correlation peak is more than or equal to correlation threshold, extracts in continuous L branch road and be in center
Branch road as optimum branch road P；
(5), after optimum branch road P delay buffer 450ms, first optimum branch road P is entered line slip phase with the described second calling word group
Close and calculate；
If correlation peak is less than correlation threshold, repeat step (4), redefine optimum branch road；
If correlation peak is more than correlation threshold, after optimum branch road P continues delay buffer 450ms, with the 3rd described calling
Word group enters line slip correlation computations, if correlation peak is less than correlation threshold, repeat step (4), redefines optimum branch road,
If correlation peak is more than correlation threshold, the optimum branch road P of locking is synchronous branch road, and makees demodulation output.
2. the fsk signal demodulation method for narrow band direct printing telegraph equipment according to claim 1 it is characterised in that
In step (4), the determination process of optimum branch road P is as follows：
Step 1：Meet quantity L that correlation peak is equal to the branch road of correlation threshold by counter records, Ln represents beginning phase
The L that pass value calculatesnIndividual branch road, during original state, L=0, n=1；
Step 2：Take LnThe data of individual branch road caching；
Step 3：LnThe data of individual branch road caching carries out correlation computations with the described first calling word group；
Step 4：Judge that whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execution step 5,
Otherwise execution step 6；
Step 5：As the L=L+1 of counter records, execution step 2, take Ln+1Data cached Yu described of individual branch road
One calling word group continues correlation computations；
Step 6：Judge whether L is more than or equal to 5, if L>=5, execution step 7, otherwise execution step 8；
Step 7：If n+ [L/2]>24, then take optimum branch road P=n+ [L/2] -24, otherwise take optimum branch road P=n+ [L/2], its
In [L/2] represent downward rounding operation；
Step 8：Counter O reset, L=0, then execute to step 2, take Ln+1The data of individual branch road caching and described the
One calling word group carries out correlation computations, repeat step 2～step 6, until optimum branch road P is determined.
3. the fsk signal demodulation method for narrow band direct printing telegraph equipment according to claim 1 and 2, its feature
It is that the determination process of synchronous branch road in step (5) is as follows：
Step a：After optimum branch road P first time delay buffer 450ms, take data cached sequence P1；
Step b：Data cached sequence P1Carry out correlation computations with the second described calling word group；
Step c：Judge that whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execution step d,
Otherwise repeat step (4), redefine optimum branch road；
Step d：After optimum second delay buffer 450ms of branch road P, take data cached sequence P2；
Step e：Data cached sequence P2Carry out correlation computations with the second described calling word group；
Step f：Judge that whether correlation peak is equal to correlation threshold, if correlation peak is equal to correlation threshold, execution step g,
Otherwise repeat step (4), redefine optimum branch road；
Step g：The optimum branch road P of locking is synchronous branch road.
4. it is used for the fsk signal demodulating system of narrow band direct printing telegraph equipment it is characterised in that the AD including being sequentially connected adopts
Sample unit, Digital Down Convert unit, instantaneous frequency unit, serioparallel exchange unit line slip correlation unit and delay locked list
Unit；
The described outfan of AD sampling unit is connected with the input of described Digital Down Convert unit, and described AD sampling is single
Unit carries out quantization sampling for the FSK radiofrequency signal that narrow band direct printing telegraph equipment is sent and obtains radio frequency sampled data, and
There is provided radio frequency sampled data to described Digital Down Convert unit；
The described outfan of Digital Down Convert unit is connected with the input of described instantaneous frequency unit, under described numeral
Converter unit is used for radio frequency sampled data is filtered with extraction process, obtains the quadrature base band number that sample rate is Fs=2400Hz
According to IQ, and provide quadrature base band data IQ to described instantaneous frequency unit；
The described outfan of instantaneous frequency unit is connected with the input of described serioparallel exchange unit, described instantaneous frequency
Unit is used for calculating the corresponding instantaneous frequency values of quadrature base band data IQ, and the instantaneous frequency values that will be greater than equal to 0 are classified as 1, will
Instantaneous frequency values less than 0 are classified as -1, obtain returning 1 or return the data after -1, and provide to described serioparallel exchange unit return 1 or
Return the data after -1；
The outfan of described serioparallel exchange unit is connected with described and line slip correlation unit input, and described string is simultaneously
Converting unit is used for return 1 or returning the data after -1, is stored in, every K=24 point, the FIFO that depth is at 21 points, obtains K simultaneously
Row branch road；
Described and line slip correlation unit outfan is connected with the input of described delay locked unit, and described is parallel
Slip correlation unit is used for respectively with the described first calling word group, K parallel branch being carried out correlation computations, when K parallel
Continuous L branch road (L in road>=5), when correlation peak is more than or equal to correlation threshold, extracts in continuous L branch road and be in
The branch road of center is as optimum branch road P；
Described delay locked unit be used for after optimum branch road P delay buffer 450ms, by by optimum branch road P with described
Second calling word group, the 3rd calling word group enter line slip correlation computations, and locking synchronization branch road simultaneously makees demodulation output.
5. the fsk signal demodulating system for narrow band direct printing telegraph equipment according to claim 4 it is characterised in that
Described Digital Down Convert unit includes the first multiplier, a CIC decimation filter, a FIR decimation filter, numerical control are shaken
Swing device, the second multiplier, the 2nd CIC decimation filter and the 2nd FIR decimation filter, described AD sampling unit, first take advantage of
Musical instruments used in a Buddhist or Taoist mass, a CIC decimation filter and a FIR decimation filter are sequentially connected, and a described FIR decimation filter is used for
Output orthogonal signal data I；Described AD sampling unit, the second multiplier, the 2nd CIC decimation filter and the 2nd FIR extract
Wave filter is sequentially connected, and the 2nd described FIR decimation filter is used for exporting in-phase signal data Q；Described digital controlled oscillator
It is connected with the first described multiplier and the second multiplier respectively.
6. the fsk signal demodulating system for narrow band direct printing telegraph equipment according to claim 5 it is characterised in that
Described instantaneous frequency unit include the first delay unit, the second delay unit, the 3rd delay unit, the 4th delay unit,
Three multipliers, the 4th multiplier, the 5th multiplier, the 6th multiplier, subtractor, adder, divider and normalization unit, institute
The first delay unit stated and the input of the second described delay unit are defeated with a described FIR decimation filter respectively
Go out end be connected, described orthogonal signalling data I is divided into four tunnels, that is, first via orthogonal signalling data, the second tunnel orthogonal signalling data,
3rd tunnel orthogonal signalling data and the 4th tunnel orthogonal signalling data, described first via orthogonal signalling data is sent directly into described
3rd multiplier, the second described tunnel orthogonal signalling data was sent into after described one caching period of the first delay unit time delay
The 5th described multiplier, the 3rd described tunnel orthogonal signalling data is sent directly into the 4th described multiplier, and the described 4th
Road orthogonal signalling data sends into the 4th described multiplier after described one caching period of the second delay unit time delay；Described
The 3rd delay unit and the 4th described delay unit the input output with the 2nd described FIR decimation filter respectively
End is connected, and described in-phase signal data Q is divided into four tunnels, that is, first via in-phase signal data, the second tunnel in-phase signal data, the
Three tunnel in-phase signal data and the 4th tunnel in-phase signal data, described first via in-phase signal data is through the 3rd described time delay
The 3rd described multiplier is sent in unit time delay after one caching period, the second described tunnel in-phase signal data is sent directly into institute
The 5th multiplier stated, the 3rd described tunnel in-phase signal data is after described one caching period of the 4th delay unit time delay
Send into the 6th described multiplier, the 4th described tunnel in-phase signal data is sent directly into the 6th described multiplier；Described
3rd multiplier is connected with the input of described subtractor respectively with the outfan of the 5th described multiplier, and the described 4th
Multiplier is connected with the input of described adder respectively with the outfan of the 6th described multiplier, described subtractor
Outfan is connected with the input of described divider respectively with the outfan of described adder, the output of described divider
End is connected with the input of described normalization unit, returns 1 or returns the outfan through described normalization unit for the data after -1
Output.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111740931A (en) * | 2020-06-02 | 2020-10-02 | 苏州云芯微电子科技有限公司 | FSK demodulation method and system based on time delay self-sampling |
| CN112054980A (en) * | 2019-06-06 | 2020-12-08 | 国家广播电视总局广播电视科学研究院 | Demodulation method and device based on MSK modulation and electronic equipment |
| CN113765545A (en) * | 2021-09-02 | 2021-12-07 | 上海微波技术研究所（中国电子科技集团公司第五十研究所） | Bluetooth receiver demodulation system and method |
| RU209338U1 (en) * | 2021-05-27 | 2022-03-15 | Ооо "Сигнал Сибирь" | DEVICE FOR DEMODULATION OF OFDM SIGNAL WITH SAMPLING FREQUENCY DECIMATING |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090156139A1 (en) * | 2007-12-14 | 2009-06-18 | Yong-Min Lee | Communication system and search and rescue terminal for vessels |
| CN104168037A (en) * | 2014-08-08 | 2014-11-26 | 南京俊禄科技有限公司 | Multifunctional navigation information receiver |
| CN104486060A (en) * | 2014-12-24 | 2015-04-01 | 中电科（宁波）海洋电子研究院有限公司 | Bit synchronization method and system based on sliding integration |
-
2016
- 2016-09-28 CN CN201610856292.8A patent/CN106453177B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090156139A1 (en) * | 2007-12-14 | 2009-06-18 | Yong-Min Lee | Communication system and search and rescue terminal for vessels |
| CN104168037A (en) * | 2014-08-08 | 2014-11-26 | 南京俊禄科技有限公司 | Multifunctional navigation information receiver |
| CN104486060A (en) * | 2014-12-24 | 2015-04-01 | 中电科（宁波）海洋电子研究院有限公司 | Bit synchronization method and system based on sliding integration |
Non-Patent Citations (2)
| Title |
|---|
| 杨庆宝: "从编码技术谈船用窄带直接印字电报(NBDP)", 《天津航海》 * |
| 赵文祥: "关于GMDSS系统中的NBDP窄带直接印字电报的探讨", 《第六届导航及海上通信学术年会》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112054980A (en) * | 2019-06-06 | 2020-12-08 | 国家广播电视总局广播电视科学研究院 | Demodulation method and device based on MSK modulation and electronic equipment |
| CN112054980B (en) * | 2019-06-06 | 2023-05-16 | 国家广播电视总局广播电视科学研究院 | Demodulation method and device based on MSK modulation and electronic equipment |
| CN111740931A (en) * | 2020-06-02 | 2020-10-02 | 苏州云芯微电子科技有限公司 | FSK demodulation method and system based on time delay self-sampling |
| RU209338U1 (en) * | 2021-05-27 | 2022-03-15 | Ооо "Сигнал Сибирь" | DEVICE FOR DEMODULATION OF OFDM SIGNAL WITH SAMPLING FREQUENCY DECIMATING |
| CN113765545A (en) * | 2021-09-02 | 2021-12-07 | 上海微波技术研究所（中国电子科技集团公司第五十研究所） | Bluetooth receiver demodulation system and method |
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