CN115149978B - Chirp spread spectrum modulation method, system and medium with anti-interception function - Google Patents
Chirp spread spectrum modulation method, system and medium with anti-interception function Download PDFInfo
- Publication number
- CN115149978B CN115149978B CN202211076166.2A CN202211076166A CN115149978B CN 115149978 B CN115149978 B CN 115149978B CN 202211076166 A CN202211076166 A CN 202211076166A CN 115149978 B CN115149978 B CN 115149978B
- Authority
- CN
- China
- Prior art keywords
- spread spectrum
- symbol
- phase
- spectrum modulation
- data
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0071—Use of interleaving
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
- H04B2001/6912—Spread spectrum techniques using chirp
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Abstract
The invention discloses a chirp spread spectrum modulation method, system and medium with anti-interception function, the invention includes inputting digital bita j Performing symbol mapping on digital code elements in the digital code stream obtained by performing randomization, channel coding and interleaving; framing and modulating data symbols obtained by symbol mapping; introducing the phase of each sampling point in the modulation output waveform [0,2 ]kπ]And random phase variables are uniformly distributed in the phase-locked loop so as to realize phase randomization processing, and the final chirp spread spectrum modulation output waveform is generated by the phase after the phase randomization processing. The invention introduces [0,2 ] when each data symbol is modulated by chirp spread spectrumkπ]Random initial phase variable distributed uniformly in the system randomizes the frequency of the broadband linear frequency modulation signal and makes the power spectral density of the chirp spread spectrum modulation follow the parameterskThe amplification is reduced, the modulation signal has a low interception probability, and the problem that the chirp spread spectrum modulation signal is easy to intercept is solved.
Description
Technical Field
The invention relates to a transmission technology of digital signals in the field of digital communication, in particular to a chirp spread spectrum modulation method, a system and a medium with an anti-interception function.
Background
The spread spectrum modulation technology comprises three spread spectrum technologies of Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) and time hopping spread spectrum (FTSS) or the combination of the spread spectrum technologies, and is used for realizing anti-interference communication, and a signal after being subjected to spread spectrum modulation is a communication signal with the characteristic of low interception probability. The chirp (chirp) spread spectrum modulation technology is different from the spread spectrum modulation communication system, and is based on wideband chirp pulse to code modulation data symbols, which has the advantages of resisting multipath interference and immune Doppler effect. The chirp spread spectrum modulation technology is mainly applied to a wireless personal area network with low power consumption and low speed; the LoRa modulation and demodulation technology based on chirp spread spectrum modulation is also widely applied to the Internet of things; however, due to the characteristics of linear frequency modulation, the chirp spread spectrum modulation technology causes the power envelope, the bandwidth and the like of a modulation signal to be kept unchanged, the frequency spectrum response of the modulation signal is easy to identify, and the signal is easy to intercept.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: aiming at the problems in the prior art, the invention provides a chirp spread spectrum modulation method, a system and a medium with an anti-interception function, and the invention introduces [0,2 ] when each data symbol is modulated by chirp spread spectrumkπ]Random phase variables distributed uniformly in the system randomize the frequency of the broadband linear frequency modulation signal and make the power spectral density of the chirp spread spectrum modulation follow the parameterskThe gain is increased and decreased, the modulation signal has a Low interception Probability (LPI), and the problem that the chirp spread spectrum modulation signal is easy to Intercept can be solved.
In order to solve the technical problems, the invention adopts the technical scheme that:
a chirp spread spectrum modulation method with an anti-interception function comprises the following steps:
s1, inputting digital bitsa j Randomizing to obtain digital bitsb j ；
S2, randomizing the obtained digital bitsb j Carrying out channel coding and interleaving processing to obtain a digital code stream consisting of 0 or 1;
s3, carrying out symbol mapping on digital code elements in the digital code stream obtained after channel coding and interleaving processing;
s4, framing the data symbols obtained by symbol mapping;
s5, modulating the framed data symbols;
s6, introducing the phase of each sampling point in the modulation output waveform [0,2kπ]And random phase variables are uniformly distributed in the phase-locked loop so as to realize phase randomization, and the final chirp spread spectrum modulation output waveform is generated by the phase after the phase randomization.
Optionally, step S1 includes: using linear shift registers, according to a given pseudo-random sequencec j Digital bits input bit by bit paira j Performing modulo-2 addition to obtain digital bitsb j To implement the randomization process.
Optionally, the given pseudo-random sequencec j Is an M-sequence with pseudo-randomness.
Optionally, step S3 includes: the digital code elements in the digital code stream obtained after the channel coding and the interleaving processing are processed according to the preset quantitySFThe bits are grouped and Gray code coded, and mapped to values [0,1, …,m,…,M]data symbol ofmWhereinMIs the maximum value of a data symbol and hasM = 2 SF -1, each data symbol having a duration ofT B In whichSFIs a positive integer and represents the spreading factor of the chirped spread spectrum modulation.
Optionally, step S4 includes using each group of data symbols obtained by symbol mapping as intra-frame data field data, and appending a prefix symbol, a frame synchronization header symbol, and a frequency synchronization header symbol before the intra-frame data field data, so as to obtain a frame of framed data.
Optionally, step S5 includes performing linear frequency modulation on the prefix symbol, the frame synchronization header symbol, the frequency synchronization header symbol, and the intra-frame data field data in each framed data frame by frame, wherein positive and negative characteristics of the frequency change rate used for performing linear frequency modulation on the prefix symbol, the frame synchronization header symbol, and the intra-frame data field data are the same, and positive and negative characteristics of the frequency change rate used for performing linear frequency modulation on the frequency synchronization header symbol are opposite to positive and negative characteristics of the frequency change rate used for performing linear frequency modulation on the intra-frame data field data.
Optionally, the frequency change rate adopted for performing linear frequency modulation on the prefix symbol, the frame synchronization header symbol, and the intra-frame data field data is a positive frequency change rate, and a functional expression of the modulated output waveform is as follows:
the frequency change rate adopted for linear frequency modulation of the frequency synchronization header symbol is a negative frequency change rate, and the functional expression of the modulated output waveform is as follows:
wherein the content of the first and second substances,
shows an output waveform obtained by linear frequency modulation at a frequency change rate of positive frequency change,jis the unit of an imaginary number,f m (t) For modulating symbolsmThe instantaneous frequency of the time of day and,tas a matter of time, the time is,
is the phase of the signal at the instant,Bin order to be the bandwidth of the channel,T B in the case of a data symbol period,man index for the mth value of the data symbol,Mis the maximum value of the data symbol,t 1 =(M-m)/B，
the output waveform obtained by linear frequency modulation using a frequency change rate having a negative frequency change rate is shown.
Optionally, step S6 is performed by introducing [0,2kπ]Internally uniformly distributed random phase variables are meant for any of the secondnGenerating sampling points by using a linear congruence random number generator [0,2 pi]Inner uniformly distributed random phase θ: (n) And withRandom phase θ (n) Multiplying by a weighting factorkAs the initial phase, the discrete time function expression for generating the final chirp spread spectrum modulation output waveform is:
in the above formula, the first and second carbon atoms are,x m (n) Represents an arbitrary symbolmTo (1)nThe resulting chirped spread spectrum modulation output waveform of each sample point,jis the unit of an imaginary number,nthe serial numbers of the sampling points are shown,Mis the maximum value of the data symbol,kin order to be a linear frequency modulation coefficient,kthe value range is [0,1]And B is a bandwidth of a channel,f s for sampling frequency, parametersN 1 Is calculated in a manner thatN 1 = f s (M-m)/B。
In addition, the invention also provides a chirp spread spectrum modulation system with the anti-interception function, which comprises a microprocessor and a memory which are connected with each other, wherein the microprocessor is programmed or configured to execute the steps of the chirp spread spectrum modulation method with the anti-interception function.
Furthermore, the present invention also provides a computer-readable storage medium having stored therein a computer program for being programmed or configured by a microprocessor to perform the steps of the chirp spread spectrum modulation method with an anti-intercept function.
Compared with the prior art, the invention has the following advantages: the invention introduces [0,2 ] when chirp spread spectrum modulates each data symbolkπ]Random phase variables distributed uniformly in the system randomize the frequency of the broadband linear frequency modulation signal and the power spectral density of the chirp spread spectrum modulationkThe gain is increased and decreased, the modulation signal has a Low interception Probability (LPI), and the problem that the chirp spread spectrum modulation signal is easy to Intercept can be solved.
Drawings
FIG. 1 is a schematic diagram of a basic process flow of a method according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of a data frame structure during framing according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of spread spectrum modulation data symbol modulation according to an embodiment of the present invention.
Fig. 4 is a schematic structural diagram of a system according to an embodiment of the present invention.
Detailed Description
As shown in fig. 1, the chirp spread spectrum modulation method with an anti-interception function of the present embodiment includes:
s1, inputting digital bitsa j Randomizing to obtain digital bitsb j ；
S2, randomizing the obtained digital bitsb j Carrying out channel coding and interleaving processing to obtain a digital code stream consisting of 0 or 1;
s3, carrying out symbol mapping on digital code elements in the digital code stream obtained after channel coding and interleaving processing;
s4, framing the data symbols obtained by symbol mapping;
s5, modulating the framed data symbols;
s6, introducing the phase of each sampling point in the modulation output waveform [0,2kπ]And random phase variables are uniformly distributed in the phase-locked loop so as to realize phase randomization processing, and the final chirp spread spectrum modulation output waveform is generated by the phase after the phase randomization processing.
Step S1 is to input digital bitsa j Randomizing to obtain digital bitsb j Different implementations may be employed as desired. As an optional implementation manner, in this embodiment, step S1 includes: using linear shift registers, according to a given pseudo-random sequencec j Digital bits input bit by bit paira j Performing modulo-2 addition to obtain digital bitsb j To realize the randomization treatment, the function expression is as follows:b j =a j ⊕c j . The bit-by-bit processing is realized by adopting a linear shift registerThe way of the randomization process is simplified. Given pseudo-random sequencec j And may be randomly generated as desired. For example, as a preferred embodiment, in this embodiment, a given pseudo-random sequence is givenc j An M sequence having pseudo-randomness, also called an M-sequence, is selected, which is a pseudo-random sequence obtained by adding a white noise random value to a periodic sequence.
Step S2 for randomizing the resulting digital bitsb j And carrying out channel coding and interleaving treatment to obtain a digital code stream consisting of 0 or 1. Specifically, the embodiment is to output the random digital bit from step S1b j According tokA group of bits is processed by (n,k) Cyclic code encoding, outputting cyclic code encodernThe x 8 coded bits are a group of digital bit sequences output after the interleaving processing of column input and row output is carried out by adopting a matrix interleavere i 。
In this embodiment, step S3 includes: digital code elements (digital bit sequence) in digital code stream obtained after channel coding and interleavinge i ) According to a preset numberSFThe bits are grouped and Gray code coded, and mapped to values [0,1, …,m,…，M]data symbol ofmWhereinMIs the maximum value of a data symbol and hasM = 2 SF -1, each data symbol having a duration ofT B In whichSF(SpreadingFactor) is a positive integer and represents the spreading factor of the chirped spread spectrum modulation.
In this embodiment, step S4 includes using each group of data symbols obtained by symbol mapping as intra-frame data field data, and appending a prefix symbol, a frame synchronization header symbol, and a frequency synchronization header symbol to the intra-frame data field data, so as to obtain a frame of framed data. Specifically, as shown in fig. 2, in the present embodiment, the symbols output in step S3 are successively multiplexed before each otherN pr A frame of data is formed by 2 prefix symbols with the value of 0,2 frame synchronization head symbols representing the address identification of the transceiver and 2.5 frequency synchronization head symbols with the value of 0 for modulation transmission.
In this embodiment, the step S5 includes performing linear frequency modulation on the prefix symbol, the frame synchronization header symbol, the frequency synchronization header symbol, and the intra-frame data domain data in each framed data, respectively, and the positive and negative characteristics of the frequency change rate used for performing the linear frequency modulation on the prefix symbol, the frame synchronization header symbol, and the intra-frame data domain data are the same, and the positive and negative characteristics of the frequency change rate used for performing the linear frequency modulation on the frequency synchronization header symbol are opposite to the positive and negative characteristics of the frequency change rate used for performing the linear frequency modulation on the intra-frame data domain data.
As an optional implementation manner, in this embodiment, the frequency change rate adopted for performing linear frequency modulation on the prefix symbol, the frame synchronization header symbol, and the intra-frame data field data is a positive frequency change rate, that is, the frequency change rate is: the frame prefix symbol and the frame synchronization head are modulated by upchirp (linear frequency modulation with positive frequency change rate), and the prefix symbol isN pr And the number of the continuous 0 frame synchronization heads is 2 symbols for describing the identity of the transceiver, the down chirp modulation (linear frequency modulation with negative frequency change rate) is adopted for the frequency synchronization heads, and the up chirp modulation is adopted for the data of the intra-frame data domain. The channel bandwidth is fixed at B (kHz) and the time-bandwidth product is T B ×B= 2 SF The chirp (chirp) spread spectrum modulation process is that the value is [0,1, … …, M]Symbol of (1)mAn upchirp modulation is performed. In this embodiment, the functional expression of the output waveform after upchirp modulation is:
the frequency change rate adopted for linear frequency modulation of the frequency synchronization header symbol is a negative frequency change rate (down chirp modulation), and the functional expression of the output waveform after the down chirp modulation is as follows:
wherein, the first and the second end of the pipe are connected with each other,
shows an output waveform obtained by linear frequency modulation using a frequency change rate with a positive frequency change rate,jis the unit of an imaginary number,f m (t) For modulating symbolsmThe instantaneous frequency of the time of day,tin the form of a time, the time,
in order to be the instantaneous phase position,Bin order to be the bandwidth of the channel,T B in the case of a data symbol period,man index for the mth value of the data symbol,Mis the maximum value of the data symbol,t 1 =(M-m)/B，
the output waveform obtained by linear frequency modulation with a frequency change rate that is negative is shown.
If at the sampling frequencyf S Sampling the modulation waveform to obtain discrete time waveforms of an upchirp modulation signal and a downchirp modulation signal, wherein the discrete time waveforms are respectively as follows:
modulating output waveform for chirp (chirp) spread spectrum
Instantaneous phase of each sampling point in
Respectively with [0,2π]Internally uniformly distributed phase random variablesθ(nT s ) Weighted initialInitial phasekθ(nT s ) Adding to realize phase randomization, and taking the phase sum as the complex baseband signal phase to obtain a data symbol periodT B Internal low probability of interception chirp (chirp) spread spectrum modulation output waveformx m (nT S ) Comprises the following steps:
in this embodiment, step S6 is introduced with [0,2kπ]The internally uniformly distributed random phase variable is referred to as being directed to any of the secondnGenerating sampling points by using a linear congruence random number generator [0,2 pi]Inner uniformly distributed random phase θ: (n) And at a random phase θ: (n) Multiplying by a weighting factorkAs the initial phase, the discrete time function expression for generating the final chirp spread spectrum modulation output waveform is:
in the above formula, the first and second carbon atoms are,x m (n) Represents an arbitrary symbolmTo (1) anThe resulting chirped spread spectrum modulation output waveform of each sample point,jis the unit of an imaginary number,nis the serial number of the sampling point,Mis the maximum value of the data symbol,kin order to be a linear frequency modulation coefficient,kthe value range is [0,1]And B is the bandwidth of the channel,f s for sampling frequency, parametersN 1 Is calculated in a manner thatN 1 = f s (M-m) and/B. As shown in FIG. 3, [0,P ] in the figure]Linear congruence random number generator is indicated in [0,P]Random numbers are generated in the range and the output random numbers are normalized to [0,1 by the "÷ P" operation]Then mapped to [0,2 pi by the establishment of 2 pi]Internally derived random phaseθ(n) Random phaseθ(n) Multiplying by a weighting factorkAs an initial phasekθ(n) Namely: introduction of [0,2kπ]Internally uniformly distributed randomA phase variable. Spread spectrum modulation of chirp (chirp) to get each data symbolmGenerating modulation symbols based on frequency control wordsmInstantaneous frequency off m (n) Then, the phase of the sampling point is obtained by accumulating the phase of the sampling point with the phase of the previous timeφ m (n) Then is reacted with [0,2kπ]Internally uniformly distributed random phase variationskθ(n) Adding to realize phase randomization, and taking the phase sum as the complex baseband signal phase to obtain a data symbol periodT B Internal low probability of interception chirp (chirp) spread spectrum modulation output waveformx m (n)。
In summary, the chirp spread spectrum modulation method with the anti-interception function of the embodiment introduces [0,2 ] when chirp spread spectrum modulates each data symbolkπ]Random phase variables distributed uniformly in the system randomize the frequency of the broadband linear frequency modulation signal and the power spectral density of the chirp spread spectrum modulationkThe gain is increased and decreased, the modulation signal has a Low interception Probability (LPI), and the problem that the chirp spread spectrum modulation signal is easy to Intercept can be solved.
In addition, the present embodiment also provides a chirp spread spectrum modulation system with an anti-interception function, which includes a microprocessor and a memory connected to each other, wherein the microprocessor is programmed or configured to execute the steps of the chirp spread spectrum modulation method with an anti-interception function. As shown in fig. 4, the chirp spread spectrum modulation system with an anti-interception function in this embodiment includes: the device comprises a digital code stream randomization unit, a digital code stream channel coding unit, a digital code symbol mapping unit, a data symbol framing unit and a data symbol modulation unit. Wherein: the digital code stream randomization unit is used for adopting a linear shift register to generate a polynomial according to a giveng(x) Generated pseudo-random sequencec j Digital bits input bit by bit paira j Performing modulo-2 addition to obtainb j =a j ⊕c j A randomization process is implemented. The digital code stream channel coding interleaving unit is used for randomly interleaving the digital code streamDigital bits output by the quantization cellb j And carrying out channel coding and interleaving processing. The digital code element symbol mapping unit is used for interleaving the channel coding and transmitting the 0/1 digital code streamSFThe bits are mapped into values [0,1, … …,M]of data symbols of, whereinM= 2 SF -1, each data symbol having a duration ofT B In whichSF(Spreadingfactor) is a positive integer representing the spreading factor of the chirp (chirp) spread spectrum modulation; the data symbol framing unit is used for multiplexing the symbols output by the digital symbol mapping unit in a front-to-back mannerN pr A frame of data is formed by 2 prefix symbols with the value of 0,2 frame synchronization head symbols representing the address identifier of the transceiver and 2.5 frequency synchronization head symbols with the value of 0 and then is sent to a data symbol modulation unit for modulation and transmission; the data symbol modulation unit is used for performing upchirp modulation (linear frequency modulation with positive frequency change rate) on the frame prefix symbol and the frame synchronization head, and the prefix symbol isN pr And the number of the continuous 0 frame synchronization heads is 2 symbols for describing the identity of the transceiver, the down chirp modulation (linear frequency modulation with negative frequency change rate) is adopted for the frequency synchronization heads, and the up chirp modulation is adopted for the data of the intra-frame data domain.
Furthermore, the present embodiment also provides a computer-readable storage medium, in which a computer program is stored, the computer program being programmed or configured by a microprocessor to execute the steps of the chirp spread spectrum modulation method with an anti-interception function.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-readable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein. The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.
Claims (10)
1. A chirp spread spectrum modulation method with an anti-interception function is characterized by comprising the following steps:
s1, inputtingDigital bit ofa j Randomizing to obtain digital bitsb j ；
S2, randomizing the obtained digital bitsb j Carrying out channel coding and interleaving processing to obtain a digital code stream consisting of 0 or 1;
s3, carrying out symbol mapping on digital code elements in the digital code stream obtained after channel coding and interleaving processing;
s4, framing the data symbols obtained by symbol mapping;
s5, modulating the framed data symbols;
s6, introducing the phase of each sampling point in the modulation output waveform [0,2kπ]And random phase variables are uniformly distributed in the phase-locked loop so as to realize phase randomization, and the final chirp spread spectrum modulation output waveform is generated by the phase after the phase randomization.
2. The chirp spread spectrum modulation method with anti-interception function according to claim 1, wherein step S1 comprises: using linear shift registers, according to a given pseudo-random sequencec j Digital bits input bit by bit paira j Performing modulo-2 addition to obtain digital bitsb j To implement the randomization process.
3. The chirp spread spectrum modulation method with anti-interception function according to claim 2, wherein said given pseudo random sequencec j Is an M-sequence with pseudo-randomness.
4. The chirp spread spectrum modulation method with anti-interception function according to claim 1, wherein step S3 comprises: the digital code elements in the digital code stream obtained after the channel coding and the interleaving processing are processed according to the preset quantitySFThe bits are grouped and Gray code coded, and mapped to values [0,1, …,m,…,M]data symbol ofmWhereinMIs the maximum value of a data symbol and hasM = 2 SF -1, each data symbol having a duration ofT B WhereinSFIs a positive integer and represents the spreading factor of the chirped spread spectrum modulation.
5. The chirp spread spectrum modulation method with an anti-interception function according to claim 1, wherein step S4 comprises using each group of data symbols obtained by symbol mapping as intra-frame data field data, and appending a prefix symbol, a frame synchronization header symbol, and a frequency synchronization header symbol before the intra-frame data field data, thereby obtaining a frame of framed data.
6. The chirp spread spectrum modulation method with an anti-interception function according to claim 5, wherein step S5 includes performing linear frequency modulation on a prefix symbol, a frame synchronization header symbol, a frequency synchronization header symbol, and intra-frame data field data in each framed data, respectively, and positive and negative characteristics of a frequency change rate used for performing linear frequency modulation on the prefix symbol, the frame synchronization header symbol, and the intra-frame data field data are the same, and positive and negative characteristics of a frequency change rate used for performing linear frequency modulation on the frequency synchronization header symbol are opposite to positive and negative characteristics of a frequency change rate used for performing linear frequency modulation on the intra-frame data field data.
7. The chirp spread spectrum modulation method with an anti-interception function according to claim 6, wherein the frequency change rate adopted for linear frequency modulation of the prefix symbol, the frame synchronization header symbol, and the intra-frame data field data is a positive frequency change rate, and the function expression of the modulated output waveform is:
the frequency change rate adopted for linear frequency modulation of the frequency synchronization header symbol is a negative frequency change rate, and the functional expression of the modulated output waveform is as follows:
wherein the content of the first and second substances,
shows an output waveform obtained by linear frequency modulation using a frequency change rate with a positive frequency change rate,jis the unit of an imaginary number,f m (t) For modulating symbolsmThe instantaneous frequency of the time of day,tas a matter of time, the time is,
in order to be the instantaneous phase position,Bin order to be the bandwidth of the channel,T B in the case of a data symbol period,man index for the mth value of the data symbol,Mis the maximum value of the data symbol,t 1 =(M-m)/B，
the output waveform obtained by linear frequency modulation using a frequency change rate having a negative frequency change rate is shown.
8. The chirp spread spectrum modulation method with anti-interception function according to claim 7, wherein [0,2 ] is introduced in step S6kπ]The internally uniformly distributed random phase variable is referred to as being directed to any of the secondnGenerating sampling points by using a linear congruence random number generator [0,2 pi]Inner uniformly distributed random phase θ: (n) And at a random phase θ: (n) Multiplying by a weight factorkAs the initial phase, the discrete time function expression for generating the final chirp spread spectrum modulation output waveform is:
in the above formula, the first and second carbon atoms are,x m (n) Represents an arbitrary symbolmTo (1) anThe resulting chirped spread spectrum modulation output waveform of each sample point,jis the unit of an imaginary number,nthe serial numbers of the sampling points are shown,Mis the maximum value of the data symbol,kin order to be a linear frequency modulation coefficient,kthe value range is [0,1]And B is the bandwidth of the channel,f s for sampling frequency, parametersN 1 Is calculated in a manner thatN 1 = f s (M-m)/B。
9. A chirp spread spectrum modulation system with an anti-interception function, comprising a microprocessor and a memory connected to each other, wherein the microprocessor is programmed or configured to perform the steps of the chirp spread spectrum modulation method with an anti-interception function according to any one of claims 1 to 8.
10. A computer-readable storage medium, in which a computer program is stored, wherein the computer program is used for being programmed or configured by a microprocessor to execute the steps of the chirp spread spectrum modulation method with anti-interception function according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211076166.2A CN115149978B (en) | 2022-09-05 | 2022-09-05 | Chirp spread spectrum modulation method, system and medium with anti-interception function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211076166.2A CN115149978B (en) | 2022-09-05 | 2022-09-05 | Chirp spread spectrum modulation method, system and medium with anti-interception function |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115149978A CN115149978A (en) | 2022-10-04 |
| CN115149978B true CN115149978B (en) | 2022-11-11 |
Family
ID=83415650
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211076166.2A Active CN115149978B (en) | 2022-09-05 | 2022-09-05 | Chirp spread spectrum modulation method, system and medium with anti-interception function |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115149978B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5369665A (en) * | 1993-07-13 | 1994-11-29 | Sri International | Coherent time-domain data storage with spread-spectrum data pulse |
| CN102959918A (en) * | 2012-08-31 | 2013-03-06 | 华为技术有限公司 | A training sequence generating method, a training sequence generating device, and an optical communication system |
| CN111181596A (en) * | 2019-12-31 | 2020-05-19 | 北京升哲科技有限公司 | Modulation-demodulation method and system |
| CN112134821A (en) * | 2020-08-24 | 2020-12-25 | 北京智芯微电子科技有限公司 | Modulation method based on linear frequency modulation signal and modulator |
| CN113315540A (en) * | 2021-03-16 | 2021-08-27 | 上海磐启微电子有限公司 | Modulation and demodulation method based on pseudorandom phase sequence spread spectrum signal |
-
2022
- 2022-09-05 CN CN202211076166.2A patent/CN115149978B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5369665A (en) * | 1993-07-13 | 1994-11-29 | Sri International | Coherent time-domain data storage with spread-spectrum data pulse |
| CN102959918A (en) * | 2012-08-31 | 2013-03-06 | 华为技术有限公司 | A training sequence generating method, a training sequence generating device, and an optical communication system |
| CN111181596A (en) * | 2019-12-31 | 2020-05-19 | 北京升哲科技有限公司 | Modulation-demodulation method and system |
| CN112134821A (en) * | 2020-08-24 | 2020-12-25 | 北京智芯微电子科技有限公司 | Modulation method based on linear frequency modulation signal and modulator |
| CN113315540A (en) * | 2021-03-16 | 2021-08-27 | 上海磐启微电子有限公司 | Modulation and demodulation method based on pseudorandom phase sequence spread spectrum signal |
Non-Patent Citations (1)
| Title |
|---|
| LPD通信波形设计方案及其性能分析;张晓彤等;《哈尔滨工程大学学报》;20180426(第08期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115149978A (en) | 2022-10-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2018103471A1 (en) | Signal processing method and device, and storage medium | |
| EP0815677B1 (en) | Multicarrier communication system and method for peak power control | |
| RU2264041C2 (en) | Device and method for transmitting and receiving with decreased relation of pike power to average power in mobile communication system with orthogonal multiplexing with frequency separation | |
| JP4913037B2 (en) | Method and apparatus for generating and processing wideband signals with reduced discrete power spectral density components | |
| US10447339B2 (en) | Communication system employing chaotic sequence based frequency shift keying spreading signals | |
| MXPA01005902A (en) | Efficient implementation of proposed turbo code interleavers for third generation code division multiple access. | |
| US8379689B2 (en) | Anti-jam communications having selectively variable peak-to-average power ratio including a chaotic constant amplitude zero autocorrelation waveform | |
| CN115149978B (en) | Chirp spread spectrum modulation method, system and medium with anti-interception function | |
| WO2007091434A1 (en) | Ofdm transmitter and its control method | |
| JP2009055395A (en) | Peak electric power reducing device in communication device | |
| CN112769455B (en) | Method, device, equipment and storage medium for generating aperiodic long code spreading code | |
| CN116614339B (en) | PAPR suppression transmitter of MC-CDMA system | |
| Massey | Towards an information theory of spread-spectrum systems | |
| Juliet et al. | Design analysis of deterministic interleaver for OFDM-IDMA system | |
| Sattarova et al. | Development of a Noise-Resistant Algorithm for Forming Signals with OCDM-OChDM Using Ternary Gordon-Mills-Welch Sequences | |
| Praveenkumar et al. | Coded Crypted Converted Hiding (C3H)-“A Stego Channel | |
| KR101093966B1 (en) | Method of Generating Frequency Hopping Sequence by interleaving, Frequency Hopping Sequence Generator, Apparatus For Code Division Multiple Access, And Record Medium For Controlling Method of The Clock Speed and The Performing Time of Clock Signal Generator to Make Frequency Hopping Sequence | |
| Manhas et al. | OFDM PAPR reduction using recurring SLM with cyclic and linear block codes schemes | |
| CN108737315B (en) | Reduce the additivity scrambling method and its emission system of ofdm system peak-to-average power ratio | |
| JP2005012706A (en) | Pulse generator, pulse generation method, communication apparatus and communication method | |
| Rohini et al. | Effectiveness and performance analysis of MC-CDMA system | |
| JP2005033341A (en) | Apparatus and method for transmitting, and amplifier circuit | |
| Abdullah et al. | PAPR reduction and data security improvement for OFDM technique using chaos system | |
| Gupta et al. | Performance analysis of NLM interleaving scheme for CPM OFDM system | |
| Juliet et al. | Concert investigation of novel deterministic interleaver for OFDM-IDMA system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |