CN114024660A - Chaotic encryption OFDM system with noise reduction function in 5G network - Google Patents
Chaotic encryption OFDM system with noise reduction function in 5G network Download PDFInfo
- Publication number
- CN114024660A CN114024660A CN202111242041.8A CN202111242041A CN114024660A CN 114024660 A CN114024660 A CN 114024660A CN 202111242041 A CN202111242041 A CN 202111242041A CN 114024660 A CN114024660 A CN 114024660A
- Authority
- CN
- China
- Prior art keywords
- converter
- chaotic
- serial
- parallel
- sequence
- 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.)
- Granted
Links
- 230000000739 chaotic effect Effects 0.000 title claims abstract description 94
- 230000009467 reduction Effects 0.000 title claims abstract description 24
- 238000006243 chemical reaction Methods 0.000 claims abstract description 41
- 125000004122 cyclic group Chemical group 0.000 claims abstract description 33
- 238000013507 mapping Methods 0.000 claims abstract description 10
- 230000005540 biological transmission Effects 0.000 claims abstract description 4
- 108010076504 Protein Sorting Signals Proteins 0.000 claims description 3
- 238000005070 sampling Methods 0.000 claims description 3
- 230000001360 synchronised effect Effects 0.000 claims description 2
- 230000009466 transformation Effects 0.000 claims description 2
- 238000004891 communication Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000012549 training Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910002056 binary alloy Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/001—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols using chaotic signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2626—Arrangements specific to the transmitter only
- H04L27/2627—Modulators
- H04L27/2628—Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2649—Demodulators
- H04L27/265—Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators
-
- 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
- H04L27/36—Modulator circuits; Transmitter circuits
-
- 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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
- H04W12/03—Protecting confidentiality, e.g. by encryption
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Computer Security & Cryptography (AREA)
- Physics & Mathematics (AREA)
- Discrete Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The invention relates to a chaotic encryption OFDM system with a noise reduction function in a 5G network, which comprises a sending end and a receiving end, wherein the sending end and the receiving end generate the same chaotic sequence by using the same initial condition for encryption and decryption respectively; a sending end: carrying out primary chaotic encryption on information, then carrying out QAM (quadrature amplitude modulation) modulation, and carrying out secondary encryption on symbols generated by QAM modulation by using the chaotic sequence; then, performing serial-parallel conversion, inverse phase, Fourier transform, parallel-serial conversion, cyclic prefix adding, digital-to-analog conversion and up-conversion on the signals; then, transmitting signals by using a 5G transmitting antenna; receiving end: receiving signals by using a 5G receiving antenna, performing down-conversion, analog-to-digital conversion, cyclic prefix removal and serial-to-parallel conversion on the signals, and then performing Fourier transform; then, carrying out phase inversion and parallel-serial conversion on the signals, and demodulating data by QAM; and the chaotic sequence is used for carrying out primary decryption on the QAM demodulated data, and then mapping and then carrying out secondary decryption on the demodulated signal by using the chaotic sequence to obtain a transmission signal.
Description
Technical Field
The invention belongs to the technical field of noise reduction communication in a 5G network, and particularly relates to a chaotic encryption OFDM communication system with a noise reduction function based on the 5G network.
Background
The 5G is a 5 th generation mobile communication technology which makes full use of frequency band resources, and Orthogonal Frequency Division Multiplexing (OFDM) used therein is a technology which uses mutually orthogonal multiple subcarriers, firstly, information is subjected to quadrature amplitude modulation (M-QAM) or phase shift keying (M-PSK) modulation, then modulated onto each subcarrier, a signal is mapped into complex symbols, and the signal is converted into a time domain signal by Inverse Fast Fourier Transform (IFFT). At the receiving end, the received information is converted into frequency domain information by frequency conversion, pilot frequency and cyclic prefix are removed, Fast Fourier Transform (FFT) is utilized, and the original information is demodulated by utilizing coherent demodulation and mapping relation.
However, the prior art also has the problem of channel noise.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a chaotic encryption OFDM system with a noise reduction function in a 5G network. The innovation of the invention is that aiming at the noise generated in the channel, the processing modes of the sending end and the receiving end are changed, thereby reducing or even eliminating the noise and improving the signal-to-noise ratio of the communication system. At a transmitting end, inverting the signal modulated by M-QAM, modulating the original signal and the inverted signal on each carrier through Inverse Fast Fourier Transform (IFFT), superposing to form a time domain signal, introducing Cyclic Prefix (CP), performing digital-to-analog conversion, filtering and performing frequency conversion, and transmitting the time domain signal through a 5G transmitting antenna, so that the transmitted signal is changed into two groups of data; at a receiving end, down conversion, filtering, digital-to-analog conversion and cyclic prefix removal are carried out, received information is converted into frequency domain information by utilizing Fast Fourier Transform (FFT), then subtraction operation is carried out on the two groups of received information, because the two groups of received information carry the same channel noise through the same channel, after subtraction, noise can be effectively reduced or even eliminated, and finally, original transmitted information is demodulated through a mapping relation.
In order to realize the purpose of the invention, the invention adopts the following technical scheme:
a chaos encryption OFDM system with a noise reduction function in a 5G network comprises:
the sending end and the receiving end utilize the same initial condition to generate the same chaotic sequence for encryption and decryption respectively; a sending end: carrying out primary chaotic encryption on information, then carrying out QAM (quadrature amplitude modulation) modulation, and carrying out secondary encryption on symbols generated by QAM modulation by using the chaotic sequence; then, performing serial-parallel conversion, inverse phase, Fourier transform, parallel-serial conversion, cyclic prefix adding, digital-to-analog conversion and up-conversion on the signals; then, transmitting signals by using a 5G transmitting antenna; receiving end: receiving signals by using a 5G receiving antenna, performing down-conversion, analog-to-digital conversion, cyclic prefix removal and serial-to-parallel conversion on the signals, and then performing Fourier transform; then, carrying out phase inversion and parallel-serial conversion on the signals, and demodulating data by QAM; and the chaotic sequence is used for carrying out primary decryption on the QAM demodulated data, and then mapping and then carrying out secondary decryption on the demodulated signal by using the chaotic sequence to obtain a transmission signal.
Preferably, the transmitting end structure is as follows: the first chaotic signal generator is connected with the first sampler, the first sampler and the signal generator are connected with the first XOR device as input, the first XOR device is connected with the first mapper, the other two ports of the first mapper are respectively connected with the first encryptor and the second encryptor, the first chaotic sequence generator is connected between the first encryptor and the second encryptor, the first encryptor is connected with the adder through the first multiplier, and the second encryptor is connected with the adder through the second multiplier; the adder is connected with a first serial-parallel converter, the first serial-parallel converter is respectively connected with N ports of the phase inverter and N ports of the IFFT converter, the N ports on the other side of the phase inverter are connected with the other N ports of the IFF converter, 2N ports on the other side of the IFFT converter are connected with 2N ports of the parallel-serial converter, the first parallel-serial converter converts the parallel sequence into a serial sequence, and an output port, a cyclic prefix importer, a digital-to-analog converter, a first filter, a down converter and a 5G transmitting antenna of the first parallel-serial converter are sequentially connected.
The structure of the receiving end is as follows: the 5G receiving antenna, the down converter, the second filter, the analog-to-digital converter, the pilot frequency removing cyclic prefix device and the second serial-parallel converter are sequentially connected, the second serial-parallel converter converts serial signals into parallel signals, and a 2N port of the second serial-parallel converter is connected with an input port of the FFT converter; the output end of the FFT converter is connected with N ports of the second parallel-serial converter after the subtraction of the ith port and the 2N-i +1 th port; the output signals of the second parallel-serial converter are divided into two paths and are respectively connected with a third multiplier and a fourth multiplier, the output ports of the third multiplier and the fourth multiplier are respectively connected with a first integrator and a second integrator, the output ports of the first integrator and the second integrator are respectively connected with a first decryptor and a second decryptor, and a second chaotic sequence generator is connected between the first decryptor and the second decryptor; the output ports of the first decryptor and the second decryptor are respectively connected to a second mapper, and the second mapper is connected with a second exclusive OR; the second chaotic signal generator is connected with the second XOR device through the second sampler.
In the structure of the transmitting end, the signal generator is XOR-ed with the first chaotic sequence after being sampled by the chaotic generator, and the step is called the encryption process of the chaotic system. The encrypted encryption sequence is connected with a mapper, wherein I, Q paths are subjected to second chaotic encryption again, an adder is connected behind each encryptor through a multiplier, the adder is connected with a first series-parallel converter, signals in the converter and the signals which are converted and then inverted through an inverter are connected to an IFFT converter through 2N ports, 2N output ports of the IFFT converter are connected with the first parallel-serial converter, and the parallel-serial converter is connected with a 5G antenna after passing through a cyclic prefix importer, a digital-to-analog converter, a filter and an up-converter in sequence and transmits the signals.
The 5G receiving antenna of the receiving end receives signals, the signals sequentially pass through a down converter, a filter, an analog-digital converter, a pilot frequency removing cyclic prefix device and are connected with a serial-parallel converter, 2N output ports of a second serial-parallel converter are connected with an FFT converter, the output end of the FFT converter subtracts the ith path of signals and the 2N-i +1 path of signals, the obtained N path of output is connected with the second parallel-serial converter, the second parallel-serial converter is connected with two multiplying units, the two multiplying units sequentially pass through an integrator and a decryptor respectively and then are connected with a second mapper, a second chaotic encryption sequence is connected between the two decryptors, and finally the original information is decrypted through chaos after passing through the parallel-serial converter.
As a preferred scheme, the chaotic signals of the receiving end and the transmitting end are strictly synchronized through coupling between Lorentz circuits, and when the chaotic signals and information are subjected to XOR operation, the chaotic signals are converted into binary systems.
Preferably, at the transmitting end, the signal generator 1 inputs the information sequence bnAfter sampling, the first chaotic signal generator 4-1 is different or the first chaotic encryption of the information is realized.
Preferably, the signal sequence after the initial encryption is subjected to digital-to-analog conversion and then subjected to M-QAM modulation, and then subjected to chaotic encryption in branch I, Q and then multiplied by subcarriers cos ω t and-sin ω t, respectively.
Preferably, the sequence { b ] is mapped according to the mapping rule of the Gray codenMapping to sequence anLet { a } ben}＝{a1,a2,…,anThere are n elements. Let { a before IFFT transformnGet into an inverter to get the sequence { a'n}＝{-an,…,-a2,-a1Then will { a }nAnd { a'nMerging and IFFT transformation are carried out to obtain a sequence { c }n}。
Preferably, at the transmitting end, the sequence b is determined by matchingnTwice chaotic encryption is carried out to obtain a new sequence { a }nThus ensuring the encryption of the information.
Preferably, at the transmitting end, the encrypted sequences are multiplied by cos ω t and-sin ω t, respectively, and then added by a first adder to generate complex symbols, thereby completing the encrypted Quadrature Amplitude Modulation (QAM), and adding the pilot sequence. The transmitting end thus converts the transmitted digital signal into a mapping of subcarrier amplitudes.
Preferably, at the transmitting end, the formed complex symbol sequence is converted into a parallel symbol stream by a first serial-to-parallel converter; and performing inverse fast Fourier transform by using an IFFT transformer to transform the symbols of the frequency domain to the time domain.
Preferably, at the transmitting end, the time domain symbol output by the IFFT converter is converted into a serial signal by the first parallel-to-serial converter, and the serial signal is transmitted through the cyclic prefix importer, the digital-to-analog converter, the filter, the upconverter, and the 5G antenna.
Preferably, at the receiving end, the first 5G receiving antenna receives the signal, and after passing through the down-converter, the filter, the analog-to-digital converter, and the pilot-removing cyclic prefix device in order, the serial symbol is converted into a parallel symbol by the second serial-to-parallel converter, and the parallel symbol at this time is { c }n}+Nw(NwAs noise).
Preferably, at the receiving end, the frequency domain symbol { a ] output by the FFT converter1+nw,a2+nw,…,an+nw,-an+nw,…,-a2+nw,-a1+nwAnd at this time, subtracting the ith symbol from the 2n-i +1 th symbol, and converting the ith symbol into a serial symbol through a second parallel-to-serial converter. Each path of serial symbols is divided into two paths, multiplied by cos ω t and-sin ω t, respectively, and integrated within one period by a corresponding integrator.
As a preferred scheme, at a receiving end, the chaos sequence generated by sampling of the chaos signal generator is utilized, the XOR operation is carried out in the chaos decryptor, and the symbol is decrypted to obtain an initial information sequence.
The invention discloses a chaos encryption OFDM system with a noise reduction function based on a 5G network, which has the following principle and process: the special processing of the signals is carried out at the transmitting end and the receiving end. At the receiving end, the signal is inverted and inverted by using an inverter and the like, which provides a condition for the receiving end to eliminate noise. The signal received by the receiving end is 'two copies' of useful information with noise, and the noise can be skillfully eliminated by simple subtraction, thereby improving the signal-to-noise ratio of the communication system.
Compared with the prior art, the invention has the beneficial effects that:
the chaos encryption OFDM system with the noise reduction function in the 5G network of the invention transmits the chaos encrypted original signal and the anti-phase signal at the transmitting end and performs subtraction operation at the receiving end, thereby eliminating noise and improving the integral signal-to-noise ratio of the system.
Drawings
Fig. 1 is a structural diagram of a chaotic encryption OFDM system with a noise reduction function in a 5G network according to an embodiment of the present invention.
Fig. 2 is a constellation diagram with noise after encryption.
Fig. 3 is a graph of bit error rate versus signal to noise ratio.
Fig. 4 is a waveform diagram of transmitted information.
Fig. 5 is a waveform diagram of the decrypted information.
Detailed Description
To more clearly illustrate the embodiments of the present invention, the following description will explain embodiments of the present invention with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.
The chaos encryption OFDM system with the noise reduction function based on the 5G network comprises a sending end and a receiving end, wherein the sending end and the receiving end are communicated through a wireless channel between sending and receiving antennas.
The sending terminal specifically comprises the following components: the device comprises a signal generator 1, a first XOR generator 2-1, a first chaotic signal generator 4-1, a first sampler 3-1, a first mapper 5-1, a first chaotic sequence generator 6-1, a first encryptor 2-2, a first chaotic encryptor 2-3, a first multiplier 7-1, a second multiplier 7-2, an adder 2-4, a first serial-parallel converter 8-1, an inverter 9, an IFFT converter 10, a first parallel-serial converter 11-1, a cyclic prefix leading-in device 12, a digital-analog converter 13, a filter 14-1, an up-converter 15 and a 5G transmitting antenna 16.
The receiving end specifically includes following components and parts: the device comprises a 5G receiving antenna 17, a down converter 18, a second filter 14-2, an analog-to-digital converter 19, a pilot-removing cyclic prefix device 20, a second serial-to-parallel converter 8-2, an FFT converter 21, a second parallel-to-serial converter 11-2, third and fourth multipliers 7-3 and 7-4, first and second integrators 22-1 and 22-2, decryptors 2-5 and 2-6, a chaotic sequence generator 6-2, a second mapper 5-2, a second exclusive-or 2-7, a second chaotic signal generator 4-2 and a second sampler 3-2.
The receiving end communicates with the transmitting end via a wireless channel of two transmitting and receiving antennas.
The noise reduction function is realized by using the change of a signal sending mode of a transmitting terminal and special processing after receiving of a receiving terminal, specifically: the sending end normally processes the signal line (specifically including chaotic encryption and M-QAM modulation), before carrying out IFFT conversion on the modulated signal, uses an inverter to carry out inverse phase and sign conversion on the modulated signal, and then carries out IFFT conversion on the signal and the modulated signal together. The time domain symbol output by the IFFT converter is converted into a serial signal through a parallel-serial converter, and the information is transmitted out through a cyclic prefix importer, a digital-to-analog converter, a filter and an up-converter by utilizing a 5G transmitting antenna.
At the receiving end, the wireless signal is received by the 5G receiving antenna, and after passing through a down converter, a filter, an analog-to-digital converter (converting the analog signal into a digital symbol), and a cyclic prefix remover (removing the prefix), the serial symbol is converted into a parallel symbol by a serial-to-parallel converter. The serial symbols are converted to parallel symbols using a serial-to-parallel converter. And the two groups of signals are correspondingly subtracted before the frequency domain symbol output by the FFT converter, the output amplitude of the original signal is twice of the original amplitude, because the information is transmitted through the same channel, the noise influence on the two groups of signals is the same, the channel noise can be effectively eliminated by subtraction operation, and finally, the corresponding information sequence is restored by utilizing an M-QAM demodulator and chaotic decryption.
The chaos encryption OFDM system with the noise reduction function in the 5G network is completed.
As shown in fig. 1, the specific connection relationship of the chaotic encryption OFDM system with noise reduction function in the 5G network according to this embodiment is as follows:
the transmitting end comprises a signal generator 1, a first exclusive OR 2-1, a first chaotic signal generator 4-1, a first sampler 3-1, a first mapper 5-1, a first chaotic sequence generator 6-1, a first encryptor 2-2, a first chaotic sequence generator 2-3, a first multiplier 7-1, a second multiplier 7-2, an adder 2-4, a first serial-parallel converter 8-1, an inverter 9, an IFFT converter 10, a first parallel-serial converter 11-1, a cyclic prefix importer 12, a digital-to-analog converter 13, a filter 14-1, an upconverter 15 and a 5G transmitting antenna 16.
The first chaotic signal generator 4-1 is connected with the first sampler 3-1, the first sampler 3-1 and the signal generator 1 are connected with the first XOR device 2-1 as input, the right port of the first XOR device 2-1 is connected with the left port of the first mapper 5-1, the first port and the second port on the right side of the first mapper 5-1 are respectively connected with the first encryptor 2-2 and the second port on the left side of the second encryptor 2-3, the lower port of the first encryptor 2-2 is connected with the upper port of the first chaotic sequence generator 6-1, and the lower port of the second encryptor 2-3 is connected with the lower port of the first chaotic sequence generator 6-1. The right port of the first encryptor 2-2 is connected with the left port of the first multiplier 7-1, the right port of the second encryptor 2-3 is connected with the left port of the second multiplier 7-2, the right port of the first multiplier 7-1 is connected with the upper port of the adder 2-4, and the right port of the second multiplier 7-2 is connected with the lower port of the adder 2-4. The right port of the adder 2-4 is connected with the left port of the first serial-parallel converter 8-1, the right port of the first serial-parallel converter 8-1 is respectively connected with the left N ports of the inverter 9 and the left front N ports of the IFFT converter 10, the right N ports of the inverter 9 are connected with the left rear N ports of the IFF converter 10, the right 2N ports of the IFFT converter 10 are connected with the left 2N ports of the parallel-serial converter 11-1, the first parallel-serial converter 11-1 converts the parallel sequence into the serial sequence, the right port of the first parallel-serial converter 11-1 is connected with the left port of the cyclic prefix importer 12, the right port of the cyclic prefix importer 12 is connected with the left port of the digital-analog converter 13, the left port of the digital-analog converter 13 is connected with the left port of the first filter 14-1, The right port of the first filter 14-1 is connected to the left port of the down-converter 15, and the right port of the down-converter 15 is connected to the 5G transmitting antenna 16.
The receiving end comprises a 5G receiving antenna 17, a down converter 18, a second filter 14-2, an analog-to-digital converter 19, a pilot-removing cyclic prefix device 20, a second serial-to-parallel converter 8-2, an FFT converter 21, a second parallel-to-serial converter 11-2, a third multiplier 7-3, a fourth multiplier 7-4, a first integrator 22-1, a second integrator 22-2, a decryptor 2-5, a second integrator 2-6, a chaotic sequence generator 6-2, a second mapper 5-2, a second exclusive-or 2-7, a second chaotic signal generator 4-2 and a second sampler 3-2.
The 5G receiving antenna 17 is connected with a right port of a down converter 18, a left port of the down converter 18 is connected with a right port of a second filter 14-2, a left port of the second filter 14-2 is connected with a right port of an analog-to-digital converter 19, a left port of the analog-to-digital converter 19 is connected with a right port of a pilot-removing cyclic prefix device 20, a left port of the pilot-removing cyclic prefix device 20 is connected with a right port of a second serial-parallel converter 8-2, the second serial-parallel converter 8-2 converts serial signals into parallel signals, and a left 2N port of the second serial-parallel converter 8-2 is connected with a right port of an FFT converter 21.
1: the N ports are connected to the right N ports of the second parallel-to-serial converter 11-2 as follows: where FFT transformer 21 has 1 st port minus 2N ports, 2 nd port minus 2N-1 st port … …, and so on. The output signal of the left port of the second parallel-to-serial converter 11-2 is divided into two paths, and is respectively connected to the two ports on the right side of the third multiplier 7-3 and the fourth multiplier 7-4, the two ports on the left side of the 3 rd multiplier 7-3 and the fourth multiplier 7-4 are respectively connected to the two ports on the right side of the first integrator 22-1 and the second integrator 22-2, and the two ports on the left side of the first integrator 22-1 and the second integrator 22-2 are respectively connected to the two ports on the right side of the first decryptor 2-5 and the second decryptor 2-6. The lower side port of the first decryptor 2-5 is connected with the upper side port of the second chaotic sequence generator 6-2, and the upper side port of the second decryptor 2-6 is connected with the lower side port of the second chaotic sequence generator 6-2. The left two ports of the first decryptor 2-5 and the second decryptor 2-6 are respectively connected to the right two ports of the second mapper 5-2, the left port of the second mapper 5-2 is connected to the second xor 2-7, the upper port of the second chaotic signal generator 4-2 is connected to the lower port of the second sampler 3-2, the upper port of the second sampler 3-2 is connected to the lower port of the second xor 2-7, and finally, the information is restored by the left port of the second xor 2-7.
The principle of the secure communication system of the present embodiment will be described below in conjunction with the above-described system configuration.
In the invention, a receiving end and a transmitting end communicate through wireless channels of two 5G transmitting and receiving antennas. Firstly, the transmitter end and the receiver end adopt chaotic signal generators 3-1 and 3-2 and chaotic sequence generators 6-1 and 6-2 with completely the same initial conditions to generate common encryption and decryption sequences which are easily obtained, the transmitting end utilizes the generated chaotic sequences to encrypt, and the receiving end utilizes the same chaotic sequences to decrypt. The signal generator is mapped into x and y symbol data according to Gray codes after chaotic encryption, and new symbols x 'and y' are obtained after chaotic encryption is carried out again. The two-time encryption ensures the security of information encryption. Then, the two symbols are multiplied by cos ω t and-sin ω t respectively, then the complex symbols x1 '+ iy 1' are obtained by adding the two symbols through a first adder 2-4, the pilot training symbols are added, the encryption Quadrature Amplitude Modulation (QAM) and the encryption and pilot addition are completed, and the transmitting end converts the transmitted digital signals into the mapping of subcarrier amplitude. The symbol sequence formed by the first adder is converted into a parallel symbol stream by a first serial-to-parallel converter. After inversion by the inverter, inverse fast fourier transform is performed by the IFFT transformer to transform the frequency domain form of the data to the time domain. The time domain symbol output by the IFFT converter is converted into a serial signal by a first parallel-serial converter, and information is transmitted by a cyclic prefix importer, a digital-to-analog converter, a first filter and an up-converter by using a 5G transmitting antenna. (Note: the OFDM system includes only one signal instance, the remaining signal transitions are similar to this path, only the subcarrier frequencies are different.)
At the receiving end, the wireless signal is received by using a 5G receiving antenna, and after passing through a down converter, a second filter, an analog-to-digital converter (converting an analog signal into a digital symbol) and a cyclic prefix remover (removing the prefix), a serial symbol is converted into a parallel symbol by using a second serial-to-parallel converter. The serial symbols are converted to parallel symbols using a second serial-to-parallel converter. And the frequency domain symbol output by the FFT converter is converted into a path of serial symbol through a second parallel-serial converter. The serial symbols are divided into two paths, multiplied by cos ω t and-sin ω t, respectively, and integrated by corresponding integrators in one period to obtain symbols 2 x (x '+ iy'), minus the training pilots. The first and second decryptors decrypt the symbols x 'and y' and restore the symbols x 'and y' into original information x and y through the second mapper and the chaotic encryptor.
The process of implementing communication is briefly summarized as follows:
1. the sending end and the receiving end utilize the same initial condition to generate the same chaotic sequence for encryption and decryption.
2. And carrying out primary chaotic encryption on the information and then carrying out QAM modulation.
3. And carrying out secondary encryption on the symbols generated by QAM modulation by using the chaotic sequence.
4. After passing through a serial-parallel converter, the signal is inverted by using an inverter, Fourier transform is performed by using IFFT, and then parallel-serial conversion and cyclic prefix are added.
5. Digital-to-analog conversion converts digital symbols into analog signals.
6. And performing up-conversion.
7. The signal is transmitted using a transmit antenna.
8. After receiving the signal, the down-conversion is carried out, then the analog-to-digital conversion is carried out, the cyclic prefix is removed, and the Fourier transform is carried out by utilizing FFT after the serial-to-parallel conversion.
9. And (3) carrying out corresponding subtraction on the data symbols after FFT conversion by utilizing the principle of an inverter to eliminate channel noise.
10. Through the parallel-to-serial converter, QAM demodulates the FFT data.
11. And the chaos sequence carries out primary decryption on the data demodulated by the QAM.
12. And performing secondary decryption on the demodulated signal by using the chaotic sequence after passing through the mapper to obtain a transmission signal.
The invention is based on a chaotic encryption OFDM system with a noise reduction function in a 5G network, a signal generator of the chaotic encryption OFDM system is exclusive-or-ed with a first chaotic sequence sampled by the chaotic generator, the step is called an encryption process of the chaotic system, the encrypted encryption sequence is connected with a mapper, I, Q paths are subjected to second chaotic encryption again, an adder is connected behind each encryptor through a multiplier and connected with a first series-parallel converter, signals in the converters and signals which are inverted through an inverter after being converted are connected to an IFFT converter through 2N ports, 2N output ports of the IFFT converter are connected with the first series-parallel converter, the parallel-parallel converter is connected with a 5G antenna after sequentially passing through a cyclic prefix importer, a digital-analog converter, a filter and an up-converter, and the signals are transmitted out.
The 5G receiving antenna of the receiving end receives signals, the signals sequentially pass through a down converter, a filter, an analog-digital converter, a pilot frequency removing cyclic prefix device and are connected with a serial-parallel converter, 2N output ports of a second serial-parallel converter are connected with an FFT converter, the output end of the FFT converter subtracts the ith path of signals and the 2N-i + 1 path of signals, the obtained N path of output is connected with the second parallel-serial converter, the second parallel-serial converter is connected with two multiplying units, the two multiplying units sequentially pass through an integrator and a decryptor respectively and then are connected with a second mapper, a second chaotic encryption sequence is connected between the two decryptors, and finally the original information is decrypted through chaos after passing through the parallel-serial converter.
While the preferred embodiments and principles of this invention have been described in detail, it will be apparent to those skilled in the art that variations may be made in the embodiments based on the teachings of the invention and such variations are considered to be within the scope of the invention.
Claims (9)
1. The chaotic encryption OFDM system with the noise reduction function in the 5G network comprises a sending end and a receiving end, and is characterized in that:
the sending end and the receiving end utilize the same initial condition to generate the same chaotic sequence for encryption and decryption respectively;
a sending end: carrying out primary chaotic encryption on information, then carrying out QAM (quadrature amplitude modulation) modulation, and carrying out secondary encryption on symbols generated by QAM modulation by using the chaotic sequence; then, performing serial-parallel conversion, inverse phase, Fourier transform, parallel-serial conversion, cyclic prefix adding, digital-to-analog conversion and up-conversion on the signals; then, transmitting signals by using a 5G transmitting antenna;
receiving end: receiving signals by using a 5G receiving antenna, performing down-conversion, analog-to-digital conversion, cyclic prefix removal and serial-to-parallel conversion on the signals, and then performing Fourier transform; then, carrying out phase inversion and parallel-serial conversion on the signals, and demodulating data by QAM; and the chaotic sequence is used for carrying out primary decryption on the QAM demodulated data, and then mapping and then carrying out secondary decryption on the demodulated signal by using the chaotic sequence to obtain a transmission signal.
2. The chaotic encryption OFDM system with noise reduction function in 5G network according to claim 1, wherein the transmitting end structure is as follows: the first chaotic signal generator (4-1) is connected with the first sampler (3-1), the first sampler (3-1) and the signal generator (1) are used as input and are connected with the first XOR device (2-1), the first XOR device (2-1) is connected with the first mapper (5-1), the other two ports of the first mapper (5-1) are respectively connected with the first encryptor (2-2), a second encryptor (2-3), a first chaotic sequence generator (6-1) is connected between the first encryptor (2-2) and the second encryptor (2-3), the first encryptor (2-2) is connected with the adder (2-4) through a first multiplier (7-1), and the second encryptor (2-3) is connected with the adder (2-4) through a second multiplier (7-2); the adder (2-4) is connected with a first serial-parallel converter (8-1), the first serial-parallel converter (8-1) is respectively connected with N ports of an inverter (9) and N ports of an IFFT converter (10), N ports on the other side of the inverter (9) are connected with the other N ports of the IFF converter (10), 2N ports on the other side of the IFFT converter (10) are connected with 2N ports of a parallel-serial converter (11-1), the first parallel-serial converter (11-1) converts a parallel sequence into a serial sequence, and an output port of the first parallel-serial converter (11-1), a cyclic prefix importer (12), a digital-to-analog converter (13), a first filter (14-1), a down converter (15) and the 5G transmitting antenna are sequentially connected.
3. The chaotic encryption OFDM system with noise reduction function in 5G network according to claim 1 or 2, wherein the structure of the receiving end is as follows: the 5G receiving antenna (17), the down converter (18), the second filter (14-2), the analog-to-digital converter (19), the pilot frequency removing cyclic prefix device (20) and the second serial-to-parallel converter (8-2) are sequentially connected, the second serial-to-parallel converter (8-2) converts serial signals into parallel signals, and a 2N port of the second serial-to-parallel converter (8-2) is connected with an input port of the FFT converter (21);
at the output end of the FFT converter (21), the ith port is subtracted from the 2N-i +1 th port and then is connected with N ports of the second parallel-serial converter (11-2); the output signal of the second parallel-serial converter (11-2) is divided into two paths and is respectively connected with a third multiplier (7-3) and a fourth multiplier (7-4), the output ports of the third multiplier and the fourth multiplier are respectively connected with a first integrator (22-1) and a second integrator (22-2), the output ports of the first integrator (22-1) and the second integrator (22-2) are respectively connected with a first decryptor (2-5) and a second decryptor (2-6), and a second chaotic sequence generator (6-2) is connected between the first decryptor (2-5) and the second decryptor (2-6); the output ports of the first decryptor (2-5) and the second decryptor (2-6) are respectively connected to a second mapper (5-2), and the second mapper (5-2) is connected with a second XOR device (2-7); the second chaotic signal generator (4-2) is connected with the second exclusive or (2-7) through the second sampler (3-2).
4. The chaotic encryption OFDM system with noise reduction function in a 5G network as claimed in claim 1 or 2,
the receiving end and the transmitting end chaotic signals are coupled and synchronized through the Lorentz circuit.
5. The chaotic encryption OFDM system with noise reduction function in 5G network as claimed in claim 2, wherein the information sequence { b) inputted from the signal generator (1) is inputted at the transmitting endnAfter sampling, the first chaotic signal generator (4-1) is different or the first chaotic encryption is realized.
6. The chaotic encryption OFDM system with the noise reduction function in the 5G network as claimed in claim 5, wherein the signal sequence after the initial encryption is subjected to digital-to-analog conversion and M-QAM modulation, and after the chaotic encryption is performed in the shunt, the signal sequence is multiplied by subcarriers cos ω t and-sin ω t respectively.
7. The chaotic encryption OFDM system with noise reduction function in a 5G network as claimed in claim 5, wherein the sequence { b } bnMapping to sequence anLet { a } ben}＝{a1，a2，...，anHas n elements, { a }nGet into an inverter to get the sequence { a'n}＝{-an，...，-a2，-α1Will then be { a }nAnd { a'nMerging and IFFT transformation are carried out to obtain a sequence { c }n}。
8. The chaotic encryption OFDM system with noise reduction function in 5G network as claimed in claim 3, wherein at the receiving end, the frequency domain symbols { a ] output by FFT transformer1+nw，a2+nw，...，an+nw，-an+nw，...，-a2+nw，-a1+nwSubtracting the ith symbol from the 2n-i +1 th symbol, and converting the ith symbol and the 2n-i +1 th symbol into serial symbols through a second parallel-to-serial converter; each path of serial symbols is divided into two paths, multiplied by cos ω t and-sin ω t, respectively, and integrated within one period by a corresponding integrator.
9. The chaotic encryption OFDM system with the noise reduction function in the 5G network as claimed in claim 8, wherein at the receiving end, the chaotic sequence sampled and generated by the chaotic signal generator is utilized to perform XOR operation in the chaotic decryptor, and the symbol is decrypted to obtain the initial information sequence.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111242041.8A CN114024660B (en) | 2021-10-25 | 2021-10-25 | Chaotic encryption OFDM system with noise reduction function in 5G network |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111242041.8A CN114024660B (en) | 2021-10-25 | 2021-10-25 | Chaotic encryption OFDM system with noise reduction function in 5G network |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114024660A true CN114024660A (en) | 2022-02-08 |
| CN114024660B CN114024660B (en) | 2024-01-12 |
Family
ID=80057815
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111242041.8A Active CN114024660B (en) | 2021-10-25 | 2021-10-25 | Chaotic encryption OFDM system with noise reduction function in 5G network |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114024660B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130159698A1 (en) * | 2011-12-19 | 2013-06-20 | Khalifa University of Science, Technology & Research (KUSTAR) | Chaotic cryptography for ofdm based communications systems |
| CN104202148A (en) * | 2014-09-12 | 2014-12-10 | 重庆邮电大学 | Secret communication method based on FM-DCSK |
| CN205792618U (en) * | 2016-04-07 | 2016-12-07 | 杭州电子科技大学 | Optical OFDM system based on one-dimensional chaos sequence mapping encrypting |
| CN108400865A (en) * | 2018-05-31 | 2018-08-14 | 长安大学 | One kind being based on DCSK chaos encrypting methods |
| CN110149286A (en) * | 2015-05-11 | 2019-08-20 | 蒋华丽 | The signal processing method of the raising signal-to-noise ratio of digital communication under additive noise environment |
-
2021
- 2021-10-25 CN CN202111242041.8A patent/CN114024660B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130159698A1 (en) * | 2011-12-19 | 2013-06-20 | Khalifa University of Science, Technology & Research (KUSTAR) | Chaotic cryptography for ofdm based communications systems |
| CN104202148A (en) * | 2014-09-12 | 2014-12-10 | 重庆邮电大学 | Secret communication method based on FM-DCSK |
| CN110149286A (en) * | 2015-05-11 | 2019-08-20 | 蒋华丽 | The signal processing method of the raising signal-to-noise ratio of digital communication under additive noise environment |
| CN205792618U (en) * | 2016-04-07 | 2016-12-07 | 杭州电子科技大学 | Optical OFDM system based on one-dimensional chaos sequence mapping encrypting |
| CN108400865A (en) * | 2018-05-31 | 2018-08-14 | 长安大学 | One kind being based on DCSK chaos encrypting methods |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114024660B (en) | 2024-01-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2020074630A (en) | Transmission device | |
| JP2017509269A (en) | Combination of amplitude-time modulation and phase modulation | |
| CN111431828B (en) | Low-power-consumption Bluetooth constant envelope phase modulation and demodulation method and equipment | |
| CN111342957B (en) | Method and device for distributing CO-OFDM (CO-orthogonal frequency division multiplexing) key based on Y-00 protocol | |
| US7627055B2 (en) | Error adjustment in direct conversion architectures | |
| EP2073474A1 (en) | Method and apparatus for transmitting an optical signal using orthogonal frequency division multiplexing | |
| JP3432156B2 (en) | Method and apparatus for generating a modulated single sideband signal | |
| JP3130716B2 (en) | OFDM transmitter and OFDM receiver | |
| US8971450B2 (en) | Transmission device, reception device, transmission method and reception method for wireless communication system | |
| CN113490206A (en) | Random number encrypted multi-address passive optical network in 5G network | |
| CN114024660B (en) | Chaotic encryption OFDM system with noise reduction function in 5G network | |
| CN101641922A (en) | Transmitter and ssb signal generation method | |
| CN114142990A (en) | Safe communication system based on chaotic index modulation in 5G network | |
| CN101641921B (en) | Transmitter and ssb signal generation method | |
| WO2012088832A1 (en) | Method and device for transmitting microwave communication data | |
| Galvão et al. | Bandwidth efficient gaussian minimum frequency-shift keying approach for software defined radio | |
| CN114024677B (en) | Elliptic curve encrypted OFDM communication system with double keys | |
| CN113507427B (en) | Carrier tracking method and device suitable for pi/4-DQPSK (differential Quadrature phase Shift keying) and readable storage medium | |
| CN113541951B (en) | Asymmetric elliptic curve encryption secure communication system based on 5G network | |
| CN114629763B (en) | OFDM system IQ signal demodulation method and device based on neural network | |
| CN105407065A (en) | Multi-carrier modulation system | |
| Kokhanov | Single sideband quadrature amplitude modulation | |
| Waraya et al. | Proposal of Single Sideband Modulation Scheme Using Frequency Domain Filtering | |
| JPH09294115A (en) | Ofdm demodulator and its method | |
| CN105553908A (en) | Multicarrier system modulation method |
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 |