283 results about "Fading" patented technology

The invention discloses a rail transit operation and maintenance state data processing method and system based on artificial intelligence, particularly relates to the technical field of rail operation and maintenance management, and is used for solving the problem that the potential multipath effect degree of a tunnel area of rail transit cannot be found in advance in the prior art. A tunnel area is divided into a complex area and a common area, when a train is located in the common area, delay diffusion caused by a complex reflection path and spectrum expansion caused by dynamic Doppler frequency shift are evaluated by analyzing a high-precision channel impulse response estimation result and signal time-varying spectrum characteristics, and whether signal transmission is normal or not is judged; in a complex area, whether the tunnel curvature and the cross structure cause signal shielding and sudden fading or not is judged firstly, and if not, signal distortion caused by electromagnetic resonance is evaluated by analyzing high-order statistical characteristics. Finally, the signal delay diffusion degree and the electromagnetic resonance distortion degree are comprehensively analyzed, and the potential risk of signal transmission is evaluated.

The invention provides a channel modeling method and device suitable for satellite-ground communication, and the method comprises the steps: generating a satellite motion track, and setting ground environment parameters and simulation parameters; converting the satellite motion trail from a global coordinate system to a local coordinate system; acquiring a satellite position from the converted satellite motion trail, and performing ray tracing calculation based on plane wave hypothesis to obtain all effective ray paths between the satellite position and the position of a ground receiver; for each effective ray path, calculating large-scale fading caused by a meteorological environment and small-scale fading caused by ground end multipath propagation and multi-end movement; and a channel model is generated by combining large-scale fading and small-scale fading. According to the method, large-scale fading caused by the meteorological environment is modeled, the influence of meteorological attenuation on the multipath receiving power is considered, small-scale fading caused by multipath propagation and multi-end movement at the ground end is modeled, and the modeling accuracy is improved.

The invention provides a channel estimation method of a multi-user uplink low earth orbit satellite wireless communication system, which is used for transmitting signals by adopting an OTFS (Over The Over The Fine Switching) modulation technology aiming at a low earth orbit satellite rapid moving scene, and provides a low-complexity uplink channel estimation method combining path number, time delay, Doppler and channel fading. The method comprises the following steps: firstly, designing different pilot symbol grid positions of multiple users in a time delay-Doppler domain; then, performing energy threshold detection on all time delay domains of low-orbit satellite receiving signals to estimate the total number of paths and the time delay value of each path; then, giving a closed expression of channel fading by using a maximum likelihood estimation method, and estimating Doppler frequency shift by using a one-dimensional search method; through simulation verification, the provided uplink joint channel estimation method can effectively realize channel detection, can be further applied to ergodic capacity derivation work, and has relatively good practicability and performance.

The invention discloses a novel phi-OTDR (optical time domain reflectometry) system with low sampling rate requirement and polarization suppression, which belongs to the field of distributed optical fiber sensing and consists of a laser, three optical splitters, two acoustic optical modulators, three 3dB couplers, three balance detectors, a polarization controller, two polarization beam splitters, a data acquisition card and a computer. On the basis of a traditional phi-OTDR, a double-path AOM structure is introduced, and one path of optical signal is led out as a reference signal to participate in signal demodulation after light splitting and coupling, so that the requirement of a system on a DAQ sampling rate is reduced. And meanwhile, a polarization fading suppression structure is added in the system to adjust the optical signal, so that the output of two paths of cross-polarization signals is realized, and the influence of polarization fading is suppressed in combination with a phase optimal selection algorithm based on a time domain window. While the requirement of a traditional phi-OTDR system for the DAQ sampling rate is effectively reduced, the influence of polarization fading on phase extraction is suppressed, and the precision of system disturbance monitoring is improved.

Methods and systems are provided for signal offloading in an mmWave environment (e.g., in the event of high fading). The methods and systems include one or more mmWave nodes that are each configured to wirelessly communicate with a user device in a geographic service area and a Wi-Fi access point configured to wirelessly communicate with the user device. The methods and systems determine that fading or loading of an mmWave signal transmitted by one of the one or more mmWave nodes is above a threshold. In response to the fading or loading being above the threshold, the methods and systems redirect a control signal of the user device through the Wi-Fi access point to the one or more mmWave nodes, such that the user device maintains a dual connection with the Wi-Fi access point via the control signal and the mm Wave node.

The invention discloses a wireless-power line dual-mode communication method based on adaptive channel selection, which comprises the following steps of: selecting a relay node, forming a system model from a source node to a relay dual-mode node and then to a destination node, and sending a signal to a relay node R by a wireless channel at a source end S; and the relay node R processes the received signal to obtain a relay signal, then adaptively selects a transmission mode with better channel quality in a power line channel or a wireless channel according to dual-mode channel state information and statistical parameter change conditions, and sends the signal to a destination end D. According to the self-adaptive channel selection algorithm, switching between a wireless channel and a power line channel can be carried out according to the channel quality, a transmission mode with better channel quality is selected in dual-mode communication, the probability that a data packet is interrupted due to channel fading and noise influence in the channel transmission process is reduced, and therefore the overall performance of a system is improved. Mobile access and long-distance communication can be realized, and the coverage effect of indoor communication is ensured.

The invention discloses a 5G waveform-based synchronous channel design method. The method comprises the following steps of: dividing a system working bandwidth into a plurality of sub-bands; determining a candidate frequency domain position of a synchronization channel in each sub-band, wherein the synchronization channel is composed of a PSS and an SSS; and determining values of the PSS sequence and the SSS sequence according to the indexes corresponding to the PSS sequence and the SSS sequence, determining one or more frequency domain positions from the candidate frequency domain positions, and filling the selected frequency domain positions with the PSS sequence and the SSS sequence. In different interference and fading scenes, the time-frequency position of the synchronization channel can be adaptively selected according to interference and fading, so that the frequency domain position of interference and fading is avoided, and better performance is obtained.

The invention provides a method for optimizing the energy efficiency of an uplink of an RIS-assisted cellular-removed large-scale MIMO (Multiple-Input Multiple-Output) system. Based on a Rayleigh channel fading model, the method firstly derives an expression of the energy efficiency of an uplink under perfect channel state information, and provides a method for jointly optimizing the user transmitting power and the RIS phase shift matrix with the purpose of maximizing the energy efficiency. In view of the non-convexity of the optimization problem, the user transmitting power is optimized by utilizing a water injection method, and the RIS phase shift matrix is optimized by adopting a genetic algorithm, so that the energy efficiency is quickly improved. According to the invention, the total power consumption of the system is effectively reduced, the wireless resource utilization rate of the system is improved, and green communication requirements are met.

The invention discloses a dynamic optimization system and method for a heterogeneous network communication protocol, and particularly relates to the technical field of communication network automation, and the system comprises a unified time base and multi-source state modeling module, a quick change detection and shadow section risk assessment module, a risk gating and hierarchical low-disturbance execution module and a closed-loop feedback and evolution management module. According to the method, a standard recording unit is constructed through unified time base and observation delay compensation, and multi-source communication state alignment is realized; a shadow section joint risk index is calculated based on online filtering and geographical priori, hierarchical low-disturbance strategy arrangement is implemented under the constraint of risk gating and comprehensive cost, and closed-loop feedback and anti-fact evaluation are utilized to drive parameter evolution governance. According to the method, the problems that short-time fading is smoothly masked in a high-speed or strong-shielding environment and unified risk assessment and low-disturbance execution are lacked are solved, the tail time delay, the disorder rate and the packet loss rate are reduced, the communication reliability is improved, and interpretable tradeoff between energy consumption and tariff is achieved.

The invention discloses an efficient short-wave and radio-frequency broadband converged communication digital signal processing system, belongs to the technical field of communication, and aims to solve the problem that defects exist when existing short-wave and radio-frequency broadband are used independently and in a converged mode. The frequency and bandwidth resource combination optimization system adopts a genetic algorithm to optimize frequency and bandwidth resource combination, and comprises a parameter setting module, a signal monitoring and data collection module, a fitness evaluation module, a genetic algorithm operation module, a termination judgment module and a signal processing and communication module. The method can better adapt to ionosphere changes, reduce signal fading and interruption, effectively cope with external interference and reduce the bit error rate through monitoring signal characteristics and reasonably allocating resources, carries out frequency and bandwidth resource combination optimization by comprehensively considering various factors by applying a genetic algorithm, avoids the problems of short-wave frequency band congestion and insufficient utilization of radio frequency broadband bandwidth, and improves the utilization rate of the radio frequency bandwidth. The fusion of two communication resources is realized, and the overall efficiency of the system is improved.

The invention discloses an unmanned aerial vehicle relay route planning method based on photoelectric hybrid switching. The method comprises the following steps: establishing a free space optical channel model, and focusing a flicker effect caused by turbulence and attenuation caused by weather; when a radio frequency channel model is constructed, line-of-sight and non-line-of-sight large-scale fading are fused, and downlink multi-user interference is quantized; establishing a hybrid obstacle model based on a Ray-AABB algorithm, fusing ground static and air dynamic obstacles, and determining a sight distance connection feasible position set; a boundary reflection type random walk model is adopted to describe user movement, and a speed and direction two-parameter updating mechanism and a boundary elastic collision rule are defined; the user throughput is dynamically optimized in combination with fractional order power distribution and non-orthogonal multiple access technologies; a deep reinforcement learning framework is provided, and a three-dimensional track, photoelectric switching and resource allocation are jointly optimized by using a dual deep Q network. According to the invention, the challenge of a low-altitude spectrum rejection environment can be effectively handled, and the robustness and adaptive capacity of the system are ensured.

The invention relates to the technical field of magnetic shielding, and provides a demagnetization method and device for a magnetic shielding device, electronic equipment and a readable storage medium, and the method comprises the steps: collecting a feedback circuit signal of a target magnetic shielding device through a voltage and current collection unit; analyzing the feedback circuit signal by using a signal acquisition processor, determining the current degaussing demand of the target magnetic shielding device, and calculating a degaussing pulse parameter matched with the current degaussing demand; a pulse generating unit is used for generating a target pulse with the adjustable pulse width according to the degaussing pulse parameters, the target pulse is a bipolar square wave pulse, and the adjusting interval of the pulse width comprises the millisecond level and the nanosecond level; and utilizing a pulse switching unit to act the target pulse on the target magnetic shielding device, so that the target magnetic shielding device is subjected to magnetic saturation or magnetic fading. According to the technical scheme provided by one or more embodiments of the invention, the average power demand of the degaussing power supply can be reduced, and the degaussing effect can be improved.

The invention provides a multi-input multi-output permutation index differential chaos shift keying communication system and method, and relates to the technical field of chaos secret communication. Generating two paths of chaotic signals in the modulator, wherein one path is used as a reference signal; delaying the other path, performing mapping permutation by using the index bit, multiplying the modulation bit subjected to space-time coding by a reference signal copy generated by permutation, generating an information signal, combining the information signal with the reference signal, and sending the information signal to a demodulator; and the demodulator is used for respectively delaying and replacing the received transmission signal, carrying out correlation operation on the delayed receiving signal and the replaced receiving signal to obtain an output signal, and carrying out comparative judgment and space-time decoding to recover the index bit and the modulation bit. According to the method disclosed by the invention, the security and the information transmission rate of a communication system are improved through different index bit mapping selection permutation rule methods; and channel fading and noise are suppressed by using multiple antennas, so that the bit error rate performance of a communication system is effectively improved.

The invention discloses a phi-OTDR vibration demodulation method based on double-segment average phase difference, belongs to the technical field of optical fiber sensing vibration demodulation, and solves the problems that in the prior art, phase demodulation is greatly influenced by phase noise such as laser frequency drift, the phase extraction precision and the signal-to-noise ratio are low due to random fluctuation of a phase curve, and the signal-to-noise ratio is low. And phase solving errors are easily caused by interference fading points. According to the method, through band-pass filtering, moving differential positioning, I / Q demodulation after reference point selection, unwinding, mean value removal and calculation of the average phase difference of two segments, the phase variation corresponding to vibration is extracted, and the demodulation precision is improved. Through the two-segment average phase difference method, the influence of phase noise and interference fading is suppressed, and the signal-to-noise ratio and stability of phase demodulation are improved; the frequency modulation pulse is replaced to break through restrictions of spatial resolution and sensing distance, high sidelobe suppression can be realized without windowing the NLFM pulse, the signal-to-noise ratio is not damaged, and the vibration detection positioning accuracy is improved.

A distributed displacement sensing phase demodulation method, comprising: determining an IQ demodulation initial phase and an IQ signal amplitude on the basis of an IQ signal (S101); performing a phase decoupling operation on the IQ demodulation initial phase, and sequentially subtracting from the IQ demodulation initial phase an initial phase of an optical fiber sensing signal sensing position, an initial phase of a laser pulse source and an accumulated phase along paths in a transmission process, so as to obtain a displacement sensing phase to be measured (S102); performing phase unwinding processing on the displacement sensing phase to be measured, so as to obtain an unwound displacement sensing phase to be measured (S103); performing calculation on the basis of the unwound displacement sensing phase to be measured, so as to obtain displacement sensing data (S104); determining a coherent fading position in the displacement sensing data on the basis of the IQ signal amplitude, and eliminating the impact of coherent fading by using linear interpolation of adjacent normal points, so as to obtain displacement sensing data that has been subjected to coherent fading noise suppression (S105); and transposing, into data recorded in trace order, the displacement sensing data that has been subjected to coherent fading noise suppression, and performing denoising by means of subsequent data processing, so as to obtain final phase-demodulated displacement sensing data (S106). By means of the phase demodulation method, displacement sensing phase demodulation can be realized, and distributed displacement response information of a wave field to be measured is recovered. In addition, further provided are a distributed displacement sensing phase demodulation apparatus, and an electronic device and a readable storage medium.

Some wireless communications systems modulate signals for transmission via a channel. Probabilistic shaping may utilize non-uniformly distributed modulation constellations to increase spectral efficiency. In some cases, wireless fading may occur in a multiple-input and multiple-output (MIMO) channel, which may cause a loss of the shaping gain from probabilistic shaping. Some examples of approaches to linear MIMO demodulation for probabilistic shaping using auxiliary dimensions are provided. A wireless device may receive information indicating a non-uniform probabilistic distribution of a modulation constellation for a MIMO signal. One or more symbols of the MIMO signal may be transmitted or received via a channel. The wireless device may demodulate the symbol based at least in part on a transformation of the modulation constellation to a subspace using dimensions associated with the non-uniform probabilistic distribution and a point of the transformed modulation constellation nearest to a projected symbol in the subspace.

Techniques are disclosed to detect deep fading caused by magnitude drop and rapid phase change on channels within a frequency band of a narrowband wireless radio operating in a BMS-like environment with strong multipath. The techniques may identify an interference channel, a deep fading channel, or a weak signal channel. A channel assessment algorithm may receive packets on one of multiple channels to determine a received signal strength for each packet associated with the channel. The algorithm may determine a PER associated with the channel based on a number of packets received in error and a difference between the received signal strength of each packet and a reference signal strength associated with other channels of the frequency band. The PER may be compared with a PER threshold. The channel may be excluded from use by the wireless radio if the PER for the channel is greater than the PER threshold.

The invention relates to a method for controlling a hydraulic brake-by-wire braking system, wherein a volume intake monitoring system detects a deviation between the actual volume intake and the target volume intake as an additional volume requirement. To prevent hazardous situations caused by decreasing braking force, fading is detected by means of a fade monitoring system, and the additional volume requirement is taken into account in the pressure control when fading is detected.

The invention relates to the technical field of unmanned aerial vehicles, in particular to a self-adaptive tracking unmanned aerial vehicle spectrum detection module which comprises a dynamic fingerprint database generation unit, a deep reinforcement learning decision unit, an intention prediction and compensation unit, an extended tracking control unit and a federal learning evolution unit. The dynamic fingerprint database accurately depicts the spatial-temporal characteristics of the signals; the deep reinforcement learning optimizes detection parameters in real time; the intention prediction unit actively compensates signal fading; the cross-modal data fusion improves the tracking robustness; therefore, the system has high-precision and high-reliability tracking capability in a complex environment.

The invention discloses a long tunnel environment train positioning method based on UWB, and belongs to the technical field of train positioning, and the method comprises the steps: arranging UWB positioning base stations above a tunnel wall in a rectangular manner, and fixing UWB labels at the top end of a train; collecting RSSI data of the train and the UWB positioning base station at different distances to obtain preprocessed RSSI data; constructing a signal large-scale fading model, and performing parameter optimization on the signal large-scale fading model by using MEGNDO according to the preprocessed RSSI data to obtain a UWB ranging model suitable for a tunnel scene; in the running process of the train, the distance between the UWB positioning base station and the train is calculated by using a UWB distance measurement model according to RSSI data received by the UWB equipment; and according to the distance from the UWB positioning base station to the train, obtaining the position coordinates of the train by using a trilateral positioning method. The problems that satellite signals cannot be received in a tunnel environment and real-time positioning is difficult to carry out are solved.

Reliable communications is a central goal of 5G and 6G. However, due to signal fading at high frequencies and interference due to crowding, message faults continue to be a problem. Disclosed are methods for base station and user devices to adjust the modulation scheme according to the types of faults received, including amplitude faults (incorrectly demodulated amplitude levels) and phase faults (incorrectly demodulated phase levels), among others. The base station can select a more suitable modulation scheme based on the types of faults observed by user devices, such as modulation schemes with more or fewer amplitude levels and phase levels. In some versions, the number of amplitude levels is different from the number of phase levels, to combat specific fault problems.

The invention relates to a terminal access method and device, communication equipment, a medium and a product, and relates to the technical field of communication. The method is applied to a satellite base station, and comprises the following steps: receiving a random access request of UE to be accessed; wherein the random access request comprises a preamble sequence and distance influence data of the UE to be accessed; determining a time-frequency adjustment parameter according to the leader sequence; the time-frequency adjustment parameters comprise TA and / or FA; correcting the time-frequency adjustment parameter according to the distance influence data; and sending the corrected time-frequency adjustment parameter to the UE to be accessed, so that the UE to be accessed performs random access according to the uplink transmission parameter adjusted based on the corrected time-frequency adjustment parameter. By adopting the technical scheme, changes of signal attenuation, propagation delay and the like caused by distance-related factors can be eliminated, so that the influence of factors such as atmosphere, multipath, shielding and the like can be reduced, the conditions of signal fading and interference are improved, and the random access success rate of the satellite network is improved.

The invention relates to the technical field of satellite navigation terminals, and discloses a Beidou terminal capable of intelligently evaluating multiple states. Comprising a Beidou positioning module used for acquiring a Beidou signal corresponding to the Beidou terminal; the control module is configured to execute the following steps: performing time sequence modeling on the propagation time delay, the geometric distribution factor, the ionosphere influence parameter and the troposphere influence parameter of the Beidou signal to generate a positioning reliability index so as to realize positioning state evaluation; performing conjoint analysis on the Beidou signal, and outputting a data credibility grade; processing the inertial navigation data, the terrain elevation data, the sky satellite geometric distribution factor and the multi-terminal altitude difference data corresponding to the Beidou terminal through a convolutional neural network to generate a three-dimensional environment interference coefficient; and fusing the channel fading parameter, the network topology data, the communication antenna signal-to-noise ratio, the transmission rate change parameter and the data integrity parameter corresponding to the Beidou terminal, and calculating a communication link stable value to realize communication state evaluation.

The invention discloses an anti-interference unmanned aerial vehicle cellular edge removal computing resource allocation method in an air-space-ground integrated network, which comprises the following steps of: firstly, constructing an air-space-ground integrated network architecture comprising a low-orbit satellite, an unmanned aerial vehicle cluster and a ground user, and establishing satellite interference space distribution mapping based on a satellite orbit and an interference measurement result; and then adopting a user-centered dynamic clustering strategy, combining with a large-scale fading coefficient and interference intensity, adaptively selecting a cooperation cluster scale and member composition, and forming an unmanned aerial vehicle cooperation cluster. Then establishing an uplink communication model of an explicitly introduced satellite direct-connected user co-frequency interference term, and on the basis, constructing a three-section end-to-end time delay model comprising wireless transmission time delay, parallel computing time delay and forward pass and backhaul time delay related to a cooperative cluster scale and a quantization bit number; according to the method, the cooperative cluster scale and the quantization bit number are used as time delay optimization variables together, controllable optimization of end-to-end time delay is achieved, the propulsion energy consumption of the unmanned aerial vehicle is considered, and therefore the unloading efficiency and the overall energy efficiency of the cellular edge removal computing system are improved.

The invention relates to the technical field of free space optical communication, in particular to an atmospheric turbulence adaptive optical compensation method for wireless laser communication, which comprises the following steps of: performing light beam coarse tracking by using a fast reflector to eliminate tilt drift; monitoring the received light intensity of the wavefront sensor in real time, and setting a threshold value for mode judgment; when a channel is good, a Kalman filtering algorithm is adopted to predict and compensate system delay, modal decoupling is carried out on reconstructed wavefront, a large-stroke deformable mirror is controlled to correct low-frequency large-amplitude aberration, and a micro-electro-mechanical deformable mirror is controlled to correct high-frequency residual error; and when the channel is in deep fading or the detector fails, the blind optimization mode is automatically switched, the state of the large-stroke deformable mirror is locked, and SPGD iterative control is applied to the micro-electro-mechanical deformable mirror based on the communication light intensity. According to the invention, through a double-deformable mirror frequency division cooperation and hybrid sensing strategy, the problems of insufficient bandwidth, limited stroke, easy interruption and the like of a traditional system under strong turbulence are effectively solved, and the optical fiber coupling efficiency and the robustness of a communication link are significantly improved.

The invention discloses a regional signal suppression method for realizing deep fading based on RIS. The method comprises the following steps: establishing a signal propagation model; acquiring a signal gain and a phase of a transmitting path of a target area receiving point; calculating the number of optimal reflection units required by the RIS to ensure that the total amplitude of the reflection signals is equal to the amplitude of the direct signal and the phase difference pi between the total phase and the direct signal; adjusting the phase and the amplitude of a reflection unit of the RIS, generating a deep fading area and effectively reducing the signal intensity in a target area; a deep fading area is expanded and a signal weakening effect is optimized by adjusting the unit number, the position, the signal frequency and other physical parameters of the RIS and combining the RIS amplitude and phase design; according to the invention, by intelligently optimizing the RIS phase and amplitude, signal weakening of the target area is realized. According to the method, a single RIS is adopted to optimize based on RIS physical parameters and an algorithm, and minimization of target area receiving power is taken as an optimization target.

The invention discloses a device and method for avoiding coherent fading in a DVS system, and relates to the technical field of optical fiber sensing. The device comprises two 1 * N optical switches and N delay optical fibers, wherein N is greater than or equal to 2; wherein the com end of one of the 1 * N optical switches is connected with the output end of the DVS system, and the com end of the other 1 * N optical switch is connected with a target optical cable to be tested; each time-delay optical fiber is arranged between the two 1 * N optical switches, and two ends of each time-delay optical fiber are respectively connected with the 1 * N optical switches at the corresponding positions. Signal measurement can be carried out through the device, the DVS system is prevented from being influenced by coherent fading, and the vibration position of the target optical cable can be positioned more accurately and efficiently.

The invention discloses a block interleaving method, a de-interleaving method, a block interleaver and a de-interleaver, and the interleaving method comprises the steps: writing a first data sequence into the interleaver according to a sequence, and obtaining a first matrix; performing transformation processing on the first matrix to obtain a second matrix; finally, the second matrix is read out according to the sequence, a second data sequence is obtained, the large minimum interleaving depth can be achieved, deep fading and periodic fading on the frequency domain can be effectively resisted, and therefore the fault tolerance performance of the system is improved.

The invention belongs to the technical field of terahertz communication physical layer security, and particularly relates to a terahertz physical layer key generation method based on leaky-wave antenna space-spectrum coupling characteristics. According to the invention, the sensitivity of the effective antenna gain of the leaky-wave antenna to the frequency and the spatial propagation direction is utilized to make up for the defect of low eavesdropping channel doubtful degree caused by lack of small-scale fading in terahertz communication, and the conditional generative adversarial network is designed to accurately speculate the equivalent channel power gain. A physical layer key is generated based on the estimated channel power gain. According to the method, the channel power gain can be accurately estimated from the received signal strength with noise and auxiliary information, the reciprocity of an equivalent channel is enhanced, and the method has a lower key mismatch rate and a higher key generation rate; under the condition of different signal-to-noise ratios, good key generation performance can be kept.

The invention discloses a radio frequency fingerprint extraction method and system using logarithmic difference characteristics of channels at different moments, and the method and system are used for extracting radio frequency fingerprints of wireless equipment, and the method comprises the following steps: carrying out the collection and preprocessing of a wireless signal, obtaining a time domain receiving signal, and carrying out the frequency domain transformation of the time domain receiving signal, and obtaining a frequency domain receiving signal; selecting two sections of receiving symbols which pass through different channels and do not generate deep fading to perform differential operation and logarithmic differential operation, and further performing division operation to obtain radio frequency fingerprints without channels; and superposing and averaging multiple groups of results after division operation to eliminate the influence of noise, and finally obtaining radio frequency fingerprints which do not contain channels and noise. According to the radio frequency fingerprint extraction method, the difference and logarithmic difference characteristics of channels at different moments are utilized, the influence of time-varying channels on radio frequency fingerprint extraction is effectively eliminated, meanwhile, noise is restrained, the stability of radio frequency fingerprint extraction under the channel variable environment is improved, and the radio frequency fingerprint extraction method is effective and universal for various wireless signals.