134 results about "Fading" patented technology

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 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 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 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 an implementation method of a sub-connection active STAR-RIS assisted secure communication system. A base station, a sub-connection active STAR-RIS, a legal user and an eavesdropping user are included. According to the invention, M units of STAR-RIS are grouped into L sub-arrays, and an amplifier is shared to reduce power consumption and cost; with maximization of system secrecy energy efficiency as a target, base station beam forming, STAR-RIS reflection / transmission coefficients and amplifier amplification coefficients are jointly optimized; and solving the non-convex optimization problem by adopting an efficient algorithm based on block coordinate descent. According to the invention, the hardware overhead and the system power consumption are effectively reduced through the sub-connection structure, meanwhile, the secure transmission efficiency of the system is remarkably improved through joint optimization, multiplicative fading is overcome, and an efficient and reliable solution can be provided for 6G secure communication.

The invention discloses an interference fading point compensation method for a coherent phi-OTDR (Optical Time Domain Reflectometer), which comprises the following steps of: identifying an interference fading point on the basis of complex envelope characteristics obtained by coherent receiving and I / Q (Input / Output) demodulation, and performing interpolation reconstruction on a fading point echo vector by using a neighborhood non-fading point on a complex plane, so as to recalculate a phase and a differential phase; therefore, phase demodulation failure and differential phase artifacts caused by fading can be suppressed. According to the method, on the premise of not increasing hardware transformation, differential phase artifacts and abnormal stripes caused by phase demodulation failure at a fading point are reduced, the stability of a differential phase result and event identifiability are improved, and relatively low calculation complexity is kept to adapt to offline or quasi-real-time processing.

The invention discloses a low-voltage power line carrier communication network repeater deployment method and system, and relates to the technical field of power communication. The method comprises the following steps: (1) according to PLC network topology information, acquiring an STA set which cannot directly communicate with a CCO, and inputting model parameters; (2) calling a general optimization solver to carry out model solution to obtain a solution result; (3) if the feasible solution exists, outputting a PCO deployment mark; if not, adjusting the received signal threshold value and the transmitting power, and repeating the step (2); and (5) once a feasible solution is obtained or the model parameter reaches the set limit value, the solution is ended. According to the deployment planning model constructed by the invention, the optimal deployment position of the PCO in the network is solved by taking the minimum weighted sum of the total transmission time delay and the total cost as a target and taking the received signal strength and the single-hop relay as constraints; the problem that seamless coverage of a low-voltage power distribution network is difficult to realize by single-hop communication due to high background noise and frequency selective fading of a PLC channel is solved.

The present invention provides an interleaving method and a related device for mapping a virtual resource block to a physical resource block (VRB-to-PRB) during a sub-band full duplex (SBFD) period, and a method for mapping a virtual resource block to a physical resource block (VRB-to-PRB) during the SBFD period of the sub-band full duplex (SBFD) period of the sub-band full duplex (SBFD) period of the sub-band full duplex (SBFD) period of the sub-band full duplex (SBFD) period of the virtual resource block to the physical resource block (VRB-to-PRB). In one embodiment, the method includes performing a VRB-to-PRB interleaving during the SBFD to interleave resource blocks (RBs) and map a VRB beam to a PRB beam in a first DL frequency domain and a second DL frequency domain. By the method, the VRB-to-PRB interleaving is enhanced in the SBFD operation, thereby being able to benefit from less frequency selective fading.

The invention provides a low-altitude cellular-free network signal detection method under wireless forward pass constraint, which belongs to the field of wireless communication and digital signal processing, and comprises the following steps: establishing a signal transmission model based on a low-altitude cellular-free network architecture; in the period, each air AP obtains a local signal processing result; transmitting signals of the air APs are distributed on B subcarriers so as to send local signal processing results to the central processing unit in real time; the central processing unit performs combination detection on the ground user signals to obtain a final ground user signal detection result; and after the period is ended, each air AP sends the channel statistical information of the period to the central processing unit, and the central processing unit optimizes the local processing matrix of each air AP and sends the optimized local processing matrix to each air AP. According to the method, the uplink rate of the ground user can be effectively improved, and meanwhile, the problems of channel fading, multiple access and network expandability of a wireless forward link are solved.

Disclosed herein are systems and methods of predicting fading loss of signals transmitted between a ground-based transceiver and an aircraft based upon a two-ray fading model that incorporates elevation information of an environment. Some examples of the disclosure are directed to determine fading loss using a plurality of geofences that are determined based on a plurality of planar shapes.

This invention relates to the field of unmanned aerial vehicle (UAV) communication technology, and in particular to a communication method for a dual-channel UAV line-of-sight (LAS) communication system. The method includes: acquiring communication quality, acquiring the optimal transmission frequency, acquiring the UAV's mission priority, transmitting video stream data, and performing multipath fading compensation steps. The method sets up high-frequency and low-frequency channels, calculates frequency quality indicators using signal-to-noise ratio (SNR), signal rate, and bit error rate (BER), and dynamically selects the optimal transmission frequency. Communication resources are allocated based on mission priority to ensure priority transmission of critical commands. Innovatively, differential geometry theory is used for multipath fading compensation, mapping the communication signal to a Riemannian manifold space, extracting fading features, and optimizing the processing. High- and low-frequency channel collaborative compensation is achieved, with mutual enhancement through received spectrum analysis and training sequence correction. Adaptive QAM modulation is supported, dynamically adjusting modulation parameters according to manifold curvature to construct a star-shaped multi-node communication network.

The invention provides a signal processing method, receiving end equipment, a signal processing device and a storage medium. The method comprises the steps that the receiving end equipment determines a target precoding matrix and a target equalization matrix which enable the signal to interference plus noise ratio (SINR) of a received symbol to be maximized; wherein the target precoding matrix satisfies a transmitting power constraint condition and a waveform subcarrier energy constraint condition, and the target equalization matrix satisfies a power normalization constraint condition; sending the target pre-coding matrix to the transmitting end equipment, wherein the target pre-coding matrix is used for the transmitting end equipment to perform pre-coding processing on the transmitting symbol sequence; and if a signal sent by the transmitting end equipment after precoding processing is received, carrying out equalization processing on the received signal based on the target equalization matrix to obtain a received symbol sequence. Therefore, the influence of channel fading can be compensated to the greatest extent, the PAPR can be reduced, and the anti-fading performance and the anti-limiting distortion performance of the signal can be improved at the same time.

The application provides a method, device and storage device for inhibiting fading interference, selects a main lobe and two first-order side lobes, extracts three sub-bands by using a filter with the same width as the main lobe, adds the intensity of three curves obtained by performing inverse Fourier transform on the three sub-bands by using a rotation vector summation method to obtain a new signal, extracts the phase information of each vibration point on the new signal curve by amplitude demodulation, sets a threshold range according to the corresponding relationship between the amplitude and the phase of Rayleigh scattering, selects the phase, retains the phase outside the threshold range, averages the phase in the threshold range, thereby avoids the wrong phase point, and obtains the final phase demodulation image of the vibration point for eliminating fading interference. The application has the beneficial effects that: the coherent fading is eliminated without multiple frequency data, the detection times are reduced, the cost is reduced, the real-time demodulation speed is accelerated, and the wrong phase demodulation is avoided.

The utility model provides an automatic frequency hopping image transmission communication system, which comprises at least one host and a plurality of slaves in wireless communication with the host, and the host and the slaves respectively comprise a frequency hopping communication circuit. The frequency hopping communication circuit is composed of a chip which supports the fastest 100 hops per second and is provided with 80 channels, the channel interval is 30 kHz, the self-correlation coefficient is 0.4, the mutual relation is 0.5, the frequency hopping sequence length is at least 80, and the synchronization time is three frames of 10 milliseconds. The host and the slave of the image transmission communication system adopt the chip supporting the frequency hopping technology for communication, single-frequency communication is not used any more, so that interference signals are difficult to aim at specific frequencies to interfere, the stability and the reliability of communication are improved, the chip supporting the frequency hopping technology can send and receive signals at different frequencies, and the communication efficiency is improved. And the influence of signal fading and multipath effect is effectively avoided.

The invention discloses a server-free edge function reliability deployment method and system based on reinforcement learning, and the method is oriented to server-free edge calculation, takes the minimization of long-term network cost as a target, and systematically solves the problems of high cold start cost, limited resources, difficult reliability guarantee and the like. A system model including user movement, channel fading, function deployment and a backup mechanism is constructed, four types of costs of cold start, maintenance, transmission and punishment are accurately described and converted into a Markov decision process, and a state-action-award framework is utilized to realize dynamic decision. The PPO algorithm fusing the greedy strategy to assist the action selection is further provided, and a function deployment scheme meeting the reliability constraint is efficiently generated under the condition that resources are limited. According to the method, through fusion of reinforcement learning and a greedy strategy, the problems of feasibility, reliability and cost of function deployment in server-free edge computing are solved, and the method has the capabilities of efficient deployment, adaptive scheduling and long-term performance optimization.

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 application discloses a navigation receiver autonomous integrity function test method, device, equipment and medium, the test method is based on the test in the real sky environment, uses the real satellite signal to the sky as the reference signal for testing, the reference signal contains environmental factors such as multipath, shielding, interference, noise, power fading, and the test result is fully reliable;Based on controllable abnormal injection, in the test signal for testing, the corresponding abnormal satellite number is controllably injected, and the abnormal type, abnormal effective time, including abnormal start time and end time, is strictly controllable, so that the reliability of the test result is guaranteed;The test method has wide universality, is suitable for autonomous integrity function test of various types of GNSS global satellite navigation receivers and low-orbit navigation receivers, and has good applicability;The test device of the application has simple structure, convenient test environment construction and simple and fast operation.

The application provides a waveform design and receiving method in orthogonal time-frequency code domain. The method comprises the following steps: allocating orthogonal spread spectrum combination to each waveform in a waveform group by using an orthogonal spread spectrum sequence pool; each waveform carries transmission data in the orthogonal time-frequency code domain according to the allocated orthogonal spread spectrum combination; after receiving each waveform, a receiver estimates the multipath time delay, multipath fading and multipath Doppler experienced by multiple waveforms according to the orthogonal spread spectrum combination of each waveform; the receiver detects the transmission data carried by each waveform by using the estimated multipath time delay, multipath fading and multipath Doppler of each waveform, using the MMSE criterion and the orthogonal spread spectrum combination structure. The method of the application designs unique orthogonal spread spectrum combination for different waveforms in the same waveform group, realizes the orthogonal transmission of multiple waveforms under the same DD domain resource, and provides an alternative scheme for multi-user data transmission under high-speed mobile conditions.

The application discloses a kind of OFDM-PON bits and power loading method based on layered modulation, belong to passive optical network field.The application includes: based on the signal-to-noise ratio between each branch optical network unit and optical line terminal in OFDM-PON, each optical network unit is grouped;Low-order quadrature phase modulation modulation format is used as base layer in the optical network unit group with low signal-to-noise ratio, high-order quadrature amplitude phase modulation-16 and quadrature amplitude phase modulation-64 modulation format are used as enhancement layer in the optical network unit group with high signal-to-noise ratio;The trough point of the frequency selective fading of each group optical network unit in OFDM-PON is calculated;According to bit allocation method, power allocation method is carried out for bit allocation and power allocation of base layer and enhancement layer.The application realizes the maximum utilization of flexible OFDM-PON in channel condition by simple and easy-to-implement algorithm, to realize the increase of overall OFDM-PON system capacity, satisfy future optical access network to the full use of channel power abundance.

The invention discloses a navigation receiver autonomous integrity function test method, device and equipment and a medium, the test method is based on a real to-sky environment test, a to-sky real satellite signal is used as a reference signal for test, the reference signal comprises multipath, shielding, interference, noise, power fading and other environmental factors, and the test accuracy is improved. The test result is sufficient and reliable; on the basis of controllable abnormal injection, corresponding abnormal satellite numbers are controllably injected in test signals for testing, and injected abnormal types and abnormal effective time including abnormal starting time, abnormal ending time and the like are strictly controllable, so that the reliability of a test result is ensured; the testing method has wide universality, is suitable for autonomous integrity function testing of various types of GNSS global satellite navigation receivers and low-orbit navigation receivers, and is good in applicability; the testing device is simple in structure, the testing environment is convenient to build, and operation is easy and fast.

The invention discloses a channel estimation method, related equipment, a storage medium and a computer program product. The method comprises the steps that a sending device determines a first symbol and first information, the first symbol is used for indicating semantics of an information source, and the first information is used for indicating the importance degree of the first symbol on information source reconstruction; in the process of superposing a second symbol to the first symbol, power is allocated for the first symbol and the second symbol based on the first information, and the second symbol is used for channel estimation; and sending the superposed first symbol to a receiving device through a first channel, the first channel having at least the characteristics of time selective fading and frequency selective fading. According to the technical scheme provided by the invention, under the scene of double selective channels, the pilot symbols are superposed on the semantic symbols, and the distribution of the pilot power is dynamically adjusted in combination with the importance of the semantic symbols, so that more accurate channel estimation and stronger anti-interference capability can be realized.

This invention provides a cross-medium visible light communication system and method based on deep learning. On one hand, it proposes an angle estimator and receiver movement strategy based on a convolutional neural network. The receiver can make movement decisions based on the angle estimation results, adaptively achieving link alignment of the transceiver in the cross-medium visible light communication system. On the other hand, this invention proposes a signal detection algorithm based on wind speed estimation and channel classification. After the system completes link alignment, this algorithm can estimate the wind speed and adaptively detect the received signal transmitted through the channel under different wind speed conditions. Furthermore, this invention proposes a loss function based on a modified mean square error criterion, which can effectively mitigate the adverse effects of wave-induced fading on signal transmission in the cross-medium visible light system communication channel, thereby reducing the system's bit error rate.

The application provides a delay-Doppler transmission method, device and equipment based on continuous domain mapping. Continuous amplitude modulation symbols generated by Shannon-Kotelnikov space filling mapping are sequentially filled into a delay-Doppler domain two-dimensional grid in a column priority rule, so that the geometric neighborhood relationship of continuous mapping is maintained in the delay-Doppler domain. The characteristics that each symbol in the domain experiences approximately uniform equivalent channel gain are utilized to avoid the destruction of the continuous mapping structure by double selected fading. Meanwhile, amplitude enhancement pilots are inserted in the grid and a guard band is set, and energy threshold adaptive adjustment based on a mapping scale parameter is combined to realize channel sparsity parameter estimation, so that the channel estimation and equalization process adapt to the continuous amplitude signal characteristics, thereby realizing the organic integration of analog joint source channel coding and orthogonal time-frequency-space modulation without relying on discrete constellation modulation.

The invention discloses an unmanned aerial vehicle over-the-horizon air-ground cooperative emergency communication system in a complex environment, and relates to the technical field of emergency communication and unmanned aerial vehicles. In order to solve the problem of'information isolated island 'in a disaster'three-break' environment and the problem that traditional communication highly depends on sight distance or relay, the system comprises an unmanned aerial vehicle platform, a beyond-sight-distance scatter communication load carried on a three-axis servo holder, a ground base station module, an air-ground collaborative networking module and a heterogeneous network fusion module. The system establishes a non-relay beyond-the-horizon link by utilizing troposphere forward scattering; driving a holder to execute narrow beam real-time alignment compensation based on the positioning and attitude data; and the pose of the unmanned aerial vehicle is solved in combination with a multi-target cost function to balance communication and energy consumption. According to the method, the defects of wave beam lock losing and meteorological multipath fading caused by platform shaking are effectively overcome, high-reliability emergency networking crossing geographical obstacles is realized without a physical relay condition, and priority stable return of core rescue services is ensured.

The application discloses a kind of distributed optical fiber monitoring sensing optical cable damage location method, it is related to distributed optical fiber monitoring technical field.The method includes: using OTDR optical time domain reflectometer to carry out preliminary measurement to sensing optical cable, it is judged whether optical cable exists damage and the preliminary measurement distance of damage point when existing damage;According to distance threshold value, it is judged whether bare optical fiber is fused, and OTDR secondary measurement is carried out, according to the measurement result record optical fading and the secondary measurement distance of each damage point;According to the optical fading, damage point is divided into two categories of " serious attenuation or broken fiber damage " and " moderate and below attenuation damage ", and the position of final damage point is positioned specifically.The application can be monitored by combined use of existing equipment of distributed optical fiber monitoring project itself, without separately purchasing other equipment.And, the optical cable damage location precision of the application can reach one meter, the positioning cost is low, the effect is good, and it is also applicable to the damage location of other communication optical cable.

The invention discloses a distributed large-scale MIMO (Multiple Input Multiple Output) system access method and equipment, and belongs to the technical field of wireless communication. The method comprises the following steps: calculating a channel large-scale fading coefficient and a channel covariance matrix; based on the channel covariance matrix, determining a spatial correlation overlapping degree between the users, and completing user clustering by taking maximization of the spatial correlation overlapping degree between the users in the user cluster as a target; selecting a service base station for the user based on the channel large-scale fading coefficient; and based on the channel covariance matrix, in combination with user clustering and base station selection results, by minimizing the multiplexing intensity of each pilot frequency, obtaining a distribution relationship between the user and the pilot frequency, completing pilot frequency distribution, and enabling the user to access a service base station according to the distributed pilot frequency. According to the method, the interference among multiple users accessed by the users in the distributed large-scale MIMO system can be effectively suppressed, and the spectrum efficiency of the users is improved.

The invention discloses a semantic communication joint training method and device, and relates to the technical field of semantic communication, and the method comprises the steps: a training platform carries out semantic coding based on a multi-modal information source, obtains an original coding result, and transmits the original coding result to a wireless communication link platform through a cross-platform interaction chain; the wireless communication link platform wirelessly transmits the original coding result to obtain a wireless transmission coding result, and transmits the wireless transmission coding result to a training platform through a cross-platform interaction chain; the training platform performs semantic decoding based on a wireless transmission coding result to obtain a multi-modal information sink; and the training platform carries out training on the semantic communication training target based on the multi-modal information sink and the multi-modal information source to obtain an optimized semantic communication training target. Through the above mode, joint training is carried out on the information source channel through the specific model, semantic communication training is completed, influences of time-varying fading, interference, noise and the like of a wireless environment can be resisted, and better transmission performance of semantic communication is achieved.

The invention relates to the technical field of optical fiber sensing, in particular to a fade suppression method and system based on a phi-OTDR, electronic equipment and a storage medium, and the method comprises the steps: obtaining a first sampling period and a second sampling period, the first sampling period is determined based on the frequency drift rate of the phi-OTDR, and the second sampling period is determined based on the frequency drift rate of the phi-OTDR; the second sampling period is composed of the first sampling period with a preset multiple; digital signals of each first sampling period of the optical fiber are obtained through the phi-OTDR; taking the first sampling periods with the preset sequence in the second sampling periods as reference periods of the first sampling periods in the second sampling periods; and carrying out fading suppression on the digital signal of the first sampling period according to the digital signal of the corresponding reference period. Compared with the prior art, the first sampling period and the second sampling period are determined through the frequency drift rate, and the first sampling period with the preset sequence is selected from the second sampling period as the reference period, so that the frequency drift between the reference periods is stable, and the phase fading of the first sampling period can be eliminated by using the reference period.