59 results about "Multipath interference" patented technology

The application discloses a marine buoy multi-source fusion positioning method and system based on a factor graph optimization, which acquires GNSS observation data, IMU measurement data and marine environment auxiliary data; a factor graph containing state nodes, GNSS position factors, IMU pre-integration factors and marine dynamics constraint factors is constructed, and wave and current theories are used to constrain buoy movement; in view of multipath effects, marine surface reflection geometry and marine root mean square wave height are combined to calculate a multipath weighting factor, and a GNSS covariance matrix is adaptively adjusted; according to IMU data, a sea state level is discriminated, and an edge window length and a trigger interval of incremental smoothing solving are adaptively linked and adjusted; through adjacent buoy ranging information, collaborative constraints are constructed, and based on Mahalanobis distance and chi-square distribution threshold value detection, abnormalities are detected and local reconstruction is performed. The application effectively suppresses marine surface multipath interference, slows down the accumulation of calculation errors during signal interruption, and realizes high-availability continuous positioning under limited computing power.

This invention relates to an IMU-assisted online GNSS anomaly detection and reporting method and apparatus. The method involves acquiring GNSS observation data and IMU measurement data and aligning them in time; generating a predicted motion state of the receiver at the current observation epoch based on the IMU measurement data; calculating the predicted GNSS observation value of at least one satellite at the current observation epoch based on the predicted motion state and satellite ephemeris information; constructing a residual sequence based on the predicted GNSS observation value and the corresponding GNSS observation value in the GNSS observation data, performing sliding time window statistics, and determining anomalies based on the statistical results; when an anomaly is determined, generating a time index and a spatial index corresponding to the anomaly, forming a spatial-level interference event, and reporting it. This invention effectively reduces the false alarm rate and missed alarm rate in scenarios involving obstruction, multipath interference, and other interference, exhibits higher sensitivity to observation anomalies caused by moving interference, effectively lowers the implementation threshold at the receiving end, and possesses high engineering application value.

This invention discloses a human fall detection system based on Wi-Fi channel state information, belonging to the field of wireless sensing technology. It includes a Wi-Fi transceiver unit, a data preprocessing unit, a multi-dimensional feature extraction unit, an adaptive threshold judgment unit, a fall recognition inference unit, an early warning output unit, and a local storage unit. This invention eliminates the need for users to wear any devices or engage in any image acquisition, fundamentally eliminating the poor compliance and strong foreign body sensation associated with wearable solutions, as well as the privacy leakage risks of visual solutions. This allows the system to be safely applied in privacy-sensitive scenarios where the elderly frequently engage in activities such as bedrooms and bathrooms. Users can receive 24 / 7 protection without changing their lifestyle. The system effectively filters out static multipath interference from walls, furniture, etc., through static environmental baseline subtraction and extracts human spatial posture features using 2D AoA estimation, accurately distinguishing falls from similar daily actions such as bending over, sitting, and lying down.

This invention discloses a waveform design method for integrated communication and sensing based on a multi-objective particle swarm optimization algorithm, relating to radar detection technology and communication technology. The method includes: constructing a multi-objective optimization problem for waveform parameter design using the subcarrier weight coefficients of the OQAM-OFDM integrated communication and sensing waveform as optimization variables; using the maximization of the sum of the signal-to-noise ratios (SNRs) of all subcarrier communication outputs as the optimization criterion for waveform parameter design; using the maximization of the sum of the SNRs of all range resolution units' sensing outputs as the optimization criterion for waveform parameter design; solving the multi-objective optimization problem for waveform parameter design using the multi-objective particle swarm optimization algorithm to obtain several non-dominated solutions for the subcarrier weight coefficients that simultaneously maximize both the communication output SNR and the sensing output SNR; and forming a Pareto front from these non-dominated solutions. The waveform designed in this invention can effectively resist multipath interference without using cyclic prefixes and blank guard intervals, exhibiting high resource utilization efficiency and excellent sensing and communication performance.

This invention discloses a pole-holding attitude control system and its data transmission method, equipment, and medium, relating to the field of pole-holding attitude control technology. The controller constructs a channel multipath interference fluctuation index, a time slot integrity risk index, and a dynamic retransmission time window adjustment coefficient based on the signal strength and signal-to-noise ratio of the channel used for wireless communication, the pole's acceleration, the actual and theoretical reception times of data packets, the packet loss rate, and a preset standard time length. It then dynamically adjusts the data packet retransmission waiting time based on the dynamic retransmission time window adjustment coefficient. After the retransmission waiting time expires, a data retransmission request is sent to the inertial sensor. By dynamically adjusting the data packet retransmission waiting time, adaptive data retransmission is achieved: prioritizing real-time performance when the network is good and ensuring data integrity under strong interference, thus improving the reliability of data transmission.

The application discloses a kind of three-dimensional radar low altitude multipath detection and elevation dynamic measurement method of double channel, and the adaptive decision threshold of multipath decision model is constructed in combination with real-time signal-to-noise ratio, so that the judgment of target echo complex signal can be accurately identified the occurrence and end of multipath interference like " switch ", when target echo is interfered by multipath, start the elevation measurement method for multipath interference, significantly improve the environmental adaptability and robustness of radar;The imaginary part characteristics of complex single pulse ratio are used in combination with the adaptive threshold of signal-to-noise ratio, which is more accurate than the simple distance threshold in identifying the multipath state, with higher detection accuracy.The application uses the characteristics that phase information is distorted but still maintains segmented monotonicity under multipath environment, first locks the subdivided monotonic interval where the target is located, and then uses high-sensitivity amplitude information to perform table lookup inversion in the interval, without changing the 1T2R hardware architecture, the problem of angle measurement error caused by multipath interference is solved.

The application relates to a space-ground integrated Beidou high-precision positioning method applied to an urban canyon, and belongs to the technical field of navigation and positioning. The method comprises the following steps: deploying a pseudolite base station, calibrating the base station coordinates through carrier phase difference, and monitoring the number of visible Beidou satellites; determining a master pseudolite, broadcasting timestamp and ephemeris data to a slave pseudolite through a Beidou short message, and combining two-way ranging data to correct a local clock to realize high-precision synchronization; then a user terminal receives Beidou and pseudolite signals, screens effective observation values through a shielding discrimination mechanism, combines pseudolite reference differential data into a non-difference observation equation, and solves a fusion result through a loose-tight coupling mode; finally, the pseudolite double-antenna is used to identify multipath interference, historical data is called to construct an error model, and the fusion result is corrected. The space-ground integrated fusion positioning of Beidou and pseudolites in the urban canyon scene is realized, stable centimeter-level positioning precision is output, and the high-precision positioning demand of urban traffic and surveying and mapping is met.

This invention relates to low-altitude security in petrochemical plant areas, specifically to a method and system for creating a three-dimensional safety map of petrochemical plant areas. The method involves multi-level grid subdivision of the petrochemical plant area based on GeoSOT, matching grid accuracy according to target size, and generating a unique BeiDou grid code for each grid cell. Multi-source data is unified to the BeiDou grid code spatiotemporal reference, an error compensation model based on environmental perception is established to suppress multipath interference, and multi-source data fusion is performed. The grid status is dynamically updated, partially updated, and version-managed to achieve real-time updates and historical backtracking of the airspace situation. Target threat assessment is conducted, and countermeasure resources are scheduled for rapid countermeasures against threatening targets. A three-dimensional map visualization rendering is performed, intuitively presenting the airspace situation, target trajectories, and countermeasure equipment status. This invention effectively overcomes the shortcomings of two-dimensional control, such as airspace blind spots, insufficient positioning accuracy in complex environments, inability to achieve three-dimensional fusion of multi-source data, and low efficiency in dynamic control response.

This invention discloses a multipath interference cancellation method, apparatus, device, and storage medium. It establishes a first expression for the path length of a first reflection path with respect to vertical distance, and a second expression for the path length of a second reflection path with respect to vertical distance. It also establishes a target function for the phase difference between the echo signals of the first and second reflection paths with respect to vertical distance. The method calculates the target vertical distance that makes the target function equal to a preset value. It calculates the position of the target reflection point on the hoistway wall of the second reflection path when the vertical distance between the radar and the reflector is equal to the target vertical distance. It controls the installation of a reflection path disruption device at the target reflection point. During car operation, when the radar is at the target vertical distance, it can only receive the echo signal of the first reflection path, avoiding the problem of echo signals canceling each other out and improving the accuracy of car position measurement.

The application discloses a kind of unmanned aerial vehicle flight control method and system, for solving the protection level failure caused by navigation error non-gaussian distribution and the problem of frequent false trigger of flight control of unmanned aerial vehicle in complex electromagnetic environment of city low altitude. Method includes obtaining bottom sensor original observation value, using robust filtering algorithm to suppress multipath interference and output residual error;Non-gaussian error boundary is constructed based on set theory geometric envelope algorithm, and the rigidity quantitative index of navigation reliability is deduced by protection level;Dynamic mapping operation risk alarm limit, and introduce time anti-shake tolerance window to filter transient signal burr;When reliability is continuously broken down, trigger state machine to execute stepwise autonomous degradation. The application breaks the limitation of traditional gaussian hypothesis, and considers the absolute safety and task continuity of flight.

The application discloses a marine buoy multi-source fusion positioning method and system based on a factor graph optimization, which acquires GNSS observation data, IMU measurement data and marine environment auxiliary data; a factor graph containing state nodes, GNSS position factors, IMU pre-integration factors and marine dynamics constraint factors is constructed, and wave and current theories are used to constrain buoy movement; in view of multipath effects, marine surface reflection geometry and marine root mean square wave height are combined to calculate a multipath weighting factor, and a GNSS covariance matrix is adaptively adjusted; according to IMU data, a sea state level is discriminated, and an edge window length and a trigger interval of incremental smoothing solving are adaptively linked and adjusted; through adjacent buoy ranging information, collaborative constraints are constructed, and based on Mahalanobis distance and chi-square distribution threshold value detection, abnormalities are detected and local reconstruction is performed. The application effectively suppresses marine surface multipath interference, slows down the accumulation of calculation errors during signal interruption, and realizes high-availability continuous positioning under limited computing power.

The application discloses a kind of open loop-based software satellite two-way comparison method, device and equipment, the method includes: by preset sampling frequency, satellite signal is sampled, and original satellite signal is obtained;The original satellite signal obtained by sampling is captured by parallel code phase search method, and the coarse value of carrier frequency Doppler shift and C / A code phase are obtained;The data signal captured is tracked using open loop logic, and TOA measurement value is obtained;During the tracking process of data signal, TOA measurement value is solved by high-resolution correlator algorithm and successive interference cancellation algorithm, to complete software satellite two-way comparison according to the solution result. It can eliminate the accumulation of error in signal tracking process by non-continuous, non-feedback demodulation algorithm, reduce the influence of diurnal effect, improve the short-term stability of comparison, integrate high-resolution correlator and successive interference cancellation technology, improve the resolution based on pseudo-random code comparison, reduce multipath interference, eliminate code interference.

A processing method, sensor system, radar, terminal, and vehicle-mounted device are disclosed, relating to the field of lidar technology. The processing method includes identifying interference echoes in the first echo based on a first echo acquired by a detection device (210) and at least two frames of images acquired by an imaging device (220). Since polarized beams are typically caused by multipath interference, which can also result in multiple undiscriminate peaks in the echo waveform signal received by the detection device (210), thus affecting the detection performance of the detection device (210). This method, combining at least two frames of images, can determine the image region or pixel corresponding to the polarized light, assisting the detection device (210) in identifying interference peaks in the first echo, thereby improving the detection performance of the detection device (210).

This invention discloses a method for improving satellite positioning accuracy in complex environments based on machine learning algorithms. The method involves data collection in complex environments such as urban high-rise areas, mountainous regions, and canyons to acquire satellite signal parameters and environmental data. Machine learning algorithms such as Deep Neural Networks (DNN), Recurrent Neural Networks (RNN), and their variant Long Short-Term Memory Networks (LSTM) are used for model training. Data is divided according to a specific ratio, and the model is optimized by adjusting hyperparameters. In the real-time positioning stage, the preprocessed real-time data is input into the trained model to assess multipath interference. Appropriate formulas and strategies are used to handle cycle slips and gross errors, ultimately achieving high-precision positioning. This invention effectively solves the problem of poor positioning accuracy caused by multipath interference in complex environments, possessing advantages such as high precision, strong adaptability, and accurate and reliable detection and processing, thus broadening the application fields of satellite positioning technology.

This invention relates to the field of non-destructive testing technology for power equipment, and discloses a transformer coil fault detection system based on ultrasonic reflected echoes. It primarily addresses the problem of severe multipath interference in ultrasonic signals caused by the multi-layered structure inside the transformer, making it difficult to accurately extract fault features of specific coils. This system transmits and receives ultrasonic waves through components on the outer wall of the tank; it calculates the theoretical time of flight using a three-dimensional acoustic mapping model of the transformer and constructs a target time window; it performs time-domain truncation on the original echo, directionally stripping away interference to extract the effective reflected echo from the specific target coil; it extracts the acoustic feature parameters and obtains the feature difference vector by differential analysis with baseline features; finally, it determines the type of physical deformation of the coil and outputs the quantified deformation degree, achieving non-invasive, high-precision fault diagnosis.

The present application relates to the technical field of non-line-of-sight target detection, and particularly relates to a RIS-assisted FMCW radar non-line-of-sight target DOA estimation method, which comprises the following steps: constructing a scene model of RIS-assisted FMCW radar non-line-of-sight target detection; performing DOA estimation on the target to calculate the angle information of the target relative to the radar; and proposing an alternating direction multiplier method based on a path gain maximization criterion to optimize the RIS phase shift matrix parameters, which can significantly enhance the received signal strength and quality by regulating the electromagnetic wave propagation environment, maximize the equivalent channel gain of the target path, effectively suppress the multipath interference and noise, make the real direction information of the target in the received signal more prominent, not only significantly improve the signal-to-noise ratio, but also ensure that the structure of the received signal covariance matrix is highly matched with the model relied on by the high-resolution estimation algorithm of the subspace class, improve the accuracy, resolution and reliability of the angle estimation, and improve the real-time performance.

The application discloses a millimeter wave radar human body posture estimation and fall detection method and system based on space-time state modeling, and belongs to the technical field of intelligent perception and behavior recognition. The application comprises the following steps: collecting FMCW millimeter wave radar point clouds and pre-processing; constructing a cross-modal knowledge distillation framework, transferring human body geometric structure priori from a Teacher network to a Student network, combining a Doppler adaptive gating mechanism to suppress multipath interference, and realizing three-dimensional human body posture estimation only relying on radar data; reconstructing a skeleton sequence into a space-time state representation, modeling the posture space-time evolution process by using an adaptive space-time graph convolution network, and distinguishing similar actions such as falling, bending and sitting; and integrating an end-to-end fall monitoring system. The application does not rely on visual sensors at all in the reasoning stage, has the functions of privacy protection and all-weather working ability, can stably reconstruct a human body skeleton from sparse radar point clouds and realize high-precision fall detection, and is suitable for real-time monitoring in privacy-sensitive scenes such as families, nursing homes and hospitals.

The application discloses a power line channel estimation method, device and medium, and the method comprises the following steps: S1, a Vandermonde structure manifold matrix containing multipath delay information is constructed; S2, based on the Vandermonde structure manifold matrix, a super-complete manifold matrix containing all potential delay point positions is constructed, and a channel estimation problem is converted into a sparse representation problem; S3, an unconstrained optimization objective function is constructed; S4, singular value decomposition is performed on received OFDM pilot signal data of multiple time periods, a signal subspace is extracted, and compression and noise suppression of sampling data are realized; S5, the data compressed through step S4 is substituted into the optimization objective function constructed in step S3 to obtain high-precision multipath delay estimation; and S6, based on the multipath delay estimation, a complete power line channel response is reconstructed, and high-resolution and high-robustness channel estimation results are obtained in a power line channel environment with high noise and strong multipath interference at a relatively low calculation complexity.

The present application relates to the technical field of narrowband internet of things, in particular to a wireless radar probe adaptive matching method and system for a towing vehicle, comprising the following steps: according to the wireless radar probe connection of the towing vehicle, obtaining a channel response dispersion variable, comparing the channel response dispersion variable with a preset interference judgment threshold, and establishing a multipath interference state identifier. In the present application, the wireless resource control protocol connection state parameter is maintained in combination with the channel switching activation instruction, and the service pushing node is redirected from the signaling bearing channel to the data bearing channel transmission path. The bandwidth improvement and data pushing flow can be completed without interrupting the existing connection state, and finally an adaptive wideband bearing data stream is generated, which promotes the wireless radar probe of the towing vehicle to consider the link continuity, data transmission and timeliness in complex road environment, multipath reflection environment and burst service environment.

This invention discloses a real-time method and system for suppressing multipath errors at a BeiDou three-frequency signal-to-noise ratio CORS station, belonging to the field of satellite navigation and engineering monitoring technology. The system includes a BeiDou continuously operating reference station subsystem, a communication subsystem, a data processing and control subsystem, and a surface displacement monitoring subsystem. It collects raw observation data from BeiDou three-frequency satellites; the data processing and control subsystem integrates adaptive cancellation logic linking the three-frequency signals and deformation data, extracts the deformation change period from the surface displacement monitoring data, converts it into a multipath interference frequency range and calculates the confidence level, and calculates dynamic weighting coefficients by combining the sensitivity thresholds of BeiDou B1, B2, and B3 signals to interference at different frequencies. Multipath errors are offset through weighted fusion, and the data is further optimized using corresponding algorithms; the surface displacement monitoring subsystem works in conjunction with the reference station subsystem to achieve engineering safety monitoring. This invention significantly improves the accuracy of multipath error suppression and adaptability to extreme scenarios.

This invention proposes a single-station localization method for non-line-of-sight targets based on angle-constrained back projection, aiming to solve the problems of low localization accuracy and low noise tolerance for non-line-of-sight targets in complex environments. Applied to the field of non-line-of-sight target detection technology, this method addresses the limitations of traditional back projection imaging algorithms. These algorithms are constrained by underlying time delay compensation and coherent accumulation mechanisms, requiring large-span physical spatial view diversity to overcome the azimuth resolution bottleneck. Furthermore, in complex environments, they are highly susceptible to background clutter and multipath sidelobe interference, and face the challenge of blind correlation due to the unknown mapping relationship between multipath signals and physical reflective surfaces. This method first introduces an angle-of-arrival constraint to limit the spatial imaging range of the back projection algorithm, obtaining a grid energy spectrum for multipath energy focusing. Subsequently, by executing a local extremum optimization strategy in the image domain, clutter and multipath sidelobe interference in the energy spectrum are accurately removed, and spatial discrete imaging feature points with strong multipath interference are extracted with high confidence. Finally, the system introduces a building layout map as a spatial topological constraint prior. Based on the aforementioned feature points, it constructs and traverses the association assumptions between multipaths and physical walls to perform a mirror-inverse mapping of the propagation link, and optimizes global coherence energy within the solution space, thereby accurately resolving the final physical location coordinates of non-line-of-sight targets. This effectively overcomes the challenges of blind association and limited physical aperture.

The application discloses a system for reducing radio frequency interference in satellite and ground TT&C system docking test, which uses a fixed attenuator to reduce the multipath interference of satellite telemetry signals on telemetry signals through a telemetry and remote control common branch, uses a first isolator to reduce the multipath interference of satellite telemetry signals on telemetry signals through a telemetry branch, and uses a second isolator to reduce the multipath interference of satellite telemetry signals on telemetry signals through a telemetry branch, so as to achieve the purpose of suppressing radio frequency multipath interference, thereby ensuring the accuracy of ranging and speed random error index testing in satellite and ground TT&C system docking test.

This invention discloses an adjustable antenna-assisted dynamic beamforming optimization method for vehicular networks, belonging to the field of vehicular network and mobile communication technology. By establishing a comprehensive near-field multipath channel model incorporating scattering cluster distribution and geometric phase shift characteristics, this invention utilizes the position reconfigurability of a fluidic antenna system to achieve dynamic port switching within the limited space of the vehicular network terminal. This transforms multipath interference in near-field rich scattering environments into spatial diversity gain, solving the scientific problem that fixed ports cannot adapt to complex channel characteristics. Simultaneously, this invention proposes a low-complexity joint optimization algorithm based on the maximum transmission ratio and maximum signal-to-noise ratio criteria. Through closed-form solutions, it rapidly achieves the joint design of base station beamforming and terminal ports, significantly improving channel capacity without requiring only a single radio frequency link or increasing hardware costs. This effectively overcomes the stringent economic constraints of large-scale commercialization on hardware costs and computational latency.

This invention discloses a method for removing multipath interference in tunnel tracks based on zero-Doppler clutter points, primarily addressing the problem of multipath interference in tracks. The steps of this invention are as follows: Step 1, establish a millimeter-wave radar signal receiving model; Step 2, obtain the distance and velocity of the target within the tunnel; Step 3, use the maximum likelihood algorithm to obtain the angles of the target, left multipath, and right multipath, respectively; Step 4, generate the zero-channel clutter point vector at each moment; Step 5, obtain the angular position of the tunnel at each moment; Step 6, remove multipath interference from the track using the target region and the multipath region. This invention, by utilizing zero-Doppler channel clutter points, divides the signal region and multipath region solely based on echo data, conveniently and efficiently removing multipath interference from tunnel tracks.

This application provides a method and apparatus for multi-domain interference identification using millimeter-wave radar in complex environments such as coal mine roadways. It relates to the field of intelligent detection and anti-interference technology, and includes: acquiring millimeter-wave radar echo signals and establishing target, interference, and noise component models; extracting features in the power spectrum, Doppler-time, range-time, and range-Doppler domains to capture interference spectrum, dust scattering, and multipath reflection features; uniformly projecting features from different domains into a representation space to ensure comparability and fusion; constructing a multi-domain fusion identification framework for target feature extraction and interference component separation; and introducing velocity consistency, spatial redundancy suppression, and temporal smoothing constraints to ensure detection stability. This invention enables robust detection and stable identification of vehicle-mounted millimeter-wave radar in coal mine roadways under interference environments such as dust, multipath interference, and electromagnetic radiation, reducing false alarm and false detection rates and improving application performance in coal mine tunneling scenarios.

The invention discloses a distance measurement method based on line structured light, electronic equipment and a storage medium. The distance measuring method comprises the following steps: acquiring position information of a ground reference light spot formed by linear structured light; acquiring an actual measurement image obtained in a distance measurement process based on the line structured light; and based on the position information of the ground reference light spot, the position relation of the line structure light in the actual measurement image and the position relation of the line structure light relative to the ground, screening out a real light spot participating in distance measurement calculation from the actual measurement image. Through the scheme disclosed by the invention, the position information between the ground reference light spot and the ground and the position information between the line structure light and the ground can be fully utilized in the distance measurement process, the required real light spot can be accurately screened out, and the multipath reduction of the line structure light is realized, so that the multipath interference pixel influence is effectively reduced.

The present application relates to the field of wireless communication and mine safety technology, and discloses a coal mine underground personnel positioning system and method based on 5G. The method establishes a node space coordinate database of the underground roadway, and directly substitutes the node constraint model matched with the current area in the positioning calculation for collaborative calculation, so that the calculation process naturally conforms to the physical structure of the roadway, and the generation of invalid position coordinates is avoided from the source. The speed distribution pattern and the steering probability matrix extracted from the historical movement of the personnel are used to evaluate the trajectory continuity of multiple geometric feasible candidate positions, so as to select the real-time position most consistent with the individual behavior habit. The method overcomes the problems of signal multipath interference and path ambiguity in the complex underground environment, and improves the physical rationality and trajectory continuity of the positioning result.

This invention discloses a short-range measurement system using a nested ring probe antenna and microwave measurement system, belonging to the field of microwave antenna technology. The antenna employs a nested, integrated transmitting and receiving structure, comprising a multi-sector truncated transmitting radiator (N≥4, where N is even) designed based on a sub-rotational symmetry group, a probe receiving antenna nested at its center, a feeding structure, a dielectric substrate, and a ground plane. Through the multi-sector symmetry structure and the principle of phase cancellation, higher-order resonant modes are effectively suppressed, achieving a single main resonance only within the target frequency band. The nested layout ensures high overlap between the transmitting and receiving beams within a preset angle range, improving signal reception purity and suppressing multipath interference. This antenna features a compact structure, high gain, extremely narrow bandwidth, excellent impedance matching, and circular polarization performance, making it suitable for high-precision short-range microwave measurement systems in fields such as precision manufacturing, medical monitoring, and aerospace. It can accurately detect parameters such as displacement, distance, and vibration.