219 results about "Radar interference" patented technology

A system, method and computer program product for positioning pulses, including positioning pulses within a specified time layout according to one or more codes to produce a pulse train having one or more predefined spectral characteristics where a difference in time position between adjacent pulses positioned to produce a spectral characteristic differs from another difference in time position between other adjacent pulses positioned to produce the spectral characteristic. The present invention may include shaping a code spectrum according to a spectral template in order to preserve a pre-defined code characteristic. A pre-defined code characteristic can include desirable correlation, or spectral properties. A transmitter incorporating the present invention can avoid transmitting at a particular frequency. Similarly, a receiver can avoid interference with a signal transmitting at a particular frequency. A radar system, can avoid a radar jammer attempting to jam a particular frequency.

This invention is related to a deep multi-sensor fusion system for inter-radar interference-free environmental perception comprising of (1) polystatic Multi-Input Multi-Output (MIMO) radars such as radio frequency radar and laser radar; (2) vehicle self-localization and navigation; (3) the Internet of Vehicles (IoV) including Vehicle-to-Vehicle communication (V2V), Vehicle-to-Infrastructure communication (V2I), other communication systems, data center / cloud; (4) passive sensors such as EOIR, and (5) deep multi-sensor fusion algorithms. The self-localization sensors and V2X formulate cooperative sensors. The polystatic MIMO radar on each vehicle utilizes both its own transmitted radar signals and ones from other vehicles to detect obstacles. The transmitted radar signals from other vehicles are not considered as interference or uselessness as conventional radars, but considered as useful signals to formulate a polystatic MIMO radar which can overcome the interference problem and improve the radar performance. This invention can be applied to all kinds of vehicles and robotics.

A system and method are provided to reduce the effect of an interfering signal in a radar return signal for a frequency modulated continuous wave (FMCW) radar. Once the interfering signal is detected, an extent of the interfering signal is determined and the data that was corrupted by the interfering signal is not included in the processing of the radar return signal. This allows the radar to detect a target in the presence of the interfering signal. The system and method can benefit any FMCW radar that is within the range of an interfering radar source (e.g. another FMCW radar, a police radar gun, a pulse radar, etc.) operating in the same frequency band as the FMCW radar. An alternative arrangement provides a system and method for determining the frequency of the interfering signal and then avoiding transmitting power in that portion of the frequency spectrum where the interfering signal is present.

A system and method are provided to reduce an interfering signal in a radar return signal for a frequency modulated continuous wave (FMCW) radar. Once the interfering signal is detected, an extent of the interfering signal is determined and the interfering signal is removed from the radar return signal. This allows the radar to detect a target in the presence of the interfering signal. The system and method can benefit any FMCW radar that is within the range of an interfering radar source (e.g. another FMCW radar, a police radar gun, a pulse radar, etc.) operating in the same frequency band as the FMCW radar.

An interleaved wireless mesh network is described where each mesh node always has at least two radios that have access to at least two parallel meshes, and where a packet stream may utilize either or both of these parallel meshes for any given hop, using the parallel (physical) meshes as a single (logical) mesh. Here, two sequentially adjacent packets in a particular packet stream may travel on the same mesh or on different meshes for any given hop, thereby enabling the performance of a specific sequential packet stream to be doubled. Dynamic frequency selection (DFS) operations can be performed by the parallel meshes upon sensing radar interference on a channel used by either mesh. While one mesh is performing the DFS, packets may continue to be propagated on the alternative mesh, thereby enabling continuous and uninterrupted data flow throughout the network.

Systems, methods, and computer program products are provided for accurately measuring frequency-and / or-phase-related parameters of a sinusoidal signal that varies non-linearly in frequency or phase. A sinusoidal signal is sampled over a finite period of time at a plurality of sample points. The sampled signals are pre-processed, and a Fourier transform is performed on the pre-processed sampled signals. Phases of the pre-processed sampled signals are extracted from the Fourier transform, and a measurement indicative of frequency of the sinusoidal signal is determined from slope of the phases of the pre-processed sampled signals. Range to a target may be determined using the exemplary signal processing described above on laser radar interference signals.

The invention provides a laser radar interference immunity enhancing method comprising the following steps: carrying out non-continuous multiple scanning for a random single target point, and carryinglaser fast coding for each time scanned laser signal. The multiple measuring behaviors aiming at each target point are non-continuous under fast scanning conditions, thus ensuring the measuring result high refresh rate and reliability; the laser fast coding is to convert the pulse signals in a single pulse period of the existing pulse laser into continuous and / or discrete subpulses with at leasttwo different pulse intensities and / or pulse widths; a series of subpulses as a whole body in the single pulse period can form a detection signal unit of the single target point emitted by the laser radar. The fast coding method is applied to each measuring time of the single target multiple measures, thus further enhancing the laser radar measuring reliability in each time, reducing the single target measuring frequency on said basis, and further improving the measuring result refresh rate.

An interference rejection device includes a change amount calculator, a detector, and a rejecter. The change amount calculator is configured to find change amounts in at least one of amplitude and phase of received signals of a plurality of sweeps in a distance direction between a first distance and a second distance. The detector is configured to detect radar interference occurring between the first distance and the second distance by comparing the change amounts calculated by the change amount calculator between the plurality of sweeps. The rejecter is configured to reduce the amplitude of the received signal corresponding to a position of the radar interference.

A wireless apparatus which can realize a DFS function that avoidance of interference with radar is considered in an Ad-Hoc mode under a multihop circumstance is provided. A Beacon frame is transmitted at a shorter interval than a previously set interval when radar is detected by wireless apparatuses N1 to N6 which have a DFS function which perform avoidance of interference with radar.

The invention discloses a radar interference signal feature-level fusion identification method based on a deep convolutional neural network, and belongs to the field of radar interference signal identification. The method aims to solve the problems that feature parameters of radar interference signals at present depend on manual extraction, are easily affected by noise and have feature redundancy.The method comprises the following steps: establishing a radar interference time domain data set, extracting feature vectors from radar interference time domain data in the radar interference time domain data set in two different forms, and carrying out series fusion on the two extracted feature vectors; training a support vector machine by adopting the fused feature vectors to obtain a trained radar interference signal feature-level fusion recognition model; and inputting the collected test sample into the identification model to obtain a radar interference signal identification result. According to the method, the CNN is utilized to extract the deep features of the radar interference signals, and different radar interference signal data fusion models are designed at the feature level, so that signal identification is not affected by noise, and meanwhile, the feature redundancy phenomenon is eliminated.

A system and method are provided to reduce the effect of an interfering signal in a radar return signal for a frequency modulated continuous wave (FMCW) radar. Once the interfering signal is detected, an extent of the interfering signal is determined and the data that was corrupted by the interfering signal is not included in the processing of the radar return signal. This allows the radar to detect a target in the presence of the interfering signal. The system and method can benefit any FMCW radar that is within the range of an interfering radar source (e.g. another FMCW radar, a police radar gun, a pulse radar, etc.) operating in the same frequency band as the FMCW radar. An alternative arrangement provides a system and method for determining the frequency of the interfering signal and then avoiding transmitting power in that portion of the frequency spectrum where the interfering signal is present.

A system and method are provided to reduce an interfering signal in a radar return signal for a frequency modulated continuous wave (FMCW) radar. Once the interfering signal is detected, an extent of the interfering signal is determined and the interfering signal is removed from the radar return signal. This allows the radar to detect a target in the presence of the interfering signal. The system and method can benefit any FMCW radar that is within the range of an interfering radar source (e.g. another FMCW radar, a police radar gun, a pulse radar, etc.) operating in the same frequency band as the FMCW radar.

The invention discloses a temporal difference radar interference method applicable to large-gradient ground surface settlement monitoring. According to the whole technical scheme, the method comprises the steps of short-time base line difference interference pattern screening, discrete point phase unwrapping, shape changing component modeling and calculation based on short-time base line difference interference patterns, shape changing component reliability testing, difference interference pattern phase gradient correction, iteration of the processes so as to ensure correctness of shape changing component calculation, and shape changing time sequence modeling and calculation based on corrected difference interference patterns. The problem that shape changing phase ambiguity calculation is difficult or fails due to the fact that shape changes and phase gradients are large in an original temporal difference radar interference technology is solved, finally the purpose of correctly extracting the large-gradient ground surface shape changing speed and the shape changing time sequence is achieved, the effect of decreasing the number of synthetic aperture radar images needed by large-gradient shape changing modeling and calculation is achieved, and the temporal difference radar interference application economic cost is reduced.

The invention belongs to the radar interference inhibition technology field and discloses a self-adaption side lobe cancellation method based on recognition processing. The self-adaption side lobe cancellation method based on the recognition processing comprises steps of utilizing a main antenna and an auxiliary antenna of the radar to receive backwave signals in a pulse repeated cycle to obtain main antenna reception signals and auxiliary antenna reception signals, performing first time of signal screening and second time of signal screening according to the main antenna reception signals and the auxiliary antenna reception signals to obtain an effective study sample, utilizing a direct matrix inversion algorithm to perform self-adaption weight calculation and obtain a corresponding weight by aiming at the effective study sample, and utilizing the self-adaption weight W to perform side lobe cancellation on the main antenna reception signal and the auxiliary antenna reception signal to obtain the self-adaption side lobe cancellation result.

The invention relates to an adaptive interference cancellation method for a radar jammer. The adaptive interference cancellation method comprises the following steps: acquiring an external signal d received by a detection antenna on the radar jammer in real time, simultaneously acquiring an interference signal which is generated in the radar jammer and is not transmitted by a transmitting antenna of the radar jammer and using the interference signal as a reference interference signal J; then conveying the external signal d and the reference interface signal J to an adaptive filter to carry out adaptive interference cancellation. According to the adaptive interference cancellation method, an active digital adaptive cancellation technology is adopted; related cancellation principles are utilized; a convergence step size is regulated; compromise of a convergence rate and convergence stability in an adaptive interference cancellation algorithm is effectively realized; finally, the interference signal entering the detection antenna can be effectively eliminated and a useful detection signal is obtained.

The invention discloses a recognizing and classifying method for broadband radar interference signals. The method comprises the following steps of S1, obtaining radar interference signals, processingthe signals, and obtaining digital video signals; S2, performing short-time Fourier conversion on the digital video signals, and obtaining a time frequency matrix; S3, according to a ranking statistics constant false-alarm method, processing the time frequency matrix, and obtaining a constant false-alarm detection matrix; S4, calculating parameters of interference signals in the constant false-alarm detection matrix, and integrating the parameters of the interference signals into a signal parameter matrix, and obtaining an interference signal detection result; S5, according to the interferencesignal detection result, calculating interference signal characteristics; S6, according to the interference signal characteristics, recognizing and classifying the interference signals. According tothe interference-based time-frequency signal characteristics, nine broadband radar interferences are recognized and classified, and the method has the capability of multi-interference (non-overlappedon frequency) classifying and recognizing.

The invention relates to a radar interference inhibition method and particularly relates to a radar dense false target interference inhibition method. The radar dens false target interference inhibition method comprises steps of importing orientation video data of an object to be detected which is scanned by the radar, calculating the orientation noise power of the object to be detected to obtain a noise evaluation value, recognizing interference, perceiving the interference environment and positioning the interference source, 3 identifying the interference, performing signal statistic analysis on the radar scanning video data in the interference field, determining whether the dense false object interference exists, 4 inhibiting the interference, adopting the frequency domain filtering technology to perform interference resistance processing on the dense false object interference data, 5 detecting an object, adopting CFAR to process the object data to be detected which has gone through anti-interference inhibition, and 6 performing tracing and track correlation on the object to be detected to finish the tracking of the object. The radar dense false target interference inhibition method can guarantee the normal operation of the radar under the interference of the dense false objects and identifies whether the false objects exist through the characteristic analysis.

The invention relates to a homotype radar same frequency interference suppression method used for a ship formation condition, and belongs to the technical field of radar interference resistance. When an inner radar is formed to conduct cooperative work, under the known condition of a working parameter, firstly, according to the feature that a linear frequency modulation (LFM) interference signal focuses in a fractional order Fourier field of a matching order and defocuses in a fractional order Fourier field of other orders, by the method of gradually filtering, interference which is different from frequency of a radar transmitting signal to be transmitted is sequentially eliminated by interference energy from big to small. Secondly, a signal after frequency domain processing is reversely transformed into a time domain to conduct matched filtering, and interference which is the same with frequency of an echo signal is filtered by using time domain adjacent period anti-asynchronous arithmetic. The homotype radar same frequency interference suppression method used for the ship formation condition effectively solves the problem of same frequency interference suppression different from the radar echo signal frequency, and simultaneously further eliminates the same frequency interference same with the radar echo signal frequency, improves anti-same-frequency interference ability and formation and networking ability of a ship-based homotype radar.

The invention discloses a radar interference detection and identification method based on a convolutional neural network. The method comprises the following steps: preprocessing radar signals; performing time domain transformation on the preprocessed signal by adopting short-time Fourier transform; performing constant false alarm detection and interference measurement on the time-frequency image ain sequence to obtain a time parameter and a frequency parameter of an interference signal; extracting an interference signal in the radar signal according to the time parameter; filtering the extracted interference signal by adopting a band-pass filter according to the frequency parameter; carrying out time domain transformation on the filtered signal by adopting short-time Fourier transform toobtain a time-frequency image b, and carrying out normalization processing; smoothing the normalized time-frequency image b by adopting a Wiener filtering algorithm, and then performing adaptive clipping on a smoothing result; scaling the adaptively clipped image by adopting a bicubic interpolation algorithm to obtain identification data; and inputting the identification data into a pre-trained CNN model for identification to obtain the type of the interference signal.

The present invention discloses a radar interference identification method with distance and speed simultaneous pull-off. The method comprises a step of establishing a radar interference signal model with interferometer transmitting distance and speed simultaneous pull-off, wherein, a target carries the interferometer, and the real target echo signal received by a radar is obtained; a step of setting an interferometer input signal, receiving a wideband linear modulation signal by the interferometer, calculating the distance-speed simultaneous pull-off interference signal outputted by the interferometer, and calculating a distance-speed simultaneous pull-off interference signal with phase quantization, a step of setting the echo signal received by a target and an echo signal received by the radar and obtaining real target echo baseband signal or a distance-speed simultaneous pull-off baseband interference signal with phase quantization, and a step of orderly setting a characteristic interference signal error angle and the category of the echo baseband signal received by the radar and thus identifying the interference signal or a target signal.

Systems, methods, and computer program products are provided for accurately measuring frequency-and / or-phase-related parameters of a sinusoidal signal that varies non-linearly in frequency or phase. A sinusoidal signal is sampled over a finite period of time at a plurality of sample points. The sampled signals are pre-processed, and a Fourier transform is performed on the pre-processed sampled signals. Phases of the pre-processed sampled signals are extracted from the Fourier transform, and a measurement indicative of frequency of the sinusoidal signal is determined from slope of the phases of the pre-processed sampled signals. Range to a target may be determined using the exemplary signal processing described above on laser radar interference signals.

The invention relates to a vehicle GPS positioning, range measuring and vehicle electronic license plate information terminal which is provided with a mobile vehicle comprehensive information processing instrument and a vehicle-rear electronic license plate information transceiver, wherein the comprehensive information processing instrument is provided with a CPU microcontroller series which comprise a main CPU and a plurality of microunit array CPUs respectively arranged on each microunit array wireless transceiver; a GPS positioning system, a storage, an audio circuit, a display circuit and the microunit array wireless transceivers are connected to a core CPU microcontroller through communication bus; a voltage stabilizing circuit connected with a vehicle storage battery provides power supply for each circuit and system through the communication bus; the core CPU microcontroller is connected with the vehicle-rear electronic license plate information transceiver through the communication bus. The vehicle GPS positioning, range measuring and vehicle electronic license plate information terminal overcomes the disadvantages that the prior vehicle anticollision system can not operate because of radar interference wave and can carry out wireless communication between fore-and-aft vehicles in real time to achieve the aim of preventing traffic accidents.

The invention discloses a radar interference recognition signal processing system, and aims to provide a processing system which is simple and reliable in circuit and high in interference resistance. The radar interference recognition signal processing system is implemented according to the following technical scheme: in the signal processing circuit, a waveform generator sends generated modulation signals to a voltage-controlled oscillator, signals with the output frequency being fr are divided into two paths, one path of the signals are subjected to M times of frequency doubling amplification through a frequency doubling amplification circuit A and turned into signals with the frequency being M*fr, one part of the signals are transmitted through a transmitting antenna A, and another part of the signals are inputted into a down-conversion circuit A to act as local oscillation signals of the down-conversion circuit A; and the other path of the signals is subjected to frequency division of a frequency dividing circuit and turned into signals with the frequency being fr / L, one part of the signals are subjected to frequency doubling amplification of a frequency doubling amplification circuit B and turned into frequency doubling amplification signals which are transmitted through a transmitting antenna B, and another part of the signals are inputted into a down-conversion circuit B to act local oscillation signals of the down-conversion circuit B. Intermediate-frequency signals A and intermediate-frequency signals B are respectively subjected to interface recognition circuit down-conversion filtering, FFT (Fast Fourier Transform), non-coherence accumulation and threshold judgment, and interference recognition judgment signals are outputted.

A radar device is realized in which an object and extraneous waves such as radar interference or white noise are distinguished and displayed in different display forms. Subtraction Flag Generator 6 determines the time-wise continuity and the planar consecutiveness of target echo data. The time-wise continuity is an amount that indicates the extent to which significant echo data continued to be present at the same position, and is obtained from the echo data of a past predetermined number of sweep rotations. Planar consecutiveness indicates the extent to which significant echo data is present around target echo data, and is obtained by acquiring in a planar fashion echo data for each of predetermined amounts in a distance direction and a heading direction, centered around the target echo data. When Subtraction Flag Generator 6 detects that there is either of time-wise continuity and planar consecutiveness, Subtraction Flag Generator 6 attaches a subtraction flag “1”. Subtraction Processor 9 sets a low attenuation amount for the data level when the subtraction flag is “1”, and sets a fast attenuation amount when the subtraction flag is “0”.

The invention discloses a detection method for SMSP interference and C&I interference, belonging to the radar signal detection technology field and particularly relating to the radar interference signal detection technology. The detection method disclosed by the invention comprises steps of utilizing a generalized likelihood ratio method to perform estimation on unknown amplitude parameters in an echo signal and an interference vector, respectively obtaining maximum likelihood estimation value, and bringing the unknown amplitude parameter and the interference vector maximum likelihood value into the generalized likelihood ratio detector to detect interference. The detection method for SMSP interference and C&I interference improves interference detection accuracy.

The invention relates to the radar interference technology field, and concretely relates to a portable high-frequency ground wave radar radio frequency interference inhibition method. Two monopole crossed rings are adopted by a high frequency ground wave radar receiver to serve as reception antennas. After channel calibration, radio frequency interference takes place in monopole channels of the two monopole crossed rings and in two respective crossed ring channels. A spatial domain subspace projection method is adopted to realize interference inhibition: setting a threshold and determining whether each frame includes radio frequency interference; and for frame periods with radio frequency interference, obtaining a radio frequency interference sample through signals of long-distance elements only containing interference, extracting a sub-space of radio frequency interference through Eigen value decomposition, and for signals of near-distance elements containing radio frequency interference and sea state information, projecting the signals onto an orthogonal sub-space of the sub-space of radio frequency interference to inhibit interference. The method has a great inhibition effect for dense radio frequency interference, and ensures that arrival angle results of monopole crossed ring antennas, estimated by a MUSIC algorithm, are reliable after interference inhibition.

The invention provides a cognitive interference method based on Markov process decision. Firstly an interference machine detects the main changes of the radar signals so as to identify the working mode of the radar and establish the Markov chain of working mode state transition, then the transition probability of the established radar working mode transition Markov chain is calculated by using theproper algorithm, and finally the radar working mode transition probability is converted into the matrix form to predict the next working mode of the radar so that the interference machine is enabledto interfere the radar signals to the greatest extent. The interference machine selects the proper interference mode for the working mode of the radar so that the benefit of interference is maximized. The radar interference threat is not assessed so as to avoid incomprehensiveness and inaccuracy of assessment. The next working mode of the radar can be further predicted according to the obtained radar working mode state transition matrix so that the interference machine is enabled to take the active position.

The invention discloses a main lobe anti-jamming method combined with JADE and CLEAN, and belongs to the technical field of radar interference resistance, in particular to a blind source separation anti-main lobe interference technique. The method comprises steps of firstly using the JADE algorithm to estimate the steering vector and the waveform of the interference signal, and then reconstructingthe interference array signal; calculating the MUSIC spectrum of the reconstructed interference array signal to obtain the MUSIC spectrum containing only the interference signal; finally, offsettingthe MUSIC spectrum of the interference signal on the MUSIC spectrum of the received signal using the CLEAN algorithm in the airspace, thereby obtaining the direction of arrival estimation of the target signal. The simulation results show that the method can complete the interference suppression well and estimate the target DOA.

The invention discloses a radar interference power allocation method for a radar and communication combination system. The method comprises the steps of firstly, acquiring frequency response of a target to a communication system, a radar signal and a communication transmitting signal according to prior knowledge; then, considering that echo of the communication transmitting signal reflected to a radar receiver by the target can be received and processed by a radar, taking the minimum total transmitting power of an onboard electronic interference system as a goal, establishing a radar interference power allocation model for the radar and communication combination system under the condition that the interference performance is satisfied, and solving the model via a Lagrange multiplier method; selecting interference power allocation J[k] absolute value 2 enabling the total interference power of the system to be minimum under the condition that the interference performance is satisfied as an optimal solution, bringing the optimal interference power allocation J[k] absolute value 2 of the interference system into the allocation model, thus obtaining the minimum total interference power satisfying the constraint condition. The method reduces the total transmitting power of the onboard electronic interference system, and improves the radio frequency stealth performance of the system.

The invention discloses a method for automatically selecting ground control points during the interference measurement of a synthetic aperture radar. The method comprises the steps of randomly selecting two images in a multi-time-sequence SAR SLC image sequence to be subjected to interference measurement to form an interference pair, obtaining an interference graph through interference phase calculation, and calculating a coherence coefficient graph; segmenting the interference graph according to the number of required GCPs, figuring out an interference phase derivative of each pixel in the interference pair, carrying out statistics on the variance of all interference phase derivatives in each pixel local window, and searching a region in each block to form a candidate subset S1 of GCPs, wherein all searched regions are stable in interference phase or continuously and uniformly changing in interference phase; on the basis of the coherence coefficient graph, screening out pixels high inboth own coherence coefficient and coherence coefficient in the pixel local window, and forming a candidate subset S2 of GCPs; obtaining the intersection set of the candidate subset S1 and the candidate subset S2 of GCPs and obtaining a preliminary GCP selection result; optimizing the preliminary GCP selection result according to the number and the distribution of GCPs, and obtaining a final GCPselection result of GCPs. According to the invention, the method has an important value for improving the automation degree and the precision of the radar interference measurement of different modes.