288 results about "Modulated continuous wave" patented technology

The invention relates to the field of heart rate monitoring, and discloses a millimeter wave radar breath and heart rate synchronous monitoring method and system, and the method comprises the steps: transmitting a linear frequency modulation continuous wave signal according to a millimeter wave radar, and collecting original echo data reflected by a target region; baseband signal demodulation and phase information extraction are carried out on the original echo data to obtain original phase time sequence data, and the original phase time sequence data comprise thoracic cavity micro-motion features; and according to a Butterworth band-pass filter, preprocessing the original phase time sequence data through human body physiological signal frequency band characteristics to obtain a breathing frequency band signal and a heart rate frequency band signal. According to the method, the apnea event triggering threshold value and the arrhythmia early warning index are updated in real time through Kalman filtering and extended Kalman filtering, so that the monitoring system can dynamically adjust the health parameters, which means that the monitoring system can be optimized in real time and the abnormal health event can be accurately responded in different physiological states.

The invention provides an underwater sonar target detection system and method. The underwater sonar target detection system comprises an optical fiber hydrophone array module which comprises a plurality of optical fiber hydrophone units, each unit comprises an optical fiber Bragg grating sensor and a sound pressure signal demodulation device, and the optical fiber hydrophone array module is used for collecting underwater sound wave signals in real time and converting the underwater sound wave signals into first electric signals; the sonar transmitting-receiving array module comprises a broadband sonar transmitter, a multi-beam receiver and a signal preprocessing circuit, and is used for actively transmitting a frequency modulation continuous wave signal, receiving a target reflection echo and generating a second electric signal; and the multi-mode signal fusion processing module comprises a high-speed data acquisition card, a self-adaptive noise suppression unit and a time-frequency analysis unit. The underwater sonar target detection system and method provided by the invention have the advantages of relatively high reliability, relatively high detection performance, relatively accurate cross-modal signal fusion and capability of performing intelligent target identification and tracking.

An optical frequency domain reflectometer with environmental disturbance resistance and large strain measurement capability belongs to the field of distributed optical fiber sensing and comprises an opposite sweep frequency light frequency modulation continuous wave signal generation module, a light splitting device, a modulation device, a circulator, a polarization controller, an optical coupling device, a photoelectric conversion module and a data acquisition and processing module. An optical signal generated by an opposite sweep frequency light frequency modulation continuous wave signal generation module is divided into probe light and local oscillation light through a light splitting device, the probe light is modulated through a modulation device and sent to an optical fiber through a circulator, and a Rayleigh back scattering light signal generated by the optical fiber and the local oscillation light interfere in an optical coupling device to obtain interference light; the photoelectric conversion module mixes beat frequency signals of interference light, and the data acquisition and processing module analyzes and processes the beat frequency signals. According to the invention, the position information of the Rayleigh backscattering point is marked by using the modulated probe light, the Rayleigh scattering signal at the corresponding position is restored, crosstalk between channels is inhibited, and high-precision measurement in a large dynamic range and resistant to environmental disturbance is realized.

Methods, systems, and devices for wireless communications are described. Generally, the described techniques enable a first wireless device to scramble at least a portion of one or more frequency-modulated continuous wave (FMCW) signals (e.g., hybrid FMCW signals) using a scrambling identifier, which may enable a second wireless device to differentiate between FMCW signals based on identifying the scrambling identifier. For example, the first wireless device may scramble at least a portion of an upchirp signal, a downchirp signal, or both, of an FMCW signal. The second wireless device may identify the scrambling identifier based on attempting to descramble the scrambled portion of the FMCW signal using multiple candidate scrambling identifiers. In some examples, a scrambling pattern (e.g., which portion of the upchirp signal, downchirp signal, or both, is scrambled) of a hybrid FMCW signal may indicate information associated with the first wireless device.

The invention discloses a breath and heartbeat detection method and system based on an FMCW (Frequency Modulated Continuous Wave) radar. The method comprises the following steps: acquiring a continuous wave signal sent by an FMCW millimeter wave radar to detect a target object so as to obtain a reflected echo signal; the echo signals are preprocessed; separating a respiration signal from a heartbeat signal of the preprocessed echo signal based on an EPH multi-stage cooperative signal processing algorithm; and carrying out anomaly correction on the separated instantaneous frequency anomaly data based on a local weighted regression algorithm. Therefore, the vital sign detection accuracy of the radar can be improved under the interference conditions of background noise, signal harmonic waves and the like.

A mechanism for generating a modulation signal for use in a radar system. The modulation signal includes a sequence of chirps. Each chirp includes an active period, a transition period and an idle period. During the active period, the frequency of the chirp moves from a start frequency to an end frequency. During the transition period, the frequency of the chirp moves towards the start frequency of the next chirp. The rate of change of the frequency, during the transition period, is different for different chirps of the modulation signal.

Certain aspects of the present disclosure provide techniques for generating and processing a frequency multiplexed continuous wave (FMCW) based synchronization signal (SS). According to certain aspects, a method for wireless communication at a wireless node, comprising obtaining a synchronization signal comprising a first frequency modulated continuous waveform signal associated with a frequency that increases in time for a duration according to a first slope and a second FMCW signal that overlaps with the first FMCW signal, wherein the second FMCW signal is associated with a frequency that decreases in time for the duration according to a second slope that corresponds to a negative of the first slope; and performing frequency offset estimation based on the first and second FMCW signals.

A radar device may generate an integrated range-velocity map by combining data from a plurality of range-velocity maps. Each range-velocity map may be associated with a respective radar channel from a plurality of radar channels. The radar device may identify a first peak in the integrated range-velocity map. The first peak may indicate one or more radar targets in the integrated range-velocity map and being identified by a first bin having a first range-velocity bin index. The radar device may determine a first data set by extracting, from each range-velocity map, data that is included in a respective bin associated with the first range-velocity bin index. The radar device may process the first data set to determine a first set of phase imbalances associated with the plurality of radar channels.

The invention discloses a distributed radar data fusion method, which relates to the technical field of radar signal processing and multi-sensor information fusion, and comprises the following steps: arranging a plurality of radar nodes, configuring and transmitting 24GHz frequency-modulated continuous wave signals, receiving echo signals reflected by a target, and transmitting the echo signals to the radar nodes; according to the invention, the radar data fusion system comprises a data acquisition and local processing module, a space-time registration module, an anti-interference module and a track association and fusion module, and a radar data fusion mode and a corresponding analysis result are managed, visualized and stored, so that radar data fusion management can be realized through cloud management and control of the Internet of Things; the target sensing precision, the system resource efficiency, the environmental adaptability, the engineering practicability and the like are remarkably broken through, and the scheme also has strong engineering adaptability, supports heterogeneous sensor dynamic networking, embedded deployment and millisecond-level real-time response, has been successfully applied to scenes such as intelligent transportation and military early warning, and has a wide application prospect. The comprehensive performance comprehensively exceeds the prior art.

According to an aspect of the present inventive concept there is provided a laser system for generating a frequency modulated continuous wave, FMCW, light signal, the system comprising: a tunable laser for generating the FMCW light signal; an optical measurement unit configured to receive a portion of the FMCW light signal, and to output, via an optical hybrid coupler, at least two angle diversity signals based on a difference between a first and second signal formed by splitting the portion of the FMCW light signal wherein the second signal is delayed relative to the first signal, wherein a pair of signals of the at least two angle diversity signals have a fixed phase shift relative to each other; and a control unit configured to: receive the at least two angle diversity signals, estimate, based on the at least two angle diversity signals, a compensation needed for adjusting a non-linearity of a frequency chirp of the tunable laser, and output a corresponding control signal to the tunable laser, wherein the control signal is configured to improve a linearity of the frequency chirp.

A radar level measuring device is provided, the device being configured to perform a measurement for determining a level of a filling material by a frequency modulated continuous wave measurement method, the radar level measuring device including: a transmitting device configured to transmit a radar signal in a direction of a filling material surface to perform the measurement; a receiving device configured to receive the radar signal reflected from the filling material surface and to evaluate the measurement; a control device configured to control the transmitting device and the receiving device; and a selection device configured to select a parameter set for controlling the transmitting device and the receiving device, the parameter set including at least a measurement duration of the measurement, a minimum measurement frequency and a maximum measurement frequency of the measurement, and a number of consecutive measurements.

A human body breathing and heartbeat signal estimation method based on a multi-channel frequency modulation continuous wave millimeter wave radar (FMCW) is characterized by comprising the following steps of (1) obtaining an intermediate frequency signal of a multi-channel frequency modulation continuous wave millimeter wave radar (FMCW) system, (2) carrying out distance dimension FFT and phase extraction and unwrapping on a Chirp intermediate frequency signal channel by channel, and (3) carrying out phase extraction and unwrapping on the Chirp intermediate frequency signal channel by channel. (3) calculating signal energy of interested breathing and heartbeat frequency bands in the phase time sequence under all distances, and weighting amplitudes of all distance dimension FFT under all distances to realize accurate positioning of a human body target, and (4) regarding the phase time sequence under the accurate distance and the adjacent distance of each channel as potential multipath signals, and performing fusion enhancement on the signals to realize accurate positioning of the human body target. And (5) processing the enhanced phase time sequences of the channels on the basis of multivariate variational mode decomposition, separating and estimating respiratory signals and heartbeat signals of the human body, and calculating an average respiratory rate and an average heart rate in an observation time period.

The invention discloses a leakage monitoring method based on an LNG fuel gas system. The leakage monitoring method comprises the steps that a self-adaptive frequency modulation continuous wave active acoustic scanning network is established; blind source separation is carried out on mixed signals in acoustic scanning network abnormal events by adopting self-adaptive kernel independent component analysis; constructing a leakage feature mapping model of the physical information neural network; leakage source accurate positioning and quantification based on acoustic tomography and Bayesian reasoning are carried out; multi-modal decision fusion is carried out based on the multi-dimensional data sources received in parallel, a false alarm suppression mechanism is set, and time continuity verification and space consistency verification are carried out; establishing a reinforcement learning model for autonomously optimizing a monitoring strategy according to environment change and system state, and realizing adaptive optimization; the strategy network after self-adaptive optimization is deployed at the cloud, actions are generated regularly according to the current state, the actions are issued to the regional gateway and the edge node for execution, and iterative updating is carried out, so that the monitoring accuracy in a complex environment is improved, and the false alarm rate is reduced.

The invention provides a leaky-wave antenna and a frequency-modulated continuous wave generation method based on the leaky-wave antenna, and relates to the field of millimeter-wave radar, and the method comprises the steps: constructing a space-time coding matrix, configuring a radiation unit state regulation and control beam direction in a space domain, modulating a radiation unit state switching rule in a time domain to generate a frequency-modulated continuous wave, and achieving space-time dual-domain regulation and control. And frequency-modulated continuous waves with controllable bandwidth are generated. The space-time coding leaky-wave antenna is formed by alternately arranging 1-bit radiation units in an upper row and a lower row, switching of radiation / non-radiation states is achieved by loading a synchronous bias PIN diode across an annular gap, a space-time coding matrix is constructed, the states of the radiation units are configured in a space domain to regulate and control the wave beam direction, and the space-time coding leaky-wave antenna is formed. Modulating the switching rule of the radiation unit in a time domain, and generating a frequency-modulated continuous wave; the radiation efficiency is improved by the alternative arrangement of the radiation units, the control difficulty and the hardware cost are reduced, multiple functions are integrated into a single device, and the problem of low integration level of the traditional separation architecture is solved.

The invention relates to the technical field of laser radars, in particular to a non-aliasing frequency-modulated continuous wave radar detection system and method, and the system comprises a light source, a beam splitter, a circulator, a 90-degree mixer, a signal conversion module and a signal processing unit. The signal processing unit is configured to construct a composite vector signal S based on the first electric signal I and the second electric signal Q, S = I + jQ, j is an imaginary part operator, obtain a double-sideband spectrum based on the composite vector signal S, determine the frequency of a signal peak in an upper frequency sweeping period and the frequency of a signal peak in a lower frequency sweeping period in the double-sideband spectrum, and determine the frequency of the signal peak in the upper frequency sweeping period and the frequency of the signal peak in the lower frequency sweeping period; and obtaining the distance and speed of the target to be measured based on the frequency of the signal peak in the upper frequency sweeping period and the frequency of the signal peak in the lower frequency sweeping period. According to the invention, the problem of signal aliasing during detection of the to-be-detected target can be solved at least.

The invention provides a multilayer medium efficient imaging method suitable for frequency modulation continuous wave ice radar data, and belongs to the field of frequency modulation continuous wave ice radar imaging. Comprising the steps of multi-layer medium signal model construction, improved distance-Doppler algorithm implementation, distance migration accurate correction and azimuth focusing processing. According to the method, a multi-layer medium signal model containing refractive index and propagation velocity changes is established for the problem of target distance distortion caused by propagation velocity differences of electromagnetic waves in different media such as ice and snow; based on the model, a traditional distance-Doppler algorithm process is improved, distance migration caused by multiple layers of media is accurately corrected by introducing a medium-dependent distance migration factor, and efficient azimuth focusing is achieved. And finally, a high-resolution ice layer internal structure image can be generated, and the method is suitable for polar region large-range ice cover detection and rapid processing of a large amount of ice radar data.

The invention relates to the technical field of physiological signal processing, and discloses a millimeter wave radar multi-dimensional physiological feature decoupling heart failure early warning system and method, and the method comprises the steps: configuring a millimeter wave radar to transmit a dual-beam frequency modulation continuous wave signal, collecting human body reflection echoes, and generating a multi-channel original digital signal matrix; generating a chest region and acra region phase signal, an overall reflection signal amplitude sequence and an overall phase drift signal after spatial isolation enhancement through distance-Doppler combined processing; decoupling to obtain a beat-by-beat heartbeat interval sequence, a pulse wave transmission time sequence and a daily net body fluid variation sequence; obtaining a rule engine risk level and a machine learning early warning sign, and determining a final risk assessment level through fusion decision; synchronous high-precision collection and decoupling of non-contact multi-dimensional physiological parameters are achieved, and accuracy and specificity of heart failure decompensation early warning are improved through double-layer model fusion.

The invention relates to the technical field of radar measurement, and discloses a millimeter wave radar-based heart rate high-precision measurement method and system, and the method comprises the steps: searching a thoracic cavity target through a frequency modulation continuous wave radar, positioning a heart position, and extracting a complex signal corresponding to the heart motion; performing calculation of different dimensions on the complex signal, and obtaining a preliminary heart rate value through mutual verification of calculation results; through a three-level verification mechanism of motion interference elimination, clutter interference elimination and breathing harmonic interference elimination, confidence degree checking is conducted on the initial heart rate value, and a high-reliability result is reserved; based on a high-reliability result of the preliminary heart rate value, data in the recent preset time period are calculated with higher precision, and the final heart rate value is output, so that the accuracy rate of radar measurement of the heart rate can be greatly improved, meanwhile, multiple interferences are effectively inhibited, low-cost hardware is adapted, the applicability to broad-spectrum crowds and complex scenes is enhanced, only the high-reliability heart rate value is output, and the method is suitable for popularization and application. And the heart rate instantaneous change is dynamically responded.

The invention relates to a high-frequency millimeter-wave radar flue dust deposition online monitoring method and system, and belongs to the technical field of industrial process detection.The monitoring method comprises the steps that a flue three-dimensional structure model is loaded, working parameters of a millimeter-wave radar are configured, and a radar scanning space coordinate system is generated; controlling the millimeter-wave radar to transmit a frequency-modulated continuous wave signal; performing temperature drift compensation on the ash deposition layer reflection signal, and outputting a compensated radar signal intensity matrix; solving a flow field distribution equation in combination with the flue three-dimensional structure model, calculating a flow field turbulence intensity coefficient, and generating a radar signal correction mapping table; calculating the ash deposition thickness of each space coordinate point based on the signal propagation time delay, and outputting an ash deposition thickness distribution map; and extracting a thickness gradient feature vector and a Doppler frequency shift feature in the soot deposition thickness distribution diagram, inputting the thickness gradient feature vector and the Doppler frequency shift feature into a soot deposition state classification model, outputting a soot deposition abnormal region coordinate set, and generating a soot blower control instruction or a maintenance alarm instruction. According to the invention, the ash deposition monitoring precision and stability can be improved.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a transmitter node may determine a set of parameters for a waveform to be transmitted by the transmitter node, wherein the waveform is to use an allocated bandwidth that is larger than a sweeping bandwidth of a frequency modulated continuous wave (FMCW) chirp. The transmitter node may transmit the waveform according to the set of parameters. Numerous other aspects are described.

This invention discloses a fall detection method based on millimeter-wave radar, comprising the following steps: S1: The millimeter-wave radar continuously transmits frequency-modulated continuous wave signals and receives echo signals reflected by the human body within the monitoring area; S2: The echo signals are processed to generate human point cloud time-series data containing distance, orientation, velocity, and micro-motion information; S3: Multi-dimensional feature vectors representing human posture and motion state are extracted from the human point cloud time-series data; S4: The multi-dimensional feature vectors are input into a primary fall recognition model to calculate a preliminary fall risk probability value; S5: If the preliminary fall risk probability value exceeds a first set threshold, it is determined to be a suspected fall event, and a secondary precise authentication process is immediately initiated; the secondary precise authentication process includes: initiating non-contact vital sign monitoring and retrieving the user's recent behavioral dynamic baseline model for comparative analysis. This invention enables more accurate fall detection.

The invention discloses a frequency-modulated continuous wave laser radar signal generation method, a frequency-modulated continuous wave laser radar signal detection method and a frequency-modulated continuous wave laser radar signal detection system. The system comprises a transmitting end and a receiving end, wherein the transmitting end determines a frequency guard interval between a frequency-modulated continuous wave signal and zero frequency according to a modulation bandwidth of a radar signal and a line width of a transmitting laser; generating a frequency modulation continuous wave signal according to the frequency protection interval, modulating the frequency modulation continuous wave signal, generating radar detection signal light which is to be sent and contains residual carrier waves, performing power amplification on the radar detection signal light, and transmitting the radar detection signal light by using an optical lens; the receiving end receives the reflected signal light reflected by the target; filtering, beat frequency and coherent detection are carried out on the reflected signal light and the radar detection signal light to obtain an electric signal, and the electric signal is converted into a digital signal; performing electric domain filtering on the digital signal, and extracting a residual carrier and a beat frequency signal; performing phase noise compensation on the beat frequency signal based on the residual carrier to obtain a signal after phase recovery; and estimating the distance and the relative speed of the target based on the residual carrier and the phase-recovered signal.

The invention discloses a frequency modulated continuous wave cable local insulation defect detection method, which comprises the following steps: S1, realizing an FMCW method by using an FMCW cable fault positioning system, performing spectrogram function extraction and analysis on an incident signal and a reflected signal at a certain moment in the FMCW method to obtain a frequency difference between the incident signal and the reflected signal at the certain moment, and determining the frequency difference between the incident signal and the reflected signal at the certain moment; therefore, the position information from the cable defect to the head end of the cable is obtained, and effective fault diagnosis is realized. S2, time domain, frequency domain and power spectrum characteristic index extraction is carried out on the spectrogram function analysis signals, and index data of the analyzed signals are known more comprehensively; the method solves the problems that in the prior art, a reflection method is limited by frequency domain reflection signal amplitude attenuation, the detection distance is short, the requirement for long-distance cable detection cannot be met, FFT positioning spectrum covering information is single, interference of environmental factors is likely to happen, and cable state evaluation is not comprehensive enough.

This invention belongs to the field of communication technology and discloses a voice communication system based on deep ultraviolet light. The system includes: a voice communication terminal, a transmitting information processing module, an electro-optical conversion module, a transmitting optical system, a receiving optical system, a photoelectric conversion module, and a receiving information processing module. Compared with traditional radio frequency communication, ultraviolet light has excellent anti-interference and anti-interception capabilities; compared with point-to-point communication in the deep infrared band, ultraviolet light has non-line-of-sight characteristics, enabling communication even in jungle warfare. This invention uniquely employs FMCW (Frequency Modulated Continuous Wave) modulation. FMCW encodes bit information as a continuous increase or decrease in frequency. The receiving end obtains the difference frequency signal through mixing, which can be demodulated using matched filtering or Fourier transform, significantly improving processing gain and noise immunity. Even under weak scattered light conditions, signals can be reliably extracted from strong backgrounds, greatly improving communication link margin.

A LIDAR transceiver includes a source input, coherent cells, and an optical switch. The optical switch is configured to switchably couple the source input to the coherent cells. At least one of the coherent cells includes an input port, an optical antenna, and a splitter. The input port is coupled to the optical switch and the splitter is coupled between the input port and the optical antenna. The splitter is configured to split a received portion of a laser signal into a local oscillator signal and a transmit signal, where the transmit signal is emitted through the optical antenna. A reflection of the transmit signal is received through the optical antenna as a reflected signal, where the splitter is further configured to output a return signal that is a portion of the reflected signal.

Determining classification(s) for object(s) in an environment of autonomous vehicle, and controlling the vehicle based on the determined classification(s). For example, autonomous steering, acceleration, and / or deceleration of the vehicle can be controlled based on determined pose(s) and / or classification(s) for objects in the environment. The control can be based on the pose(s) and / or classification(s) directly, and / or based on movement parameter(s), for the object(s), determined based on the pose(s) and / or classification(s). In many implementations, pose(s) and / or classification(s) of environmental object(s) are determined based on data from a phase coherent Light Detection and Ranging (LIDAR) component of the vehicle, such as a phase coherent LIDAR monopulse component and / or a frequency-modulated continuous wave (FMCW) LIDAR component.

Disclosed are techniques for wireless sensing. In an aspect, a sensing node receives, from a sensing entity, a. configuration to report interference measurements, obtains, at a first time, one or more sensing measurements of one or more first sensing reference signals transmitted by a transmitter sensing node, obtains, at the first time, one or more interference measurements of one or more second sensing reference signals transmitted by one or more aggressor sensing nodes, and transmits, to the sensing entity, an interference measurement report including at least the one or more interference measurements.

A radar apparatus includes a local oscillator configured for generating a continuous wave (CW) local oscillator signal or a frequency modulated continuous wave (FMCW) local oscillator signal. The radar device further comprises a test signal generator which is designed to generate a test signal and to modulate the test signal onto a signal derived from the local oscillator signal in order to generate a feedback signal. The radar device further comprises a transmitting device which is designed to emit a radar signal as a function of the local oscillator signal. The radar apparatus further includes a receiver device configured to receive the reflected radar signal, generate a received signal, and feed back a feedback signal with the received signal to generate an output signal. The radar device further comprises an evaluation device which is designed to ascertain at least one characteristic variable of the radar device using the output signal. The frequency range of the test signal lies outside the frequency range provided for the application of the radar device.

There is provided a device for phase noise compensation for a frequency modulated continuous wave, FMCW, light detection and ranging, LIDAR, system, said device comprising: an optical interferometer receiving a light signal from a source of the LIDAR system, splitting the light signal into a first and a second light signal into a first and a second path having a preset delay therebetween, and combining the light signals having passed the first and the second path, a detector detecting the combined light signals; a phase noise determination module receiving the detected signal and determining a plurality of phase noise signals corresponding to integer numbers of the preset delay; and a phase noise compensation module receiving and processing a LIDAR response signal in a plurality of branches, and for each branch, compensating phase noise in the LIDAR response signal using one of the phase noise signals, and determining a fast Fourier transform, FFT, of the compensated signal for a specific range of distances to a target, the branches being configured to determine the FFT for mutually unique ranges.

A radar device includes a frequency modulated continuous wave (FMCW) generator, a radio frequency (RF) circuit, a computing circuit, and a coherent subtractor. The FMCW generator is configured to generate an FMCW signal. The RF circuit is configured to modulate the FMCW signal into an RF signal and demodulate a reflection signal reflected at a target from the RF signal, so as to obtain a received signal. The computing circuit is configured to reconstruct a short-range leakage signal according to the FMCW signal and an estimated channel coefficient, a delay coefficient, a phase coefficient, and an amplitude coefficient obtained in a short-range leakage estimation stage of the radar device. The coherent subtractor is configured to compensate the received signal by the reconstructed short-range leakage signal.