382 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.

The invention relates to the technical field of laser radars, in particular to an obstacle detection method and system based on a frequency-modulated continuous wave laser radar, and the method comprises the steps: transmitting a chaotic frequency-modulated continuous wave signal to a detection region, and obtaining a reflection echo signal of a target object; performing decoupling calculation on the difference frequency electric signal to obtain a target time frequency distribution matrix; according to the target time-frequency distribution matrix, predicting the Doppler frequency shift amount of the target object at the next moment; based on the chaos frequency modulation adjustment signal, obtaining a distance measurement deviation compensation amount; the chaos frequency modulation adjustment signal is obtained by dynamically adjusting the chaos frequency modulation slope of the chaos frequency modulation continuous wave signal through the Doppler frequency shift amount; and compensating the difference frequency electric signal frequency value of the target object according to the distance measurement deviation compensation amount and the environmental noise data so as to solve obstacle distance speed detection information. According to the invention, the Doppler frequency shift amount is predicted in real time and the chaotic frequency modulation continuous wave signal parameters are dynamically adjusted, so that the accurate compensation of the distance measurement deviation is realized, and the accuracy of obstacle distance speed detection is improved.

A monitoring system is presented for monitoring vital signs of subject(s). The monitoring system includes a control system configured for signal communication with a frequency modulated continuous wave (FMCW) radar to process measured data which is received from a single-channel front end of receiver of said FMCW radar and which is in the form of data matrix indicative of consecutive beat signals. The control system comprises a data processing utility comprising: a localization module configured and operable to process the measured data indicative of said data matrix and provide support recovery data indicative of the received signals originated at localized one or more subjects; and a vital signs monitoring module configured and operable to analyze the support recovery data and monitor vital signs of said localized one or more subjects.

The invention discloses a non-contact electrocardio detection method which comprises the following steps: transmitting a frequency modulation continuous wave signal to the heart part of a human body by using an MIMO millimeter wave radar so as to obtain an echo signal reflected by the human body and pre-process the echo signal to obtain a discrete three-dimensional radar signal; enhancing the discrete three-dimensional radar signal by using a 2D beam forming technology to obtain a 2D signal; extracting a target area signal from the 2D signal, and performing phase extraction on the extracted target area signal to obtain phase data; the method comprises the following steps: constructing a WaveGRU-Net network comprising an MODWT module, a CNN module and a Bi-GRU module; and training the WaveGRU-Net network by using the phase data so as to output a reconstructed electrocardiogram by using the trained WaveGRU-Net network, thereby realizing non-contact electrocardiogram detection. According to the method, accurate extraction of the electrocardiosignal is realized, and meanwhile, the signal reconstruction precision is improved.

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.

Disclosed are systems and techniques for wireless joint communications and sensing. For example, a network device can receive, from a network entity, at least one configuration signal indicating at least one configuration comprising a resource for a physical uplink control channel (PUCCH) and for sensing. The network device can output, for transmission to the network entity, the PUCCH based on the at least one configuration comprising the resource. The network device can transmit a sensing signal based on the at least one configuration comprising the resource.

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.

The invention provides a frequency modulated continuous wave laser radar-based target identification method and a laser radar system, which can be applied to the technical field of laser radars. The method comprises the following steps: acquiring an interference beat frequency signal after polarization orthogonal demodulation; performing signal demodulation on the electric signal of the interference beat frequency signal to obtain a target detection feature; performing feature matching on the target detection features and a typical target polarization feature library to obtain a feature matching result; and under the condition that the feature matching result represents that the target feature similarity meets a first threshold condition, performing identification processing on the target detection features based on an air intrusion target identification model to obtain a target type identification result.

The photonic integrated chip comprises a substrate, a demultiplexer and a light guide assembly, and the light guide assembly and the demultiplexer are integrated on the substrate; the light guide assembly comprises a first light splitting coupler, a second light splitting coupler and a frequency mixer, and the first light splitting coupler is in optical communication connection with the output end of a corresponding channel of the demultiplexer so as to allow the demultiplexer to transmit an optical signal to the first light splitting coupler; the first light splitting coupler is used for splitting a received optical signal into local oscillation light and signal light, and the first light splitting coupler is in optical communication connection with the second light splitting coupler and the frequency mixer so as to allow the first light splitting coupler to transmit the local oscillation light to the frequency mixer and transmit the signal light to the second light splitting coupler; the second light splitting coupler is used for transmitting the signal light to a detection object and receiving echo signal light fed back by the detection object, and the second light splitting coupler is in optical communication connection with the frequency mixer so as to allow the second light splitting coupler to transmit the echo signal light to the frequency mixer.

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.

This application provides a signal transmission method, a communication apparatus, and a communication system, that serve to suppress interference between signals of a plurality of transceivers sharing a same resource. In the method, a first apparatus generates parameter information and sends the parameter information to a second apparatus, such as a transceiver. The parameter information may be determined based on one or more multiplexing modes. The parameter information indicates a value of at least one of a time shift of a time for transmitting a frequency modulated continuous wave (FMCW) signal relative to a reference time, a slope of the FMCW signal, a plus-minus sign of the slope, and a coding parameter used to generate the FMCW signal through phase coding. The second apparatus receives the parameter information and, generates the FMCW signal based on the received parameter information, and sends the FMCW 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 cross section water depth continuous measurement method and system based on millimeter waves, and relates to the technical field of hydrographic measurement. According to the invention, through a millimeter wave radar array and a multiple-input-multiple-output antenna, a frequency modulation continuous wave signal is transmitted and a mixed echo signal is received; extracting time-frequency characteristics by using wavelet transform and short-time Fourier transform, and classifying reflection peaks in combination with a Gaussian mixture model; calculating the thickness of an ice layer, the thickness of an air interlayer and an initial water level based on the delay inequality, and dynamically correcting an error through adaptive Kalman filtering; a dynamic focusing algorithm is adopted to synthesize water surface and riverbed reflection signals, and a sand content compensation and flow velocity correction model is introduced to optimize water depth and riverbed elevation inversion; the three-dimensional interpolation weight is optimized through an ant population algorithm, and a high-precision cross section continuous water depth distribution diagram is generated; according to the invention, the problems of poor penetrability, weak anti-interference capability and low continuous water depth precision are solved, and full-section dynamic monitoring of the ice layer thickness, the water level, the water depth and the riverbed form is realized.

A low-cost lightweight single-bit multiplexing array radar signal processing method and system. The method comprises: on the basis of a radio frequency multiplexer, acquiring an array echo signal, and preprocessing the array echo signal to obtain a first zero-intermediate-frequency signal and a second zero-intermediate-frequency signal (S100); performing single-bit synchronous sampling on the first zero-intermediate-frequency signal and the second zero-intermediate-frequency signal to obtain symbol data (S200); and on the basis of the symbol data, estimating an intermediate parameter, and on the basis of the estimation result of the intermediate parameter, calculating target information (S300). The problem of a traditional frequency-modulated continuous wave array radar using a plurality of receivers and a multi-bit analog-to-digital converter to acquire echo signals from a plurality of antennas, resulting in a complex hardware system, a large size, a heavy load and high power consumption, thus limiting the application of the radar in a low-cost and small-payload unmanned system is solved.

The invention provides a laser radar, a detection method thereof and a transmitting and receiving device, and the transmitting and receiving device comprises a light splitting modulation unit which carries out the light splitting modulation of original light, so as to form a detection light signal group and a local oscillation light signal group; the coherent unit is suitable for receiving and coupling the echo optical signal group and the local oscillation optical signal group to form a coherent optical signal group, and the coherent optical signal group comprises a plurality of coherent optical signals in time division. Different coherent optical signals in the coherent optical signal group have preset time delay, so that in the process of processing the coherent optical signal group, interference signals can be further eliminated by using the preset time delay, thereby achieving the purpose of improving the anti-interference capability, especially the anti-interference capability in a microwave frequency band, of the laser radar formed by the laser radar, and improving the anti-interference capability of the laser radar in the microwave frequency band. Full-spectrum anti-interference of the frequency-modulated continuous wave laser radar can be realized, and popularization of the frequency-modulated continuous wave laser radar can be further promoted.

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.

In some implementations, a radio frequency (RF) sensing node may receive a non-linear frequency-modulated (NLFM) configuration from a configuring node of a wireless network, where the NLFM configuration is indicative of a set of one or more parameters of a non-linear function describing time-varying frequency characteristics of an NLFM signal to be used by the sensing node for RF sensing. In addition, the device may perform an RF sensing function with the sensing node in accordance with the NLFM configuration.

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 discloses a frequency-modulated continuous wave laser radar, and relates to the technical field of laser detection. The laser radar comprises at least two laser light sources, an optical switch assembly and an optical chip. The wavelengths of light signals emitted by the laser light sources are different from each other. The optical switch assembly comprises an optical switch and a wavelength division multiplexer. The wavelength division multiplexer comprises at least two first input ends and a first output end, the first input ends are correspondingly and optically connected with the optical switches, and the first output end of the wavelength division multiplexer outputs optical signals with different wavelengths in a time-sharing mode.

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.