3350 results about "Intermediate frequency" patented technology

A method for retrieving tropospheric wet delay and atmospheric water vapor content over polar sea ice with TDS-1 satellite grazing angle spaceborne GNSS-R is provided, including: Si, obtaining TDS-1 GNSS-R raw intermediate frequency signal data, VMF3 grid data, GPT3 grid data and ERA5 data; S2, correcting an error of tropospheric wet delay estimation of grazing angle spaceborne GNSS-R; S3, constructing a grazing angle spaceborne GNSS-R tropospheric wet delay estimation model; S4, calculating grazing angle spaceborne GNSS-R ZWD; S5, calculating a Tm value of a target point based on GPT3 model, substituting the Tm value into a conversion factor II, and combining calculated GNSS-R ZWD to obtain a GNSS-R IWV estimated value; and S6, verifying inversion performance of GNSS-R ZWD and integrated water vapor (IWV) by using reference data.

The invention provides a lithium battery internal short circuit fault intelligent detection method based on electrochemical impedance spectroscopy. According to the system, battery data are obtained through electrochemical impedance spectroscopy testing, and innovative feature extraction is carried out. The core technology is to extract four key features from a Nyquist graph: a minimum value point of an intermediate frequency region, a straight slope of a low frequency region, a radius of a circle of a high frequency region and an intersection point of the high frequency region and a real part axis. The characteristics effectively characterize the short circuit state in the battery. And the system inputs the extracted features into a long short-term memory (LSTM) network deep learning model to realize accurate identification and classification of the internal short circuit fault. The model is deployed in a cloud after being trained, and monitors the battery state in real time and performs graded early warning. According to the invention, the accuracy and efficiency of short-circuit fault detection in the lithium ion battery are obviously improved, and powerful support is provided for battery safety management of an electric vehicle and an energy storage system.

Provided is a detection method of spaceborne GNSS-R original intermediate frequency coherent reflection signals in ocean, polar and inland water areas, including: acquiring spaceborne GNSS-R original intermediate frequency signal data of TDS-1 or CYGNSS and preprocessing the data; selecting coherent detection feature engineering; setting data labels of different scenes and coherent and incoherent reflected signals; dividing a training set and a test set; and training and testing a multimode-oriented hybrid model for coherent and incoherent detection and classification of spaceborne GNSS-R signals, using the training set to train a model, applying a trained detection model to a test data set, and comparing and evaluating obtained detection results with a classical coherent detection algorithm.

The present invention relates to a modular architecture for transmitting and / or receiving radio frequency (RF) signals using a phased antenna array. A first portion of the RF signal is transmitted / received by a master IC (21) and a second portion of the RF signal is transmitted / received by a plurality of satellite ICs (22). RF distribution between the master IC (21) and the satellite ICs (22) occur over a low-RF-loss interposer (51). The master IC (21) performs upconversion / downconversion between RF signal and a baseband or intermediate frequency signal.

An electronic device may include wireless circuitry with a non-coherent receiver and a phased antenna array that receives a radio-frequency signal having a sub-THz carrier and one or two sidebands separated from the carrier by an intermediate frequency and carrying wireless data. The receiver may include respective receive paths coupled to each antenna in the phased antenna array, a signal combiner coupled to each of the receive paths, and a demodulator. Each receive path may have a respective passive square law envelope detector and a respective phase shifter. The envelope detectors may generate intermediate frequency signals at the intermediate frequency based on the radio-frequency signals. The phase shifters may phase shift the intermediate frequency signals to generate a phase-aligned intermediate frequency signal. The demodulator may recover the wireless data by demodulating the phase-aligned intermediate frequency signal.

The invention relates to the technical field of intermediate frequency furnace sintering temperature control, and discloses a sintering temperature control system of an intermediate frequency furnace. The system comprises a multi-source data acquisition module which is used for acquiring multi-dimensional thermodynamic data, covering temperature distribution, sintering power and heat flow track data in a sintering process in real time; and the temperature field analysis module is used for carrying out dynamic compensation correction processing on the multi-dimensional thermodynamic data, inputting the multi-dimensional thermodynamic data into a sintering analysis processing layer for characteristic modeling, and generating a sintering temperature regulation and control instruction. The sintering analysis processing layer comprises a data preprocessing module and a thermodynamic modeling module, the data preprocessing module performs operation such as temperature interval division and abnormal value elimination on original data, and the thermodynamic modeling module is obtained based on historical data cooperative training. According to the system, through multi-dimensional data acquisition and analysis processing, the sintering temperature can be accurately regulated and controlled, the quality of sintered products and the production efficiency are effectively improved, and the system has good universality and adaptability.

The invention discloses a frequency hopping signal real-time detection method and system based on FPGA + DSP. The system comprises a time frequency analysis module, a data communication module and a frequency hopping signal detection module. The method comprises the following steps: a time frequency analysis module performs analog-to-digital conversion and digital down-conversion on an intermediate frequency signal received from a radio frequency end, and performs short-time Fourier transform on a zero intermediate frequency signal by adopting a four-pipeline processing mode; the data communication module transmits the frequency spectrum information from the FPGA to the DSP through an SRIO protocol; the frequency hopping signal detection module calculates a dynamic threshold of a current frame signal according to the received frequency spectrum information, and completes preliminary detection of the signal according to a threshold value; and carrying out binarization processing and connected domain marking on the detected frequency spectrum, screening non-frequency hopping signals according to time-frequency information of a connected domain, and packaging and uploading parameter information of the detected frequency hopping signals to an upper computer. The method is simple in algorithm, low in hardware resource requirement and high in detection efficiency, and the feasibility of engineering implementation is improved.

The multi-interaction-mode intermediate frequency furnace automatic slag salvaging mechanism comprises a guide rail, an industrial robot and intermediate frequency furnaces, the guide rail is used for bearing the industrial robot, the guide rail is installed between the two intermediate frequency furnaces, furnace openings of the two intermediate frequency furnaces are each provided with a furnace cover, and the interiors of furnace bodies of the intermediate frequency furnaces are used for storing molten iron; a coaxial slag salvaging mechanism is arranged at the tail end of the industrial robot, a slag salvaging spoon is arranged at the bottom of the coaxial slag salvaging mechanism, the slag salvaging spoon is used for salvaging slag, and a slag hopper used for storing the slag is arranged at the bottom of the slag salvaging spoon. The rotation angle of the stepping motor is controlled by an instruction sent by the control system, opening and closing of the slag salvaging spoon can be further controlled, the motion mode of the slag salvaging mechanism is unique and different from the prior art, the slag salvaging mechanism can salvage the slag to the maximum extent, and the problem that in the prior art, the slag salvaging spoon needs to be replaced every day is solved.

The invention discloses a millimeter wave radar vital sign detection method based on an HHO-CEEMDAM algorithm, and the method comprises the steps: building a millimeter wave radar experiment system, and collecting an intermediate frequency signal of a human body echo; performing data reading and recombination, extracting phase features, and enhancing a target signal through non-coherent accumulation to determine the distance between the chest of the human body and the radar; recovering the phase of the vital sign signal from the incoherent accumulation FFT result by using the linear characteristic of arc tangent demodulation, and performing phase unwrapping and phase difference to obtain optimized phase information; setting a CEEMDAN parameter initialization range and designing a fitness function; a CEEMDAN parameter is optimized by using an HHO algorithm; performing CEEMDAN decomposition by using the optimized parameters, and screening breathing and heartbeat IMF components; and according to the IMF component, obtaining estimated values of the respiratory rate and the heart rate. The method improves the estimation precision of the respiratory rate and the heart rate of the millimeter wave radar in fatigue driving detection.

The invention belongs to the technical field of airborne radio frequency equipment testing, and particularly relates to a comprehensive simulation test system and method for airborne radio frequency equipment, and the system comprises a man-machine interaction unit, a comprehensive radio frequency rack unit, a power supply and control unit, and a cabinet matching test cable. Broadband radio frequency signal processing, waveform modulation and demodulation, audio analysis processing and data storage and recording of each airborne radio frequency device are realized through the integrated radio frequency rack unit; and signal processing and channel switching functions are realized through the intermediate frequency switching matrix module and the broadband radio frequency front-end processing module, so that different to-be-tested systems and radio frequency signals can be matched. According to the invention, a software radio technology is adopted, a software dynamic loading reconstruction scheme is adopted on a general radio frequency hardware platform to realize soft switching among different task functions of the airborne radio frequency equipment, a comprehensive simulation test on the complex airborne radio frequency equipment is realized, and the utilization rate of test resources is improved.

A millimeter wave radar altimeter structure disclosed by the present invention comprises a shell, the shell is provided with a plurality of functional areas and integrates a plurality of functional units, the functional units comprise a radio frequency unit, an intermediate frequency processing unit and a signal control unit, and the plurality of functional units are compactly arranged in the shell. The radio frequency unit comprises at least one high-power emission chip, the chip is installed on a heat conduction substrate, and the substrate is in contact with the shell to form a heat conduction path. The shell is made of a high-heat-conductivity material, and a plurality of heat dissipation structures are arranged outside the shell, so that the heat dissipation efficiency under natural convection is improved. The heat conduction substrate, the shell material and the heat dissipation structure form a continuous heat dissipation path from the chip to the environment, heat accumulation is effectively restrained, and stable work of the chip is guaranteed. The shell further comprises a sealing structure, a sealed space is formed by a sealing groove, a sealing element, the antenna cover and the packaging cover plate, and environment sealing protection is achieved. The signal control unit is connected with peripheral equipment through an external interface, and the interface supports power supply and data communication of the altimeter.

The invention provides a broadband signal channelized receiving and high-precision reconstruction method and device, and belongs to the technical field of wireless communication broadband signal processing.The method comprises the steps that a preselection filtering module conducts first-stage channel division on broadband radio frequency signals; the receiving frequency conversion module performs down-conversion on the narrowband radio frequency signal to intermediate frequency, and the mirror image frequency is suppressed through an intermediate frequency filter; the digital channelization module performs down-conversion on the digital intermediate-frequency signal to a baseband, and realizes second-stage channel division by using a baseband digital channelization low-pass filter to obtain narrowband sub-signals; the high-precision reconstruction module synthesizes a broadband signal through up-conversion and interpolation filtering to obtain a reconstructed signal; the playback calibration module calculates the initial phase difference of the calibration signal among different channels for phase compensation, and obtains a reconstructed signal after phase calibration; and performing up-conversion on the reconstructed signal after phase calibration to radio frequency, and sending the reconstructed signal back to a frequency hopping communication system. According to the invention, the precision index and the engineering reliability of the channelized receiving and reconstruction design method are improved.

The invention relates to the technical field of signal analysis, in particular to a GNSS (Global Navigation Satellite System) detection method and system based on machine learning, and the method comprises the steps: receiving a navigation radio-frequency signal containing reality and deception, and carrying out the down-conversion of an RF (Radio Frequency) front end to obtain intermediate-frequency data; gNSS signal capture is completed by searching correlation peaks in frequency and code phases based on intermediate frequency data; in the capturing stage, a motion state, a correlation peak number, a noise value, capturing parameters and peak + / -1 chip sampling features are extracted and input into a machine learning classification model to judge whether cheating exists or not; if so, separating the deception signal from the real signal, and respectively sending the deception signal and the real signal into independent tracking channels; measuring an array element carrier relative phase by an array antenna, establishing a phase center model, and correcting to obtain an effective phase center and a differential baseline; according to the method, a deception azimuth angle and a pitch angle are obtained, a beam weight is calculated, a deception direction is subjected to null setting, a real direction is subjected to main lobe protection, and a weight value is fed back in real time to improve a signal carrier-to-noise ratio and locking stability. According to the invention, the problem that the existing commercial GNSS signal is low in power and easy to be interfered by deception is solved.

The invention provides a multifunctional satellite-borne integrated radio frequency system and device. The multifunctional satellite-borne integrated radio frequency system comprises a broadband low-profile integrated transceiver array, a reconfigurable integrated radio frequency front end and a flexible high-performance processing platform, the broadband low-profile integrated transceiving array adopts a multi-subarray design, has the capabilities of multi-beam signal transceiving, two-dimensional wide-angle beam scanning and received signal low-noise amplification, and adopts a low-profile and foldable structural design to adapt to the constraint of a satellite-borne platform; the reconfigurable integrated radio frequency front end has the capabilities of full-band signal up-down conversion processing and multi-channel full-interaction radio frequency routing; the flexible high-performance processing platform adopts a reconfigurable, open-type and high-reliability digital processing architecture, and has the functions of intermediate-frequency signal high-speed sampling, high-performance digital processing, software definition and on-orbit dynamic upgrading. According to the invention, a traditional discrete satellite-borne radio frequency system can be converted into a high-integration, multifunctional and conformal system, and the scale of the satellite-borne radio frequency system can be effectively reduced.

A multi-sensor furnace lining thickness measuring method for an intermediate frequency furnace adopts a visual algorithm, is realized based on a structured light camera and a laser radar, and comprises the following steps: firstly, calibrating an RGB camera and an infrared camera to obtain respective internal and external parameter matrixes; secondly, aligning the RGB camera with the infrared camera to obtain three-dimensional information; recognizing a reference target through a target detection model, extracting a plurality of groups of three-dimensional feature points in a target area, and calculating to obtain a structured light camera transformation matrix, namely, realizing pose estimation; joint calibration is carried out on the structured light camera and the laser radar; and finally, enabling a camera pose estimation result and a joint calibration result to act on laser radar data under multiple times of measurement, and enabling the two times of radar data to be in the same coordinate system, thereby realizing thickness measurement and monitoring of the furnace lining. According to the invention, under the condition that the furnace lining is not damaged, no harm is caused to the environment, the influence of the environment is small, and meanwhile, the thickness of the furnace lining can be rapidly measured and monitored in a large-scale and high-precision manner.

The invention relates to an unmanned aerial vehicle RemoteID signal detection, demodulation and analysis system and method, an upper computer sends a task instruction to a central control module through a network module to carry out radio frequency data acquisition, the central control module controls a radio frequency receiving module to acquire an electromagnetic wave signal of a specified frequency band in an airspace environment, and the electromagnetic wave signal is transmitted to the central control module; carrying out low-noise amplification and filtering processing on the electromagnetic wave signal of the specified frequency band; iQ data acquisition is carried out, wherein an intermediate frequency acquisition module acquires signals and carries out frequency mixing, filtering and AD sampling processing; inputting the acquired IQ data into a baseband data processing module, and performing analysis processing through the baseband data processing module based on an unmanned aerial vehicle RemoteID signal detection algorithm, an unmanned aerial vehicle RemoteID signal demodulation algorithm and an unmanned aerial vehicle RemoteID signal analysis algorithm; and an operation result of the baseband signal processing module is transmitted to an upper computer for display through the network transmission module. Remote and non-standard frequency band Remote ID signal supervision and analysis can be realized, the system stability is high, and the algorithm detection, demodulation and analysis accuracy is high.

The invention discloses a high-throughput satellite communication terminal system, which comprises a radio frequency channel unit, a signal processing unit, a terminal processing unit, a power supply management unit and an anti-electromagnetic interference module, and is characterized in that the radio frequency channel unit carries an agile device and a power amplifier and is used for realizing bidirectional conversion between a baseband signal and a radio frequency signal; communication frequencies of a Ka frequency band, a valley value of 5GHz and a peak value of 40GHz are supported, a zero intermediate frequency receiver structure is adopted, image frequency interference is eliminated through one-time frequency conversion to a baseband, and a high-integration design that a radio frequency signal directly enters a frequency mixer after passing through an antenna, a radio frequency filter and a low-noise amplifier is realized. According to the high-throughput satellite communication terminal system, the coverage problem of traditional communication in a blind area of a power grid is solved, safe, efficient and stable transmission of power data is realized, the emergency communication capability and the equipment environment adaptability are remarkably improved, and key technical support is provided for constructing global visual monitoring and intelligent scheduling of the digital power grid.

A displacement-sensing Doppler radar with ultra-low noise and high sensing resolution is provided. The radar includes N two frequency synthesizers to respectively generate, at different frequencies, a transmitted signal that is radiated toward a target object, and a local oscillator (LO) signal. The radar further includes a mixer and a rectifier to: (1) receive a returned signal from the target object carrying phase delays corresponding to detected displacements of the target object; (2) mix the returned signal and the LO signal to generate a down-converted sine-wave intermediate frequency (IF) signal; and (3) rectify the sine-wave IF signal to a square-wave IF signal, which also carries the displacement-induced phase delays. The radar also includes a phase demodulation module to convert the displacement-induced phase delays into a pulse-modulated signal. The radar further includes a low-pass filter to convert the modulated pulse signal into an output voltage signal indicative of the detected displacements.

The invention relates to the technical field of time sequence data processing, in particular to a drainage basin flood process automatic deduction method based on time sequence analysis, which comprises the following steps: obtaining drainage basin historical hydrological data, processing by applying adaptive wavelet transform, and extracting an intermediate frequency wavelet feature sequence and a transform residual sequence as data features; establishing a first calculation model, and generating a first predicted water level sequence; obtaining an error sequence based on the first predicted water level sequence and the actual water level sequence; constructing a second calculation model by using the data features and the rainfall data, and fitting the error sequence by using the second calculation model to obtain a prediction error sequence; performing weighted fusion on the first predicted water level sequence, the predicted error sequence and the rainfall sequence to generate a second predicted water level sequence; and combining the second predicted water level sequence with a hydrodynamic numerical calculation model, and obtaining predicted data through flow field calculation and analysis. According to the method, high-precision automatic deduction is realized through automatic processing and hybrid modeling.

The invention discloses a method and a system for capturing an ultra-wideband navigation signal of a low-orbit satellite, which are used for solving the technical problem that the existing method for capturing the ultra-wideband navigation signal of the low-orbit satellite is easy to cause that the signal cannot be locked, and finally the capturing success rate is low. The method comprises the following steps: acquiring ka-band low-orbit satellite signals and low-orbit satellite pseudo-random noise codes corresponding to a plurality of low-orbit satellite ultra-wideband navigation signals; generating a complex signal and an original intermediate-frequency signal according to a preset sampling rate, preset skipping time and the ka-band low-orbit satellite signal; constructing a pseudo-code spectrum library based on the pseudo-random noise codes of the low-orbit satellites, and outputting the pseudo-code spectrum library; determining a discrete frequency search sequence based on known intermediate frequency parameters of the original intermediate frequency signal, performing matrix construction in combination with the complex signal and the pseudo code spectrum library, and outputting a three-dimensional result matrix; and capturing and judging the ultra-wideband navigation signals of the low-orbit satellites by adopting the three-dimensional result matrix, and determining a plurality of successfully captured ultra-wideband navigation signals of the low-orbit satellites.

The invention belongs to the field of unmanned aerial vehicle technologies and radars, and discloses a radar phase difference unmanned aerial vehicle height measurement method based on frequency spectrum refinement calibration, which comprises the following steps: receiving a radar echo carrier frequency signal, and forming a radar data cube by an intermediate frequency signal after frequency mixing processing; performing time-frequency domain conversion on the data cube distance dimension to obtain a radar one-dimensional distance image sequence; interference clutters are filtered based on a constant false alarm detection technology, and a maximum peak value in a range is searched to determine a distance threshold of an observation area; performing frequency spectrum refinement processing on a specific frequency band of the observation area by using Chirp-Z transformation, constructing a quadratic polynomial in combination with parabola fitting to perform spectral line calibration, and obtaining frequency information of the observation area after frequency spectrum refinement calibration; and extracting a phase sequence of an observation area distance threshold, unwrapping adjacent frame phases by using phase unwrapping, and determining height information of the unmanned aerial vehicle relative to the ground by combining frequency and phase information. The unmanned aerial vehicle can be assisted to quickly feed back the relative ground height, and the collision risk is avoided.

The invention discloses a multi-channel transceiving integrated system based on an RFSOC (Radio Frequency System On Chip) and a radio frequency SIP (Session Initiation Protocol). The multi-channel transceiving integrated system comprises an RFSOC system, a multi-channel clock synchronization module, a radio frequency SIP system and a power supply network, the RFSOC system comprises a control sampling module, a storage module and an optical fiber module, the control sampling module comprises a plurality of RFSOC chips, a CPLD (Complex Programmable Logic Device) chip and a main control chip, and the RFSOC chips are used for processing intermediate frequency signals and realizing data interaction with the optical fiber module; the CPLD chip is used for enabling a power supply network; the main control chip is used for performing control coordination among the plurality of RFSOC chips; the storage module is used for realizing program solidification of the RFSOC system; the optical fiber module is used for realizing high-speed transmission of broadband receiving data; the multi-channel clock synchronization module is used for providing a clock reference of the whole system; the radio frequency SIP system comprises a radio frequency SIP module, a Balun network and a local oscillator power division amplification module. The radio frequency SIP module realizes receiving, transmitting and processing of multi-channel radio frequency signals. According to the invention, a multi-channel transmit-receive integrated system with high integration, large bandwidth and miniaturization can be realized.

The invention belongs to the field of power transmission network load prediction, and particularly provides a small hydropower load prediction method based on quadratic modal decomposition and an improved sparrow algorithm, which comprises the following steps: performing primary decomposition on load data by using variational modal decomposition to obtain a modal component and a residual sequence; carrying out secondary decomposition on the residual error by adopting improved self-adaptive noise complete set empirical mode decomposition; calculating permutation entropies of all mode components after decomposition, screening out low-frequency components and intermediate-frequency components according to a set threshold value, and reconstructing the low-frequency components and the intermediate-frequency components; building a two-way gating circulation unit network load prediction model, performing parameter optimization on the two-way gating circulation unit network load prediction model by using a sparrow algorithm based on firefly improvement, and predicting the screened low and intermediate frequency components through the optimized two-way gating circulation unit network load prediction model. And superposing the low-frequency predicted value and the intermediate-frequency predicted value to obtain a final predicted value. According to the prediction method, high-precision load prediction can be carried out aiming at the characteristics of the small hydropower station.

The invention provides a radiation source individual identification method and system based on unintentional phase modulation characteristics, and relates to the technical field of radar signal processing. The method comprises the following steps: acquiring intermediate frequency data of radar signals emitted by different radar radiation source individuals to obtain a plurality of intermediate frequency data, and extracting a plurality of monopulse signals corresponding to the plurality of intermediate frequency data from the plurality of intermediate frequency data; phase extraction is carried out on the multiple monopulse signals, and unintentional modulation phase feature maps corresponding to the multiple pieces of intermediate frequency data are obtained; and constructing a radar individual identification model and training by using the data set, and identifying the plurality of unintentional modulation phase feature maps through the trained radar individual identification model to obtain a plurality of radar radiation source individual identification results. By extracting unintentional modulation phase features of radar signals, original fingerprint information of the signals is reserved to reduce calculation complexity, and a deep residual network of a small convolution kernel is constructed as a radar individual recognition model to improve recognition accuracy.

The invention discloses a lithium battery solid electrolyte interface film forming quality evaluation method. The method comprises the following steps: in a lithium battery formation stage or a circulation process, applying an alternating current disturbance signal with an amplitude of 1-20mV, and collecting full-band electrochemical impedance spectroscopy data in real time; a relaxation time distribution method is adopted to decouple the electrochemical impedance spectrum of the intermediate frequency region; constructing an equivalent circuit model containing SEI film characteristics, and fitting the decoupled electrochemical impedance spectrum curve by the equivalent circuit model; the compactness index of the SEI film is calculated according to the SEI film resistance and the film capacitance, and whether the compactness of the SEI film reaches the standard or not is judged according to the compactness index; and calculating a lithium ion diffusion coefficient by combining the charge transfer resistance and the Warburg diffusion impedance, and evaluating the SEI membrane ion transmission efficiency. According to the invention, non-destructive monitoring is supported, quantitative evaluation of SEI membrane compactness, ionic conductivity and short circuit faults in the module can be realized, and the cycle life and safety of the lithium battery are improved.

The invention relates to the technical field of communication technologies and navigation systems, and discloses a multi-channel narrowband data link comprehensive processing module, which comprises a radio frequency transceiver module which comprises a radio frequency transceiver and is used for converting a received radio frequency signal into a baseband signal and converting the baseband signal into a radio frequency signal; the analog channelization module is connected with the radio frequency receiving and transmitting module and used for receiving the baseband signals converted by the radio frequency receiving and transmitting module, carrying out preliminary channel division on the signals and dividing the signals into a plurality of frequency band signals; and the digital channelization processing module is connected with the analog channelization module and is used for carrying out digital processing on the signal after analog channelization. By adopting a zero intermediate frequency architecture, a multi-stage channelization design, cooperative work of the FPGA and the SOC, precise clock synchronization and an anti-interference technology, the multi-channel signal processing precision and the system stability are improved, and meanwhile, the power consumption and the hardware complexity are reduced.

The invention relates to the technical field of wireless communication, and discloses a millimeter wave backscatter communication positioning and identification system for multiple tags, which comprises a Chirp signal sending module used for generating and transmitting continuous Chirp signals and receiving signals reflected by customized backscatter tags; and the received signal processing module is used for carrying out demodulation and frequency analysis on the received radar echo signal, determining the distance of the target backscattering tag by measuring the frequency offset of the intermediate frequency signal, and determining the azimuth of the tag through the antenna array of the receiving module. The identity label of the backscattering label is extracted by analyzing the signal intensity; the customized backscattering label is used for adjusting the intensity of the signal reflected back to the radar by changing the reflection state of the backscattering label so as to transmit the identity label of the backscattering label; and the DSSS coding module is used for coding the identity label of the backscattering label so as to increase the signal bandwidth and reduce the signal interference between the labels. According to the method, the customized backscattering tag is matched with the FMCW radar, so that positioning and identification of multiple tags are realized, and the method has a wide application prospect.

The invention provides a GNSS signal interference monitoring and suppression method and system, a receiver and a medium, and particularly relates to the technical field of satellite navigation communication, and the scheme comprises the steps: obtaining an intermediate frequency signal based on a received GNSS signal; based on the differential cumulative power spectrum of the intermediate frequency signal, performing interference detection on the intermediate frequency signal, identifying the type of the interference signal according to the characteristic parameter of the interference signal, setting the notch frequency, and performing filtering processing on the intermediate frequency signal to obtain a target signal and a filtered signal; and evaluating the filtered signal according to the energy of the signal, and when the filtered signal is evaluated to be invalid, identifying the characteristic parameters of the interference signal again, and adjusting the notch frequency to perform filtering processing until the evaluation is valid. According to the scheme, the interference signals in the environment can be dynamically detected and identified, and the notch frequency can be adjusted, so that the interference signals are effectively detected and adaptively suppressed, and the anti-interference performance of the single-antenna GNSS receiver to various interference environments is improved.

The invention discloses a sleep sign monitoring method based on a millimeter-wave radar, which comprises the following steps: firstly, presetting acquisition parameters of the millimeter-wave radar, transmitting signals of the millimeter-wave radar, capturing reflected signals by a receiving antenna, sampling to obtain intermediate-frequency digital signals, and sending a sampling result to a rear-end computing device; extracting features related to the sleeping posture and the breathing frequency from the collected intermediate frequency digital signals; and recognizing the sleep posture of the user by using the point cloud features and the breathing features obtained after feature extraction. And then, effective reflection points are extracted, and the respiratory rate is accurately estimated by using the reflection points through a weighted average method. The invention aims to realize an accurate and reliable vital sign monitoring system by using commercial millimeter wave radar equipment which is low in cost and easy to deploy, stably recognize six sleeping postures and accurately measure the respiratory rate; rich and stable point cloud information is obtained; the characterization of the point cloud on the sleep posture is enhanced; and a more accurate respiratory rate estimation result is obtained.

In some examples, a method includes receiving, at a first device, a radar signal transmitted by a second device at a transmission frequency offset from a local oscillator (LO) frequency of the first device by a target offset and reflected off a target. The method also includes determining an intermediate frequency (IF) of the radar signal based on the transmission frequency and the LO frequency. The method also includes determining a parts per million (ppm) offset between the first device and the second device based on the intermediate frequency and the target offset.