762 results about "Chirp" patented technology

The invention relates to an all-fiber sub-hundred femtosecond laser based on an SESAM. The all-fiber sub-hundred femtosecond laser comprises the SESAM, a wavelength division multiplexer, a pumping source, a pumping protector, a gain fiber, a chirp fiber bragg grating, an isolator, a reflector, a compression unit and an autocorrelator. According to the invention, the chirp fiber bragg grating with the dispersion amount of 0.115 ps / nm is adopted to compensate positive dispersion in the cavity, so that mode-locked pulse with the spectral width of 23nm is realized. A transmission-type diffraction grating pair is adopted, the pulse width is compressed to 88fs, and the maximum spectral width 27nm is obtained under the dispersion of 0.00087 ps2 in a near-zero cavity. The condition that the optimal spectral bandwidth of the optimal seed source pulse based on the optical fiber chirped pulse amplification laser should be larger than 15 nm is met, and the compression pulse distortion of the amplifier is reduced. By adopting the linear cavity, the SESAM is adhered to the surface of the single-mode optical fiber patch cord for starting mode locking, so that an all-optical-fiber structure of the system is realized, and the single-mode optical fiber patch cord is suitable for industrial integrated application.

A system for emulating an over-the-air environment for testing a Frequency-modulated Continuous Wave (FMCW) light detection and ranging (LiDAR) unit under test (UUT). The system includes an optical lens system that receives an FMCW laser signal from the LiDAR UUT, and provides the signals to one or more optical fibers. A slope, chirp timing and intensity of the FMCW laser signal is determined using digital signal processing, and a modulation waveform is determined to emulate an over-the-air (OTA) environment based at least in part on the slope, chirp timing, and intensity. An in-phase quadrature phase (IQ) modulator modulates the FMCW laser signal using the modulation waveform and provides the modulated laser signal back through the optical lens system to the LiDAR UUT.

The invention discloses a tower grounding grid multi-frequency composite wave electric field imaging and soil environment medium diagnosis method, which comprises the following steps of: generating a composite excitation signal through superposition of a low-frequency sine wave and a high-frequency CHIRP square wave, and collecting multi-dimensional data such as voltage / current response, soil temperature and humidity, electric field intensity and the like in combination with a distributed sensor array; separating signal features by using wavelet transform and extracting impedance information of a target frequency point; a multi-grid homotopy algorithm is adopted to realize grounding grid three-dimensional resistivity distribution reconstruction, corrosion spots and abnormal areas are marked, and high-precision positioning of underground conductors is completed through UWB radar or a capacitance detector; meanwhile, based on the information entropy maximization optimization frequency band combination, the grounding grid state is comprehensively evaluated in combination with a multi-parameter fusion model. The method has the non-contact patrol capability, the unmanned aerial vehicle carries equipment to scan the grounding grid, the detection efficiency and convenience are remarkably improved, and an efficient and accurate solution is provided for guaranteeing safe operation of the power grid.

The invention provides a distributed feedback laser with a double-layer grating structure, and relates to the technical field of lasers, the laser forms an InGaAlAs multi-quantum well active region, an upper sampling grating layer and a lower phase shift grating layer on an n-type InP substrate in sequence, the upper grating layer is designed based on a reconstruction equivalent chirp technology, and the lower phase shift grating layer is designed based on a reconstruction equivalent chirp technology. Two sections of asymmetric modulation areas with sampling periods linearly gradually changing in opposite directions are arranged in the axial direction of the resonant cavity, and the lower grating layer is a quarter-wave phase shift grating matched with the period of the upper seed grating. Through the synergistic effect of equivalent phase modulation and phase shift generated by the double-layer grating, the photon density distribution in the cavity can be improved, the longitudinal space hole burning effect can be weakened, the sensitivity to end face phase fluctuation can be reduced, high single-mode power and large modulation bandwidth can be realized in a wide temperature range, and the double-layer grating is suitable for a high-speed optical communication and coarse wavelength division multiplexing transmission system.

The invention discloses a micro meteorological change real-time monitoring method based on a millimeter wave radar, and relates to the technical field of meteorological monitoring. The method comprises the following steps: carrying out dynamic acquisition on millimeter wave radar signals and carrying out coordinate system conversion; converting the converted information into a programmable chirp signal through a DDS (Direct Digital Synthesizer) chip; performing space-time adaptive filtering processing on the received signal to eliminate interference; abnormal phase points are detected, and a dynamic noise base model is established; inputting the preprocessed phase data into a pre-trained DPGN network, and outputting a weather result map; a lightweight engine is deployed at a radar end to process the weather result map; when it is detected that the weather gradient exceeds a threshold value, weather early warning is triggered. The adaptive chirp waveform modulation is adopted, the frequency slope and the pulse width of the radar transmitting signal are dynamically adjusted according to the real-time environmental noise level, the meteorological monitoring sensitivity and the small change detection efficiency are improved, and the environmental noise interference is optimized.

The invention belongs to the technical field of metal crack detection, and discloses a metal microcrack ultrasonic detection method, which comprises the following modules: an ultrahigh frequency composite array probe with a center frequency dynamic adjustable range of 5-50 MHz; the dual-mode excitation and receiving module is used for independently generating a pulse reflection mode excitation signal and a diffraction mode chirp frequency modulation signal; the phase-controlled synthetic aperture dynamic focusing module is used for realizing + / -60-degree deflection and sub-wavelength level focusing of acoustic beams; the nonlinear harmonic enhancement module is used for exciting a crack nonlinear effect by superposing 1-2MHz fundamental waves; and a time-space-frequency three-domain data fusion module. According to the method, signal-to-noise ratio collapse caused by the diffraction effect in a traditional method is overcome, more importantly, the system has low-frequency penetrability and high-frequency resolution at the same time due to 80%-120% of broadband coverage of chirp frequency modulation signals, the diffraction signal gain is increased by 20 dB or above, a near-surface blind area is compressed to be within 0.2 mm, and the system can be applied to the field of radar imaging. And the core pain point of missing detection of the near-surface microcracks of the thin-wall component is solved.

The invention relates to the technical field of laser micromachining, in particular to a TGV drilling machining system and method based on a space-time modulation Bessel beam, an initial laser beam is output through a laser device, the initial laser beam is modulated into a dynamic pulse sequence through a pulse chirp regulation and control module, axial energy attenuation is compensated, a machining subsystem generates the Bessel beam, and the TGV drilling machining system and method based on the space-time modulation Bessel beam are obtained. The angle is finely adjusted in real time through piezoelectric driving, and a dynamic spatial light modulator loads an exponential decay type phase mask, so that light beam airspace shaping, non-diffraction light beam generation, pulse time sequence and phase parameter synchronous control and high-peak power pulse array are realized, and finally, integrated micro-perforation and channel modification of the glass substrate are realized; and the machining efficiency and precision are obviously improved.

A system may include a digital front end (DFE). The DFE may be configured to generate a command signal. The system may also include a sweeper. The sweeper may be configured to generate an intermediate in-phase signal, an intermediate quadrature signal, and a LO signal based on the command signal. In addition, the system may include a mixer. The mixer may be configured to generate a mixed in-phase signal based on the intermediate in-phase signal and the LO signal. The mixer may also be configured to generate a mixed quadrature signal based on the intermediate quadrature signal and the LO signal. Further, the system may include an amplifier. The amplifier may be configured to generate an in-phase signal based on the mixed in-phase signal and an amplification setting. The amplifier may also be configured to generate a quadrature signal based on the mixed quadrature signal and the amplification setting.

The invention relates to the technical field of power systems, and discloses a cable defect positioning method, system and device, a medium and a product, and the method comprises the steps: taking a Gaussian envelope linear chirp signal as an initial incident signal for frequency domain reflection, optimizing the signal characteristic parameter of the initial incident signal, obtaining an incident signal, and carrying out the positioning of a cable defect. The method comprises the following steps: exciting a target cable through an incident signal, obtaining a reflection signal on a preset measuring point of the target cable, respectively carrying out time-frequency conversion on the incident signal and the reflection signal to obtain an incident time-frequency domain signal and a reflection time-frequency domain signal, and obtaining a time-frequency domain signal and a reflection time-frequency domain signal on the basis of a cross-correlation function. The peak position of a cross-correlation function is determined through the incident time-frequency domain signal and the reflected time-frequency domain signal, the signal propagation defect time delay of the target cable is determined according to the peak position of the cross-correlation function, and the defect position of the target cable is determined according to the signal propagation defect time delay and the propagation speed of the incident signal. Therefore, surrounding signal interference can be filtered out, and the accuracy of cable defect positioning is improved.

The invention discloses a porcelain insulator nondestructive testing device and method based on chirp modulation photoacoustic spectroscopy. The device comprises a signal generator, a signal processing module and a signal processing module, the laser is connected with the signal generator; the power amplifier is connected with the laser; the laser collimator is connected with the power amplifier; and the signal collector collects the sound wave signals, converts the sound wave signals into electric signals, transmits the electric signals to the computer through a cable for data processing, obtains a spectrogram of the sound wave signals, and judges whether defects exist in the porcelain insulator or not according to the spectrogram. According to the porcelain insulator nondestructive testing device adopting chirp modulation and photoacoustic spectroscopy, characteristic frequency scanning is achieved through chirp modulation, a porcelain insulator acoustic signal spectrogram is obtained through the solid photoacoustic effect, non-power-cut nondestructive testing of porcelain insulators can be achieved, and the detection efficiency of porcelain insulator defects is greatly improved.

The invention belongs to the technical field of communication, and particularly relates to a high-robustness multi-channel frequency shift Chirp modulation signal generation method and system for a time-frequency doubly selective channel. The method comprises the following steps of: 1, calculating robust code digits based on statistical characteristics of time delay and Doppler frequency shift of an ionized layer channel; 2, based on the number of robust code bits in the step 1, setting an address code, and realizing RO-MFSCM signal mapping of binary information bits; 3, modulating and transmitting the RO-MFSCM signal based on the information mapping in the step 2, thereby realizing the transmitting process of the RO-MFSCM signal; step 4, based on the emission signal in the step 3 and the robust code digit in the step 1, the receiver carries out robust domain energy aggregation on the RO-MFSCM signal; and step 5, based on the multi-channel robust domain energy aggregation signal in the step 4, adopting a multi-channel parallel demodulation algorithm and de-mapping to realize the receiving process of the RO-MFSCM signal under the time-frequency doubly selective channel. The method aims at the transmission fading problem of the FSCM signal in the ionosphere time-frequency doubly selective channel.

The invention provides a chirp modulation-based downlink wake-up receiver implementation method and system, and the method comprises the steps: S1, transmitting a preset wake-up frame to achieve the synchronization with terminal equipment before a transmitter of a wake-up receiver transmits a data frame, the wake-up frame comprises a pure carrier of a preset frequency, a lead code, and a terminal device address sequence and a data sequence based on Manchester encoding; s2, the transmitter generates a baseband signal conforming to a radio frequency front-end mode of the receiver through the wake-up frame, and the baseband signal is subjected to up-conversion and then transmitted in a 433MHz frequency band; and S3, the terminal equipment monitors a channel at any time, demodulates the wake-up frame through envelope detection and intermediate frequency amplification, demodulates a data frame, and finally synchronously sends a wake-up signal and data obtained through demodulation to a post-stage circuit. According to the invention, by designing the wake-up sequence and manufacturing the wake-up circuit, asynchronous wake-up with ultra-low power consumption is realized for the Internet of Things terminal equipment.

The invention provides an ultrasonic three-dimensional imaging method and system based on an FPGA, and relates to the technical field of ultrasonic imaging, and the method comprises the steps: transmitting a chirp signal, receiving an echo signal reflected by a target object, and carrying out the preprocessing; carrying out adaptive filtering, constant false alarm rate detection, adaptive beam forming and three-dimensional positioning algorithm processing on the preprocessed signal to generate target position data; and performing three-dimensional point cloud image reconstruction on the target position data by using a density-based spatial clustering algorithm and a deep learning model, and outputting a target three-dimensional image. Through the innovation of a signal processing algorithm and the collaborative design of the system, the technical bottlenecks of a traditional ultrasonic sensor in detection distance, anti-interference, real-time performance and positioning precision are solved, and the three-dimensional sensing capability with high reliability and strong environmental adaptability is provided for intelligent driving.

Mastering systems and methods of fabricating waveguides and waveguide devices using such mastering systems are described. Mastering systems for fabricating holographic waveguides can include using a master to control the application of energy (e.g. a laser, light, or magnetic beam) onto a liquid crystal substrate to fabricate a holographic waveguide into the liquid crystal substrate. Mastering systems for fabricating holographic waveguides in accordance with embodiments of the invention can include a variety of features. These features include, but are not limited to: chirp for single input beam copy (near i.e. hybrid contact copy), dual chirped gratings (for input and output), zero order grating for transmittance control, alignment reference gratings, 3:1 construction, position adjustment tooling to enable rapid alignment, optimization of lens and window thickness for multiple RKVs simultaneously, and avoidance of other orders and crossover of the diffraction beam.

The invention discloses an underwater acoustic adaptive transmission method based on channel prediction, and belongs to the technical field of communication. The method comprises the following steps of: 1, designing a transmitting link of an underwater acoustic self-adaptive transmission system based on channel prediction; and 2, designing a receiving link of the underwater acoustic adaptive transmission system based on channel prediction. According to the method, chirp parameters are dynamically selected on a sending link based on a predicted channel state, then adaptive transmission is carried out on an imitated radio frequency division multiplexing signal, channel state information is estimated through embedded pilot frequency at a receiving end, channel characteristics are fully learned through a channel prediction model of Transform, and the channel state information is subjected to channel prediction. And the obtained accurate future channel state information is used for balancing and self-adaptive parameter adjustment, and the flexibility and the transmission reliability of underwater acoustic communication are improved by the method provided by the invention. The method is very suitable for a half-duplex-based underwater acoustic adaptive transmission system, and the excellent performance of the method is fully embodied.

The invention relates to the technical field of signal processing of intelligent voice equipment, and discloses an equalization method and system for a Chirp modulation signal of audio equipment, and the equalization method for the Chirp modulation signal of the audio equipment comprises the steps: analyzing the non-stationary characteristic of the Chirp modulation signal through an information geometric mapping algorithm, and generating non-stationary complexity mapping; processing the Chirp modulation signal by using a multi-scale entropy analysis algorithm to generate a multi-scale complexity spectrum; extracting long-range correlation characteristics of the Chirp modulation signals by adopting a fractal analysis algorithm, and outputting Hurst index characteristic mapping; constructing a complexity-perceived adaptive equalization system; a time-frequency joint optimization algorithm is constructed, and global optimization and adaptive adjustment of equalization parameters are realized; signal complexity characteristics are quantized by using a multi-scale entropy analysis algorithm, and the adaptability of the equalization system to signals with different complexities is enhanced.

The invention discloses an underwater acoustic signal communication and positioning integrated method. The existing method does not jointly consider the problem of channel resource occupation caused by integration of communication and positioning. According to the method, mutually orthogonal Chirp subcarriers are used as communication signals, meanwhile, long Chirp signals are used as pilot frequency, and the pilot frequency and the communication signals are overlapped together to be sent at a sender, so that extra channel overhead caused by additional pilot frequency is saved, and the signal sending time interval is shortened. A receiver uses a plurality of pilot signals to perform joint Doppler estimation and compensation and time of arrival estimation, and the result of the time of arrival estimation is used for a positioning system and a communication system on the one hand. According to the demodulation mode, correlation calculation is carried out by using different Chirp subcarriers, and symbol demodulation is carried out according to correlation values. According to the communication and positioning integrated waveform design method, the signal sending time interval can be shortened, the system complexity can be reduced, and good communication performance is achieved.

The invention discloses a cloud wireless access network millimeter wave signal optimization method based on machine learning, which adopts a double-ring OEO to replace a traditional radio frequency signal source, improves phase noise and improves signal stability. Meanwhile, the gain behavior of the millimeter wave signal is modeled by using a BiLSTM network, and high-precision power prediction is realized by combining the DML chirp effect and the influence of optical fiber dispersion. Besides, the BiLSTM model is optimized through the ACO algorithm, the optimization weight can be flexibly adjusted according to different communication scene requirements, and millimeter wave signals meeting the requirements are generated.

The invention discloses an ultra-wideband femtosecond optical parametric oscillator capable of being quickly tuned, and relates to the technical field of optical parametric oscillators. The oscillator comprises a frequency doubling device, an optical parametric oscillator resonant cavity device and a dispersion compensation chirp mirror pair module. According to the invention, the original phase matching bandwidth is further broken through by adopting a non-collinear phase matching mode that the transmission included angle between the pump light and the signal light is 2.5 degrees, and rapid wavelength tuning can be realized only by finely tuning the cavity length under the condition that the angle of the nonlinear crystal is not adjusted; the broadband tunable optical parametric oscillator can break through the bottlenecks in the aspects of wavelength tuning range, wavelength tuning speed and the like of the existing near-infrared optical parametric oscillator, and provides a novel light source with larger wavelength tuning range and higher tuning speed for the fields needing broadband tunable light sources, such as spectroscopy, micro-nano processing, optical frequency combs and the like.

The invention discloses an anti-multipath and anti-frequency offset satellite communication method based on chirp spread spectrum modulation joint architecture, and relates to the technical field of satellite or data chain communication, the method comprises the following steps: mapping input K bit information into a modulation symbol K, K belongs to {0, 1,..., N-1}; s02, a corresponding chirp baseband signal s [n] is generated according to the modulation symbol K, and the expression of the chirp baseband signal s [n] is as follows: n = 0, 1,..., N-1; and S03, carrying out digital-to-analog conversion on the chirp baseband signal. According to the invention, through integrated design of spread spectrum and modulation depth, and by use of the complete orthogonal autocorrelation characteristic of chirp signals and an FFT demodulation mechanism, the problems that a traditional architecture has significant bottlenecks in the aspects of resource efficiency, dynamic adaptability, anti-interference capability and the like and is difficult to meet high-performance communication requirements in a high-speed moving and complex multipath scene are effectively solved; the anti-multipath and anti-Doppler performance is significantly improved, and the calculation and resource overhead of the receiving end is greatly reduced.

A radar system employs a self-test to determine time synchronization of cascaded radar transceiver integrated circuits (ICs) in the radar system that are used in a motor vehicle. To effectively detect information in the environment, the radar system periodically executes the self-test operation by sending a trigger signal to at least one follower radar transceiver IC. Moreover, the leader radar transceiver IC generates a chirp signal at a set frequency and transmits this. In response to receiving the trigger signal, the at least one follower radar transceiver IC receives the chirp signal transmitted from leader and generates its own local chirp signal with the set frequency, but also includes a frequency offset. The local chirp signal is then used to down-convert the received signal into an intermediate frequency (IF) signal. The IF signal is filtered, analog-to-digital converted, and processed to determine a beat frequency. The beat frequency is compared to the frequency offset to determine the level of synchronization between the leader radar transceiver IC and the at least one follower radar transceiver IC.

The invention provides a low earth orbit satellite communication initial time frequency offset estimation method, and belongs to the technical field of satellite communication. When satellite communication initial time-frequency offset estimation is carried out, initial time-frequency offset coarse estimation is firstly completed based on a first auxiliary synchronization signal, time-frequency offset coarse compensation is carried out on a received signal by using an estimation result, then initial time-frequency offset fine estimation is further completed based on a second synchronization signal, and the compensated signal is sent to a demodulation module for demodulation. The two-step time-frequency offset estimation method provided by the invention combines the advantages of the symmetric Chirp reference signal and the pseudo code sequence for time-frequency offset estimation, can realize rapid and accurate time-frequency offset estimation in a large-frequency offset scene, and improves the performance of a low-orbit satellite communication system.

The invention relates to the field of optical fiber sensing detection, and discloses a forward transmission distributed optical fiber sensing detection method and system based on chirp modulation, a terminal and a storage medium, and the method comprises the steps: obtaining a sensing detection task of a sensing optical fiber, obtaining a single-frequency continuous optical signal and a radio frequency signal according to the sensing detection task, performing chirp modulation on the single-frequency continuous optical signal according to the radio frequency signal to obtain a plurality of modulated optical signals; superposing all the modulated light signals to obtain a sweep-frequency light field, and dividing the sweep-frequency light field to obtain a sensing light field and a reference light field; performing interference processing on a target sensing light field output by the sensing optical fiber and the reference light field to obtain beat frequency interference light intensity, and performing filtering to obtain a target beat frequency interference signal; and performing demodulation processing on the target beat frequency interference signal to obtain a light field phase change, and performing vibration positioning on the sensing optical fiber to obtain an optical fiber vibration position so as to obtain a sensing detection result. According to the invention, not only is the detection cost reduced, but also the vibration on the sensing optical fiber can be accurately positioned.

The invention relates to the technical field of photoelectronics, and discloses a chirp parameter measuring device and method based on a directly modulated laser optical module, and the device comprises an arbitrary waveform generator, an optical module, a tunable dispersion compensation module, and an oscilloscope. The optical module comprises a directly modulated laser; the output of the arbitrary waveform generator is electrically connected with the radio frequency input port of the directly modulated laser; the output optical signal end of the directly modulated laser is connected with the input optical end of the adjustable dispersion compensation module; the adjustable dispersion compensation module is used for controlling dynamic switching between a zero dispersion state and a preset non-zero dispersion state by introducing dispersion into a link, and an output optical signal port of the adjustable dispersion compensation module is optically connected with a receiving port of the optical module; and the radio frequency output end of the optical module is electrically connected with the oscilloscope. According to the invention, the problems of long chirp parameter test time and high measurement cost in the prior art are solved, and the chirp parameter measurement method has the characteristic of being capable of realizing rapid and accurate chirp parameter measurement.

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.

The invention discloses a double-index modulation simulated radio frequency division multiplexing (AFDM) communication method. The method comprises the following steps: step 1, a transmitting end performs serial-parallel change; step 2, obtaining a transmission signal according to the index position of the joint selection AFDM activation subcarrier in the mapping table, the modulation bit mapping and the pre-chirp parameter of the activation subcarrier; step 3, obtaining a time domain signal; 4, performing parallel-serial conversion on the time domain signal; step 5, performing propagation transmission through a time-varying channel based on the time domain signal; step 6, constructing a time domain channel matrix, and performing serial-to-parallel conversion on the time domain receiving signal to obtain a receiving signal; step 7, performing channel estimation on the chirp parameter equivalent channel matrix; step 8, detecting an activated subcarrier position, an activated subcarrier modulation bit and an activated subcarrier pre-chirp parameter based on the chirp parameter equivalent channel matrix, and performing pre-chirp parameter transformation; and step 9, recovering the bit stream through parallel-serial change. The spectrum efficiency of the AFDM system is further improved, and the bit error rate is reduced.

A radar system injects a calibrated current at a signal generator during a reset portion and acquisition portion of each chirp period. The signal generator employs “gear-switching” to reduce PLL bandwidth during an acquisition phase and to increase the phase lock loop (PLL) bandwidth during a reset phase. By employing gear switching to change the bandwidth of the PLL circuit during the different portions of each chirp period, the length of the reset period is reduced, thus improving overall efficiency of the radar system while maintaining good performance.

The invention discloses an unmanned aerial vehicle target active detection method and system based on a millimeter wave radar, and relates to the technical field of unmanned aerial vehicle detection, and the method comprises the steps: carrying out the frequency mixing of an obtained emission frequency modulation continuous wave signal and an echo signal, and obtaining an intermediate frequency signal; performing fast Fourier transform on the intermediate frequency signal to obtain distance information of the target unmanned aerial vehicle; acquiring a plurality of Chirp signals based on the echo signals; based on the phase difference among the plurality of Chirp signals, calculating to obtain the speed information of the target unmanned aerial vehicle; performing angle estimation on the echo signal to obtain angle information of the target unmanned aerial vehicle; integrating the distance information, the speed information and the angle information of the target unmanned aerial vehicle to obtain motion parameters of the target unmanned aerial vehicle; and transmitting the motion parameters of the target unmanned aerial vehicle to a flight control system or other data receiving equipment of the unmanned aerial vehicle. The detection capability and the tracking effect of the unmanned aerial vehicle target can be improved, and the operation safety of the unmanned aerial vehicle is effectively guaranteed.

Some aspects of the present disclosure provide methods and devices that enable a framework for selection or configuration, or both, of a waveform for use in integrated sensing and communications (ISAC). Use of the framework provides a new waveform, based in part on various criteria, which provides a trade-off among different ISAC requirements. Therefore, when different criteria are important for a particular implementation, a waveform that best meets the requirement of those criteria may be used. The various criteria may include factors such as hardware constraints at the UE, radio frequency (RF) chirp generation or detections capability at the UE, spectral emission or leakage such as OOBE, sensing performance, and sensing complexity. In some embodiments, a cyclic prefix (CP) is provided to use the chirp-based sensing waveforms as a demodulated reference signal (DMRS). In some embodiments, the CP enables alignment with a communication signal frame.

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.