48 results about "Digital demodulation" patented technology

The invention discloses a detection method of an ocean magnetic field sensor based on a diamond NV color center. The detection method comprises the following steps: S1, calibrating a base line; s2, alternately measuring fluorescence between two single quantum resonance frequencies, and obtaining a difference to realize DQ reading; s3, three-axis compensation current is adjusted based on closed-loop control, and the NV working point is maintained at zero magnetization bias; s4, obtaining background magnetic field change through digital demodulation and adaptive filtering; and S5, calculating a gradient based on the spatial difference of the multi-point light spots, judging the existence and trajectory of the underwater vehicle in combination with a threshold value and a spectrum matching method, calibrating the threshold value according to the magnetic field characteristics of the existing underwater vehicle, adopting short-time Fourier transform signal spectrum, comparing the threshold value with known submarine characteristic spectrum data, and prompting if the similarity exceeds a set threshold value. According to the detection method, the measurement precision and the anti-interference capability can be improved, and the method is suitable for real-time monitoring of weak magnetic anomalies (such as magnetic moment disturbance of an underwater vehicle).

The invention relates to the technical field of digital demodulation, in particular to a digital demodulation method suitable for deep ultraviolet light communication, which comprises the following steps of: adopting multiple delay processing with half code element width, and respectively carrying out double extraction processing on a discrete sampling signal which is not subjected to delay processing and a plurality of delay sampling signals to obtain a plurality of delay extraction signals; in this way, the key sampling time in the coverage code element period can be ensured, and a basis is provided for subsequent accurate synchronization; a plurality of delay extraction signals are respectively input into corresponding equalization processing units, a preset local training sequence is loaded to each equalization processing unit to obtain a plurality of equalization filtering signals, and the plurality of equalization filtering signals and the preset local training sequence are respectively subjected to related judgment processing, so that the inter-symbol interference is inhibited, and meanwhile, the equalization processing efficiency is improved. The synchronization signal can be quickly screened out, so that the problem that inter-symbol interference and synchronization are difficult to consider in a traditional demodulation method is solved, and the demodulation efficiency and reliability are remarkably improved.

This application relates to the field of electrical technologies, and provides a full even harmonic digital demodulation method based on full-phase analysis for a magnetic modulator. According to the full even harmonic digital demodulation method based on full-phase analysis for a magnetic modulator, standard voltage timing data output by the magnetic modulator is obtained when a DC calibration current with a set amplitude is fed into the magnetic modulator during calibration of the magnetic modulator; an output voltage sequence from full-phase Fourier analysis is established based on the standard voltage sequence data, and the output voltage sequence is preprocessed; comprehensive analysis is performed on the preprocessed output voltage sequence from full-phase Fourier analysis to obtain all standard even harmonic signals and current conversion coefficients.

The invention discloses an active pen and touch screen interaction system resistant to common-mode interference and a signal demodulation method. The system comprises a signal receiving terminal and a signal transmitting terminal. The signal transmitting terminal modulates data to be transmitted by adopting a differential binary phase shift keying modulation method, and transmits a generated modulation signal to the signal receiving terminal; the analog front-end receiving module is coupled with the signal transmitting terminal, receives the modulation signal and outputs a digital square wave signal after fidelity extraction processing; and the digital demodulation processing module performs differential coherent digital demodulation on the digital square wave signal based on the prior characteristics of the modulation signal, inhibits residual noise and recovers data to be sent. The analog front end focuses strong common-mode noise suppression and analog filtering, the digital demodulation algorithm performs secondary digital purification by using signal time sequence characteristics, and the two constructs an efficient anti-interference pipeline. Meanwhile, the regular square wave signals can be directly processed through differential coherent demodulation, and the requirements for performance and power consumption of a rear-end processor are lowered.

The present application provides a Y waveguide waveform slope measurement and compensation method to solve the problem that the existing high-precision fiber-optic gyroscope Y waveguide waveform slope measurement method is based on the characteristics of the Y waveguide itself, ignoring the error of the fiber-optic gyroscope closed loop modulation wave when resetting caused by the Y waveguide waveform slope after the Y waveguide is connected with the optical path of the fiber-optic gyroscope. The present application uses the existing optical path and circuit for testing the performance of the fiber-optic gyroscope, uploads the Y waveguide waveform slope test results to the upper computer through the circuit, and when a ±23 / 8π square wave is used as a digital demodulation circuit to apply a waveform slope trigger signal, the pressure difference of the fiber-optic gyroscope demodulation signal before and after resetting is the largest. The upper computer calculates the Y waveform slope error, compensates for the error of the fiber-optic gyroscope closed loop modulation wave when resetting, improves the gyroscope precision of the fiber-optic gyroscope at a small rate of rotation, and improves the application range of the fiber-optic gyroscope.

The invention relates to a digital demodulation method for a mining wireless electromagnetic wave scenograph, belongs to the technical field of mining electromagnetic wave detection, and aims at solving the problems that an existing scenograph depends on an analog filtering and rectifying circuit, so that the circuit is complex, and the reliability is poor. According to the method, after a receiver receives and amplifies an electromagnetic wave signal, the electromagnetic wave signal is sampled by an analog-to-digital conversion module, a field programmable logic gate array performs fast Fourier transform on a digital signal, and an amplitude corresponding to a transmitting frequency is extracted as an effective signal, so that digital demodulation is realized. Filtering and rectifying circuits do not need to be simulated, the circuit structure can be remarkably simplified, the reliability and the real-time performance of an instrument are improved, and the stable detection requirement in the mine environment is met.

A chirp multi-carrier transmission method based on windowing and truncation belongs to the field of wireless communication technology. The purpose of the present invention is to achieve efficient spectrum utilization while improving the bit error rate performance. The present invention first performs digital modulation and serial-to-parallel conversion on a random bit stream sequence, then performs a discrete Fresnel inverse transform on the conversion result, and after the discrete Fresnel inverse transform result passes through a time domain truncation window, the intercepted signal is converted into parallel and serial, and the parallel-to-serial conversion result is then sent through a channel. The receiving end performs serial-to-parallel conversion, zero padding, discrete Fresnel transformation, and inter-subcarrier interference elimination on the received signal, and then digitally demodulates the signal after interference elimination to restore the original bit stream data. The present invention saves transmission time and improves transmission efficiency by performing windowing and truncation in the time domain, and the bit error rate performance is better than that of existing systems. The method of the present invention can be applied to the field of wireless communication technology.

The application discloses a kind of based on bimodal resonance's photoacoustic-scattering aerosol dual-wavelength synchronous detection system and method, belong to photoelectric detection technical field, in the system, dual-wavelength light source modulation module generates two different frequency modulated laser, respectively from two ends into double-difference bulb pipe coupling photoacoustic-scattering combined gas cell;The gas cell includes the two ends of two acoustical tubes arranged in parallel and each is connected with an integrating sphere, form H type coupling structure;Scattering signal collection module, photoacoustic signal acquisition and processing module respectively acquire two-channel scattering photon counting data in two integrating spheres, sound wave signal in two acoustical tubes and two integrating spheres;Digital lock-in signal processing module based on FPGA outputs modulation signal to light source, and receives sound wave signal in two acoustical tubes and two integrating spheres to carry out full-digital demodulation and processing.The application effectively solves the problem of time-space asynchronization and sampling cumulative error caused by time-sharing multiplexing or multiple machine parallel connection.

The application discloses a laser phase noise measurement method based on delay self-heterodyne and digital demodulation, and relates to the technical field of laser measurement, and comprises the following contents: after being adjusted by a variable optical attenuator, to-be-measured laser is divided into a frequency shift arm and a delay arm, the frequency shift arm is frequency-shifted by an acousto-optic modulator, the delay arm is delayed by a delay optical fiber, and original electric beat frequency signals are obtained by a balanced photoelectric detector after the two arms are coupled; homologous and synchronous quadrature demodulation is carried out on the original electric beat frequency signals, envelope credibility judgment and abnormal sample repair are combined, and a continuous differential phase sequence is obtained; actual optical time delay is determined according to the beat frequency spectrum characteristics and the continuous differential phase sequence, and a differential phase power spectral density is formed; then, transmission relationship conversion is carried out according to the actual optical time delay, bounded spectrum compensation is implemented on a zero point neighborhood and a low credibility frequency point, and an intrinsic phase noise power spectral density is obtained. The application can improve the stability, continuity and result credibility of phase noise measurement under the condition of short delay.

The application discloses a pulse high-voltage divider calibration device and method, wherein the device comprises a pulse high-voltage source, a high-voltage voltage dividing network, a high-voltage multi-node acquisition module, a high-voltage optical fiber transmission module, a high-voltage signal demodulation module, a multi-channel acquisition module and a calibration controller. The high-voltage voltage dividing network is composed of RC parallel circuits in series and is used for dividing high-voltage signals. The high-voltage multi-node acquisition module is used for measuring pulse voltage signals after voltage division. The high-voltage optical fiber transmission module comprises a fiber transmitter and a high-voltage weather-resistant single-mode optical fiber and is used for transmitting pulse voltage signals in the form of optical signals. The high-voltage signal demodulation module comprises a fiber receiver and a digital demodulator and is used for receiving and demodulating optical signals. The multi-channel acquisition module comprises a synchronous clock source, an acquisition unit and a cache unit and is used for acquiring and storing pulse voltage signals. The calibration controller is used for calculating pulse voltage signals. The application solves the problems of a complex calibration system, weak anti-electromagnetic interference and a complicated calibration process.

This application belongs to the field of lock-in amplifier technology, specifically disclosing a large dynamic range digital lock-in amplifier, comprising: a signal generator for generating sine and cosine reference signals; a DAC for performing digital-to-analog conversion on the generated reference signal and providing the converted analog quantity to the device under test (DUT); an ADC for performing analog-to-digital conversion on the signal output by the DUT and providing the converted digital amplitude to a gain controller and a digital demodulator; a gain controller for comparing the difference between the desired voltage amplitude and the digital amplitude provided by the ADC, and adjusting the amplitude of the reference signal according to a negative feedback method; and a digital demodulator for approximating the amplitude-frequency and phase-frequency characteristics of the DUT based on the reference signal and the digital amplitude provided by the ADC through a fitting method, and outputting an estimated vector. This application adjusts the amplitude of the reference signal according to a negative feedback method to avoid the signal link entering the nonlinear region, thus achieving a large dynamic range.

The invention provides a digital demodulation type quartz MEMS tuning fork trimming device, and belongs to the field of MEMS tuning fork trimming. The device comprises an upper computer and a quartz MEMS tuning fork which are respectively connected with a first controller and a second controller. The upper computer is used for sending a first driving command to the first controller and sending a second driving command and a third driving command to the second controller; the second controller is used for controlling the quartz MEMS tuning fork to work in a gyro function mode according to the second driving command and the first parameter when a driving end mass block of the quartz MEMS tuning fork is roughly repaired; and the fine trimming module is used for performing linear frequency sweeping on the quartz MEMS tuning fork according to the third driving command during fine trimming to obtain a target mechanical orthogonal item, and determining that fine trimming of the driving end mass block is completed when the target mechanical orthogonal item reaches the standard. The trimming efficiency and precision can be considered through double-stage trimming and automatic control, and meanwhile the trimming cost is reduced.

The present invention provides a receiving device and a receiving method that can obtain an appropriate RSSI value corresponding to the signal quality of the actual received signal received by the antenna. [Solution] The receiving device and receiving method include an RSSI detection unit 13 in the receiving high-frequency unit 10 that detects a detected RSSI value from the input received signal, a signal quality level calculation unit 23 in the receiving control unit 20 that calculates the signal quality level from the received signal digitally demodulated by the digital demodulation unit 21, a virtual RSSI conversion unit 24 that converts it into a virtual RSSI value corresponding to the signal quality of the actual received signal received by the antenna, and an RSSI output display unit 25 that displays the virtual RSSI value and the detected RSSI value.

The invention relates to an intelligent microbial electrode impedance analysis device, which belongs to the technical field of electrochemical impedance spectroscopy analysis, and comprises a three-electrode system used for collecting microbial impedance signals; the response signal acquisition and conditioning module is used for preprocessing the acquired microbial impedance signal; the self-adaptive digital phase-locked amplification module adopts a synchronous orthogonal digital demodulation technology and utilizes known excitation signal digital phase information to generate an orthogonal reference signal, extract amplitude and phase information of an impedance response signal, perform self-adaptive noise suppression and decouple core parameters; the reinforcement learning optimization unit is used for evaluating a current measurement state and selecting a next frequency step length; the self-adaptive excitation module is used for generating a sine excitation voltage signal and outputting the sine excitation voltage signal to the three-electrode system; and the data display module is used for displaying the impedance spectrum and the Rct curve.

The invention relates to a PID parameter adaptive adjustment method and system, electronic equipment and a readable medium, and the method comprises the steps: outputting an analog voltage signal corresponding to an expected gradient waveform to a gradient amplifier through a gradient output module, so as to form an actual current corresponding to the analog voltage signal through the gradient amplifier; a voltage feedback signal which is output by the gradient amplifier and corresponds to the actual current is transmitted to the spectrometer radio frequency module; performing amplitude modulation and frequency mixing on the voltage feedback signal through a spectrometer radio frequency module to obtain a frequency mixing signal; digital sampling and digital demodulation are carried out on the frequency mixing signal through an optical fiber box, and an actually measured gradient waveform is obtained; and calculating a time domain error between the expected gradient waveform and the actually measured gradient waveform, and under the condition that the time domain error is greater than a target error, adaptively adjusting the PID parameter according to the error type of the actually measured gradient waveform until the time domain error is less than the target error. The problem that the PID parameters of the gradient amplifier are difficult to adaptively calibrate accurately is solved.

This invention discloses a low-power analog front-end circuit and control method for animal tags. The circuit includes: a radio frequency (RF) unit, a power management unit, and an antenna. The power management unit includes a rectifier and a low-power power management circuit. The rectifier is connected to the antenna. The low-power power management circuit supplies power to the RF unit and digital circuits. The RF unit includes a load modulation and limiting circuit, a demodulation circuit, and a clock generation circuit. The demodulation circuit receives the demodulated envelope signal sent by the rectifier and outputs digital demodulated data to the digital circuits. The clock generation circuit extracts a clock signal from the antenna signal generated by the antenna and outputs the clock signal to the digital circuits. The load modulation and limiting circuit receives the limiting reference voltage sent by the rectifier and the uplink data output by the digital circuits. In this embodiment, an animal identification tag adapted for wireless communication achieves a balance between low power consumption and small area while ensuring communication reliability.

The present invention relates to an MF-TDMA frequency hopping anti-interference system based on secondary interference judgment. The method includes an AD sampling unit, a digital branch filtering unit, a power estimation and secondary interference judgment unit, and a digital demodulation unit. Combining the characteristics of the MF-TDMA system, the method performs power estimation after AD sampling and power estimation after digital branch filtering on multi-carrier signals. The method utilizes the two power estimates combined with secondary interference judgment to accurately detect and identify interference. Furthermore, based on a joint discrimination flag, the method determines whether the signal participates in timing error calculation and data interpolation. Furthermore, the method scales the useful signal through digital forward automatic gain control (AGC). This method can effectively counteract the effects of narrowband interference on a multi-mode, multi-carrier frequency hopping anti-interference communication system.

The invention relates to the technical field of microwave and millimeter wave imaging, in particular to a microwave and millimeter wave sparse array wavenumber domain algorithm combined compressed sensing imaging method and system. According to the technical scheme, the method comprises the following steps: obtaining a backscattering echo signal from a target, and carrying out digital down-conversion processing to obtain a digital IQ demodulation signal; according to the method, the wavenumber domain algorithm and the compressed sensing technology are combined in a cross-dimension mode, efficient focusing and data decoupling are achieved through the wavenumber domain algorithm in the motion scanning dimension, high-quality reconstruction is conducted through the compressed sensing algorithm in the array-distance dimension, and therefore image sidelobes are remarkably restrained, the imaging quality is improved, and meanwhile the image quality is improved. The dimension and calculation complexity of the sensing matrix are greatly reduced, the algorithm efficiency and practicability are improved, and the method can flexibly adapt to various sparse array configurations such as straight lines, broken lines and arc lines.

This invention provides a coherent acquisition platform with a full-dimensional mismatch self-correction time-interleaved ADC system, belonging to the field of mismatch self-correction technology. The architecture includes an analog front-end conditioning module, a time-interleaved ADC sampling array, a clock synchronization distribution module, a full-dimensional mismatch self-correction module, and a high-speed data transmission module. The ADC sampling array employs an interleaved structure with multiple main channels and multiple sub-ADCs per channel, achieving ultra-high-speed synchronous acquisition of multiple coherent signals. The full-dimensional mismatch self-correction module pioneers a dual-mode detection mechanism of "calibration sequence injection + blind estimation," which can detect and correct four types of mismatches—gain, delay, bias, and bandwidth—between sub-ADCs in real time, balancing initial calibration accuracy with dynamic environmental adaptability. This invention has advantages such as high sampling rate, good synchronization, excellent mismatch suppression effect, and strong signal integrity, and can be directly used in coherent acquisition equipment with speeds of 100G and above, providing high-quality signals for subsequent digital demodulation.

This invention relates to the field of digital signal communication technology and discloses a DBPSK digital demodulation method based on the principle of baseband signal envelope phase tracking, comprising the following steps: S1: capturing the DBPSK modulated signal; S2: performing digital down-conversion processing on the DBPSK modulated signal to obtain the I-channel baseband signal envelope and the Q-channel baseband signal envelope; S3: comparing the amplitudes of the I-channel and Q-channel baseband signal envelopes and selecting the baseband signal envelope with the larger amplitude as the demodulation basis; S4: based on the correlation between the demodulation basis and the original information symbols, outputting a binary symbol sequence that maintains a fixed correspondence with the original information symbols. This invention can perform digital demodulation and obtain a binary symbol sequence after capturing a valid DBPSK modulated signal, can adapt to most Doppler frequency shift ranges in engineering applications, occupies and consumes few resources, and has good portability.

To provide a method for digital demodulation of all even harmonics of a magnetic modulator based on full phase analysis.SOLUTION: According to the digital demodulation method for all even-order harmonics of a magnetic modulator based on full-phase analysis, when the magnetic modulator is calibrated, standard voltage time sequence data output by the magnetic modulator when a direct current calibration current of a set value flows through the magnetic modulator is obtained, an output voltage sequence of full-phase Fourier analysis is established and pre-processed according to the standard voltage time sequence data, and the pre-processed output voltage sequence of full-phase Fourier analysis is comprehensively analyzed to obtain standard even-order harmonic signals and current conversion coefficients of each order. The present invention uses the full-phase Fourier analysis technology to perform comprehensive pre-processing and comprehensive analysis on the output voltage signal of the air modulator, which greatly reduces the problems of spectrum leakage and phase disturbance, so that the data sampled at different time points are fully utilized, and the signal processing is more accurate.SELECTED DRAWING: Figure 1

An analog-to-digital converter (ADC) circuit (200) is provided, designed to process an input signal. The ADC circuit (200) includes a modulation circuit (210) designed to modulate the input signal with a modulation frequency to generate a modulated signal. The ADC circuit (200) includes a combination circuit (206) designed to receive the modulated signal and combine it with a feedback signal (208) to generate a combined signal. The ADC circuit (200) includes a conversion circuit (220) designed to convert the combined signal into a digital signal at a sampling frequency. The ADC circuit (200) includes a tracking register (230) designed to store and update the digital signal.The ADC circuit (200) includes a prediction circuit (240) designed to estimate a future value of the digital signal based on historical data from the digital signal and to load the estimated value into the tracking register (230) at a modulation transition time. The ADC circuit (200) includes a feedback circuit (250) designed to convert a digital output signal from the tracking register into the feedback signal provided to the combination circuit. The ADC circuit (200) includes a demodulation circuit (260) designed to demodulate the digital signal at the modulation frequency to produce a digital demodulated output signal.

Embodiments of the invention relate to a single pin impedance measurement system and phase offset compensation for a single pin impedance measurement system. An impedance measurement system comprising: a signal generator comprising a memory and arranged to generate a digital test signal and at least one digital demodulation signal based on the memory, where the digital test signal has a first frequency and the at least one digital demodulation signal has a first frequency; a single pin for providing an analog test signal based on the digital test signal to a device under test (DUT) and measuring an analog input signal in response to providing the analog test signal to the DUT; and a demodulator configured to obtain a first filtered digital signal based on the input signal to generate at least one digital demodulated signal indicative of the impedance; and at least one digital demodulation signal.

To improve the stability and reliability of STL / TTL.SOLUTION: The reception device 30 includes a digital demodulation unit 31 that receives a modulation signal of encoded data via a wireless line and performs demodulation processing on the modulation signal to estimate first encoded data, an encoded data extraction unit 33 that receives a packet of the encoded data via a wired line and extracts second encoded data from the packet, an LLR combination control unit 35 that determines a synchronization reference indicating which of the first encoded data and the second encoded data is used as a reference to synchronize both of the first encoded data and the second encoded data and an LLR combination technique when combining LLRs of the first encoded data and the second encoded data, a synchronization unit 36 that synchronizes the first encoded data and the second encoded data according to the synchronization reference, and an LLR combination unit 39 that combines the LLRs of the first encoded data and the second encoded data according to the LLR combination technique.SELECTED DRAWING: Figure 1

Light emitted by an erbium light source assembly is split through a 30 / 70 single-mode optical fiber beam splitter, 30% of the light enters an X-axis optical path, 70% of the light enters a first 50 / 50 single-mode optical fiber beam splitter, and 35% of the light enters a Y-axis optical path and a Z-axis optical path respectively; the light entering the light path of each axis is split by the second 50 / 50 beam splitter and then enters the Y waveguide, the Y waveguide performs polarization processing on the light and then divides the light into two beams, the two beams of light return to the Y waveguide to generate interference after passing through the optical fiber ring, and an interference light signal enters the photoelectric detector through the second 50 / 50 beam splitter and enters the photoelectric detector through the second 50 / 50 beam splitter. The photoelectric detector converts the interference light signal into an electric signal and sends the electric signal to the gyroscope digital circuit; the gyroscope digital circuit is used for carrying out signal conditioning, AD sampling and digital demodulation on the electric signals output by the photoelectric detector; and the light source driving and signal integrated processing circuit is used for converting the output of the three-axis fiber-optic gyroscope circuit into three-axis angular velocity information and respectively carrying out temperature compensation on the three-axis angular velocity information.

An impedance measurement system is provided. [Solution] The impedance measurement system includes a signal generator with memory. The signal generator is configured to generate a digital test signal and at least one digital demodulated signal based on the memory. The digital test signal has a first frequency, and at least one digital demodulated signal has a first frequency. The impedance measurement system also includes a single pin. The single pin is configured to supply an analog test signal based on the digital test signal to the device under test (DUT) and to measure an analog input signal in response to supplying the analog test signal to the DUT. The impedance measurement system also includes a demodulator. The demodulator is configured to acquire a first filtered digital signal and at least one digital demodulated signal based on the input signal and generate at least one demodulated digital signal indicating impedance.

A method for digitally demodulating all even-order harmonics of a magnetic modulator based on full phase analysis is provided. [Solution] A digital demodulation method for all even-order harmonics of a magnetic modulator based on full-phase analysis involves calibrating a magnetic modulator by obtaining standard voltage time series data output by the magnetic modulator when a set DC calibration current is passed through the magnetic modulator, establishing and preprocessing an output voltage sequence through full-phase Fourier analysis based on the standard voltage time series data, and comprehensively analyzing the preprocessed output voltage sequence through full-phase Fourier analysis to obtain standard even-order harmonic signals and current conversion coefficients for each order. By using full-phase Fourier analysis technology, the present invention performs comprehensive preprocessing and comprehensive analysis of the output voltage signal of the magnetic modulator, significantly reducing the problems of spectral leakage and phase disturbance, making full use of data sampled at different times and making signal processing more accurate.

The invention belongs to the technical field of wireless communication, and relates to a digital demodulation method based on a GAMP algorithm. For a scene that the number of radio frequency links of a base station is less than that of users, the digital demodulation method comprises the following steps: the base station receives superposed signals input by multiple users; estimating a user input signal to obtain an initial solution of optimal estimation; determining a prior distribution of the user input signal; calculating conditional posteriori distribution of the user input signal and the noise-free user input signal modulated by the analog matrix, wherein the conditional posteriori distribution comprises expectation and variance; and obtaining a column of estimation results and corresponding variances based on a GAMP algorithm, wherein the estimation results are modulation data. The analog matrix adopted by the digital demodulation method demodulates the multi-user modulation signals under the condition that the number of radio frequency links of a base station is smaller than the number of users, and the modulation information of the multiple users is recovered by using fewer observation signals, namely, the users with the number larger than that of the radio frequency links can be served by using a limited number of radio frequency links.