782 results about "Phase deviation" patented technology

An image processing apparatus includes: an imaging information calculation unit acquiring a first image and higher-resolution second images, and calculating coordinate positions of the second images to the first image and differences in imaging direction between second cameras and a first camera; an eyepoint conversion unit generating eyepoint conversion images obtained by converting the second images based on the differences in imaging direction so that eyepoints of the second cameras coincide with an eyepoint of the first camera and matching the first image with the eyepoint conversion images to calculate phase deviations of the eyepoint conversion images from the first image; and an image synthesizing unit extracting high-frequency images, having frequency components higher than or equal to a predetermined frequency band, from the second images, and pasting the high-frequency images at the coordinate positions in correspondence with the first image to eliminate the phase deviations to generate a synthesized image.

A radar receiver receives reflection wave signals which are a radar transmission signal reflected by a target with plural respective antenna system processors, and estimates an incoming direction of the reflection wave signals. A correlation vector power calculator calculates a correlation vector power based on a correlation vector including outputs of the plural respective antenna system processors. A direction vector correlation calculator calculates a direction vector correlation power on the basis of the correlation vector and a direction vector including information of amplitude and phase deviations that occur between the plural respective antenna system processors for each azimuth angle range of an incoming direction of the reflection wave signals. A distance/azimuth angle detector estimates an azimuth angle of an incoming direction of the refection wave signals based on the correlation vector power and the direction vector correlation power.

The invention discloses a method for estimating a phase deviation in a precise single-point positioning technology, which comprises the steps of: firstly, carrying out parameter estimation on single-difference non-ionized layer combined ambiguity by using a position as a restraint condition according to data of a reference station in a tracking network; secondly, carrying out parameter estimationon single-difference wide-lane ambiguity by adopting an M-W combination, separating out a decimal part of the single-difference wide-lane ambiguity, and carrying out decimal deviation calculation by using a directional data statistic theory, modifying and fixing the single-difference wide-lane ambiguity as an integer; thirdly, resolving a single-difference L1 ambiguity floating point solution according to a single-difference non-ionized layer ambiguity estimation value and a single-difference wide-lane ambiguity integer solution, separating the decimal part, carrying out decimal deviation calculation by using the direction data statistic theory; and finally, broadcasting the wide-lane and the L1 phase deviation decimal part to a user of a roving station so as to be used for fixing the single-difference integral ambiguity solution of the wide lane and the L1 and further obtaining a PPP (Point to Point Protocol) static solution.

The invention relates to high-precision detection of complex optical curved-surface parts with large-curvature surface shapes, and aims to provide a high-precision detection method for the complex curved-surface parts with large curvature surface shapes, such as optical curved-surface parts, which has the advantages of rapidity, non-contact and no damage to part surfaces and surface layers. The technical scheme adopted by the invention is that the invention provides a grating projection rapid non-contact measurement method and device for high-reflectance free-form curved-surface parts, and the method comprises the following steps that: three degree-of-freedom motion of a measured object is realized with the help of a precision motion control system; coded grating fringes are projected onto the surface of the measured object by using a grating projection device; phase distribution information of the surface of the measured object is obtained from a deformed fringe pattern by using a digital phase shifting technology and a phase unwrapping algorithm; reference phase distribution information is obtained by using a virtual reference surface technology; and three-dimensional morphological information of a measuring area of the surface of the measured object is recovered according to a corresponding relation between phase deviation information and the gradient of the surface of the measured object. The grating projection rapid non-contact measurement method and device are mainly applied to the measurement of the optical curved-surface parts.

A receiver includes an input circuit, which is coupled to at least one antenna so as to receive, process and digitize first and second signals, thus generating first and second streams of input samples. An interference cancellation circuit in the receiver includes first and second adaptive filters, which are respectively coupled to filter the first and second streams of input samples using respective first and second coefficients to generate respective first and second filter outputs. A phase rotator is adapted to apply a variable phase shift compensating for a phase deviation between the first and second signals, the phase rotator having at least one configuration parameter. A control module is operative to estimate signal characteristics of the interference cancellation circuit and to set the at least one configuration parameter of the phase rotator responsively to the estimated signal characteristics.

The invention discloses a quick locking type digital time delay lock loop circuit and relates to the technology of signal phase deviation. The digital time delay lock loop circuit comprises a duty ratio adjusting circuit, a phase discriminator, a digital control time delay chain, a digital time converter, a shift counter and a replication time delay unit, wherein the digital control time delay chain comprises at least four levels of identical time delay units, all time delay units are controlled by the same controller and has the same time delay quantity; and each level of time delay units comprises a coarse tuning time delay unit and a fine tuning time delay unit, and the coarse tuning time delay unit and the fine tuning time delay unit are connected in series to expand the working frequency range of the delay lock loop. The digital time delay lock loop circuit provides an accurate 90-degree phase shift signal to a DQS (Data Strobe Signal) signal in a DDR (Data Direction Register) controller and has the properties of quickly locking and avoiding wrong lock of the loop.

A moving target detection imaging method of a dual-channel frequency modulation continuous wave SAR system comprises the steps of recording echo data by a radar system, performing residual video phase removing processing on the echo data, performing Doppler frequency shift compensation on the data, performing phase deviation compensation on two-channel conversion data, and performing subtraction processing on the two-channel data; performing migration correction and direction dechirping processing on an image with clutter cancellation to realize the rough imaging of a target, and detecting the moving target and extracting one by one; performing inverse transformation on the extracted targets to an original data domain, estimating motion parameters to construct a precise direction dechirping function of the moving target, performing residual video phase removing processing, precise direction dechirping processing and distance migration correction, constructing a fuzzy function for compensation, and then performing Keystone transformation to finish the precise image of the moving target. The moving target detection imaging method solves the imaging problem of the fast moving target when motion parameters are unknown under the continuous wave system, so the signal-to-noise rate and the target detection probability are greatly improved.

Disclosed is a non-equal probability constellation labeling method based on an absolute phase shift keying (APSK) constellation diagram. The non-equal probability constellation labeling method based on the APSK constellation diagram is characterized by comprising the steps that: the APSK constellation diagram is constructed, number of steps of the constellation labeling is M, M=2m, and m is a positive integer, numbers of constellation points on each ring is the same, phase deviations of each ring are also the same; a constellation labeling mode of the APSK constellation diagram is designed, and the constellation labeling mode is enabled to be a gray labeling; the constellation points are grouped, and constellation points on the same ring are combined to be a new constellation point; labeling bits of the prior constellation points on the same ring are distributed to the new constellation point in sequence. According to the non-equal probability constellation labeling method based on the APSK constellation diagram, the inhomogeneous constellation diagram and a non-equal probability labeling technology are adopted, distribution of output signals of the constellation labeling is enabled to be close to Gaussian distribution, shaping gain is achieved, performance of a coded modulation system is improved, and signal to noise ratio in a modulation process is reduced.

Phase correction circuits and methods for reducing phase skew between multiphase clock signals and a semiconductor device including the circuit are provided. The semiconductor device includes a phase correction circuit and an output buffer. The phase correction circuit corrects phase skew between multiphase clock signals and generates skew-corrected clock signals. The output buffer outputs data in synchronization with the skew-corrected clock signals. The phase correction circuit includes a phase corrector, a replication output buffer, a phase detector, and a controller. The phase corrector corrects a duty cycle of a first clock signal, a duty cycle of a second clock signal, and phase skew between the first and second clock signals and generates skew-corrected first and second clock signals. The replication output buffer has the same structure as a data output buffer and outputs replication data in synchronization with the skew-corrected first and second clock signals. The phase detector detects a phase error in data output from the replication output buffer and generates a detection signal. The controller controls the phase corrector in response to the detection signal. Accordingly, phase skew between multiphase clock signals can be reduced or eliminated.

A three-dimensional shape measuring apparatus of the invention is an apparatus which measures a three-dimensional shape of a target object by analyzing an optical pattern projected to the target object. The three-dimensional shape measuring apparatus includes a line sensor and an image analysis unit. The line sensor reads the target object, onto which the optical pattern is projected, as the image. The image analysis unit analyzes the optical pattern in the image read by the line sensor based on a spatial fringe analysis method, and the image analysis unit computes the three-dimensional shape information on the target object. An apparatus, method and program for measuring the three-dimensional shape of an object by analyzing an optical pattern projected onto the object. The phase of a pixel included in an image taken of the optical pattern is determined based on the brightness values of the pixel and at least one neighboring pixel in the image; thus the height information of the object can be determined. In addition, the height of the target object at a given position can be computed based on how much the phase of the optical pattern projected onto a certain position of the object is shifted from a reference phase.

The invention discloses a Beidou three-frequency non-differential non-combined observation value time transmission system and method. The method includes the steps that phase observation value, pseudo-range observation value, satellite ephemeris, earth rotation, antenna phase center and other parameters of China Beidou satellite navigation systems at two time transmission stations are obtained; data check, gross error reject and cycle slip detection are carried out, error models of ephemeris, tide, relativity, the earth rotation, atmosphere and antenna phase deviation are corrected; an ionospheric virtual observation model with additional ionospheric prior information constraints, spatial domain constraints and time domain constraints is constructed; and a three-frequency non-differentialnon-combinatorial precise single-point positioning model is constructed, a single-point positioning timing solution is carried out on corrected data, and comprehensive clock corrections of receivers of the two transmission time stations are obtained and compared to obtain a time transmission difference; and compared with standard time of one of the two transmission time stations, precise time of the other one of the two transmission time stations is obtained. According to the Beidou three-frequency non-differential non-combined observation value time transmission system and method, the observation noise can be reduced, and the accuracy and reliability of time transmission are improved.

A reticle inspection system and method for complete and fast inspection of phase shift mask reticles, both for incoming inspection and for periodic and pre-exposure inspection tool, is employable by facilities such as mask shops as an inspection tool compatible to the mask shop's customers. The inventive system and method detect phase errors in an aerial image by acquiring the image of the phase shift mask under the same optical conditions as the exposure conditions (i.e. wavelength, numerical aperture, sigma, and illumination aperture type). Images are acquired at a positive out-of-focus and a negative out-of-focus, and are compared in order to enhance possible phase error. The term “phase error” refers to the acceptable range of the phase deviation from the programmed 180° on the phase shift mask, by using the exposure system to achieve the image on the photoresist, satisfying the requirements of the wafer specification.

The invention discloses a fully-digital direct sequence spread spectrum communication system and a rapid pseudo code capturing method thereof. A digital signal is processed by using an FPGA (Field Programmable Gate Array) which comprises a pseudo code capturing module, a sampling signal of an ADC (Analog To Digital Converter) is subjected to frequency mixing with a signal of a local carrier NCO (Numerically Controlled Oscillator) and filtered to obtain a baseband signal, residual carrier Doppler frequency is eliminated from the baseband signal by adopting a differential multiplying mode, thus the phase deviation of a receiving signal and a local pseudo code is further obtained through an FFT (Fast Fourier Transform) algorithm without scanning on a carrier frequency domain; and when the phase deviation of the pseudo code is obtained, a local pseudo code phase is modified and is subjected to correlation degree of dissociation with the receiving signal, and the carrier Doppler frequency is figured out by using the FFT algorithm, and is compensated to a carrier NCO and a pseudo code NCO, thus carrier frequency capturing and pseudo code capturing are realized.

A serial input signal is sampled in synchronization with a plurality of first clock signals to obtain a plurality of sampling data pieces. A phase comparison circuit outputs a serial phase information signal based on the sampling data pieces. A serial-parallel conversion circuit performs a serial-to-parallel conversion on the serial phase information signal in synchronization with a second clock signal having a lower frequency, to output a parallel phase information signal. A digital filtering circuit calculates phase deviation and phase advance-delay signals based on the parallel phase information signal in synchronization with the second clock signal. By these signals, a phase control amount processing circuit generates a phase control signal. The phase control signal is in synchronization with third clock signals having a higher frequency. A phase interpolation circuit adjusts the phases of the third clock signals based on the phase control signal to output the first clock signals.

The automatic frequency correction method and device includes two stages of coarse frequency correction and fine frequency correction. The coarse frequency correction includes the steps of signal extraction, sliding correlation and phase deviation estimation, multiple frequency merging, creating time delay envelope, route selection, multipath merging, frequency control, etc. and corresponding modules. The fine frequency correction includes the steps of signal extraction, channel estimation and route search, route merging, frequency deviation estimation, SINR estimation, Kalman gain factor calculation, the first order loop filtering, frequency control, etc. and corresponding modules. The present invention makes it possible for the receiver to realize frequency sync in time division system fast accurately in harsh mobile communication environment.

The invention discloses an SOQPSK (shaping offset quadrature phase shift keying) carrier synchronization method based on pilot frequency and soft information combined assistance, mainly solves the problem in the existing short frame burst communication system carrier synchronization technique that the complexity is high and the carrier deviation estimation range is small. The implementation steps are as follows: firstly, according to pilot frequency assistant maximum likelihood carrier synchronization method, the rough estimation values of carrier frequency deviation and phase deviation are obtained, and the phase rough estimation value is used to revise the receiving signals; then, the frequency deviation one dimensional fine estimation interval, and phase deviation one dimensional fine estimation interval are respectively determined; and in the frequency deviation and phase deviation fine estimation intervals, according to the rule of maximizing the mean square value obtained during demodulation of soft information by SOQPSK, one dimensional search is performed to obtain the precise estimation value of carrier frequency deviation and phase deviation. A small amount of pilot frequency overhead is utilized, large carrier deviation with comparatively low operation complexity is revised, effective carrier synchronization is realized, nearly ideal bit-error performance of coherent demodulation is obtaind, and the method is suitable for the short frame burst communication system.

The application discloses a method for phased array calibration. The method is applied to a calibration device consisting of a first phased array and a second phased array. The first phased array includes a first RF channel and the second phased array includes a second RF channel. The topological structure of the first RF channel and the topological structure of the second RF channel forms a mirror symmetry relationship. The second phased array and the first phased array are spaced at a sub-wavelength distance. A coupling signal transmitted through the first RF channel is received by the second RF channel; according to the coupling signal, an amplitude deviation value and a phase deviation value corresponding to the first RF channel are determined; if a preset error correction condition issatisfied, an amplitude coefficient and phase coefficient corresponding to the first RF channel are corrected; and with a target amplitude coefficient and a target phase coefficient, a performance index parameter of the first phased array is measured. In addition, the invention also discloses a calibration apparatus. rapid amplitude and phase correction on all RF channels of a to-be-calibrated phased array is realized; the detection efficiency is improved; the occupied area is reduced; and the cost is lowered.

A transmitter for reducing time selectivity and/or frequency selectivity in a wireless communication system includes a plurality of transmit antennas, a phase shifter which is disposed for each transmit antenna and is configured to shift a phase of data transmitted through the transmit antenna by a phase shift value, and a channel selectivity processor configured to obtain the phase shift value by using a channel phase value fed back from a receiver.

The invention discloses a method for realizing TD-SCDMA base station synchronization, which is used for synchronizing a base station in the absence of GPS signal and includes that: step1, a GPS receiver receives a GPS satellite signal and transmits pulse per second signal to a synchronization module; the synchronization module adopts the pulse per second signal to measure the deviation value of work frequency and standard frequency of a crystal oscillator, and compute the frequency deviation compensation of the crystal oscillator; step 2, when the GPS receiver receives no GPS satellite signal, the GPS receiver informs the synchronization module; when the synchronization module is informed that the GPS receiver receives no GPS satellite signal, the synchronization module adopts frequency deviation compensation to compensate a frame timing signal generated by a clock signal of the crystal oscillator, and the frame timing signal is used for synchronizing the base station. The invention can eliminate phase deviation caused by the frequency deviation of the crystal oscillator and continuously accumulated with time, and enable the frame timing signal of the base station to be synchronous with frame timing signals of other base stations in longer time.

The invention relates to a method for combined compensating the sampling frequency bias and the carrier wave frequency bias, used in the orthogonal frequency division multiplexing system, and a relative device, wherein based on the phase bias of pilot sub carrier wave, the invention uses the weight least square method and another two simplify methods to estimate the slope and intercept of phase bias curvature of sub carrier wave, whose weight is decided by the increment function or signal/noise ratio of pilot channel; compensates the phase bias of data sub carrier wave via the estimated phase bias curvature; and supports the accurate estimated value of FFT window drift based on the curvature slop, to adjust the position of FFT window by FFT window controller, to compensate the sampling frequency bias; then based on the curvature intercept, supports the estimated value of carrier wave frequency bias, to feedback and compensate the carrier wave frequency bias. The invention can improve the compensate accuracy of sampling frequency bias and carrier wave frequency bias under multi-path condition.