178results about How to "Guaranteed SNR" patented technology

Embodiments of the invention disclose a thin film transistor and a method for fabricating the same, an array substrate, and a display device, wherein the thin film transistor includes: a first gate disposed on one side of a substrate, an active layer, a second gate, and a source/drain electrode; the active layer is disposed on one side of the first gate away from the substrate; the second gate isdisposed on one side of the first gate away from the substrate; the source/drain electrode is disposed on one side of the second gate away from the substrate; and an overlapping area exists between the orthographic projection of the source/drain electrode on the substrate and the orthographic projection of the second gate on the substrate. The embodiments of the invention avoid hydrogen atoms fromentering the active layer in the subsequent process, avoid the threshold voltage negative drift of the thin film transistor, and reduce the leakage current of the thin film transistor, thereby ensuring the dark current decrement and the signal-to-noise ratio during optical detection, and optically compensating the display accurately.

The application provides a method for controlling the state of a light sensor and electronic equipment, and relates to the technical field of communication. The method can be applied to the electronicequipment with the light sensor under a full screen, and is used for controlling the light sensor to emit a light signal when pixels of a display area of an OLED display screen corresponding to the light sensor do not emit light in a refresh period of a picture, so that the problem of screen flicker caused by infrared light emission of the light sensor on the full screen can be solved, and the display effect of the full screen is improved. The method comprises the steps of: determining a display time period and a non-light-emitting time period in a refresh period of a picture by a processor;controlling, by the processor, a light emitter of the light sensor to emit a light signal when the pixels of the display area of the OLED display screen corresponding to the light sensor do not emit light in the refresh period of the picture; and controlling, by the processor, the light emitter to not emit a light signal when the pixels of the display area of the OLED display screen correspondingto the light sensor emit light.

The method discloses a method for expanding a post-stack seismic data frequency band based on a wavelet compression. The method comprises the following steps: a stack record is subjected to Fourier transformation in a time coordinate to obtain a frequency spectrum; an average value is calculated, and a zero-phase original wavelet is obtained by conducting Fourier transformation of the time coordinate; a frequency spectrum of a compressed wavelet is calculated according to a given contraction operator; the frequency spectrum of the compressed wavelet is subjected to Fourier transformation of the time coordinate to obtain the compressed wavelet; a frequency spectrum of a broadband wavelet is calculated; the wavelet of the broadband wavelet is subjected to Fourier transformation related to the time coordinate to obtain the broadband wavelet; autocorrelation of an original wavelet is calculated; mutual correlation of the original wavelet and the broadband wavelet is calculated; a record of a frequency-expanded convolution of a shaping operator and an original stack record is calculated. Through the adoption of the method, the resolution ratio of seismic post-stack data can be improved, and meanwhile, signal to noise ratio, relative amplitude relation, and time-frequency characteristics of seismic data can be basically maintained.

The invention discloses a simultaneous multipoint excitation and matched receiving photoacoustic three-dimensional imaging device and method, in the device, a computer processing system controls opening and closing of a photoacoustic signal excitation system, receives data processed by a photoacoustic signal preprocessing system, processes the data, performs reconstruction imaging, and controls athree-dimensional scanning system to run; the photoacoustic signal excitation system shapes pulse laser into a linear light source, and uses a micro lens array to focus a plurality of light focuses, and a sample is excited simultaneously by the plurality of light focuses to produce a multi-source photoacoustic signal; a photoacoustic signal receiving system receives the multi-source photoacousticsignal; the photoacoustic signal preprocessing system amplifies and filters the multi-source photoacoustic signal and sends the multi-source photoacoustic signal to the computer processing system; a to-be-imaged sample is put in a water tank, and the three-dimensional scanning system is used for regulating the spatial position of the water tank and the photoacoustic signal excitation system. Through use of the spatial layout of a microlens array and a linear acoustic detection array, rapid and wide range of photoacoustic three-dimensional imaging can be realized.

The invention discloses a spatial synchronization device and a synchronization method for bistatic SAR (synthetic aperture radar). The device comprises a transmission station part and a receiving station part, and particularly comprises a positioning and attitude determination system, an antenna server, a transmission synchronization system, a wireless transmit-receive system, a receiving synchronization system and a display unit. According to the spatial synchronization device and the method, direction angles at which antenna beams of transmit-receive aerial carrier platforms aim at an target area are revolved and obtained by utilizing actual spatial positions of the transmit-receive aerial carrier platforms; the antenna server is utilized to accomplish aiming of the beams to allow the antenna beams of the transmit-receive platforms to aim at the target area; the spatial synchronization of the onboard bistatic SAR is achieved; a signal-to-noise ratio of a radar echo is ensured; and the precision of the spatial synchronization is improved.

The invention discloses a frame synchronization device capable of suppressing and measuring Doppler in underwater acoustic communication, relating to underwater acoustic communication equipment. The frame synchronization device is provided with a front-loading module, an analogue-digital conversion module, an operation module and a frame synchronization establishment/Doppler measurement module. The input end of the front-loading module is connected with the signal output end of an underwater acoustic transducer at a receiving end; the analogue-digital conversion module is composed of three paths of AD (analogue-digital) sampling converters, namely, an ADC (Analogue-Digital Converter) 1, an ADC2 and an ADC3 which are controlled by DDS (Digital Direct Frequency Synthesis) chips, namely, a DDS1, a DDS2 and a DDS3, and the input ends of the three paths of AD sampling converters, namely, the ADC1, the ADC2 and the ADC3 are connected with the output end of the front-loading module; the input end of the operation module is connected with the digital signal output ends of the three paths of AD sampling circuits, namely, the ADC1, the ADC2 and the ADC3 after analogue-digital conversion; and the input end of the frame synchronization establishment/Doppler measurement module is connected with the three operation result output ends of the operation module after related processing copying. Doppler effect suppression can be simply and conveniently realized, and Doppler can be measured in underwater acoustic communication.

The invention provides a magnetic resonance T2 * weighted rapid imaging method and device which relate to the magnetic resonance imaging technology field wherein the method comprises: according to single-band radio frequency pulses, generating multi-band radio frequency pulses; according to the fast parallel imaging technique based on controllable mixing and superposing, modulating the initial phases of the multi-band radio frequency pulses in different repetition times to generate the modulated multi-band radio frequency pulses; through the layer separation scanning and echo migration technique, generating the T2 * weighted imaging sequence based on multi-layer co-excitation technique and the layer separation scanning and echo migration technique; obtaining the multi-layer mixed and superposed images of a to-be-processed object; and using the reconstruction algorithm to reconstruct and process the multi-layer mixed and superposed images to determine the single layer T2 * weighted images. The method and apparatus of the invention can further accelerate the layer separation scanning and echo migration technique through the multi-layer co-excitation technique to realize faster T2 * weighted imaging to ensure the signal-to-noise ratio and reduce the influence of the artifacts and distortions on the image quality. The use of small flip angled radio frequency pulses effectively reduces the specific absorption rate.

The invention relates to a system and a method for optical and digital mixed imaging. The system comprises an optical imaging object lens, a rational form wavefront coder, a photoelectrical detector and a digital image decoding and processing unit. The method adopts the rational form wavefront coder to code a wavefront phase of an incident light wave. Phi RPM(x) as an introduced phase distribution function is equal to sigma sign(x)an|x|(1+ sigma bm|x|), wherein x is a normalized radial coordinate; N and M are the highest power of a fraction and denominator polynomial respectively; {an} and {bm} are undetermined coefficients; and sign is a signum function. An intermediate blurred image which is not sensitive to defocusing is acquired on the photoelectrical detector after coding, and the digital image decoding and processing unit carries out deconvolution wave filtration on the intermediate blurred image to acquire the final clear image.

The invention relates to a waveform design for a double-cycle pinch-off type pseudo-random code and a signal processing method for an echo. The waveform design for the double-cycle pinch-off type pseudo-random code and the signal processing method for the echo is characterized in that the needed radar signal-transmitting time width is computed combined with a radar equation, codon time width of random codes of a first group, the digit of the random codes and subcode time width when a wave form is pinched off are ascertained. An echo signal after analogue-to-digital sampling is finished under despreading and spread spectrum and section matched filtering is carried out. The result of the section matched filtering is under fast fourier transform (FFT) treatment, the constant false alarm rate (CFAR) technology is utilized, and a target is detected in a velocity dimension and a distance dimension. The waveform parameters of random codes of a second group are ascertained to cover a dead zone. Target data obtained through the first group and the second group are mixed to discover and complement the dead zone. The waveform design for the double-cycle pinch-off type pseudo-random code and the signal processing method for the echo has the advantages of being short in instantaneous pulse width and high in waveform duty ratio, short in distance of the dead zone, small in transmitting power and time sharing in receiving and dispatching.

The present invention relates to a high squint attitude maneuver method for a fast response SAR satellite, which comprises the following steps: 1) the time when the velocity of a scene center relativeto the satellite is zero is determined; 2) a central time of squint observation and a position vector and a velocity vector of the satellite in the earth centered earth fixed coordinate system at thecentral time of the squint observation are calculated; 3) a start time and an end time of imaging in the squint observation are calculated; 4) the satellite attitude maneuver parameters at the central time of the squint observation are calculated; 5) in a time range from the beginning to the end of the squint observation, the satellite maneuvers according to the attitude maneuver parameters at the central time of the squint observation; 6) injection interfaces for a range angle and an azimuth angle of a beam are reserved in the satellite body coordinate system, and the beam pointing is corrected according to the in-orbit beam pointing calibration value. The invention ensures that an antenna beam accurately points to a target in the high squint observation of the fast response SAR satellite; and at the same time, the Doppler frequency change of each range sampling point meets the imaging requirements.

The invention relates to a rotor blade surface dynamic pressure measuring method and system based on a phase locking method. The measuring system designed by the measuring method comprises a high-sensitivity photoelectric sensor, a micro dynamic pressure sensor, an infrared trigger, a data recorder fixed to a rotating shaft, a data acquisition card and other devices. The rotor blade surface dynamic pressure measuring method and system based on the phase locking method can overcome the defects of an existing device, sampling frequency of the designed system is only related to sampling frequencyof the sensor and the data recorder, and the limitation on the sampling frequency caused by a data transmission mode is avoided. As a data transmission line is adopted for data transmission, noise interference can be avoided to the greatest extent, and the accuracy of acquisition data can be ensured; and meanwhile, the instability of rotating speed is considered, the phase locking method is adopted, so that the rotor surface dynamic pressure is accurately recorded, a rotor blade rotating phase is recorded in an absolute coordinate system, and the pressure information of the blade surface at acertain phase is accurately extracted.

The method includes steps: detecting state of chain, if broken chain, then office end is changed to basic mode corresponding to remote modem; detecting whether chain is built at basic mode; if yes, setting up configuration at office end and remote end to maximum speed rate mode; detecting whether chain is built at mode in speed rte setup; if yes, calculating SNR value at office end and remote end, and comparing with GoodSNR value respectively through looking up table; if the calculated SNR value is in range of GoodSNR value; then, present speed rate is optimal configuration of speed rate; if no, setting up office end and remote end to speed rate mode lower than previous configured mode in one kevel in speed queue. Repeating the said step is till to optimal speed rate mode is built. The method guarantees SNR of line to meet standard requirement.

The present invention provides a method for processing signal, a system and an optical line terminal thereof. The bandwidth authorization information of next time period distributed for each optical network unit (ONU) is obtained. The offset current of a semiconductor optical amplifier (SOA) is regulated at the next time period according to the obtained bandwidth authorization information. The SOA is leaded to be satisfied to the set condition to the gain generated by the signal passing through the SOA. The SOA executes power amplification to the received signal. The signal transmission stateof each ONU at the next time period can be obtained through the obtained bandwidth authorization information. The offset current of SOA is dynamically adjusted according to the signal transmission state of each ONU thereby causing that the gain generated by SOA is satisfied for the preset condition. Thereby the signal quality after power amplification can be increased when the existing passive optical network (PON) device and the next generation access (NGA) network device coexist.

The invention discloses a parameter optimization method for a communication integration signal of an asymmetric triangular frequency modulation radar. The shape of a frequency curve of the integration signal is an asymmetric triangle, and the integration signal consists of two LFM (linear frequency modulation) signals with opposite frequency modulation ratio symbols. The first signal is an LFM signal with the frequency modulation ratio k1, has no modulated communication information and is used for the synchronization or capturing of a communication signal, and the second signal is an LFM signal with the frequency modulation ratio k2, wherein k1*k2 is less than zero. Communication code element information is modulated on the second signal in a mode (-1, 1). The method is based on a parameterized model of the communication integration signal of the asymmetric triangular frequency modulation radar, and employs a fuzzy function for representing radar detection performances and a target function for representing communication performances to optimize and design the parameters of the integration signal. The method guarantees the probability of successful capturing of communication through employing a shortest synchronization signal, and guarantees an information transmission rate at a certain signal to noise ratio under the condition of guaranteeing the radar detection performances.

The invention provides a tactical communication network countermeasure method based on signal recognition and network reconnaissance. The method comprises the steps of tactical communication network comprehensive situation awareness, tactical communication target attribute recognition based on time-frequency-space characteristics, detection of the specific tactical communication target based on synchronization characteristics, time-division multi-target jamming based on network key information and tactical communication network countermeasure based on synchronization decoy. The core of the method is to recognize the target attributes, locate the network node, analyze the traffic type and perform statistics of the traffic volume by using the signal time-frequency spatial domain characteristic and network characteristic information so as to realize communication signal recognition and network comprehensive situation analysis under the complex battlefield electromagnetic environment. Time-sharing jamming is performed by using the sparsity of the network key information for different target networks to improve the multi-target jamming capacity, and synchronization decoy jamming is performed by using the vulnerability of the synchronization mechanism to effectively counter the ad hoc encrypted communication network characterized by multi-hop routing and forwarding and high-speed frequency hopping.

The invention discloses a safety monitoring system based on distributed optical fiber, comprising a transmitted and received light signal processing module 100, a light delay component 101 and a loop optical fiber part 102 which are formed into a double-variant-type optical fiber Sagnac interferometer. The transmitted and received light signal processing module 1 comprises a computer 1, a light source driver 2, a light source 3, a polarization remover 4, a detector 10 and a circuit processing board 11 with a detector. The light delay component 2 comprises a 3*3 optical fiber coupler 5, a short fiber 6, a long fiber 7 and a 2*1 coupler 8. The loop optical fiber part 102 relates to induction optical fibers 9 of two cases, i.e. vibration and impact act on the two optical fibers in a loop or on one optical fiber in the loop. A single system is additionally provided with a light switch to perform multi-channel periodic route-inspection measurement and monitor large-area vibration. The remote intelligent monitoring can be realized through the networking of a plurality of monitoring systems.

A high precision positioning method of dark space debris comprises the following working steps: (1) acquiring three continuous frames of CCD images; (2) calculating negative models of a first frame image and a third frame image; (3) calculating a negative model of a second frame image; (4) positioning a dark space debris; (5) carrying out the above four steps to finally obtain a positioning result of the dark space debris on the second frame CCD image; and (6) storing and displaying the positioning result. The method of the invention can realize high precision positioning on the dark space debris, when the CCD image has a long exposure time, and is quite a good method for positioning the dark space debris. The method has good actual treatment and can be widely applied to monitoring of space debris.

The invention provides an algorithm for searching H.263/AVC integer pixel vectors, which introduces an algorithm for searching H.263/AVC integer pixel vectors which is suitable for hardware to achieve through various common integral pixel vectors searching algorithms. The algorithm realizes the rapid searching of integral pixel through the prediction of a vector and a zonal searching, which is successfully realized on an IP tone and video encoding chip at present. The result shows that the invention can greatly relieve the pressure of memory access, decrease the computation, and simultaneously guarantees the SNR of video peak value and the bit rate size.

The invention provides a coupling magnetic-positioning well logging pup joint and a high-speed telemetry well logging instrument provided with the pup joint. The coupling magnetic-positioning well logging pup joint is provided with a probe part, an iron core, a coil, an analog-digital circuit processing part and a CAN bus receiving and sending module, wherein the probe part comprises a pair of permanent magnet steel with opposite magnetic poles; the iron core is located between the pair of permanent magnet steel; the coil is wound on the iron core; the analog-digital circuit processing part is used for processing a signal collected by the probe part; and the CAN bus receiving and sending module is used for sending the signal processed by the analog-digital circuit processing part to the high-speed telemetry well logging instrument through a CAN bus and receiving a signal from the high-speed telemetry well logging instrument. According to the coupling magnetic-positioning well logging pup joint and the high-speed telemetry well logging instrument provided with the pup joint, the well logging instrument is convenient to debug and high in antijamming capability, and the logging reliability and stability are improved; through the novel probe structure and the integrated processing circuit, the signal to noise ratio is increased, the overall size of the pup joint is reduced, and the capacity to accurately position casing couplings with different casing sizes and in severe well conditions of the pup joint is improved.

The invention relates to the technical field of wind lidars, and, more specifically, relates to an all-fiber coherent wind lidar, taking a photonic crystal laser as a light source, and a wind measurement method of the all-fiber coherent wind lidar. The all-fiber coherent wind lidar comprises the photonic crystal laser, a fiber circulator device, an optical detection device, a transmitting/receiving optical device, and a signal processing and laser drive device. The method carries out the linear modulation of a drive current supplied by the signal processing and laser drive device to the photonic crystal laser, so as to obtain fundamental frequency and echo signals with bigger frequency shifts. The frequency mixing of the fundamental frequency and echo signals is carried out so as to obtain a differential frequency signal. The method carries out the processing and calculation of the differential frequency signal, thereby obtaining the radial wind speed and wind direction through measurement. The all-fiber coherent wind lidar is low in complexity, is low in cost, is high in signal to noise ratio of a transmitted laser signal, and can measure the high-precision radial wind speed and direction.