12results about How to "Shorten capture time" patented technology

The invention discloses an ultrahigh-voltage direct-current shielding material and a preparation method thereof, and the shielding material is prepared from the following raw materials in parts by mass: 65-80 parts, preferably 70-80 parts, of matrix resin; 15 to 25 parts of carbon black-MXene-ionic liquid composite conductive agent, preferably 18 to 23 parts of carbon black-MXene-ionic liquid composite conductive agent; 0.2 to 5 parts of an antioxidant, preferably 0.5 to 2.5 parts of the antioxidant; 1-2 parts, preferably 1-1.5 parts, of a lubricant; 0.5 to 2 parts of cross-linking agent, preferably 0.8 to 1.2 parts of cross-linking agent. By introducing the MXene-ionic liquid modified superconductive carbon black, the conductive effect is improved, the use amount of the carbon black is reduced, and uniform dispersion of the conductive filler is realized, so that the generation of surface bulges is reduced, the surface smoothness of the shielding material is improved, and meanwhile, due to the synergistic conductive effect of the ionic liquid and MXene, the shielding material has good conductivity. The PTC effect of the shielding material is reduced; and the generation of space charges is reduced.

The invention relates to a high-orbit Beidou signal capturing method and device, and the method comprises the steps: converting a Beidou satellite signal into a digital intermediate frequency signal, and determining the number of sampling points of a 1-millisecond signal; fourier transform compensation data and inverse Fourier transform compensation data are determined; mixing the 1 millisecond digital intermediate frequency signal with a local carrier to strip the carrier; fourier transform compensation is carried out on the carrier stripping signal, and then Fourier transform is carried out; fourier transform compensation is carried out on the 1-millisecond local ranging code sequence, and then Fourier transform is carried out; carrying out conjugate multiplication on the two Fourier transform results; inverse Fourier transform is carried out on a conjugate multiplication result, and then inverse Fourier transform compensation is carried out; delaying an inverse Fourier transform compensation result by a code phase and then performing differential coherent operation; and performing peak value judgment by using the accumulated sum of the differential coherence results, and determining that the signal is successfully captured when the peak value is greater than or equal to a threshold value. According to the method, storage resources and computing resources are saved, the influence of noise is small, and the signal capturing sensitivity is high.

The invention provides a satellite signal capturing method and device, equipment and a storage medium, and relates to the field of satellite communication system signal processing, and the method comprises the steps: receiving a satellite signal, and determining a search window; sliding one sampling point in the search window every time by using the data window, and obtaining a plurality of window sequences after sliding is finished; first correlation operation is carried out on the multiple window sequences and local sequence data at the same time, and the peak value of a correlation peak corresponding to each sampling point is obtained; dividing the satellite data sequence into a plurality of subsequences, and summing peak values of correlation peaks of sampling points which are located in different subsequences and have the same position in the subsequences to obtain a peak value sequence; and when determining that a target peak value exceeding a preset capture threshold exists in the peak value sequence, determining that the satellite signal is successfully captured. The acquisition efficiency of satellite signals is improved through a full-parallel operation mode; in addition, the peak values of the correlation peaks of the sampling points which are located in different subsequences and have the same position in the subsequences are summed, so that the signal-to-noise ratio is improved.

The invention provides a satellite communication signal rapid capturing method and device, electronic equipment and a storage medium, and belongs to the technical field of communication. The method comprises the following steps: sampling a received signal at a first sampling rate and a second sampling rate respectively to obtain a first sampling signal and a second sampling signal; on this basis, correlation calculation is performed on the first sampling signal to determine the target sub-sampling signal, and the sampling frequency of the first sampling signal is equal to that of the first sampling signal in a preset proportion, so that the number of sampling points is reduced, and the calculation amount is reduced during correlation calculation; by performing segmentation parallel processing on the first sampling signal, the complexity of capturing the target signal in the time-frequency domain is reduced, and the capturing time is shortened; and finally, according to the target sub-sampling signal, determining a superposed enhanced signal in the second sampling signal, and analyzing the enhanced signal to obtain a target signal, so that the target signal can be accurately obtained in a low signal-to-noise ratio environment on the basis of reducing the calculation amount.

The invention provides a variable light beam detection center scanning device which comprises a first plane mirror, a second plane mirror and a convex lens, incident light is reflected to the convex lens through the first plane mirror and the second plane mirror in sequence and enters a scanning mechanism after being refracted by the convex lens, and the first plane mirror and the second plane mirror are translated through a moving mechanism. The central position of a scanning view field can be continuously changed in real time and the scanning center can be actively adjusted to the target direction only by controlling the translation of the two movable plane mirrors at the front end under the conditions of not changing the posture of an equipment main body and fixing the direction of incident light, so that the probability of missing scanning at the edge is reduced, the capturing time is shortened, and the capturing efficiency is improved.

The present application provides a method for capturing UAV measurement and control signals, related devices and computer storage media. The predicted value of the Doppler frequency deviation of the UAV measurement and control signal is calculated based on the current time in the current low-orbit satellite ephemeris information, the distance between the current low-orbit satellite and the UAV, the carrier frequency of the transmitted signal and the speed of light; the rough estimated value of the Doppler frequency deviation of the UAV measurement and control signal is determined based on the sampling result of the UAV measurement and control received signal and the prediction error range; the rough estimated value of the Doppler frequency deviation of the UAV measurement and control signal is corrected using the Shannon interpolation algorithm to obtain the value of the Doppler frequency deviation of the UAV measurement and control signal; finally, the carrier frequency is compensated based on the rough estimated value and the precise estimated value of the Doppler frequency deviation of the UAV measurement and control signal to obtain the compensated UAV measurement and control signal. The frequency domain search range is effectively narrowed, the signal capture time is shortened, and the estimation accuracy of the Doppler frequency deviation is improved, thereby improving the accuracy of the UAV measurement and control signal.

The invention discloses a miniaturized intelligent cooperative control airborne laser communication terminal, and the terminal comprises a coarse aiming unit which comprises a universal rotary table and is used for achieving the large-angle range coarse positioning and posture adjustment of the laser communication terminal, and providing a basic positioning reference for the subsequent fine aiming adjustment; the fine sighting unit is driven by piezoelectricity-electromagnetism in a hybrid mode, is matched with the coarse sighting unit, obtains positioning information of the coarse sighting unit and is used for achieving small-angle high-precision correction and compensating for positioning errors of the coarse sighting unit; the intelligent control unit is respectively connected with the coarse aiming unit and the fine aiming unit, and is used for receiving an external control instruction and scanning information fed back by the coarse aiming unit and the fine aiming unit, and generating and outputting a corresponding driving control signal; the invention further discloses an application method of the airborne laser communication terminal. The direct-driven coarse aiming unit is adopted to improve the coarse aiming efficiency, the fine aiming performance is considered through piezoelectric-electromagnetic hybrid driving, platform vibration from low frequency to high frequency can be comprehensively compensated, and the tracking precision and the link stability are improved.

The utility model belongs to the technical field of phase-locked loop capture, disclose a kind of phase-locked loop capture device, including temperature compensation crystal oscillator, frequency discriminator phase detector, loop filter, adder, voltage-controlled oscillator, power divider, phase detector, operational amplifier, amplifier and frequency divider;Temperature compensation crystal oscillator is connected with frequency discriminator phase detector, frequency discriminator phase detector is connected with adder by loop filter, adder is connected with voltage-controlled oscillator, voltage-controlled oscillator is connected with delay line by power divider, and one road is connected with phase detector;Wherein, phase detector is connected with adder by operational amplifier.The utility model initial locking voltage adopts phase discrimination conversion mode, with fast conversion speed, pre-set voltage precision higher advantage.Shorten the time of phase-locked loop capture while not influence phase noise and other indexes, and simplify circuit structure and space layout, so that application is more simple and convenient, cost is also reduced.In circuit design and structure form, it is more flexible, easy to expand.

The invention provides a synchronization method and system for power line carrier communication and electronic equipment, and the method comprises the steps: obtaining signal data of a sender in power line carrier communication, and processing the signal data to obtain a plurality of data frames; inserting a leader sequence at an initial position in a data frame to generate a marked data frame; acquiring a local sequence of a sender, and performing convolution calculation on the marked data frame and the local sequence to obtain a convolution value; judging whether the convolution value exceeds a preset threshold value or not, and if yes, determining the position exceeding the threshold value as a peak value position; intercepting a marked data segment according to the peak value position, and performing autocorrelation calculation on the marked data segment to determine the initial position of the data frame; and enabling the receiver to receive the data frames from the starting position of each data frame. The problem of insufficient high-precision synchronization rate in power line carrier communication is solved.

The present invention relates to the field of wireless communication equipment, and in particular to a fast code capture method in BPSK modulation direct sequence spread spectrum communication. The present invention can reduce the capture time, and the capture time is independent of distance uncertainty, improve the code capture efficiency, and the main operation is completed by the most commonly used FIR filter in digital signal processing, which is easy to implement.

The present invention belongs to the field of satellite navigation technology, and discloses a method and system for capturing weak GPS signals based on code difference and code parallelism, including a digital down-conversion module, a code merging module, a data storage module, a Doppler stripping module, a data folding module, a step-by-step matching coherent module, a code difference module, a Doppler compensation module, a step-by-step coherent module and a step-by-step incoherent module, a peak judgment module, a Doppler search completion judgment module, a Doppler control module, and a result output module. The high-orbit GPS signal capture method based on code difference and code parallelism of the present invention provides a fast and efficient capture algorithm for a navigation receiver; the use of the code difference algorithm avoids the influence of navigation data jumps on the coherent integration time, and improves the capture sensitivity of the GPS signal by increasing the coherent integration time. The present invention adopts step-by-step coherent and step-by-step incoherent algorithms to achieve rapid capture of signals of different strengths and shorten the first positioning time of the navigation receiver.