5 results about "Distortion factor" patented technology

This invention discloses a method for amplitude and phase distortion correction in ISAR broadband direct sampling receivers. First, an amplitude and phase distortion echo signal model for the ISAR broadband direct sampling receiver is constructed. Matched filtering is applied to the amplitude and phase distortion echo signal at a single scattering point, and a fitness function is constructed based on the matched filtering results. Then, the PSO algorithm is used to iteratively optimize the amplitude and phase distortion coefficient vector of the echo signal at each scattering point, obtaining an estimated vector of amplitude and phase distortion coefficients, thus obtaining the amplitude and phase distortion estimates for the echo signal at each discrete point. Finally, an amplitude and phase compensation factor is calculated based on the estimated amplitude and phase distortion values ​​of the echo signal at the discrete points. This factor is used to correct the amplitude and phase distortion echo signal at each discrete point in real time, obtaining the corrected echo signal at each discrete point. The corrected echo signals at each discrete point are then superimposed to obtain the final corrected echo signal. This method solves the problems of insufficient targeting and easy getting trapped in local optima in high-dimensional solutions, thus improving ISAR imaging performance.

This invention discloses a dynamic frequency allocation method for wireless communication networks, belonging to the field of wireless communication processing technology. Through offline measurement and model identification, a quantitative relationship between the input signal of the preceding time slot and the nonlinear distortion at the current moment is established. Historical usage sequences of frequency bands and power are collected and stored in real time, providing the input signal characteristics of the preceding time slot for memory effect residual assessment. Combining the historical usage sequences with the memory effect model, the residual intensity of the memory effect in each frequency band is calculated in real time, providing a quantitative basis for frequency band scheduling. Protective time slots are set for high-residual frequency bands to avoid their use before the memory effect has completely disappeared. Low-residual frequency bands are preferentially allocated to high-power users through priority ranking. The memory effect residual of power amplifiers is compensated in real time by dynamically updating the predistortion coefficients. The predistortion coefficients are adjusted according to the preceding and current signal characteristics to ensure good predistortion performance in different operating scenarios.

The present application relates to the technical field of data calibration, and discloses a reinforcing bar detector precision calibration system and method, the system comprises: a detection unit, a calculation unit, an analysis unit, an equalization unit and a calibration unit, after the detection unit acquires a double-frequency mixed echo signal, the calculation unit first decomposes the signal mode to obtain a double-main-mode response vector and a secondary-mode coordination value, then calculates a double-frequency distortion factor in combination with interlayer amplitude variation, interlayer rate of coordination and other parameters, and further can quantify the strength of the electromagnetic lens effect, while the mode adaptation critical value obtained by the analysis unit can provide a basis for signal calibration, the signal equalization coefficient of the equalization unit can determine the direction of signal calibration, and finally the calibration unit combines double-frequency layer domain superposition degree, medium adaptation superposition adjustment amount and other parameters to superimpose and calibrate double-frequency signal components based on the signal equalization coefficient, effectively corrects signal distortion, and realizes precision calibration of ancient building wall reinforcing bar detection.

This invention relates to the field of optical imaging testing, and more particularly to a camera field of view testing device and method. The method includes first acquiring a calibration image and a test image; calibrating the distortion parameters of the vehicle-mounted camera using the calibration image; and using these distortion parameters to correct the distortion of the subsequent test image used for field of view calculation, resulting in a distortion-free test image. On the distortion-free test image, the full field of view of the camera under test is calculated based on angle markings with known angle values. This invention innovatively employs a calibration-correction-calculation approach to test the camera's field of view, fundamentally eliminating the influence of distortion factors on the measurement results, achieving a breakthrough in technical principles, and thus improving the accuracy of field of view testing.

A control unit for a switching converter operating in continuous conduction and peak current control mode. The control unit has an inductor element coupled to an input and a switching element coupled to the inductor element, generates a command signal having a switching period to switch the switching element, and determines a first time period in which an inductor current flows in the inductor element for storing energy and a second time period in which energy is delivered to a load. The input current is distorted with respect to a sinusoidal curve by a distortion factor caused by a current ripple on the inductor current. A duration of the first time period is determined based on a comparison between a value of a peak of the inductor current and a current reference dependent on an output voltage of the voltage converter. A reference modification stage modifies the current reference to compensate for the distortion introduced to the input current by the distortion factor.