107results about How to "Improve SNR" patented technology

A method for adjusting the signal to noise ratio of a receiver comprises measuring the peak power for an RF signal and determining, based on the measured peak power, whether the RF signal power is within a desired operating range. The method further includes adjusting an RF attenuation for the receiver, when it is determined that the RF signal power is not within the desired operating rang. The method further comprises measuring a peak power foe an IF signal, determining based on the measured peak power, whether the IF signal power is within a desired operating range, and adjusting an IF attenuation for the receiver, when it is determined that the IF signal peak power is not within the desired operating range.

This invention solves a problem of registration and improves signal-to-noise ratio (SNR) when using division-by-focal-plane array to produce multiple polarization images. This is achieved by processing a sequence of angular-position-dithered frames to generate a high-definition, Nyquist-sampled, integrated image for each of the polarizations. The integration method transforms individually under-sampled, high-resolution image frames into resultant high-resolution frames that meet the Nyquist sampling criterion. During the resampling transformation, each polarization or waveband is resampled to produce precise registration to the other polarizations, since registration offsets are fixed and defined by the arrangement of the polarized pixels in the focal-plane-array. In the most straight-forward implementation, these offsets would be integer pixel shifts in X and Y.

The invention discloses a single-channel synthetic aperture radar moving target detection and positioning method based on two-view real image processing. The steps include: (1) calculating the azimuth spectrum; (2) separating sub-view images; (3) suppressing ground clutter ; (4) Using the constant false alarm detection method to detect moving targets; (5) Locating moving targets. The invention overcomes the disadvantages of multi-channel hardware system complexity, high cost and narrow application range by adopting the single-channel SAR-GMTI method, and has the advantages of simple hardware system, low cost and wide application range. Through adaptive amplitude filtering of the two-view real image and then suppressing the interference of static clutter, it overcomes the fact that there is still a large amount of static clutter left after the sub-view image cancellation of the existing single-channel system, and can only detect moving targets outside the main lobe of clutter The shortcomings of the signal have the advantages of high signal-to-noise ratio, the ability to detect moving target signals in the main lobe of clutter, low false alarm probability, and high accuracy of motion parameter estimation and positioning.

The invention relates to the field of radar signal processing and especially relates to a radar anti-interference method by utilizing polarization cancellation. In the method, through determining a cancellation main channel and an accessory channel, and then, by utilizing the main channel and the accessory channel as well as channel weight coefficients thereof, no-interference signals are obtained after cancellation. The method is especially suitable for escort self-defense noise interference and general clutter interference; signal-to-clutter-noise ratio of the system can be greatly improved, detection of follow-up radar signal processing is convenient, and detection capability of the radar can be effectively improved under the complex electromagnetic environment.

Provided in the invention is an ionospheric clutter suppression method of a high-frequency ground wave radar. The invention relates to an ionospheric clutter suppression method of a high-frequency ground wave radar so that problems that the existing methods are mainly used for suppressing the narrowband radio-frequency interference and transient impact interference in the high frequency radar butnot suppressing the ionospheric interference, the existing methods are not suitable for wide-beam radars, and first-order Bragg peak information shortage and wave echo energy weakening are caused canbe solved. Compared with the traditional clutter suppression algorithm, the ionospheric clutter suppression method provided by the invention is characterized in that cancellation processing is completed by using the cross-correlation between the ionospheric multi-aggregation regional clutters; and the ionospheric clutters are suppressed, the wave echo and the first-order Bragg peak information arekept, and the declining in normal ocean echo energy is reduced. With the ionospheric clutter suppression method, the strong ionospheric clutter in the radar echo spectrum is obviously suppressed; theclutter suppression amplitude is improved, and the echo signal noise ratio is significantly increased. The ionospheric clutter suppression method is mainly applied to the high-frequency ground wave radar detection field.

A method of driving a touch display panel includes sequentially providing gate signals to a plurality of gate lines, outputting data signals to a plurality of data lines, the data lines being disposed on the first surface and crossing the gate lines, and reading out a first sensing signal through a plurality of sensing lines in response to the gate signals. The gate lines are disposed on a first surface of a base substrate, the touch display panel including the base substrate. The data signals are synchronized with the gate signals. The sensing line is disposed on a second surface of the base substrate, the second surface being opposite to the first surface.

The invention provides methods and systems useful for quickly and accurately sampling a switched capacitive load. Systems are disclosed in which the methods are implemented using an operational amplifier operably coupled to a pre-charge capacitor for storing an input charge. A sampling capacitor is also coupled to the operational amplifier and to the pre-charge capacitor for receiving and holding the input charge. The system is so configured for a coarse sampling phase and a fine sampling phase the to ensure that the sampling capacitor settles quickly to provides an output.

A method of processing audio signals for an auditory prosthesis is provided. The method includes a noise reduction step (22) and a later compression step (24). A gain control step is provided prior to the compression step (24). The gain control step operates so as to minimize the occurrence of signal compression in the compression step (24). An auditory prosthesis arranged to provide the method is also provided.

The present invention relates to a method and apparatus providing tissue harmonic imaging using an ultrasound machine. Coded pulses and the phase inverted version of the said coded pulses with time bandwidth greater than 1 are transmitted into the tissue. Backscattered echoes are received and filtered before or after coherent summation. Decoding/compressing of the received echoes of the coded pulses is implemented naturally through the propagation of the specially designed ultrawide band (>80%) waveforms inside tissue and pulse inversion. Costly decoding/compression filter are not necessary.

The invention discloses an anti-interference method based on an intelligent antenna and a neural network algorithm. According to the method, a back frame structure of the antenna is used as a model; based on an artificial neural network, an intelligent antenna structure deformation estimator and a shape controller are designed; an improved error algorithm is adopted, so that the characteristics of high convergence rate and small calculation amount are realized; and a relatively high anti-interference characteristic is achieved. A typical applicable type is adopted by the conventional artificial neural network topology structure; the intelligent antenna is combined, and a bipolar intelligent antenna is used, so that the convenience in actual operation is achieved; the capacity of the 8-unit bipolar intelligent antenna can be met; the coverage aspect is within a normal cell coverage range; and obvious coverage loss does not exist. The transverse size of the bipolar intelligent antenna is reduced by over 50 percent compared with the conventional single-polar intelligent antenna and has obvious advantages of reducing the windward area, reducing the engineering mounting difficulty and reducing the electromagnetic radiation panic of common users.

The method includes following procedures: receiving synchronizing pilot sequence, and obtaining oversampling in frequency domain for synchronizing pilot sequence; on discrete frequency spectrum of oversampling in frequency domain in synchronizing pilot sequence, calculating square of amplitudes of discrete frequency spectrum lines, and summarizing them in order to obtain measure sequence; based on measure sequence to carry out estimation for carrier frequency shift. The invention increases precision of estimating carrier frequency shift, and range of estimation remarkably without increasing complexity.

The present invention provides a Sigma-Delta analog-to-digital converter, which comprises first and second adders, first and second integrators, a first quantizer, a first-order Sigma-Delta modulation circuit of a first DA converter, third and fourth adders, third and fourth integrators, a second quantizer, a second-order Sigma-Delta modulation circuit of a second DA converter, and a noise shaping circuit for shaping the noises of the first-order Sigma-Delta modulation circuit and the second-order Sigma-Delta modulation circuit. The noise shaping circuit performs the integration and scale conversion on digital signals output by the first quantizer, performs the scale conversion on digital signals output by the second quantizer, and then adds up and outputs the converted signals. The Sigma-Delta analog-to-digital converter eliminates quantizing noise of the first-order Sigma-Delta modulation circuit and can improve SNR (signal to noise ratio) and reduce total harmonic distortion by cascading two Sigma-Delta modulation circuits of second order or more than two order and then performing noise shaping on signals output by the second-order Sigma-Delta modulation circuits.

A passive radar device includes: a pulse-by-pulse range compression unit executing cross-correlation processing between received signals of a direct wave and scattered wave on each of pulses divided by a direct-wave reception unit and a scattered-wave reception unit, and calculating a pulse-by-pulse range profile; a block-by-block Doppler processing unit calculating a first Doppler frequency spectrum by executing pulse-direction Fourier transform in block units each grouping plural pulses; a Doppler frequency cell-associated range migration compensation unit compensating a range-direction movement amount with respect to the first Doppler frequency spectrum on a Doppler-frequency-cell-by-Doppler-frequency-cell basis and on a block-by-block basis; and a block-direction Doppler processing unit calculating a second Doppler frequency spectrum by executing block-direction Fourier transform on an output from the Doppler frequency cell-associated range migration compensation unit.

The invention relates to a radar micro-Doppler measurement system and method, and the system comprises a radar subsystem and a terminal subsystem. The radar subsystem is electrically connected with the terminal subsystem. The radar subsystem is used for transmitting radar signals, receiving echo signals of the radar signals and carrying out first-stage signal processing on the echo signals to generate target data information; and the terminal subsystem is used for controlling system parameters of the radar subsystem and is also used for carrying out second-stage signal processing on the target data information to complete detection of the micro-motion target so as to obtain micro-Doppler characteristic parameters. According to the radar micro-Doppler measurement system and method, a micro-motion target is sensed by the transmission of the radar signal, so as to achieve the detection of the micro-motion target. The system and method can adapt to a severe working environment, and the micro-Doppler characteristics of the micro-motion target can be measured all the time and all weather.

A method is provided for multiplexing control information with persistently scheduled data in a spectrally efficient operation. In particular, the invention operates to determine and send a power offset parameter in a message carrying a persistent data allocation from a base station to a corresponding mobile station. The power offsets are related to the control information being sent, and specify the amount by which the mobile should increase its transmit power level when multiplexing particular control information together with the persistent data. The increased transmit power then operates to maintain the required QoS on the data channel.

Current supply switch voltage clipper used in high-speed digital analog converter, belonging to electric installation field, is composed of eke-inverter consisting of connected PMOS tube and one NMOS tube, and another NMOS inserted in this eke-inverter and one standard inverter. The present invention can effectively reduce output signal burr and improve output signal SNR, raising high-speed digital analog converter total performance.

The present invention provides an X-ray dose compensation method for X-ray dose compensation of the detector signals from a multiple array detector with improved SNR, used for the detector signal detected by using the multiple array detector in which a plurality of X-ray detector channels placed in one dimensional array in the channel direction is stacked in a plurality of rows in the row direction to form X-ray detector channels of two dimensional matrix. A plurality of specific X-ray detector channels in the multiple array detector or X-ray planar detector or X-ray image intensifier are used as the X-ray dose reference channels for the X-ray dose compensation by means of signal sum or mean of detector signals from those X-ray dose reference channels.

A biometric feature identification device includes a substrate, an electrode layer, and a switch and trace layer. The electrode layer is arranged at one side of the substrate and has a plurality of electrodes. The switch and trace layer has a plurality of switches and a plurality of traces. The switches are provided to divide the plurality of electrodes sequentially or dynamically into at least one sensing electrode group and a plurality of deflection electrode groups corresponding thereto. Each sensing electrode group corresponds to at least two deflection electrode groups. Each sensing electrode group has at least one electrode for sensing. Each deflection electrode group has a plurality of electrodes for deflection.

A method and apparatus for processing radio-frequency (RF) signals suitable for magnetic-resonance imaging (MRI) and/or magnetic-resonance spectroscopy (MRS) from radio-frequency (RF) coils that have strongly-coupled coil loop pairs, each pair including a transmit loop and a receive loop, wherein the transmit loop and the receive loop are of equal sizes and shapes and in close proximity to each other, and wherein a suitable attenuated and phase-adjusted version of a transmit pulse is subtracted from a receive signal obtained from tissue being examined to improve signal-to-noise ratio (SNR) of the received signal.

The invention relates to a low-orbit moonlet distributed GNSS-S radar system and an in-orbit processing method, and the system comprises a main satellite (50) which is used for receiving, capturing and tracking a navigation satellite signal of a detection region, receiving and processing a GNSS-S echo signal of a sea surface ship target, and carrying out the fusion processing of distributed GNSS-S radar information; and the slave satellites (10, 20, 30 and 40) are used for receiving, capturing and tracking the navigation satellite signals of the detection area and receiving and processing the GNSS-S echo signals of the ship target on the sea surface. The system has the advantages of high imaging detection performance, high information timeliness, high concealment, low system power consumption, low system cost and the like.

The invention relates to a method for improving the ranging precision of a radar based on Gaussian interpolation, and belongs to the technical field of pulse method radar ranging. Based on prior information, on the premise that a sampling rate, a bandwidth and a window function are selected and noise is not added firstly, when a high reference sampling rate is selected to fit an echo pulse pressure result of a 3dB beam width into a Gaussian distribution function, only sampling points with a maximum value and a second maximum value are taken from the echo pulse pressure result, the sampling time is normalized into a sampling time unit by using a real sampling rate, Gaussian interpolation processing can be performed according to a variance value obtained by prior information to estimate a mean value of the fitted Gaussian distribution function, namely the sampling time unit where an echo peak value appears, the echo peak value time can be obtained through simple calculation and conversion, and therefore, the purpose of reducing the distance quantization error is achieved. Simulation results show that the method can significantly improve the ranging precision of a radar.