36results about How to "Accurate signal reception" patented technology

The invention discloses an underground magnetic signal receiving device and receiving method based on the Hall effect. The device consists of a Hall element, an excitation current control circuit, a front-end signal processing module, a decoding and a main control module. When the system starts to run, the excitation current of the Hall element is first adjusted by the excitation current control circuit, then the main control module measures the communication frequency through TIM1 and then sets the clock of the FPGA decoding module, and then the Hall element converts the magnetic signal into The electrical signal is input to the front-end signal processing module, and the digital signal obtained after signal amplification, filtering, and analog-to-digital conversion is input to the FPGA decoding module, and finally the decoded data is input to the MCU. The invention utilizes the Hall element to receive the magnetic signal, and adjusts the excitation current according to the magnetic field distribution at different positions to obtain better voltage output. At the same time, under the response speed of the Hall element, the reception of signals in the frequency range of 2kHz~100kHz can be realized.

The invention discloses a low-orbit satellite communication dynamic time delay and Doppler simulation method, which calculates the dynamic transmission time delay and dynamic Doppler frequency deviation according to the real-time communication distance between the low-orbit satellite and the ground terminal, and calculates the dynamic time-delay and dynamic Doppler frequency deviation according to the low-orbit satellite The signal transmission model designs the corresponding dynamic delay simulation system. After the sending signal of the satellite terminal passes through the dynamic time delay simulation system, the ground receiving signal under the real-time dynamic time delay scene can be simulated. In the dynamic delay simulation system of the present invention, the dynamic delay filter does not need to calculate the filter coefficients in real time, and the filter coefficients can be updated only by inputting the real time delay using the Farrow structure. Compared with other schemes, the structure is simple and the implementation complexity is low. And the simulation results are accurate. At the same time, the use of up-sampling and down-sampling processing makes the frequency band of the satellite transmission signal in the working frequency band of the time-delay filter with good amplitude-frequency response, further reducing the error of the time-delay simulation system.

The invention discloses a self-offset well shock detection device, and relates to a well shock detection device. A motor is arranged in a shell; the output shaft of the motor is provided with a lead screw connected with a sliding nut; the sliding nut is hinged with a support rod; one end of the lead screw connected with the output shaft of the motor is provided with a flat-hole connector, and theoutput shaft of the motor is a flat shaft correspondingly; the flat-hole connector on the lead screw is in sliding connection with the output shaft of the motor; a compression spring is arranged between the flat-hole connector on the lead screw and the sliding nut; and after the support rod is unfolded, if conditions that soil on the well wall is loose and collapsed, a position is moved and a support point slides occur, the elasticity of the compression spring can push the sliding nut to drive the support rod to reliably support the well wall, so that the automatic support and offset can be achieved. The shock detection device is reliable to couple the well wall, low in noise, and high in precision, accurately receives signals, acquires signals truly and reliably, accurately performs analysis and judgment, and is suitable for well shock detection.

A circuit applied to a display apparatus includes a front-end circuit, a conversion circuit and an impulsive interference detection circuit. The front-end circuit converts an analog input signal into a digital input signal. The conversion circuit, coupled to the front-end circuit, converts the digital input signal from a time domain to a frequency domain to generate a frequency-domain signal. The impulsive interference detection circuit, coupled to the conversion circuit, detects a noise intensity of the frequency-domain signal to generate a detection result, which is used to determine whether the analog input signal has impulsive interference.

The invention discloses a method and a device for eliminating co-channel interference in quadrature amplitude modulation signals. The method for eliminating the co-channel interference in the quadrature amplitude modulation (QAM) signals comprises the following steps of: performing fast Fourier transform on time domain received signals to acquire frequency domain received signals corresponding to the time domain received signals; calculating the power spectrum density of each signal component in the frequency domain received signals, and eliminating the co-channel interference in the frequency domain received signals according to the comparison relationship between the power spectrum density of each signal component in the frequency domain received signals and a power spectrum density threshold value; and performing inverse fast Fourier transform on the co-channel interference eliminated frequency domain received signals to acquire co-channel interference eliminated time domain received signals.