33results about How to "Eliminate signal distortion" patented technology

Aiming at the condition that primary line current and voltage are not easily monitored by a sensor due to high voltage and large current when a high voltage circuit breaker works online, the invention provides an online monitoring method and an online monitoring device of a high voltage vacuum circuit breaker. The method comprises the steps of: using a displacement sensor directly connected with a moving contact of the high voltage circuit breaker to collect a stroke signal of the moving contact; calculating characteristic points on a stroke curve through a series of filtering and correction; and analyzing the characteristic points to calculate relevant parameters so as to judge the work condition of the circuit breaker online. The online monitoring method and device provided by the invention effectively monitor the high voltage circuit breaker online and can resist the monitoring environment of high voltage and large current. As the displacement sensor directly connected with the moving contact of the circuit breaker is just used as a unique signal collecting device in the invention, the problem of difficulty in implementation and high cost caused by the fact that high voltage resisting voltage or current sensors are needed to be used on a primary side line is solved.

The invention provides a depression risk screening system and method based on a virtual reality scene electroencephalogram signal. Under the stimulation of a virtual reality scene, real-time acquisition, processing and analysis of data are carried out on the electroencephalogram signal by an electroencephalogram acquisition system, and finally, a depression risk is screened by a data mining method. The system provided by the invention comprises a virtual reality induction system, a electroencephalogram signal acquisition system and a data analysis system; the virtual reality induction system is used for establishing different virtual reality scenes; the electroencephalogram signal acquisition system is used for acquiring the electroencephalogram signal of a human brain, which is generated under the stimulation of the virtual reality scene and is continuously changed, and outputting the processed electroencephalogram signal and extracted real-time feature information; the data analysis system has a classification discrimination model trained by labeled healthy populations and depression risk populations, compares feature information required in a depression screening process with feature parameters of the classification discrimination model, and distinguishes and discriminates the healthy populations and the depression risk populations.

A rigid-flexible circuit board includes at least one flexible circuit board and at least one rigid circuit board. The flexible circuit board includes a flexible-board substrate, a plurality of flexible circuit board differential mode signal lines, at least one flexible circuit board grounding line, a flexible circuit board insulation layer formed on the upper surface of the flexible-board substrate and covering the flexible circuit board differential mode signal lines and the flexible circuit board grounding line. The rigid circuit board is stacked on the stacking section of the flexible circuit board. A shielding layer is formed on the flexible circuit board insulation layer of the flexible circuit board and corresponds to the extension section of the flexible circuit board. The shielding layer further extends from the extension section to the stacking section. An impedance control structure is formed on the shielding layer to control the impedance of the flexible circuit board differential mode signal lines.

Disclosed is a device under test (DUT) tester using a redriver. The DUT tester more effectively tests the DUT, which is a predetermined semiconductor device, by applying an electrical signal to the DUT and measuring the electrical signal. The DUT tester includes a DUT test unit, a printed circuit board (PCB) provided therein with connectors for the connection with the DUT test unit, one DUT or more horizontally arranged on the PCB, and redrivers horizontally provided under the PCB and one-to-one matched with one DUT or more to compensate for the distortion of the signal integrity of test signals caused according to the variation of the transmission distance.

The invention provides a signal processing system for a four-quadrant photoelectric detector, relates to the field of signal detecting and processing of photoelectric detectors, and aims at solving the problems of distortion of pulse signal acquiring, reduction of system precision and influence from environmental temperature of the exiting processing system for the four-quadrant photoelectric detector. The system is that a signal outputted by the four-quadrant photoelectric detector flows through an amplitude limiting protecting circuit and then is outputted to a high-pass filter; the filtered signal is converted into a differential signal through a single-end converting differential driver; the differential signal is adjusted by a variable gain adjusting module to be zoomed to reach a proper amplitude value and then inputted into a high speed differential analog-to-digital converter; the generated digital signal is inputted to a signal processing unit; the signal processing unit sends a control signal to a detector gain control module according to the intensity of the received digital signal; the detector gain control module controls the output gain of the four-quadrant photoelectric detector; the signal processing unit processes the signal to obtain the spot center position and then sends to a host control system. With the adoption of the system, the spot center position calculation precision can be improved.

Provided are an apparatus and a method for compensating signal distortion caused by noise. The apparatus comprises a noise reduction unit which reduces noise of an input signal including non-zero mean random noise, and a signal compensator which compensates the output signal of the noise reduction unit so that a signal distortion due to the non-zero mean random noise is removed from the output signal of the noise reduction unit.

The invention provides a mu-law method and a mu-law system for reducing nonlinearity of a light source LED of a visible light communication system, being capable of eliminating signal distortion caused by nonlinear characteristic of the LED from a sent signal and thus improving reliability of the system. The method comprises the steps of acquiring the signal to be sent at a sending end; performing mu-law logarithm compression on the acquired signal to be sent and multiplying the compressed signal with a preset predistortion coefficient to acquire a mu-law compressed signal; and sending the mu-law compressed signal out. The method and the system provided by the invention are applicable to the technical field of visible light multi-carrier communication.

The invention provides a method and system for reducing light source LED nonlinearity in a visible light communication system. According to the method and the system, signal distortion resulting from the nonlinearity characteristic of the LEDs can be eliminated from the sent signals themselves. The method comprises following steps of obtaining to-be-sent signal sequences; processing the signal sequences based on a selective mapping algorithm, thus obtaining a set of multi-carrier signal sequence with the minimum peak-to-average power ratio; converting the multi-carrier signal sequence into serial signals; generating a set of marking sequence with same length to the serial signals; if the amplitude value of the serial signals is more than an LED saturation threshold value, multiplying a pre-distortion compression coefficient by the multi-carrier signals of which amplitude value is more than the LED saturation threshold value; and assigning 1 at corresponding position in the marking sequence. The method and the system are applicable to the technical field of visible light wireless communication.

The invention discloses a full differential equalization random number generating method based on optical quantum four-quadrant detection. A matched wavelength LED is adopted as a light source, two photo-current signals are extracted by a method of four quadrant detector diagonal pixel splice to achieve double path balance zero difference detection. Two symmetrical pre-operational amplifiers respectively amplify two current signals in full differential amplification to eliminate common-mode interference signals and eliminate classical optical noise of a low frequency segment and electrical noise produced during primary amplification. Quantum random number noise generated by processing conforms to gaussian distribution. A true random number sequence can be obtained by binarization of gaussian distribution. Integration level is high, signal quality is improved, and the product cost is lowered. The photo-current signals are subjected to IV conversion, inverse amplification and fully differential processing, and high frequency modulation and demodulation, FIR filtering, direct current elimination and distribution processing, a high-quality quantum random number sequence is generated. Devices such as a beam splitter mirror and optical fibre are omitted, and structure is simpler.

The invention relates to an ethernet tranceiving device on the basis of a coaxial cable network and a method for transmitting the Ethernet, the receiving device comprises an analog interface (110) which is connected with a coaxial cable, a voltage amplification unit (260) which is connected with the analog interface (110) and used to amplify sent signal electric levels of the analog interface (110), a receiving unit (200) which is connected with the analog interface (110), wherein the receiving unit (200) comprises a receiving and amplifying unit (210) which is used to amplify received signal electric levels form the analog interface (110), wherein the magnification factors of the voltage amplification unit (260) and the receiving and amplifying unit (210) are confirmed by attenuation characteristics parameters of a coaxial cable distributing network. The method for transmitting comprises: amplifying service signals before sending services and amplifying the service signals on the direction of receiving the services. The invention can realize that baseband electrical signals of the ethernet are transmitted in a coaxial distributing network and the cost is low.

According to the multimode high-sensitivity high-speed signal receiving circuit disclosed by the invention, the communication reliability and the transmission efficiency can be improved. According to the technical scheme, a fixed-point sampling module converts an input analog signal into a digital signal and sends the digital signal to a time delay calculation module, the time delay between two paths of signals is calculated and corrected, and a decimation filtering module recovers a baseband digital signal and sends the baseband digital signal to a self-adaptive equalization module 1 for dynamic correction; sending a cancellation result to a mode identification module, sending an identification result to a carrier tracking module, selecting a corresponding carrier tracking algorithm to carry out carrier tracking, sending the carrier tracking algorithm to a symbol tracking module to carry out symbol tracking, sending a symbol tracking result to an adaptive equalization module 2, and carrying out channel equalization by adopting a blind equalization algorithm; processing results are respectively sent to a variable code modulation processing channel and a fixed mode code modulation processing channel, and lossless receiving of self-adaptive code modulation signals is realized by adopting automatic mode recognition, unified carrier tracking, symbol tracking and decoding processing.

An audio signal processing method and an audio equalizer, both implemented in an embedded system without incurring excessive computation, use a Kaiser-Bessel-derived (KBD) window and an Overlap-and-Add (OLA) processing to eliminate signal distortion of a time domain audio signal during signal conversion and to generate filters according to audio effects desired by a user.