72 results about "Amplitude noise" patented technology

The present invention provides an optical filter assembly that reduces the phase and amplitude noise of a detection laser used to detect ultrasonic displacements. The filtered detection laser is directed to the surface of a remote target. Ultrasonic displacements at the surface scatter the filtered detection laser. Collection optics then gather phase modulated light scattered by the surface and direct the phase modulated light to an optical processor to produce a signal representative of the ultrasonic displacements with an improved SNR. Additional processors may determine the structure of the remote target.

Automatic background signal removal for input data, such as for spectrometry data, is provided. Input data includes input pixel points, such as those read by a CCD spectrometer of chromatography device, and intensity values corresponding to the data points. A distribution of changes in the intensity values between the data points is determined, and a noise level is judged by setting a threshold for the distribution. A noise region is identified as a predetermined number of consecutive input points for which the changes in the intensity values are within the noise level. Adjacent noise regions may be connected and the background signal is thus determined and subtracted. A spike noise region may also be identified and filtered, such that a peak obtained from fewer than a second predetermined number of the pixel points is determined as a spike, not a true peak. Non-spike large amplitude noises are optionally filtered.

A regenerator for restoring the originally encoded optical phase of a differential-phase-shift-keyed signal. In an embodiment, the regenerator simultaneously provides limiting amplification and reduces amplitude noise based on a phase-sensitive optical amplifier that combines a weak signal field of a degraded input data with a strong pump field supplied by a local oscillator in a nonlinear interferometer. The two fields interact through degenerate four-wave mixing, and optical energy is transferred from the pump to the signal and vice versa. The phase sensitive nature of the optical gain leads to amplification of a specific phase component of the signal, determined by the input pump-signal phase difference and the incident signal phase is restored to two distinct states, separated by 180° according to the original encoding. Simultaneously, gain saturation of the pump wave by the signal wave results in limiting amplification of the signal wave for removing signal amplitude noise.

The present invention pertains to the field of the design technology of wireless communication system transceiver chip. The characteristics reside in that: the novel back-to-back series connected type MOS varactor adopting the digital signal control forms the main hypercap part of the numerical controlled LC oscillator, and the phase noise converted from the amplitude noise from the oscillator is reduced, and the restraining ability of the oscillator to the noise from the current source is improved, thus, the phase noise of the output signal of the oscillator is finally reduced. The method in the present invention, comparing with the prior method, can improve the performance of the on-piece CMOS oscillator and reduce the power consumption of the oscillator effectively, thus, the method is useful to the reduction of the manufacturing cost and power consumption of the receiver.

The invention discloses a non-contact breathing detection method and a device thereof. The method comprises the following steps: a receiving device R receives a radio frequency signal from a sending device T, and the receiving device R includes two or more receiving antennas; by aiming at the channel state information CSI corresponding to the radio frequency signals received by any two receiving antennas, a ratio of the two is taken, and a new channel state information of each subcarrier is constructed, which can eliminate phase offset and amplitude noise; an optimal breath detection characteristic of each subcarrier is determined according to new channel state information in a window of a period time; According to the optimal respiratory detection characteristics of the plurality of subcarriers, and the fusion calculation is performed to obtain the respiratory rate of a detection target. By adopting the technical scheme of the invention, a sensing range of the respiratory detection can be greatly expanded, and the method has the technical advantages of non-intrusiveness, convenience and low cost.

Automatic background signal removal for input data, such as for spectrometry data, is provided. Input data includes input pixel points, such as those read by a CCD spectrometer or chromatography device, and intensity values corresponding to the data points. A distribution of changes in the intensity values between the data points is determined, and a noise level is judged by setting a threshold for the distribution. A noise region is identified as a predetermined number of consecutive input points for which the changes in the intensity values are within the noise level. Adjacent noise regions may be connected and the background signal is thus determined and subtracted. A spike noise region may also be identified and filtered, such that a peak obtained from fewer than a second predetermined number of the pixel points is determined as a spike, not a true peak. Non-spike large amplitude noises are optionally filtered.

An optically pumped tunable VCSEL swept source module has a VCSEL and a pump, which produces light to pump the VSCEL, wherein the pump is geometrically isolated from the VCSEL. In different embodiments, the pump is geometrically isolated by defocusing light from the pump in front of the VCSEL, behind the VCSEL, and / or by coupling the light from the pump at an angle with respect to the VCSEL. In the last case, angle is usually less than 88 degrees. There are further strategies for attacking pump noise problems. Pump feedback can be reduced through (1) Faraday isolation and (2) geometric isolation. Single frequency pump lasers (Distributed feedback lasers (DFB), distributed Bragg reflector lasers (DBR), Fabry-Perot (FP) lasers, discrete mode lasers, volume Bragg grating (VBG) stabilized lasers can eliminate wavelength jitter and amplitude noise that accompanies mode hopping.

The invention discloses a design method for reducing crosstalk influence between high-speed differential pairs. Polarity of the parts, in front and rear of DC (direct current) coupling capacitors, of differential pair lines is reversed; crosstalk positive and negative amplitude noises of far ends are mutually stacked; differential overall noise is weakened. Theoretical analysis and simulation verification show that the design method has the effect of improving crosstalk quality of high-speed signals on high-density layout PCBs (printed circuit boards); by the use of the design method, development cost of products can be lowered, product quality is stable, and the products are more competitive in the market.

The disclosed testing device for laser phase noise comprises: a phase noise conversion device with two polarization beam-splitting lens (1) and (3), and an atom gas chamber or molecule gas chamber (2). Wherein, coupling two beam linear polarization light by (1) to spread into (2), converting the phase noise into amplitude noise by electromagnetic induced coherence effect, using (3) to divide the detecting light and coupling light, and using a balance zero-beat system to detect the outgoing noise. This invention simplifies device fit to mobile and wide application.

The present invention provides an optical filter assembly that reduces the phase and amplitude noise of a detection laser used to detect ultrasonic displacements. The filtered detection laser is directed to the surface of a remote target. Ultrasonic displacements at the surface scatter the filtered detection laser. Collection optics then gather phase modulated light scattered by the surface and direct the phase modulated light to an optical processor to produce a signal representative of the ultrasonic displacements with an improved SNR. Additional processors may determine the structure of the remote target.

A multistage system and method for estimating respiration parameters from an acoustic signal. At a first stage, the method and system detect and isolate portions of the signal that exhibit long-term, moderate amplitude noise by analyzing cumulative energies in the signal, and portions of the signal that exhibit short-term, high amplitude noise by analyzing peak energies in the signal. At a second stage, the method and system filter heart sound from the signal energy envelope by applying an adaptive filter that minimizes the loss of respiration sound. At a third stage, the system and method isolate respiration phases in the signal by identifying trends in the energy envelope. Once respiration phases are isolated, these phases are used to estimate respiration parameters, such as respiration rate and I / E ratio.

A method for cancellation of amplitude modulation noise using feedforward or feedback topologies. The method is adaptable to cancel amplitude modulation noise (contamination) of an input signal, including: receiving an input signal including an amplitude modulation noise signal; demodulating the amplitude modulation noise signal to generate a baseband amplitude modulation noise signal; signal processing the baseband amplitude modulation noise signal to generate a amplitude re-modulation signal; and re-modulating the input signal based on the amplitude re-modulation signal to generate an output signal, the output signal having less amplitude modulation noise than the input signal. In a feedforward embodiment, the methodology includes: signal processing the baseband amplitude modulation noise signal based on signal inversion to generate the amplitude re-modulation signal; and feeding forward the amplitude re-modulation signal to re-modulate the amplitude re-modulation signal with the input signal. In a feedback embodiment, the methodology includes: receiving the input signal in a gain controlled amplifier, generating a gain-controlled output signal; detecting the amplitude of the amplitude noise modulation signal in the gain-controlled output signal to generate a feedback amplitude noise signal; integrating the feedback amplitude noise signal to generate a gain control signal; and adjusting the gain controlled amplifier based on the gain control signal, such that the gain-controlled output signal has less amplitude modulation noise than the input signal.

A method for determining jitter and noise of an input signal. The method includes acquiring one or more uncorrelated waveform records by an acquisition unit of a test and measurement instrument, determining a correlated waveform from the acquired waveform(s), dividing the correlated waveform into unit intervals, dividing an uncorrelated waveform into unit intervals, measuring a timing displacement (t 1 ) between the correlated waveform and the uncorrelated waveform for each unit interval to form an apparent-jitter array ([t 1 ]), measuring a voltage displacement (V 1 ) between the correlated waveform and the uncorrelated waveform for reach unit interval to form an apparent-noise array ([V 1 ]), calculating a horizontal shift (t s ) between the correlated waveform and the uncorrelated waveform for each unit interval to form a compensated edge time array ([t s ]), and calculating a vertical shift (V s ) between the correlated waveform and the uncorrelated waveform for each unit interval to form a compensated amplitude voltage array ([V s ]).

Automatic background signal removal for input data, such as for spectrometry data, is provided. Input data includes input pixel points, such as those read by a CCD spectrometer or chromatography device, and intensity values corresponding to the data points. A distribution of changes in the intensity values between the data points is determined, and a noise level is judged by setting a threshold for the distribution. A noise region is identified as a predetermined number of consecutive input points for which the changes in the intensity values are within the noise level. Adjacent noise regions may be connected and the background signal is thus determined and subtracted. A spike noise region may also be identified and filtered, such that a peak obtained from fewer than a second predetermined number of the pixel points is determined as a spike, not a true peak. Non-spike large amplitude noises are optionally filtered.