374 results about "Noise generator" patented technology

An apparatus and method provide non-intrusive in-service testing of audio/video synchronization testing without using traditional audio marker tones. The network includes an A/V synchronous test signal generator which injects video and audio markers into the video and audio non-intrusively and routes the two signals into a switch where they are switched into a channel for encoding and transmission via the ATM network. At the distant end the signal is decoded and routed by a switch into the A/V test generator and measurement set where the markers are detected and the A/V skew calculated, after which the audio and video are routed to the subscriber. The A/V test set signal generator includes a Video Blanking Interval (VBI) test signal generator and a white noise generator, the former injecting a marker into the video signal and the later injecting an audio marker into the audio signal. The video marker is injected into the VBI and broadband, background audio noise to measure the delay between the audio and video components of a broadcast. The marking of the audio is accomplished by gradually injecting white noise into the audio channel until the noise level is 6 dB above the noise floor of the audio receiver. As a precursor A/V sync signal, a small spectrum of the white noise is notched or removed. This signature precludes inadvertent recognition of program audio noise as the audio marker.

A background noise estimate based upon a modified Doblinger noise estimate is used for modulating the output of a pseudo-random phase spectrum generator to produce the comfort noise. The circuit for estimating noise includes a smoothing filter having a slower time constant for updating the noise estimate during noise than during speech. Comfort noise is smoothly inserted by basing the amount of comfort noise on the amount of noise suppression. A discrete inverse Fourier transform converts the comfort noise back to the time domain and overlapping windows eliminate artifacts that may have been produced during processing.

The present invention provides a system and method for introducing white noises into a digital audio signal so that there is progressive and cumulative degradation in audio quality after each successive reproduction of the audio sound signal in a fashion analogous to analog audio reproduction. The invention provides a white noise generator, and a digital entroping unit. In a preferred embodiment, the white noise generator is implemented by a hardware random number generator. The digital entroping unit controls the magnitude of white noise desired based on a random number generated by the random number generator, and adds the white noise to the input audio sound signal to produce a degraded audio sound signal. The magnitude of white noise can be controlled by using various masking and formatting of random number data.

In an aircraft cabin floor adjacent to the cockpit, a trap door opens downwardly into a security cell, to trap a terrorist trying to enter the cockpit. Two walls with lockable airtight doors bound a safety buffer cabin between the cockpit and the passenger cabin. Sensors like seat occupancy sensors, motion detectors, video cameras and microphones provide data regarding the location, movement and activities of passengers to a system that evaluates the data to recognize unusual data situations indicating one or more escalation levels of suspicious or aggressive actions by passengers. Alarm signals and terrorist countermeasure devices such as fogging or tranquilizer gas generators, noise generators, high intensity blinding/glaring lights, a cabin lighting master shut-off, window darkening devices, and tranquilizer dart guns are actuated automatically by the evaluation system, or manually by a cockpit input device or a portable signaling device carried by a flight attendant.

This invention is an ultra-low frequency electromagnetic telemetry receiver which fuses multiple input receive sources to synthesize a decodable message packet from a noise corrupted telemetry message string. Each block of telemetry data to be sent to the surface receiver from a borehole tool is digitally encoded into a data packet prior to transmission. The data packet is modulated onto the ULF EM carrier wave and transmitted from the borehole to the surface and then are simultaneously detected by multiple receive sensors disbursed within the rig environment. The receive sensors include, but are not limited to, electric field and magnetic field sensors. The spacing of the surface receive elements is such that noise generators are unequally coupled to each receive element due to proximity and/or noise generator type (i.e. electric or magnetic field generators). The receiver utilizes a suite of decision metrics to reconstruct the original, non noise-corrupted data packet from the observation matrix via the estimation of individual data frames. The receiver will continue this estimation process until: 1) the message validates, or 2) a preset “confidence threshold” is reached whereby frames within the observation matrix are no longer “trusted”.

A decoding arrangement for decoding pictures in an incoming video stream includes a noise generator for adding a dither signal containing random noise to the pictures after video decoding, to improve the subjective video quality. The noise generator adds noise to each pixel in an amount correlated to the luminance of at least a portion of the current picture.

A mobile device uses sensor data related to the type of surface in contact with the mobile device to determine an action to perform. The sensors, by way of example, may be one or more of a microphone and noise generator, a light based proximity sensor, and pressure sensors, such as dielectric elastomers, configured to detect a texture of the surface, and/or pressure waves produced by setting the mobile device down or by a noise generator and reflected by the surface. The mobile device may identify the type of surface and perform the action based on the type of surface. The mobile device may further determine its location based on the sensor data and use that location to identify the action to be performed. The location may be determined using additional data, e.g., data not related to determining the type of surface with which the mobile device is in contact.

A low power oscillator having fast start-up times. The low power fast starting oscillator uses an oscillator circuit having an input and an output for generating a signal of a desired frequency. A start-up detect circuit is coupled to the output of the oscillator circuit for detecting when the oscillator circuit has reached steady state operation and for generating a start-up circuit output signal which adjusts the gain of the oscillator circuit when steady state operation has been reached by the oscillator circuit. A noise generator is coupled to the input of the oscillator circuit and to the start-up detect circuit for inputting a noise pulse into the oscillator circuit. The noise pulse is used for biasing the input of the oscillator circuit to approximately an optimal bias voltage level. The noise generator is further used for sending an enable start-up detect signal to the start-up detect circuit to activate the start-up detect circuit. A prestress circuit is coupled to the input and to the output of the oscillator circuit for prestressing a piezoelectric resonator of the oscillator circuit to shorten start-up times of the oscillator circuit. The prestress circuit is further used for sending an enable noise generator signal to the noise generator to activate the noise generator.

The embodiment of the invention provides a comfortable noise generator, a method for generating a comfortable noise, and a device for counteracting an echo, and belongs to the technical field of voice communication. The generator comprises a background noise estimation module, a white noise generation module, a white noise shaping module and a comfortable noise filling module, wherein the background noise estimation module is used for estimating a frequency spectrum characteristic and an energy level of a present frame signal in a frequency domain when the present frame signal of an input signal is a background noise so as to obtain a frequency spectrum characteristic estimated value and an energy level estimated value; the white noise generation module is used for generating a white noise in the frequency domain; the white noise shaping module is used for shaping the white noise generated by the white noise generation module so as to obtain a comfortable noise according to the obtained frequency spectrum characteristic estimated value and the obtained energy level estimated value, and the frequency spectrum characteristic and the energy level of the obtained comfortable noise are matched with those of the background noise; and the comfortable noise filling module is used for filling the present frame signal of an output frequency domain signal in which a residual echo is suppressed by using the shaped comfortable noise. By the generator, the quality of a voice can be guaranteed.

A system and method for generating a masking noise level and spectrum automatically adjusted to obtain a target masking noise spectrum in a room. The system comprises a white noise generator and a mask filter automatically determined according to a correction of an acoustical response of the room and to the target masking noise corrected by an ambient noise.

Electromagnetic compatibility of an information handling system and peripheral for achieving defined electromagnetic interference constraints is tested through a test adapter that interfaces with an external cable connecting the information handling system and peripheral. Signals from the external cable are passed through an isolation resistor and parallel capacitance to compensate for input capacitance of a signal tester. A common mode choke isolates a common mode component of the signal at the external cable. A noise generator applies a signal through the test adapter to the external cable to allow measurement of signals emitted from the peripheral due to injected noise.

The invention discloses a Gaussian white noise generator and an implement method thereof, which relates to the technical field of noise generator. The digital Gaussian white noise generator of the invention acquires good time-domain Gaussian noise signals, and simultaneously obtains the output bandwidth as large as possible. The Gaussian white noise generator comprises a pseudo-random sequence generator, an FIR filter, a digital-analog converter, a low-pass filter and a high speed amplifier, wherein the pseudo-random sequence generator is used for generating a pseudo-random sequence; the FIR filter filters the pseudo-random sequence to obtain a band limited Gaussian white noise sequence; the digital-analog converter converts digital signals to analog signals; the low-pass filter inhibits out-of-band noise interference; and the high speed amplifier amplifies noise signals.

A bandpass filter bandpass-filters an inputted signal X to pass therethrough a partial band of a band of the inputted signal X, and a level correlated white noise generator circuit generates a white noise signal having a level changing according to a level of the inputted signal and correlated to the inputted signal. A signal processing circuit executes a signal processing that includes a predetermined bandpass filtering processing, an echo adding processing, and a level adjustment processing, and that multiplies the inputted white, noise signal by a predetermined transfer function, and outputs a processed white noise signal to an adder. The adder adds up the white noise signal from the signal processing circuit and the inputted signal X, and outputs a band-extended signal having an addition result, as an outputted signal.

A sound masking device comprises a housing having an open end, a white noise generator within the housing, and a speaker to receive a white noise signal from the white noise generator and to emit a white noise corresponding to the white noise signal. The speaker is set back from the open end and positioned within the housing to emit the white noise toward the open end. The housing may comprise a shelf or shoulder around an inner surface of the housing located between the speaker and the open end.

A cache may comprise a memory and control logic. The memory may be configured for storing data buffered by the cache. The control logic may be configured controlling accesses to the memory. The control logic may comprise a pseudo-noise generator and a trigger device. The pseudo-noise generator may be configured for generating a pseudo-random number representing, for a miss access requiring allocation, which of a plurality of possible addresses in the memory to use for the allocation. The trigger device may be configured for controlling a cycle of the pseudo-noise generator to output the pseudo-random number therefrom.

The invention provides a pulse radar echo signal generator and a signal generating method thereof, relating to the moving target detection technical field. The pulse radar signal generator utilizes parameters input by a pulse radar parameter generator to control a synchronizing signal generator, a noise generator, a target signal generator, a noise wave generator and a signal synthesizer in real time, and a full in-kind pulse radar echo signal is generated. The target, noise and noise wave in the pulse radar echo signal of the invention can be regulated in wider range, the pulse radar echo signal can be used for verifying target detecting and tracking performances of a radar signal processing system, thus being an economic and effective means and having wide application range.

A comfort noise generator (104) suitable for use in a communication system includes a finite impulse response (FIR) filter (136), a random number generator (140), and a coefficient updater (138). The coefficient updater (138) determines an updated set of filter coefficients (142) based on the signal frame of the input signal (102). The updated set of filter coefficients (142) is output to the FIR filter (136). The FIR filter (136) shapes a white noise signal (146) supplied by the random number generator (140) to provide a simulated background noise signal, or comfort noise signal (122). The comfort noise signal (122) is selectively output from an echo suppression system or corresponding method to overwrite or suppress reflected residual echoes.

The present invention relates to an echo canceler for training an echo path estimation without providing a hindrance to a speech. The echo canceler of the present invention includes a pseudo noise generator for generating a certain pseudo noise. This pseudo noise is forcibly supplied to a transmission line for transmitting a far-end talker's voice. Here, in the case where the far-end talker's transmitting speech level is faint or the far-end talker is in a speechless condition, a certain correlation is established between the pseudo noise and a signal of the transmission line for transmitting the near-end talker's voice. Based on such a correlation as just mentioned, a coefficient for generating an echo replica is calculated. Therefore, a training for estimating an echo path is performed based on the pseudo noise and without depending on the far-end talker's voice, thereby generating an appropriate echo replica.

A device is provided for acoustically reproducing the respiratory function for a respirator, with a patient respiration circuit. The device has a noise generator, a volume flow sensor device, which determines the volume flow in the patient respiration circuit and generates an electric signal representing the volume flow, and a volume flow evaluating unit, which is set up to pick up the volume flow signal and to generate a control signal for the noise generator as a function of this in such a way that an acoustic signal with a loudness rising (falling) with rising (falling) volume flow is generated. To optimize the loudness of the acoustic signal, a microphone and an evaluating unit connected thereto are provided, which said evaluating unit is set up to generate at least a first measure for the instantaneous ambient noise level on the basis of the microphone signal by averaging over at least one period of time and to increase (reduce) the loudness of the acoustic signal with rising (falling) ambient noise level as a preset monotonic function of the at least one measure.

A system and method of spread-spectrum fan control for an air-cooled system is provided for reducing the vibrational and acoustical noise associated with the air-cooled system. The method includes generating a first control signal that controls a blade-passing frequency of a first cooling fan and a second control signal that controls a blade-passing frequency of a second cooling fan, wherein the first and second control signals may be pulse width modulated (“PWM”) signals. One or more noise generators independently vary duty cycles for the first and second PWM signals within a range around respective first and second blade-passing frequency set points. As a result, the blade-passing frequencies for the first and second cooling fans are independently and randomly modulated within a range around the respective first and second blade-passing frequency set points.

Method and apparatus for generating random numbers are disclosed. In one aspect, a method for generating random numbers for use in a wireless communication device provides for generating random numbers, gathering a sample of the generated random numbers, and computing at least one metric, such as mean value, standard deviation, and/or entropy. The method further provides for comparing the metric with a corresponding reference value and adjusting the metric based on a result of said comparison so that the generated random numbers achieve a desired distribution. In another aspect, an apparatus for generating random numbers includes an analog noise generator and hardware components for generating random numbers and feedback values to adjust the random numbers. The apparatus further includes a processor capable of executing instructions to carry out control algorithms for adjusting the random numbers.

A method is provided for generating noise in an interior and exterior of a motor vehicle in which a control unit is provided which can be activated and which is operatively connected to a noise generator. The noise generator is connected to at least one noise emitting device (3). The noise emitting device (3) is mounted underneath a hood of the motor vehicle, and is connected to the vehicle interior via at least one hose with at least one sound transmitting element. Sound waves are extracted from the noise emitting device (3) and are transmitted into the vehicle interior.