Abstract: A vibration controller includes an input signal generator for generating input signals based on cyclically pulsating signals emitted from a vibration generating source, an actuating waveform detector for detecting actuating waveforms of an electromagnetic actuator of active vibration insulators, a waveform analyzer for determining higher harmonic component datum information by carrying out a waveform analysis, a higher harmonic component signal generator for generating higher harmonic component signals of the actuating waveforms based on the higher harmonic component datum information, a higher harmonic component signal remover for removing the higher harmonic component signals from the input signals and outputting the resulting processed input signals, and an actuator for receiving the processed input signals, generating output signals based on the processed input signals and actuating the electromagnetic actuator in accordance with the output signals.

Abstract: A signal analysis instrument (10) and a receiver. The signal analysis instrument (10) comprises a computer (12), a phase shift mechanism, a receiver mechanism and data acquisition device. The phase shift mechanism comprises an input (100) for receiving a first high frequency signal; a phase shifter (114) arranged to act on the first high frequency signal to produce a phase-shifted first high frequency signal; and a phase shift controller (116) arranged to control operation of the phase shifter (114) in response to instructions from the computer (12). The receiver mechanism comprises a mixer (104) and a first signal conditioning circuit (106). The mixer (104) is responsive to the phase-shifted first high frequency signal and to a second high frequency signal to produce a mixer output signal. The first signal conditioning circuit (106) is responsive to the mixer output signal to produce a receiver output signal.

Abstract: The accuracy of certain sensors is greatly improved by improving their signal to noise ratio (SNR) in the presence of an interfering noise. Sensors were discovered which have a SNR which substantially changes when an operating parameter is selectively modulated to different magnitudes. Some noise can be practically eliminated. In the simplest form, the sensor is operated where it is both stable and close to its best SNR This is usually faster and less costly, but the noise is never completely eliminated. Often, the method involves operating the sensor in first one state and then another wherein the operating parameter has conditions where the sensor is stable, reproducible, and reliable, and wherein the SNRs are substantially different. The output of a state is combined with the output of another state in such a way that the noise cancels but a signal remains. Often the output in a state having greater noise is attenuated until it matches the noise content of another state having less noise.

Abstract: An image processing system includes an image collector and a light falloff correction system. The light falloff correction system comprises a polar transformer that converts an image into radial traces and a falloff fitter that fits the radial traces to a model of falloff to determine a light falloff correction for the image.

Abstract: A measuring method and system for liquid crystal display driver chips applies a new method to measure voltages of driver chips, and utilizes probability and statistics for analysis and determination so as to yield a rather accurate effect even under noisy environments. Accordingly, analog-to-digital converters can be replaced for faster sampling. The measuring method and system can be implemented using comparator circuits or pin electronics cards so that the measuring procedure for driver chips is simplified. Measured results are analyzed and verified by application of probability and statistics. As such, testing of liquid crystal display driver chips is more accurate, testing time is reduced, and accuracy level is promoted.

Abstract: A method for performing region growing in a data volume that accounts for noise in the data on a probabilistic basis. The data volume is divided into discrete cells, and a probability distribution for each cell's datum value is calculated. Each probability distribution is randomly sampled to generate one probabilistic, noise-free realization for the data volume, and region growing is performed using selected criteria. The process is repeated for different realizations until sufficient statistics are accumulated to estimate the probable size and connectivity of objects discovered.

Abstract: An analytical apparatus for optimally combining measurements from N individual rate sensing devices or gyros into a single rate estimate significantly improves performance over that of any individual component device. Kalman filtering is used to combine rate sensed devices optimally in the sense of minimizing the variance of the rate error. The Riccati differential equation (RDE) associated with combining a collection of rate sensed devices is completely and exactly solved to derive to the matrix RDE. This analytic solution serves as the key for understanding all of the theoretical properties of the optimal filter, and provides a complete characterization of the final virtual rate sensed performance. In addition, the analytic RDE solution allows many practical problems to be solved that have proved essential for developing successful filter implementations. A discrete-time minimum variance filter implementation combines sensor measurements optimally.

Abstract: An electronic device for distorting sensitive information in one or more electromagnetic emanations from the electronic device is disclosed. The device has one or more active layers having one or more electronic components that emit the electromagnetic emanations and one or more conductive substrate layers planarity adjacent to one or more of the active layers that distort the electromagnetic emanations. In alternative embodiments of the inventions, shielding is added with frequency selective openings. In other alternative embodiments, a signal source is added to distort sensitive information.

Abstract: Correcting a signal offset may include observing a finite duration signal yn that comprises a representation of a mixture of a desired signal that may include data of interest, and an undesired signal based on interference of an external interference source. The undesired signal may include an offset component which may be modeled as comprising a step function u defined by unknown step function parameters. The unknown step function parameters may be estimated using, for example, a maximum likelihood method. Thereafter, yn may be corrected based on the estimated step function parameters.

Abstract: A method and apparatus for monitoring and controlling exposure to noise related to a headset are described. The method includes sampling an input sound signal to produce samples of the input sound signal, calculating from these samples a headset sound level corresponding to the input sound signal, calculating cumulative exposure of a headset user to the headset sound level at a specific point in time, and calculating a gain adjustment for the input sound signal to ensure that the total sound to which the headset user will be exposed during a selected time period is within the regulatory maximum level. Advantageously, the method and apparatus of the present invention allow accurate real-time monitoring of cumulative exposure to headset noise and real-time adjustment of headset gain to ensure compliance with regulatory maximum sound exposure levels.

Abstract: A hierarchical power supply noise monitoring device and system for very large scale integrated circuits. The noise-monitoring device is fabricated on-chip to measure the noise on the chip. The noise-monitoring system includes a plurality of on-chip noise-monitoring devices distributed strategically across the chip. A noise-analysis algorithm analyzes the noise characteristics from the noise data collected from the noise-monitoring devices, and a hierarchical noise-monitoring system maps the noise of each core to the system on chip.

Abstract: A system for determining a response characteristic of an nth order linear system, such as a phase locked loop, is disclosed. An input signal is supplied to the linear system, and the system measures an output signal produced by the linear system. A variance record is constructed for a measurable quantity, such as jitter, extracted from the output signal. The response characteristic of the linear system is then obtained from the variance record. The response characteristic, such as the transfer function, noise processes, and/or power spectral density (PSD), may be found through a numerical or analytical solution to a mathematical relationship between a response function of the nth order linear system and the variance record.

Abstract: A method for estimating one or more parameters of a propagation channel, with a priori knowledge of at least one signal, in a system having one or more sensors. The method includes correlating one or more signals received by the sensors with the known signal, sampling the received signals at a sampling period and selecting a number of samples per concatenation, and determining at least one parameter of the propagation channel which enables the most efficient reconstruction of the signals via a maximum likelihood method.

Abstract: The invention relates to a method for measuring the effects of on-chin noise on signal propagation comprising measuring an inactive operating frequency of a first test circuit having a first plurality of elements connected by a first plurality of traces, measuring an inactive operating frequency of a second test circuit having a second plurality of elements connected by a second plurality of traces, measuring an inactive operating frequency of a third test circuit having a third plurality of elements connected by a third plurality of traces, and measuring an inactive operating frequency of a fourth test circuit having a fourth plurality of elements connected by a fourth plurality of traces, wherein the inactive operating frequencies of the first second, third, and fourth test circuits represent one or more effects of on-chin noise on signal propagation.

Abstract: The invention relates to a method for dynamically testing the effects of signal noise and cross-talk on an integrated circuit having a core logic area. The method comprises measuring an inactive operating frequency for each of the plurality of test circuits, measuring an active operating frequency for each of a plurality of test circuits, and analyzing the plurality of inactive operating frequencies and the plurality of active operating frequencies to determine the effects of signal noise and cross-talk on the integrated circuit.

Abstract: The invention relates to a combination for determining the effects of signal noise and cross-talk on on-chip propagation, comprising an integrated circuit, and a testing system having a signal generator, a plurality of ring oscillators responsive to the signal generator and a signal analyzer responsive to the plurality of ring oscillators for dynamically measuring the effects of noise and cross-talk on the integrated circuit. The plurality of ring oscillators includes a first ring oscillator constructed to mimic a data path within the integrated circuit, a second ring oscillator constructed with traces routed within the core logic area, a third ring oscillator randomly placed within the core logic area, and a fourth ring oscillator constructed to mimic a data path within the integrated circuit, the fourth ring oscillator sharing a power source with at least one component of the plurality of components within the core logic area.

Abstract: The invention relates to an integrated circuit, comprising a core logic area having a plurality of components therein, a first test circuit constructed to mimic a data path within the core logic area, a second test circuit constructed with a plurality of traces routed within the core logic area, a third test circuit constructed with a plurality of elements randomly placed within the core logic area, and a fourth test circuit constructed to mimic a data path within the core logic area, the fourth test circuit sharing a power source with at least one of the plurality of components within the core logic area. Each of the test circuits is operable to produce one or more signals for analyzing the effects of on-chip noise on signal propagation.

Abstract: A method for optimizing electromagnetic interference (EMI) comprising: an EMI analyzing step of analyzing a quantity of electromagnetic interference of an LSI by execution of simulation; a step of selecting an instance with a large quantity of noise in said EMI analyzing step; and a step of adjusting a driving capability of said instance so that it is lowered to an extent that a delay does not occur in a signal timing of said instance selected. In order to optimize the analyzed EMI, the portion for which optimizing is required is extracted, and such a measure as increasing the area where the decoupling capacitance is created is implemented for this portion in a necessary degree. Further, by changing the aspect ratio of the block, changing the block position or changing the cell line, the decoupling capacitance can be easily created at the most efficient inserting position.

Abstract: A transducer-based sensor system including a drive signal generator for generating a drive signal, a transducer coupled to the drive signal generator and configured to receive the drive signal, a mixer coupled to the transducer and configured to receive output from the transducer where such output results at least in part from physical movement of the transducer, and a diplexer operatively coupled with an output of the mixer and configured to present a substantially matched output impedance to the mixer over an operative range of output frequencies.

Abstract: Methods for determining a corrected intermodulation distortion (IMD) product measurement for a device under test (DUT) are provided. A ratioed receiver IMD product is measured, where the receiver IMD product results from non-linearities in a receiver. Next, a ratioed composite IMD product is measured, where the composite IMD product results from non-linearities in both the receiver and the DUT. The corrected DUT IMD product (DUTP) can then be determined by subtracting the ratioed receiver IMD product from the ratioed composite IMD product to remove the effects of IMD due to the receiver.

Abstract: One embodiment of the present invention provides a system for calibrating a model of a digital circuit to account for noise effects between signal lines. The system operates by first fabricating a digital circuit for calibration purposes. Next, an input signal is applied to an aggressor net within the digital circuit. The system then measures how noise from the input signal affects the amplitude of a signal on a victim net within the digital circuit. Finally, the system adjusts parameters of the circuit model using the measured results.

Abstract: A CPU of an effector calculates envelopes of an impulse response waveform from sample data of impulse response waveform data supplied from a microphone via an A/D converter circuit. Next, CPU detects a section during which a slope of the detected envelopes takes a value near “0” during a predetermined time or longer. CPU calculates an average value of sample data during the detected section to correct a DC offset. Thereafter, CPU acquires a maximum value of absolute values among the sample data during the detected section, and determines this maximum value as a background noise component value. The background noise components are removed from each sample data constituting the impulse response waveform data.

Abstract: A hierarchical power supply noise monitoring device and system for very large scale integrated circuits. The noise-monitoring device is fabricated on-chip to measure the noise on the chip. The noise-monitoring system comprises a plurality of on-chip noise-monitoring devices distributed strategically across the chip. A noise-analysis algorithm analyzes the noise characteristics from the noise data collected from the noise-monitoring devices, and a hierarchical noise-monitoring system maps the noise of each core to the system on chip.

Abstract: A method and apparatus for removing glitches, interference or noise from a clock signal are provided by the present invention. In accordance with the invention, a glitch-ridden clock signal is monitored to determine when a transition in the glitch ridden clock signal occurs. When a transition occurs, a counter is initiated in accordance with a second high-speed clock signal. The value of this counter is compared to a compare value. The compare value is selected to approximately equal the expected period of the glitch-ridden clock signal. If the counter value equals the compare value, it is assumed that the transition was a valid transition and the transition is carried through and output as a glitch-free clock signal. However, if a transition occurs before the count value equals the counter compare value, it is assumed that the transition is invalid and no transition is carried to the glitch-free clock output.

Abstract: The correction device comprises a block for decomposition into total proper elements, according to the Kato spectral decomposition method, of the covariance matrix to be corrected. The block supplies to a correction block the total proper values and the total projectors of the covariance matrix, as well as first coefficient vectors for the combination of the source signals of the covariance matrix. The correlation block estimates the reconstructed variances of combinations of the source signals using the first coefficient vectors and second used-defined coefficient vectors. It looks for the corrected matrix closest to the matrix to be corrected, in relation to the variances and total projectors while is applying a quasi-Newton type method to the dual of a semi-defined lesser error square programme.

Abstract: An instrument is provided for measuring a noise figure with significant flexibility. The instrument includes a noise source (306) and a vector network analyzer (VNA) (300). The VNA (300) includes an external connector port (302) for removable connection of the noise source (306). The noise source (306) can be connected to the VNA backplane port (302), or directly to a DUT (350). The DUT (350) can be connected to both VNA test ports (310,314) if the noise source (306) is connected to port (302), or only to test port (314) if the noise source (306) is directly connected to the DUT. A receiver connected to the test port (314) includes a downconverter (324) providing an IF signal through either a narrowband IF channel (350) or a wideband IF channel (352) for providing both wideband and narrowband power measurements enabling fast accurate measurement of a noise figure.

Abstract: A product-sum operation portion for performing a product-sum operation (wavelet transformation) with respect to an input time-series signal by using as a base of integral a complex function in which the imaginary number portion is &pgr;/2 shifted in phase from the real number portion, a phase calculation portion for calculating a phase &thgr; from the ratio between the real number portion and the imaginary number portion of a result of the product-sum operation, a peak time detection portion for detecting a time point at which the calculated phase &thgr; changes from 2&pgr; to zero, as a peak time, are provided. Since the wavelet transformation is performed by using a basic wavelet function that is localized in terms of time and frequency, a peak time can be promptly detected. Furthermore, since a differential operation is not employed but the product-sum operation is performed, false detection caused by noises or the like can be prevented.

Abstract: A noise analyzing method analyzes a crosstalk noise based on circuit data in which buses having the same signal transmitting direction and buses having opposite signal transmitting directions are distinguished from each other, by analyzing the crosstalk noise only for the same signal transmitting direction with respect to the buses having the same signal transmitting direction.

Abstract: A method and system are invented for adaptively and automatically retuning a closed-loop servo motor that is operating within normal limits. A first active set of configurable tuning constants is assigned to the servo motor, and motor performance is periodically measured to determine if performance is outside a retuning threshold, in which case the active set of configurable tuning constants is replaced by selecting a replacement set of tuning constants from a finite group of discrete predesigned sets of tuning constants. Actual performance of the servo motor is remeasured, and this process is repeated if the performance remains outside the retuning threshold. The predesigned sets of tuning constants are derived and stored in the servo motor software, typically as a result of pretesting the servo motor model by the manufacturer, for example using manual retuning.

Abstract: In order to check an occurrence of a signal component in an input signal, a method and a device is provided. The method comprises the steps of generating a measure for the frequency of the input signal from the input signal, determining a variance of the measure for the frequency of the input signal, comparing the determined variance with a predetermined limit value, and confirming the occurrence of the signal components if the variance lies within a predetermined range in relation to the predetermined limit value. The occurrence of a signal component in an input signal can be determined very fast and by performing only a few steps. Therefore, the method according to the invention and the device according to the invention can very well be used in particular in mobile devices, as for example in hearing devices.

Abstract: An intermodulation detector (11) that operates standalone or in parallel with a radio receiver (10) of a radio receiver system (100) including a receiver tuning logic module (12), and, in the case of operating standalone, provides signals conveying information about intermodulation power in the receiver frequency band, and in case of operating in parallel with a radio receiver (10), provides to the receiver tuning logic module signals conveying information about power aliasing into the frequency band to which the radio receiver is tuned.

Abstract: A method and apparatus for monitoring and controlling exposure to noise related to a headset are described. The method includes sampling an input sound signal to produce samples of the input sound signal, calculating from these samples a headset sound level corresponding to the input sound signal, calculating cumulative exposure of a headset user to the headset sound level at a specific point in time, and calculating a gain adjustment for the input sound signal to ensure that the total sound to which the headset user will be exposed during a selected time period is within the regulatory maximum level. Advantageously, the method and apparatus of the present invention allow accurate real-time monitoring of cumulative exposure to headset noise and real-time adjustment of headset gain to ensure compliance with regulatory maximum sound exposure levels.

Abstract: A multi-sensor data fusion system and method provide an additive fusion technique including a modified belief function (algorithm) to adaptively weight the contributions from a plurality of sensors in the system and to produce multiple reliability terms including reliability terms associated with noise for low SNR situations. During a predetermined tracking period, data is received from each individual sensor in the system and a predetermined algorithm is performed to generate sensor reliability functions for each sensor based on each sensor SNR using at least one additional reliability factor associated with noise. Each sensor reliability function may be individually weighted based on the SNR for each sensor and other factors. Additive calculations are performed on the reliability functions to produce at least one system reliability function which provides a confidence level for the multi-sensor system relating to the correct classification (recognition) of desired objects (e.g., targets and decoys).

Abstract: Distortion compensation controller reduces harmonic distortion in an AC circuit current and/or voltage of a power converter bridge operating under digital current and/or voltage control. Within distortion compensation controller, an array of memory locations are used, each corresponding to a particular angle range in the AC cycle. Enough memory locations are allocated to cover all of the AC cycle. For each of these memory locations, historical information is collected over a number of AC cycles about the distortion measured during the corresponding angle range in the AC cycle. Using the historical information, a compensation signal is calculated for use at that angle in the next AC cycle. As the AC cycle progresses, the appropriate compensation signal is added to the output of a conventional current controller. In this way, a near perfect sinusoid can be achieved in the steady state for the current/voltage waveform in the AC circuit.

Abstract: The prior art knows two different approaches to calibration of multichannel instruments, viz., the so-called physical and statistical calibration methods. The new methods translate the difficult inverse-problem posed by the statistical method into simpler, forward-problem, “physical” measurements of the signal and the noise. The new methods combine the quality of the statistical method with the low cost and interpretability of the physical method. The new methods disclose how to compute the optimal regression vector; how to update the optimal regression vector to account for small changes in the noise; how to choose a “good” subset of channels for measurement; and how to quantify the noise contributions from the multichannel measurement and from the reference measurement individually. The new methods are adapted to different situations to enable users in different situations to realize maximum cost savings.

Abstract: The invention provides for improved signal to noise ratios in evaluation techniques. This is done by acquiring a signal, processing it to obtain a complex form thereof, obtaining a filtering factor from the complex form and processing the acquired signal with the filtering factor. The signal may be areturned ultrasonic, radar or sonar signal which may be reflected from a suitably sharp pulse. In particular, the invention may be used to evaluate articles to detect defects therein. In a preferred form, the complex form is filtered with a number of compelx filters and the phases of the complex filtered signals determined. These phases are then used to provide the filtering factor.

Abstract: A general method of anomaly detection from time-correlated sensor data is disclosed. Multiple time-correlated signals are received. Their cross-signal behavior is compared against a fixed library of invariants. The library is constructed during a training process, which is itself data-driven using the same time-correlated signals. The method is applicable to a broad class of problems and is designed to respond to any departure from normal operation, including faults or events that lie outside the training envelope.

Abstract: A noise reduction/resolution enhancement signal processing method and system is disclosed, wherein the influence of noise spikes and gaps is substantially reduced. The data for the noise reduction may be amplitudes (bx) measured at corresponding values (x) over a given domain D, wherein the data defines a composite wave form. The composite wave form is decomposed into instances of a discrete wave form, each having reduced noise amplitudes. A candidate point c in D for, e.g., an amplitude extreme is determined for each discrete wave form instance (having unknown amplitude). A minimization technique determines a first set of discrete wave form instances (having known amplitudes) by collapsing on the amplitudes (bx) from above. A maximization technique determines a second set of discrete wave form instances (having known amplitudes) by rising up to the amplitudes (bx) from below.

Abstract: An apparatus for signal amplitude restoration has a received signal input and a scaled received signal output. An amplitude correction factor generator has an estimated signal-to-noise power ratio input and a received signal input. A variable gain amplifier uses the correction factor generator output to control its gain, and amplifies or attenuates the received signal input to provide the scaled received signal output. An average SNR estimator uses the amplifier output as its input, and provides an output connected to the estimated signal-to-noise power ratio input. The apparatus processes received signals in an iterative fashion, such that at least one of the outputs is stored for use as a feedback input during later iterations.

Abstract: An adaptive forward error correction technique based on noise bursts and the rate at which they occur is disclosed. The forward error correction parameters are determined using statistics describing the noise burst duration and period. The occurrence, duration and period of the noise burst are determined by the error vector magnitude calculated during the decoding process.

Abstract: A thorough error suppression signal measurement system (20) having a transmitter (300) for propagating a transmission signal to a first probe 100, through a device under test (26), and into a second probe (200), and for propagating reference signals to the probes (100,200). The probes (100,200) extract normalization signals from the reference signals, exchange specific ones of the normalization signals, and combine the normalization signals with data signals derived from the transmission signal to form receiver signals. The probes (100,200) propagate the receiver signals to a receiver (400), where the signals are gain-ranged, digitized, normalized, and compensated for phase-noise.

Abstract: A system and method of tracking ambient signals, detecting or receiving desired signals, and suppressing undesired signals. An array of sensors receives ambient signals and generates N channels of data. A transformation device accepts the data from the array and generates N′ channels of data. An adaptive processor accepts the N′ channels of data from the output of the transformation device and processes the N′ channels of data to update the settings of the transformation device, such that only N′ degrees of freedom are adaptively manipulated by the adaptive processor at an instant, the manipulation being done in a manner that instantaneously senses changes in signal environment and adjusts the settings of the transformation device in a closed-loop. The adaptive processor optionally combines these N′ channels to produce system output beam(s) that remove residual interference present out the output of the transformation device.

Abstract: Raw DNA data is filtered with a multi-component analysis that is applied to the difference of the signal intensity on each of the raw DNA data signals to remove cross talk between the signals. The analysis is done before any baseline adjustment of the raw DNA data. Instead, the baseline adjustment occurs after the raw DNA data has been filtered. Additionally, an additional processing step is applied to the data to account for the non-linear nature of cross talk filtering. The additional processing step involves combining the signal with its derivative to account for the correlation of each of the data signals with the other three data signals.

Abstract: A process variable transmitter providing a transmitter output representing a process variable sensed by a sensor. The transmitter has a filter with a bandwidth which is automatically adjusted based on noise detected in a sensor output. When the transmitter senses higher sensor noise levels, it automatically decreases the bandwidth to damp noise in the transmitter output. When the transmitter senses lower sensor noise levels, it automatically increases the bandwidth to provide faster response to changes in the process variable.

Abstract: A method and system for implementing a simple Gaussian white noise generator for real time speech synthesis applications. According to an embodiment of the present invention, a method for generating a Gaussian random noise signal comprises the steps of: generating a first predetermined number of outputs from a first random number generator having a first period; generating a second predetermined number of outputs from a second random number generator having a second period different from the first period; calculating a first average from a first combination of inputs from the first random number generator and the second random number generator; calculating a second average from a second combination of inputs from the first random number generator and the second random number generator; and generating a Gaussian output based on the first average and the second average.

Abstract: An N-clock system, for use for example in a ranging receiver using a Kalman filter. The clock system uses N clocks (to save power by using some clocks that consume less power) with a schedule for switching from one clock to another (so that only one clock is on at any instant of time). It uses an N-clock model that, in case of an application using clock 1 for time interval &Dgr;t1, clock 2 for time interval &Dgr;t2, . . . , and clock N for time interval &Dgr;tN, provides a state update equation for updating the N-clock system state (the state components being typically time and fractional frequency). The state update equation results from propagating the state of the assembly of N clocks (providing a single output, i.e. acting as a single clock) forward from interval to interval until the entire interval of &Dgr;t1+&Dgr;t2+ . . . +&Dgr;tN is covered.

Abstract: An electronic device for distorting sensitive information in one or more electromagnetic emanations from the electronic device is disclosed. The device has one or more active layers having one or more electronic components that emit the electromagnetic emanations and one or more conductive substrate layers planarity adjacent to one or more of the active layers that distort the electromagnetic emanations. In alternative embodiments of the inventions, shielding is added with frequency selective openings. In other alternative embodiments, a signal source is added to distort sensitive information.

Abstract: Disclosed is a method and apparatus of creating a virtual beam in a desired beam direction from an array of analog signal components. Preferably, a random number generator provides a random sequence of indices of said array and provides an associated sequence of time delays, the random sequence of indices including specific statistical properties. A multiplexer selects individual analog signal components of said array in a sequence based on the specific statistical properties. An analog to digital converter digitizes the analog signal components of said array to generate an aggregate digital signal comprising digital signal components to provide the single sequence of sampled digital signal components. An alignment unit provides a time alignment between the digital signal components, according to the random sequence of delays and indices. A down-filter filters the time aligned signal components for selecting a desired signal frequency band and eliminating noise outside the band.

Abstract: The phase noise of an oscillator described by a known set of differential algebraic equations (DAEs) can be predicted by a) finding the steady state waveform of the oscillator, e.g., by using harmonic balance techniques or so-called “shooting” techniques, either of which involves developing a mathematical quantity known as the augmented Jacobian matrix; b) solving a prescribed linear system of equations that uses the augmented Jacobian matrix, the solution being called a perturbation projection vector (PPV), c) plotting a graph of the phase noise of the oscillator as a Lorentzian function of the solution of the prescribed linear system of equations. The prescribed linear system of equations which is used is the system of equations formed by setting a matrix product equal to a unit vector.

Abstract: A jig is successively mounted on each of the four wheels of a vehicle. The jig is struck in three orthogonal directions independently, and at the same time, a microphone inside the vehicle measures the sound pressure of noise generated due to the exciting force. An FFT analyzer operates a frequency response function from the exciting force to the sound pressure. In a drum testing machine, a tire to be subject to noise prediction is mounted on a shaft, the tire is rotated, and the axial force in the three orthogonal directions is measured. The axial force signal is input to the FFT analyzer and the auto power spectrum in the three orthogonal directions and the cross power spectrum between two different axial directions are operated. The frequency response functions are synthesized with the auto power and cross power spectrums, and the power spectrum of the road noise is operated.