82 results about "Spectral noise" patented technology

A novel and useful apparatus for and method of improving the quantization resolution of a time to digital converter in a digital PLL using noise shaping. The TDC quantization noise shaping scheme is effective to reduce the TDC quantization noise to acceptable levels especially in the case of integer-N channel operation. The mechanism monitors the output of the TDC circuit and adaptively generates a dither (i.e. delay) sequence based on the output. The dither sequence is applied to the frequency reference clock used in the TDC which adjusts the timing alignment between the edges of the frequency reference clock and the RF oscillator clock. The dynamic alignment changes effectively shape the quantization noise of the TDC. By shaping the quantization noise, a much finer in-band TDC resolution is achieved resulting in the quantization noise being pushed out to high frequencies where the PLL low pass characteristic effectively filters it out.

An optical hyperspectral/multimodal imaging method and apparatus is utilized to provide high signal sensitivity for implementation of various optical imaging approaches. Such a system utilizes long working distance microscope objectives so as to enable off-axis illumination of predetermined tissue thereby allowing for excitation at any optical wavelength, simplifies design, reduces required optical elements , significantly reduces spectral noise from the optical elements and allows for fast image acquisition enabling high quality imaging in-vivo. Such a technology provides a means of detecting disease at the single cell level such as cancer, precancer, ischemic, traumatic or other type of injury, infection, or other diseases or conditions causing alterations in cells and tissue micro structures.

An automotive tire pressure monitoring assembly 10 for installation in a vehicle 12 is provided. The automotive tire pressure monitoring assembly 10 includes at least one tire pressure sensor 34 generating a signal based on the pressure of air within a tire 14. The at least one tire pressure sensor 34 further includes a sensor receiver 68 in communication with a sensor control logic 38. The sensor control logic 38 is adapted to receive spectral noise 20 from at least one noise generating assembly 18. The automotive tire pressure monitoring assembly 10 further includes a controller assembly 52 positioned within the vehicle 12 and in remote communication with the at least one tire pressure sensor 34. The automotive tire pressure monitoring assembly 10 includes a positioning logic adapted to determine the position of the at least one tire pressure sensor 34 based on the strength of the spectral noise 20.

A system is provided for transmitting information through a speech codec (in-band) such as found in a wireless communication network. A modulator transforms the data into a spectrally noise-like signal based on the mapping of a shaped pulse to predetermined positions within a modulation frame, and the signal is efficiently encoded by a speech codec. A synchronization sequence provides modulation frame timing at the receiver and is detected based on analysis of a correlation peak pattern. A request/response protocol provides reliable transfer of data using message redundancy, retransmission, and/or robust modulation modes dependent on the communication channel conditions.

An apparatus and method are provided for simply estimating joint channel and Direction-of-Arrival (DOA) to efficiently estimate a channel impulse response associated with a spatially selective transmission channel occurring in a mobile radio channel, and performing efficient beam forming using the simplified joint channel and DOA estimation are provided. A receiver estimates the total interference power using power for each interference signal, estimates a spectral noise density, calculates steering vectors considering predetermined DOAs, and jointly calculates optimal weight vectors for each DOA of each user by applying the interference power and the spectral noise density to the steering vectors. The beam forming reduces implementation complexity of a TDD system such as a TD-SCDMA and increases beam forming efficiency in a mobile environment by efficiently using spatial diversity.

Systems and methods for improving efficiency of a data converter. An example method generates a noise signal, alters the spectrum of the noise signal based on operation of an associated data converter, and supplies the altered spectrum noise signal to the associated data converter. The data converter is a digital-to-analog converter or an analog-to-digital converter. The altered spectrum noise signal is notched at frequencies of interest. The spectrum is altered by sending a signal generated by a random number generator to a delay device and adding the output of the delay device from the output of the random number generator. Also, the spectrum is altered by seeding first and second identical random number generators, delaying the operation of the first random number generator, and adding the output of the delayed first random number generator from the second random number generator.

A system estimates the spectral noise power density of an audio signal includes a spectral noise power density estimation unit, a correction term processor, and a combination processor. The spectral noise power density estimation unit may provide a first estimate of the spectral noise power density of the audio signal. The correction term processor may provide a time dependent correction term based, at least in part, on a spectral noise power density estimation error of the actual spectral noise power density. The correction term may be determined so that the spectral noise power density estimation error is reduced. The combination processor may combine the first estimate with the correction term to obtain a second estimate of the spectral noise power density that may be used for subsequent signal processing to enhance a desired signal component of the audio signal.

A spectroscopy system comprises a tunable semiconductor laser, such as an external cavity laser, that generates a tunable signal. A detector is provided for detecting the tunable signal after interaction with a sample. In this way, the system is able to determine the spectroscopic response of the sample by tuning the laser of the scan band and monitoring the detector's response. An integrating device, such as an integrating sphere, is interposed optically between the tunable semiconductor laser and the detector. This integrating device is used to mitigate the effects of parasitic spectral noise, such as noise that is generated by speckle or the combination of single- and multi-mode optical fibers in the transmission link between the tunable semiconductor laser and the detector.

A convenient and economical method and instrumentation to efficiently reduce offensive spectral noises due to water vapor and carbon dioxide gas often encountered in FTIR spectrophotometry is provided by spectrally monitoring and controlling the amount of water vapor and carbon dioxide gas inside the spectrophotometer such that both amounts in the sample and background measurements become congruent through remote open-close operation of water-vapor (or carbon dioxide gas) supplier and dehumidifier (or carbon dioxide gas adsorber). This new technique can be used: (1) Under the ambient humidity condition, saving time and money effectively. (2) Both in the closed spectrophotometer and in the open system. (3) And applicable to any FTIR accessory and measurement method, including transmission, external reflection, reflection-absorption, attenuated total reflection (ATR), and microscopy measurements.

Techniques for detecting noise with a capacitive sensing device. The includes driving a set of one or more sensor electrodes of a plurality of sensor electrodes with a sensing signal at a first frequency, receiving resulting signals based on the sensing signal for each of the one or more sensor electrodes driven, probing the set of one or more sensor electrodes to obtain a set of probing signals, and summing the probing signals of the set of probing signals to generate a noise-analysis signal.

A spectral harvesting system has one or more sensor modules and a processor. The sensor modules autonomously scan RF signals over a range of frequencies in a region of interest. The processor receives observed RF signals from the sensor modules, and performs signal analysis on the observed RF signals received. The signal analysis includes converting the observed RF signals into a frequency signal in a frequency domain, temporally averaging the frequency signal to provide a temporally averaged frequency signal, performing a coarse estimate of the spectral noise floor of the observed RF signals based on the temporally averaged frequency signal using an opening technique that performs an erosion process followed by a dilation process on the temporally averaged frequency signal, and determining an a-posteriori signal presence probability of a signal being present from an RF emitter in the region of interest based on the coarse estimate.

The present invention discloses a pump jet propeller model with Helmholtz resonant cavities, and a design method thereof. The pump jet propeller model comprises a conduit, a front stator, an impeller, a ring rib and a longitudinal rib that are arranged inside the conduit, a Helmholtz resonator with two parallel resonant cavities arranged at the inner front end of the conduit, and a Helmholtz resonator with two parallel neck portions arranged at the inner rear end of the conduit. The resonant frequency of the front resonator is the pump jet blade frequency and 2 times blade frequency, and the resonant frequency of the rear resonator is the 2 times pump jet blade frequency. Compared with the reference pump water jet model, the hydrodynamic performance of the pump jet model with the Helmholtz resonant cavities is basically the same, and the spectral noise at the blade frequency and 2 times blade frequency is reduced by 2-3dB. The number of stator blades is 11 leaves, the number of impeller blades is 9 leaves, and the impeller blades have large lateral slope characteristics, and can be used as the main propeller with the speed of 16 knots, the thrust of 300kN and the power of 3.5MW. According to the technical scheme disclosed by the present invention, pump jet low-frequency spectral noise can be further prohibited, and total noise can be further reduced; and the muffler technical scheme can be applied to the spectral noise optimization design of the non-axis drive integrated motor pump water jet model.

In the present invention that considerable advantage is to be gained in the provision of apparatus and methods for spectral noise logging that exhibit improved frequency resolution and thus sensitivity over those systems known in the art since this would allow for improved detection and characterisation of fluid flow through, or behind, a casing of a well penetrating subsurface formations

The invention discloses an airspace interference signal detection method and device, and relates to the field of array signal processing. The method is realized through the following technical scheme:based on an FPGA chip parallel hardware processing architecture, forming a data covariance matrix through employing array sampling signal data, obtaining a spatial spectrum value based on an MVDR algorithm, and forming a two-dimensional spatial spectrogram; and then, employing the AGC value for assisting spatial spectrum search to realize interference coming direction detection; meanwhile, performingdigital AGC reverse detection on the interference power which changes rapidly, thus acquiring an interference power value, and therefore the detection result of interference information is enriched. According to the method, a steering vector is obtained in a preprocessing mode and spectral peak calculation is converted into spectral valley calculation, so that the complexity of implementationis further reduced; finally, a spatial spectral noise bottom threshold and a local maximum value are used for jointly judging to replace eigenvalue solution of a sampling data covariance matrix to judge the number of interferences, so that detection of the number of interferences is obtained, and engineering application is efficient and feasible.

The invention belongs to the technical field of hyperspectral remote sensing analysis, and particularly relates to a segmented mineral spectral noise treatment method. The method includes the steps that a mineral spectral array is read; the spectral array is segmented and divided into three one-dimensional arrays; one-dimensional discrete wavelet decomposition is carried out on the three arrays obtained after segmentation; the arrays obtained after one-dimensional discrete wavelet decomposition is subjected to wavelet reconstruction according to different high-frequency component levels; a newone-dimensional array is built, the array obtained after wavelet reconstruction is written into the new one-dimensional array, and segmented de-noising is carried out on the one-dimensional arrays; the array obtained after segmented de-noising is written into mineral spectral data, and segmented mineral spectral noise treatment is completed. The method can be used for pertinently reducing the influence of measurement errors of an instrument on the noise of certain wave band ranges, and the influence of de-noising treatment on the information loss in the wave band ranges with important information is reduced.

The invention discloses a mineral constituent hyperspectral remote sensing fine identification method. The method comprises the following steps: subjecting mineral powder in a research region to spectrum scanning to obtain the spectral curves of the mineral powder; extracting and removing abnormal spectral curves in the obtained spectral curves of the mineral powder, carrying out average calculating operation to obtain the average spectral curve of the mineral powder; carrying out a de-noising treatment to obtain a spectral curve without any noise; carrying out a standardization treatment to obtain the absorption peaks of the spectral curve; obtaining all end members of the spectral curve, obtaining the optimal end member group through a least square method model; according to spectral reflectivity values of end members of the optimal end member group and the spectral reflectivity value measured in the research region, establishing a spectral reflectivity inversion equation set, and solving the equation set to obtain the mineral components contained by the spectral curve measured in the research region through remote sensing. The problems such as uncertainty of end members, removal of spectral noise, de-mixing of mineral spectrums, and the like, are solved by the provided method.