64results about How to "Low signal noise" patented technology

Method enabling multiple communication nodes to access a transmission means on an electrical grid, which permits access in a fair manner by nodes on a shared medium such as the electrical network, achieving the maximum access speed when there are no collisions between reservation requests and the detection of coexistence signals in a robust way in noisy environments. It is characterized by the use of signals for reservation (5) and release (10) of the communication and by the random waiting prior to a reservation of the electrical network with minimum and maximum values fixed in advance.

A DTV signal includes frames, and the frames include data segments. Data segments are replaced by codewords which represent digital data. The DTV signals are broadcast and received by receivers. The receivers recover the digital data from the codewords in the DTV signals, for example by using matched filtering. By using long codewords, the digital data can be broadcast over a longer range and recovered by simpler circuitry in comparison to the television programming contained in the DTV signal. In one implementation, the DTV signal is an American Television Standards Committee (ATSC) DTV signal.

A bandwidth efficient advanced modulation waveform modem using concatenated iterative turbo coding and continuous phase modulation is disclosed. A demodulator in the modem has a turbo decoder and a decision feedback carrier and time tracking algorithm to track a carrier and adjust timing. The decision feedback carrier and time tracking algorithm may use an APP decoder as a decision device to provide symbol decisions at a high error rate and low latency for a coded input data stream. A symbol phase estimator produces a symbol phase error estimate from the symbol decisions. An erasure decision function decides which symbol decisions are correct and which symbol decisions are erasures. A carrier tracking function receives the symbol phase error estimates when the symbol decisions are correct and receives erasure inputs when the symbol decisions are erasures to maintain carrier tracking.

A transmitter communicating data using Orthogonal Frequency Division Multiplexed (OFDM) symbols including plural sub-carrier symbols in the frequency domain for modulating with data to be carried. The transmitter includes a modulator to receive data symbols from a first data pipe according to a first communications channel, to receive data symbols from a local service insertion data pipe according to a local communications channel, and to modulate the sub-carrier signals of the OFDM symbols with either the data symbols from the first data pipe or from both the first data pipe and the local service insertion pipe; modulation from the first data pipe maps the data symbols is according to a first modulation scheme, and modulation from the first data pipe and the local service insertion pipe maps the data symbols is according to a second modulation scheme.

Method and system for channel-invariant robust audio hashing, the method comprising:

• • a robust hash extraction step wherein a robust hash is extracted from audio content, said step comprising:
    • dividing the audio content in frames;
    • applying a transformation procedure on said frames to compute, for each frame, transformed coefficients;
    • applying a normalization procedure on the transformed coefficients to obtain normalized coefficients, wherein said normalization procedure comprises computing the product of the sign of each coefficient of said transformed coefficients by an amplitude-scaling-invariant function of any combination of said transformed coefficients;
    • applying a quantization procedure on said normalized coefficients to obtain the robust hash of the audio content; and
  • a comparison step wherein the robust hash is compared with reference hashes to find a match.

The present invention provides a remote communication device (i.e., radio frequency identification (RFID) tag) and system for communicating between one or more RFID tags and a reader using a frequency modulation method to encode binary data.

A method of reducing channel scan time is achieved by knowing important location information such a zip code. This allows a locally stored database of available broadcast channels to be used to skip unused frequencies and to allow finding the direction of the most likely broadcast station. Once one active channel is located, it is possible to calculate the most likely direction to search for the remaining active channels in the data base using a smart antenna.

A receiver recovers local service data symbols from first Orthogonal Frequency Division Multiplexed (OFDM) symbols in the presence of second OFDM symbols. The second OFDM symbols carry national broadcast data symbols and modulated on to the sub-carriers of the second OFDM symbols using a first modulation scheme. The first OFDM symbols carry the national broadcast data symbols and the local service data symbols from a local insertion pipe and modulated on to the sub-carriers of the first OFDM symbols using a second modulation scheme. The receiver comprises an OFDM detector which includes an equalizer to recover local service modulated sub-carriers of the second modulation scheme.

The invention concerns a hearing aid, which has a casing accommodating one or more sound to electric signal converting transducers (11,12) and a signal path from the transducer (11,12) to a receiver which provides a sound signal at the ear of the user. The signal processing is provided in the signal path to ensure a signal amplification/attenuation according to the needs of the user. A battery (6) is accommodated in the casing and a battery lid is arranged with a first side (1) facing the surrounding and a second side (2) facing the interior of the casing whereby the battery lid is operable for replacement of the battery. According to the invention the battery lid has means (3) for receiving at least one sound to electric signal converting transducer (11,12) and a sound transmission path is provided between the first side (1) of the battery lid and the at least one transducer (11,12).

The invention provides an optical phase device with its application method and system. The optical phase device consists of a transparent dielectric substrate, a multilayer stack of dielectrics and a buffer layer. The refractive index of the transparent dielectric substrate, the multilayer stack of dielectrics and the buffer layer are all larger than that of the external medium. For the wavelength of the incident beam, the optical phase device has a phase variation in the angular range [α, β] and the critical angle for total reflection on the interface between the buffer layer and the external medium adjacent to the buffer layer is θ, θ<β. Our invention of the optical device has both low loss and large phase variation, which leads to a large Goos-Hanchen shift. As a dispersion compensation component, it can produce bigger and tunable dispersion, and different dispersion compensations can be got by adjusting the operating angle or parameters in the structure.

A cellular communications system may include one or more cellular base stations and a plurality of mobile cellular communications devices for communicating therewith. More particularly, the cellular base station and the mobile cellular communications devices may each include an encoder for generating an information signal. Furthermore, a modulator may generate a modulated waveform based upon the information signal, a carrier signal having a frequency and phase associated therewith, and at least one carrier phase reference symbol. The modulator may also include an offset circuit so that the modulated waveform includes a carrier frequency indicator. A transmitter may also be included for transmitting the modulated waveform to the desired cellular base station or mobile cellular communications device.

A sensor, in particular for the spatially resolved detection, includes a substrate, at least one micropatterned sensor element having an electric characteristic whose value varies as a function of the temperature, and at least one diaphragm above a cavity, the sensor element being disposed on the underside of the at least one diaphragm, and the sensor element being contacted via connecting lines, which extend within, on top of or underneath the diaphragm. In particular, a plurality of sensor elements may be formed as diode pixels within a monocrystalline layer formed by epitaxy. Suspension springs, which accommodate the individual sensor elements in elastic and insulating fashion, may be formed within the diaphragm.

In the present invention, the histogram model used in H-PMHT is extended to treat the problem of tracking using hyper-spectral data. Completely general spectral density functions are handled via the use of non-parametric methods. The present invention is not restricted to derivations based on knowledge of the spectral character of the source being tracked. The source spectrum can be estimated in a non-parametric fashion based on an initial track, and this allows the invention to adapt to the source spectrum in situ. The resulting method has improved crossing track performance on sources that have some degree of spectral distinction and will perform no worse than regular H-PMHT on sources that have identical spectral densities.

Disclosed are a method and an NDT/NDI inspection device deploying digital circuitry to conduct detection and compensation of phase and amplitude shift in responding signals. A digital waveform generator, such as a direct digital synthesizer (DDS) is used to generate a digital sine-wave of a specific frequency and amplitude, mimicking the pulser frequency and amplitude. The sine-wave is converted to analog signal through a DAC and transmitted to the transducer. The received analog sine-wave from the transducer is converted back to a digital signal through an ADC. The transmitted and received digital signals are then compared for phase and amplitude differences. A null circuit involving another waveform generating component is employed to compensate the detected phase and amplitude differences. As a result the phase and amplitude differences are effectively eliminated before being further processed and analyzed for defects information.

This invention relates to a hyperspectral imaging system for denoising and/or color unmixing multiple overlapping spectra in a low signal-to-noise regime with a fast analysis time. This system may be configured to carry out Hyper-Spectral Phasors (HySP) calculations to effectively analyze hyper-spectral time-lapse data. For example, this system may be configured to carry out Hyper-Spectral Phasors (HySP) calculations to effectively analyze five-dimensional (5D) hyper-spectral time-lapse data. Advantages of this imaging system may include: (a) fast computational speed, (b) the ease of phasor analysis, and (c) a denoising algorithm to obtain the minimally-acceptable signal-to-noise ratio (SNR). An unmixed color image of a target may be generated. These images may be used in diagnosis of a health condition, which may enhance a patient's clinical outcome and evolution of the patient's health.

A sampling frequency offset estimation apparatus of an orthogonal frequency division multiplexing (OFDM) system according to an aspect of the invention may include: a first differential operation unit performing complex conjugate multiplication of scattered pilots of complex symbols subjected to a fast Fourier transform (FFT) in an OFDM receiver; an interpolation unit repeating an operation of obtaining a median complex symbol between two consecutive symbols among complex symbols having first phase difference information from the first differential operation unit by a predetermined number; a second differential operation unit performing complex conjugate multiplication of two consecutive median complex symbols among median complex symbols from the interpolation unit; and a sampling frequency offset estimation unit estimating sampling frequency offset using complex symbols having second phase difference information from the second differential operation unit.

The invention provides an optical phase device with its application method and system. The optical phase device consists of a transparent dielectric substrate, a multilayer stack of dielectrics and a buffer layer. The refractive index of the transparent dielectric substrate, the multilayer stack of dielectrics and the buffer layer are all larger than that of the external medium. For the wavelength of the incident beam, the optical phase device has a phase variation in the angular range [α, β] and the critical angle for total reflection on the interface between the buffer layer and the external medium adjacent to the buffer layer is γ, γ>β. Our invention of the optical device has both low loss and large phase variation, which leads to a large Goos-Hanchen shift. As a dispersion compensation component, it can produce bigger and tunable dispersion, and different dispersion compensations can be got by adjusting the operating angle or parameters in the structure.

A method for detecting icing at an angle-resolving radar sensor in a driver assistance system for motor vehicles, in which signals of a plurality of antenna elements each having a specific angle characteristic are compared with the corresponding angle characteristics, and the azimuth angle of a located object is determined on the basis of an angle fit quality which indicates how well the signals of the antenna elements correspond to the angle characteristics for a given azimuth angle, wherein an indicator for icing is formed which is a monotonically falling function of the angle fit qualities of the located objects, with objects having a low signal-to-noise ratio being included in the indicator at the most with a reduced weighting.

A digital broadcasting transmission and/or reception system having an improved reception performance and a signal-processing method thereof. A digital broadcasting transmitter comprises a TRS encoder for to TRS-encode a MPEG-2 transmission stream having null data for inserting a Known data and a TRS parity at predetermined positions, randomizer to input and randomize data stream from the TRS encoder, a null packet exchanger to replace the null data for inserting the Known data to the known data, and an encoder for encoding a data streams to which the Known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization and further uses the TRS parity for correcting error of the received signal, so that the digital broadcasting reception performance can be improved at poor multipath channels.