3028 results about "Signal characteristic" patented technology

The present invention provides a solution to mistaken location calculations based on multipath effects. The present invention determines a real-time location of an object in a facility using a combination of location algorithms, with a signal characteristic for a wireless signal from a communication device attached to the object received at a sensor of a mesh network. The location algorithms preferably include at least two of a proximity algorithm, a radial basis function algorithm, a maximum likelihood algorithm, a genetic algorithm, a minimum mean squared error algorithm, a radiofrequency fingerprinting algorithm, a multilateration algorithm, a time difference of arrival algorithm, a signal strength algorithm, a time of arrival algorithm, an angle of arrival algorithm, a spatial diversity algorithm, and a nearest neighbor algorithm.

The invention concerns a method (500) and system (100) for suppressing receiver audio regeneration. The method (500) includes the steps of receiving a communication signal (502), at a Radio Frequency (RF) unit (102), demodulating the communication signal to an audio signal (504), monitoring a volume level of the audio signal (506), and shifting the pitch of the audio signal when the volume level reaches a predetermined threshold (508), and playing the pitch-shifted audio signal out of a speaker to produce a pitch-shifted acoustic signal (510). The method can shift the pitch of the audio signal to produce a pitch-shifted acoustic signal with signal properties suppressing regeneration of the acoustic signal onto the audio signal at the RF unit. The amount of pitch-shifting can be a function of the volume level.

Methods, apparatus and systems for dynamically controlling a digital communication system, such as a DSL system, collect information about digital communication lines in the system and adaptively and / or dynamically determine line and signal characteristics of the digital communication lines, including interference effects. Based on the determined characteristics and the desired performance parameters, operation of the digital communication lines is adjusted to improve or otherwise control the performance of the system. The collection and processing of information may be performed by a party that is not a user in the system. This independent party also may control operational characteristics and parameters of the system. The invention can be used to eliminate or reduce signal interference such as crosstalk that can be induced on communication lines in systems such as DSL systems. Specific iterative power allocation and vectored transmission techniques and apparatus are disclosed.

Systems and methods of identifying molecules of polymers such as, for example, a nucleic acid, are described. The method involves centering a bias voltage across a pair of nanoelectrodes separated by a channel that corresponds to one of any of the energy differences between any two internal energy levels of a molecule of interest, and modulating the bias voltage with a modulation waveform while the molecule of interest is in the channel. An electrical signal characteristic of the molecule of interest is derived from the tunneling current between the nanoelectrodes, and the characteristic electrical signal is compared with known values of the signal for chemically-known molecules in order to identify the molecule of interest. Multiple pairs of nano-electrodes may be employed to identify more reliably a single molecule or multiple molecules.

The present invention is directed toward a pulse oximetry system for the determination of a physiological parameter capable of removing motion artifacts from physiological signals comprises a hardware subsystem and a software subsystem. The software subsystem is used in conjunction with the hardware subsystem to perform a method for removing a plurality of motion artifacts from the photo-plethysmographic data and for obtaining a measure of at least one physiological parameter from the data. The method comprises acquiring the raw photo-plethysmographic data, transforming the data into the frequency domain, analyzing the transformed data to locate a series of candidate cardiac spectral peaks (primary plus harmonics), reconstructing a photo-plethysmographic signal in the time domain with only the candidate cardiac spectral peaks (primary plus harmonics), computing the second order derivative of the reconstructed photo-plethysmographic signal, analyzing the candidate second order derivative photo-plethysmographic signal to determine the absence or presence of cardiac physiologic signal characteristics, and finally selecting the best physiologic candidate from the series of potential cardiac spectral peaks (primary plus harmonics) based upon a second derivative scoring system. This scoring system is preferentially based upon second derivative processing analysis, but can be equally applied using the first, third, fourth or other similar derivative processing analysis.

An envelope tracking radio frequency (RF) power amplifier having an adaptive envelope signal processing circuit is disclosed. An RF input voltage is sampled by the adaptive envelope signal processing circuit which provides control signals to the power supply which supplies voltages to RF power devices in order to simultaneously satisfy two operating conditions: a) provide best possible efficiency of the power amplifier stages depending on the input signal characteristics and b) provide compensation for RF transistor AM-AM and AM-PM distortion compensation across the power range. In particular, the voltage control provides for constant power amplifier gain across the input signal dynamic range, thus minimizing power amplifier amplitude distortions and extending the useful power amplifier linear dynamic range up to saturation point. The power amplifier thus exhibits better linearity and efficiency than offered by conventional techniques and topologies.

A vibrotactile transducer provides a point-like vibrational stimulus to the body of a user in response to an electrical input. The apparatus includes a housing held in contact with the skin and a moving mechanical contactor protruding through in an opening in said housing and preloaded into skin. The contactor is attached to a torroidal moving magnet assembly suspended by springs in a magnetic circuit assembly consisting of a housing containing a pair of electrical coils. The mass of the magnet / contactor assembly and the compliance of the spring are chosen so that the electromechanical resonance of the motional masses, when loaded by a typical skin site on the human body, are in a frequency band where the human body is most sensitive to vibrational stimuli. By varying the drive signal to the vibrotactile transducer and activating one or more transducer at specific location on the body using an appropriate choice of signal characteristics and / or modulation, different information can be provided to a user in a intuitive, body referenced manner.