458 results about "Signal of interest" patented technology

An audio processing system for a listening device includes an input device, a voice activity detector and a ratio-based attenuator. The input device is configured to receive a first audio signal emanating from an environment and including a signal of interest. The voice activity detector is configured to generate a control signal in response to the first audio signal. The ratio-based attenuator is configured to receive the control signal and determine whether the signal level of the first audio signal exceeds the signal level of an audio signal received from an audio playback device by at least a target difference. If so, then the audio level of the playback audio signal is maintained. Otherwise, the audio level of the playback audio signal is adjusted, where, at the adjusted value, the first signal level exceeds the playback signal level by at least the target difference.

A photoplethysmographic system and method is provided for filtering a photoplethysmographic (pleth) signal to reduce the effects of noise in the signal. The system and method utilize a combination of frequency, time and / or magnitude information, to identify and separate transient signal components within a pleth signal from repeating signal components within the pleth signal. Typically, signal components of interest repeat over a period that corresponds with a patient's heartbeat. Such periodically repeating signals may be identified as stationary signals / objects within a frequency and time-based analysis. In contrast, motion artifacts or other sources of noise are often isolated (i.e., non-repeating) transient events and may be identified as non-stationary objects in a frequency and time-based analysis. Data associated with identified transient events may be filtered from or otherwise removed from a given signal. In this regard, a pleth signal may be cleansed prior to its use for, e.g., blood analyte determinations.

In the context of array sensors such as radar, sonar, and communications receiver arrays, the present invention exploits the geometry phase components of radiated wavefronts associated with the signals of interest in order to reduce the bandwidth requirements for DOA and beamforming processing. Additionally, geometry phase is exploited in order to effectively increase the resolution of an array without changing the size of its physical footprint or the number of array elements. Other embodiments of the invention include the use of virtual array elements for increase in effective array size.

Replica correlation processing, and associated representative signal-data reduction and reconstruction techniques, are used to detect signals of interest and obtain robust measures of received-signal parameters, such as time differences of signal arrival and directional angles of arrival, that can be used to estimate the location of a cellularized-communications signal source. The new use in the present invention of signal-correlation processing for locating communications transmitters. This enables accurate and efficient extraction of parameters for a particular signal even in a frequency band that contains multiple received transmissions, such as occurs with code-division-multiple-access (CDMA) communications. Correlation processing as disclosed herein further enables extended processing integration times to facilitate the effective detection of desired communications-signal effects and replication measurement of their location-related parameters, even for the communications signals modulated to convey voice conversations or those weakened through propagation effects. Using prior, constructed, signal replicas in the correlation processing enables elimination of the inter-site communications of the signal representations that support the correlation analyses. Reduced-data representations of the modulated signals for voiced conversation, or for the variable components of data communications, are used to significantly reduce the inter-site communications that support the correlation analyses.

An adaptive interference canceller for canceling an interfering signal corresponding to a delayed, frequency translated, amplitude and phase offset version of a transmitted signal contained in a composite received signal relayed through a relay system such as a satellite transponder. The canceller digitally downconverts the received signal and a local replica of the transmitted signal from IF to baseband, applies a variable delay and frequency compensation to the replica as a coarse delay and frequency correction, and tracks fine delay, amplitude and phase differences using an adaptive finite impulse response filter to generate a cancellation signal corresponding to the delayed and frequency shifted version. A minimum output power process produces an error signal that drives the variable delay and adaptive filter to minimize the power in the signal of interest to maximize cancellation of the interfering signal.

A system and method for processing an acoustic input signal and providing at least one output acoustic signal to a user of a hearing-aid system. The hearing-aid system includes first and second channels with one of the channels having an adaptive delay. The first channel includes a directional unit for receiving the acoustic input signal and providing a directional signal; a correlative unit for receiving the directional signal and providing a noise reduced signal by utilizing correlative measures for identifying a speech signal of interest in the directional signal; and, a compensator for receiving the noise reduced signal and providing a compensated signal for compensating for a hearing loss of the user.