119 results about "Burst noise" patented technology

An apparatus performs burst noise detection and then reduce the interference of the burst noise by controlling an operation of an adaptive apparatus, such as an equalizer. It includes: an adaptive apparatus having multiple coefficients, processing incoming signals according to these coefficients, and employing an error estimator to update the coefficients; a burst noise detector used to detect a burst noise; and an ON / OFF switching unit used to stop the error estimator from updating the coefficients when the burst noise is detected.

A system, method and computer program product is provided for mitigating the effects of burst noise on packets transmitted in a communications system. A transmitting device applies an outer code, which may include, for example, a block code, an exclusive OR (XOR) code, or a repetition code, to one or more packets prior to adaptation of the packets for transmission over the physical (PHY) layer of the communications system, wherein the PHY layer adaptation may include FEC encoding of individual packets. The outer coded packets are then separately transmitted over a channel of the communications system. A receiving device receives the outer coded packets, performs PHY level demodulation and optional FEC decoding of the packets, and then applies outer code decoding to the outer coded packets in order to restore packets that were erased during transmission due to burst noise or other impairments on the channel.

A communication system and a method which can reduce the effect of burst noise. The communication system comprises a controllable oscillator, a mixer, a decision circuit, a comparator, a loop filter, and a controller. The controllable oscillator generates an oscillating signal. The mixer coupled to the controllable receives input data and mixes the input data with the oscillating signal. The decision circuit receives the mixed input data and generates an estimated symbol. The comparator generates a decision error between the estimated symbol and the mixed input data. The loop filter coupled to the controllable oscillator filters the decision error, and generates a filtered decision error, and the controllable oscillator generates the oscillating signal according to the filtered decision error. The controller reduces a bandwidth of the loop filter according to the decision error.

A method is provided for reading distorted optical symbols using known locating and decoding methods, without requiring a separate and elaborate camera calibration procedure, without excessive computational complexity, and without compromised burst noise handling. The invention exploits a distortion-tolerant method for locating and decoding 2D code symbols to provide a correspondence between a set of points in an acquired image and a set of points in the symbol. A coordinate transformation is then constructed using the correspondence, and run-time images are corrected using the coordinate transformation. Each corrected run-time image provides a distortion-free representation of a symbol that can be read by traditional code readers that normally cannot read distorted symbols. The method can handle both optical distortion and printing distortion. The method is applicable to “portable” readers when an incident angle with the surface is maintained, the reader being disposed at any distance from the surface.

A system and method for detecting burst noise during quadrature amplitude modulation (QAM) communications are provided. A QAM signal is acquired at a receiver in communication with a network. The QAM signal is demodulated at the receiver to identify a plurality of symbols. Amplitudes for each of the plurality of symbols are determined, and are compared to a predetermined threshold. For each amplitude that is greater than the predetermined threshold, information is recorded at the receiver relating to a burst noise event. The magnitude of the burst noise can be determined by measuring a difference between a received constellation point and a perimeter constellation point closest to the received constellation point. The information about the burst noise event can be transmitted to an error correction module for reducing future burst noise in the network. Equalizer coefficients and tracking loop performance can be adjusted / enhanced using the burst noise information.

A speech recognition system includes: a speed level classifier for measuring a moving speed of a moving object by using a noise signal at an initial time of speech recognition to determine a speed level of the moving object; a first speech enhancement unit for enhancing sound quality of an input speech signal of the speech recognition by using a Wiener filter, if the speed level of the moving object is equal to or lower than a specific level; and a second speech enhancement unit enhancing the sound quality of the input speech signal by using a Gaussian mixture model, if the speed level of the moving object is higher than the specific level. The system further includes an end point detection unit for detecting start and end points, an elimination unit for eliminating sudden noise components based on a sudden noise Gaussian mixture model.

Method and system for reducing impulsive burst noise in less delayed reception in pilot based OFDM systems, especially using DVB-T standard such as Digital Video Broadcasting (DVB) is provided. The method contains following steps: recognition of the impulse position and possibly length in the time domain symbol, blanking of those samples of the symbol where significant amount of impulse noise is present, calculating the first estimate of the received signal from the blanked symbol, derving correction values for the carrier estimates by applying prior information (pilot carriers), and the corrected estimate of the received symbol is derived by subtracting the correction values of step from the first estimate of carriers derived in step. The method and arrangement allow correction of fairly long bursts of impulse noise with minor degradation only. The complexity of the scheme and the additional energy consumption are fairly low. The method provides considerably more effective more simple and less delay in broadcast data reception than previously known solutions in interfered multi-carrier signal reception.

A receiver for receiving a multi-carrier modulated symbol is arranged to suppress a burst noise signal which may have been induced in the symbol. The symbol includes a plurality of pilot carriers as well as a plurality of data bearing carriers. The receiver comprises a burst noise detection processor operable to detect the temporal position of the burst noise signal which may have corrupted the symbol within a period occupied by the symbol, and a channel estimation processor operable to generate a decimated noise signal corresponding to the burst noise, from the recovered pilot carriers. An inverse Fourier transform of the decimated noise signal provides a plurality of estimated versions of the burst noise signal. A noise signal processor is operable to generate an estimate of the burst noise signal by identifying one of the plurality of estimated burst noise versions at the detected temporal location of the burst noise signal. The noise signal processor may be operable to set the signal samples other than the identified estimate of the burst noise signal to zero and to perform a Fourier transform, to provide a frequency domain version of the burst noise signal, thereby interpolating the decimated noise signal. The frequency domain noise signal estimate may be cancelled from the symbol by a noise cancellation processor in the frequency domain, before data is recovered from the symbol. The receiver finds application for Digital Video Broadcasting in which COFDM is employed.