4 results about "Impulse noise detection" patented technology

The object of the present invention is to provide a method for suppressing impulse noise in underwater acoustic OFDM communication in polar regions. By using OFDM pilot subcarriers, channel estimation and equalization are performed on the received passband signal based on the least squares criterion, and then the background noise is estimated. At the same time, only this estimated value is used to obtain the position information of impulse noise, and the impulse noise is detected and marked using the 3σ principle based on the generalized signal-to-noise ratio. After suppressing the impulse noise using an adaptive median filter, the noise estimated value is added to the noise-free received signal to obtain the received passband signal after impulse noise suppression processing. Then, subsequent channel estimation, channel equalization, and decision-making processes are carried out, and finally the source information is decoded. The present invention effectively avoids the interference of OFDM signals on the impulse detection process; the 3σ impulse noise detection method based on the generalized signal-to-noise ratio realizes a detection threshold that can be adaptively adjusted according to impulse noise. The impulse noise suppression step reduces the computational complexity of the algorithm.

The present application relates to a kind of power line carrier communication system pulse noise suppression method, belong to power line data communication field.The method includes: S1: parameter adaptation: in receiving end, input parameter adaptation module to receiving signal, through the way of sliding window, pulse noise detection module and pulse noise suppression module are adapted condition parameters, i.e.detection parameter and noise suppression parameter;S2: pulse noise detection: received data is input pulse noise detection module according to block, obtain the peak of detection data block, and the peak is compared with the detection parameter of adaptation, judge whether there is pulse noise;S3: pulse noise suppression: through the way of iteration, constantly find out the maximum value of each section of received data and its position, and the maximum value and the data in its adjacent interval are zero, finally, the data higher than a certain threshold is limited to reach the effect of inhibiting pulse noise.The present application method is simple, and does not need to rely on experience to select amplitude threshold.

The application discloses an airplane lifesaving explosion cutting pulse noise detection method based on a simulation platform, the simulation platform comprises a seat model, a hatch model and a simulation man model; the method comprises the following steps: arranging components of the simulation platform and adjusting characteristic parameters so as to be consistent with parameters of a detection scene when a pyrotechnic device explodes; recording adjustment parameters and corresponding data of the simulation platform; setting detection points according to pulse noise detection requirements, measuring and recording the blast center distance of the detection points; and performing explosion cutting pulse noise test to obtain test data. According to the application, the airplane lifesaving explosion cutting pulse noise detection scene can be simulated and corresponding test can be performed, and accurate and effective test data can be obtained.

The application provides a power distribution network harmonic measurement method and system based on adaptive detection and parallel calculation, belongs to the technical field of dynamic harmonic measurement, and comprises the following steps: acquiring a power distribution network signal and performing discrete sampling in an observation time window to obtain a discrete signal sequence; calculating kurtosis, spectral entropy and residual gradient norm of the initial residual vector; dynamically adjusting an adaptive threshold parameter based on the kurtosis, spectral entropy and residual gradient norm; calculating a pulse noise detection threshold according to the adaptive threshold parameter; performing point-by-point comparison on the initial residual vector by using the pulse noise detection threshold, identifying a pulse noise occurrence position, and forming a pulse noise support set; constructing an enhanced basis matrix based on the pulse noise support set; decomposing a pseudo-inverse of the enhanced basis matrix into four sub-block matrices; performing parallel calculation on the four sub-block matrices; and finally obtaining amplitudes, phases, first derivatives and second derivatives of each harmonic.