31results about How to "Eliminate Nonlinear Distortion" patented technology

A digital reception apparatus includes a receiver that performs reception processing on a received signal and an adjuster that adjusts the amplitude of the received signal after the reception processing. A distortion estimator estimates a non-linear distortion of the received signal after the reception processing, the non-linear distortion being caused by the reception processing. A distortion corrector performs a distortion correction on the estimated non-linear distortion. A controller controls the adjuster based on a gain control signal such that the amplitude of a desired signal contained in the received signal after the reception processing and the distortion correction approaches a required level. The distortion estimator estimates the non-linear distortion of the received signal with reference to the gain control signal.

The embodiments of the present invention provide a method and an apparatus for compensating nonlinear distortions in an intensity modulation-direct detection (IM-DD) system; wherein the method comprises: calculating, according to nonlinear coefficients and differences between values of an input signal at different time, nonlinear distortions of the input signal, so as to eliminate the nonlinearity distortions. By applying the method and the apparatus provided by the embodiments of the present invention, nonlinear cost of the IM-DD system can be effectively reduced, thereby improving the system capacity.

The invention provides an optical coherence tomography (OCT) system correction method. The method comprises the steps of obtaining correction data and correcting, wherein in the step of obtaining correction data, the OCT system scans a reference slide to obtain the relation function between the reference slide measured value and different depth positions; and in the correcting step, the obtained detection data are corrected according to the relation function between the thickness and the depth positions.

This invention discloses a microphone echo elimination device and method, which eliminates echo between microphone and sound circuit, wherein, the device comprises long frame adjust module to combine one self adaptive filter parameter data frame for self adapting filter.

The invention discloses an unrestrictive line voltage-following and power-buffering amplifier, and belongs to the technical field of amplifiers. The unrestrictive line voltage-following and power-buffering amplifier comprises a first control circuit and a second control circuit symmetrical to the first control circuit, wherein the first control circuit comprises a reference voltage comparing, buffering and amplifying circuit and a power buffering and amplifying circuit; the reference voltage comparing, buffering and amplifying circuit comprises a first effect tube, a third triode, a fifth triode, a first constant current source circuit for providing working currents and a first current mirror circuit for providing bias currents; the power buffering and amplifying circuit comprises a nineteenth triode, a twentieth triode, a twenty fourth triode, a twenty seventh effect tube and a second constant current source circuit for providing driving currents. When a follower works dynamically, input bias voltage and output bias voltage form a peering relationship, so that input signal voltage is approximately equal to voltage output to a load and zero distortion amplification of a signal is achieved.

The invention discloses a bass loudspeaker box, which is characterized by comprising a loudspeaker box body, an upper cover and a lower cover, wherein the front side of the loudspeaker box body is provided with a first bass unit, the top surface and the bottom surface of the loudspeaker box body are provided with an upper groove and a lower groove respectively, the upper groove and the lower groove are internally provided with a third bass unit and a second bass unit respectively, both the second bass unit and the third bass unit face towards the internal part of the loudspeaker box, the uppercover and the lower cover are respectively connected at the top and the bottom of the loudspeaker box body, a first cavity is formed between the upper cover and the upper groove, the first cavity iscommunicated with the upper groove, a second cavity is formed between the lower cover and the lower groove, the second cavity is communicated with the lower groove, and the internal part of the wholeloudspeaker box forms a closed space. The bass loudspeaker box can have an astonishing low distortion degree at an extremely low low-frequecy submergence degree, achieves an excellent speed by explosive unit motion and can eliminate the phenomena of nonlinear distortion and dynamic shortage caused by swinging and shifting of a vibration basin when only one bass unit is adopted.

The invention discloses an optical transmission method and device based on power spectrum shaping, which supports direct detection of optical signals with high spectral efficiency, that is, square demodulation. The present invention adopts the power spectrum shaping modulation method at the sending end, and the modulation method is passed at the zero point, that is, V π Bias the Mazeng optical modulator, increase the level, combine with nonlinear precoding, realize multi-level improved duobinary coding and multi-level biased duobinary coding, and also combine optical filters to realize vestigial sideband improved duobinary coding; At the receiving end, nonlinear equalization is used to remove intersymbol interference from the received signal, and at the same time, the difference in received level can be fed back to the transmitter to realize non-equidistant multi-level modulation and reduce the complexity of nonlinear equalization. The present invention enables direct detection of signals requiring coherent demodulation through proper nonlinear precoding and nonlinear equalization, thereby reducing hardware complexity.