Provided is an adaptive filter apparatus including: a decimation filter which outputs an output signal obtained by down-sampling an input signal; and a filter control unit which adjusts an order of the decimation filter on the basis of a characteristic of the input signal.

In a distance measurement apparatus, a light emitter emits pulse-like light. A light receiver receives reflected light of the emitted light and converts the received light to an electrical signal. An AD converter converts the electrical signal to a digital value at a predetermined sampling rate to generate a conversion data series. An interpolation processor upsamples the outputted conversion data series by inserting interpolation data therein to generate an up-data series. A distance calculator calculates a distance to an object that reflects light using a signal waveform indicated by the up-data series. The interpolation processor inserts the interpolation data having an interpolation value between pieces of data belonging to the conversion data series, and smooths the data series in which the interpolation data is inserted using a low-pass filter that has characteristics in which waveform distortion caused by ringing does not occur.

In a distance measurement apparatus, a light emitter emits pulse-like light. A light receiver receives reflected light of the emitted light and converts the received light to an electrical signal. An AD converter converts the electrical signal to a digital value at a predetermined sampling rate to generate a conversion data series. An interpolation processor upsamples the outputted conversion data series by inserting interpolation data therein to generate an up-data series. A distance calculator calculates a distance to an object that reflects light using a signal waveform indicated by the up-data series. The interpolation processor inserts the interpolation data having an interpolation value between pieces of data belonging to the conversion data series, and smooths the data series in which the interpolation data is inserted using a low-pass filter that has characteristics in which waveform distortion caused by ringing does not occur.

A propagation delay tune correction apparatus comprising a means for generating a frequency spectrum signal by performing short-term Fourier transform on an audio signal; a means for setting a propagation delay time for each of a plurality of predetermined frequency bands; a means for calculating a phase control amount for each of the plurality of predetermined frequency bands on a basis of the propagation delay time set for each of the plurality of predetermined frequency bands; a means for generating a phase control signal by smoothing the calculated phase control amount for each of the plurality of predetermined frequency bands; a means for controlling a phase of the frequency spectrum signal for each of the plurality of predetermined frequency bands on a basis of the generated phase control signal; and a means for generating an audio signal on which a propagation delay correction is performed by performing inverse short-term Fourier transform on the frequency spectrum signal of which the phase is controlled for each of the plurality of predetermined frequency bands.

A finite impulse response (FIR) filter circuit design method using approximate computing, the FIR filter circuit design method including: replacing adders of the FIR filter with approximate adders; and performing a synthesis work according to a set approximate synthesis flow when the replacing of the adders of the FIR filter are replaced with the approximate adders is performed, wherein, in the approximate synthesis flow, a numeric column of each of the approximate adders is divided into an accurate part and an inaccurate part, and a numeric column of the inaccurate part is approximated. In the FIR filter, conventional adders/subtractors are replaced with addition/subtraction having an automated synthesis flow so that energy consumption can be reduced.

The present application relates to an adaptive filter using resource sharing and a method of operating the adaptive filter. The filter comprises at least one computational block, a monitoring block and an offset calculation block. The computational block is configured for adjusting a filter coefficient, c.sub.i(n), in an iterative procedure according to an adaptive convergence algorithm. The monitoring block is configured for monitoring the development of the determined filter coefficient, c.sub.i(n), during the performing of the iterative procedure. The offset calculation block is configured for determining an offset, Off.sub.i, based on a monitored change of the filter coefficient, c.sub.i(n), each first time period, T.sub.1, and for outputting the determined offset, Off.sub.i, to the computational block if the determined filter coefficient, c.sub.i(n), has not reached the steady state. The computational block is configured to accept the determined offset, Off.sub.i, and to inject the determined offset, Off.sub.i, into the iterative procedure.

A phase control signal generation device generating a phase control signal for each of frequency bands for an audio signal converted into a frequency domain, the phase control signal generation device comprising: a setting change means that is able to change setting of a propagation delay time for each of predetermined frequency bands; a difference obtaining means that obtains a difference between propagation delay times before and after setting change; an updating means that updates a phase control amount of the frequency band for which the propagation delay time is changed, based on the obtained difference; and a phase control signal generating means that generates a phase control signal of each frequency band by performing a smoothing process for the phase control amount in a frequency domain using the updated phase control amount.

A filter for use with a brushless DC motor to filter a signal received from a floating terminal of the brushless DC motor, wherein the filter is configured such that a time delay introduced by the filter to the signal received from the floating terminal is equal to the time taken for a rotor of the motor to rotate through an angle equal to half of a commutation step of the motor.

A digital signal processing system and its design method are disclosed. The digital signal processing system is a digital differentiator with a frequency response coefficient h.sub.m and a frequency response function H.sup.(K)(w), where

[00001]$H^{\left(K\right)}\left(w\right).Math..Math.\mathrm{is}.Math..Math.\mathrm{one}.Math..Math.\mathrm{of}.Math..Math.\{\begin{array}{c}-{\mathrm{jw}}^K,0w<\\ {\mathrm{jw}}^K,-w0\end{array},\{\begin{array}{c}{\mathrm{jw}}^K,0w<\\ -{\mathrm{jw}}^K,-w0\end{array},.Math.-w^K,-w<,\mathrm{and}.Math..Math.\{\begin{array}{c}{\mathrm{jw}}^K,0w<\\ -{\mathrm{jw}}^K,-w0\end{array},$

or combination thereof, where m of h.sub.m has a range 0mM1 and M is the sampling point quantity.

In accordance with an example, an integrated circuit includes a linear combiner having an input for receiving a signal. The linear combiner also has a plurality of operator circuits for applying weighting factors to the signal, in which a first operator circuit in the plurality of operator circuits performs a first operation on the signal using a first sub-weight of one of the weighting factors to provide a first tile output and a second operator circuit in the plurality of operator circuits performs a second operation on the signal using a second sub-weight of the one of the weighting factors to provide a second tile output. The linear combiner also has an adder having a first input coupled to receive the first tile output and the second tile outputs and providing a combined output.