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5341387 
Viterbi detector having adjustable detection thresholds for PRML class IV sampling data detection
A Viterbi detector for a PR4,ML data channel includes a data sample input for receiving digital data samples from a source. Digital data samples are taken of data which has been coded in a... 

5339263 
Combined decimation/interpolation filter for ADC and DAC
A COMBINED DECIMATION/INTERPOLATION FILTER FOR ADC AND DAC (analogtodigital converter and digitaltoanalog converter) provides a single filter which may be used both as a decimation filter and... 

5337264 
Time reversal gaussian approximation filter
A time reversal filter uses exponential decay infinite impulse response filters to achieve an approximation to a true Gaussian low pass filter. In one embodiment, a time reversal Gaussian... 

5331583 
Runningaverage/decimation filter for an oversampling A/D converter
A filter processing unit 2 receives the output of an oversamplingtype analog/digital (A/D) converter circuit 1. Predetermined information is acquired by a compensation circuit 31 with... 

5325317 
Digitally programmable linear phase filter having phase equalization
A digitally programmable Bessel filter includes a plurality of serially connected stages or biquads with each biquad including a plurality of programmable operational transconductance amplifiers.... 

5315539 
Method and apparatus for debouncing signals
Debounce and lockout filters include an input part for receiving a plurality of input signals from switches, a microprocessor and an output part. The filters simultaneously process a plurality of... 

5289395 
Signal processing method employing a digital filter
A method is disclosed for processing a signal having a monochromatic signal component with the aid of a digital filter. The method includes determining the real amplitude, phase and frequency of... 

5283813 
Methods and apparatus particularly useful for blind deconvolution
A method and apparatus for controlling an equalizer receiving the output of an unknown system in order to produce a desired response for recovering the input to the system are characterized by... 

5278910 
Apparatus and method for speech signal level change suppression processing
A level measuring circuit first measures a level of an input speech signal. Next, a coefficient calculating circuit determines a value for suppressing a change of the level of the input speech... 

5258933 
Timing control for PRML class IV sampling data detection channel
A multimode timing loop for a PR4,ML sampled data channel includes an analog to digital converter and a digital finite impulse response filter for providing conditioned digital samples. The... 

5255202 
Digital signal processing method and system, electric power system signal processing system and electric power control system
Analog signals are sampled and converted into digital data which is then filtered by a digital filter. The filtered digital data is then subjected to an arithmetic operation. The blocking band of... 

5255215 
Digital filter system with changeable cutoff frequency
Using stored discrete samples of filter coefficients at each of a plurality of discrete operating points, a filter control (e.g., CPU) provides dynamic control of a digital filter through an... 

5250748 
Tone signal generation device employing a digital filter
An address signal generation circuit generates an address signal which changes at a rate corresponding to tone pitch of a tone to be generated. This address signal consists of an integer section... 

5249150 
Process and circuit to determine estimates of the instantaneous value of parameters of at least one sinusoidal signal with constant and known frequency which is an additive component of a measuring signal
A circuit and method for iteratively estimating Fourier coefficients of one or more Fourier components of a measuring signal utilizes a filter to determine the Fourier coefficients for sampling... 

5235534 
Method and apparatus for interpolating between data samples
A method and apparatus for interpolating between data samples (VS) that preserves the frequency spectrum of a sampled analog signal (VO) is provided. Data samples (VS) are interpolated to produce... 

5227972 
Matched filter data smoothing system
An efficient spatial smoothing algorithm for filtering data while preserving spatial detail is obtained using the system (impulse response) function of the sensor. In contrast to the normal... 

5226057 
Receiver and adaptive digital notch filter
Adaptive IIR digital notch filters useful with RF receivers for reducing interference. One or more notch filters automatically tune, to an interferer frequency, via adapting of coefficients in the... 

5224061 
Method of and arrangement for restoring invalid samples of an equidistantly sampled signal
A method and apparatus for replacing invalid samples of an equidistantly sampled signal with corrected samples derived from an environment of valid samples preceding and following the invalid... 

5193070 
Transversal filter circuit having tap circuits including bidirectional shift registers for serial multiplication
A transversal filter circuit including a plurality of tap circuits, each having a serial multiplication circuit having a simplified construction and not requiring a shift of decimal (binary)... 

5150317 
Adaptive digital filter which is responsive to the rate of change of an input signal
The time constant of an adaptive digital filter is regulated as a function of the magnitude of the rate of change of the input signal to the filter. When the input signal has a large step input or... 

5149902 
Electronic musical instrument using filters for timbre control
A filter calculating section has a plurality of basic filters formed on a timedivisional basis. The timbre of a musical tone signal is controlled by a memory section, an accumulator, a selector,... 

5144569 
Method for filtering digitized signals employing allpass filters
A method for filtering digital input signals (e) makes use of allpass filters of a firstclass having the transfer function S1 and allpass filters of a secondclass having the transfer function... 

5142170 
High repetition rate signal reject apparatus and method
A circuit is illustrated for eliminating a repetitiously occurring or constant frequency pulse signal from a train of signal pulses. The design is such that a plurality of such circuits can be... 

5140543 
Apparatus for digitally processing audio signal
A digital signal processing apparatus for digitally performing a limiting or compressing process with respect to an input signal. The apparatus includes a comparator responsive to the input signal... 

5130938 
Device and method for filtering weight indicative signal from weighing device
A digital filter for filtering a weight indicative signal provided by a weighing device to remove undesirable oscillatory components caused by mechanical vibration of the weighing device. The... 

5122718 
Gain/phase compensation circuit for use in servo control system of optical disk device
A gain and phase compensation circuit for use in the servo control system for an optical disk device comprises a digital signal input terminal for receiving an input digital signal to be treated,... 

5119321 
Adaptive threshold suppression of impulse noise
Impulse noise suppression upstream of digital processing circuitry contains a sample and hold mechanism which samples the input signal and stores a plurality of sequential sample values... 

5105377 
Digital virtual earth active cancellation system
A digital virtual earth active cancellation system which receives a phenomena input signal representing residual phenomena to be cancelled and has an adaptive filter which generates a cancellation... 

H001005 
GramSchmidt spacetime adaptive filter using transverse orthonormal ladder filters
A spacetime adaptive filter system is provided for eliminating unwanted signals from a radar or communication system. The filter system receives a main channel and several auxiliary channels... 

5068799 
System and method for detecting flaws in continuous web materials
A method and apparatus for detecting flaws in continuous web material illuminated by a light source and optically scanned to produce a digitalized electronic image of said material. The digitized... 

5056054 
Digital phase locked loop utilizing a multibit phase error input for control of a stepped clock generator
A digital loop filter translates a multibit phase error input into a high resolution control signal utilizable as an advanceretard control for a multiphase clock generator. The digital filter... 

5051942 
Method and apparatus for calculating filter factors
A transfer function is determined in accordance with an amplitude characteristic and a phase characteristic. The transfer function is subjected to inverse Fourier transform. An imaginary part of a... 

5043653 
Noise filter for zero crossing detector
A noise filter for the zero crossing detector of a digitized sine wave signal uses an adjustable noise integrator. The noise integrator incorporates a counter. The integration characteristic of... 

5027410 
Adaptive, programmable signal processing and filtering for hearing aids
A hearing aid system utilizes digital signal processing to correct for the hearing deficit of a particular user and to maximize the intelligibility of the desired audio signal relative to noise.... 

5027423 
Imageprocessing integrated circuit device
An imageprocessing integrated circuit device comprises a delay circuit and adder group, a multiplication block group, and an adder group. Image data in a window are fed to the delay circuit and... 

5025453 
Method of measuring the signature of digital transmission equipment, and apparatus for implementing such a method
A method of measuring the signature of digital transmission equipment, in which the measurement can be performed during operation without adding special apparatus, and in which: the digital... 

5016207 
Highspeed digital filter processor including parallel paths for processing data, suitable for use in spatial filter image processing
A digital filter processor includes an input part for distributing an input digital data train including a plurality of digital data to a plurality of systems. Each of the systems is provided with... 

5010507 
Sampled digital filter system
A sampled digital filter system for filtering a signal that has a frequency lower than an unwanted signal component in the input signal. The digital filter system samples the input signal in... 

4970637 
Digital antialiasing filter
An original analog signal is supplied to A/D converter 2 through analog LPF 1. LPF 1 has a cutoff frequency of fa/2 (fa is the frequency of a clock pulse supplied to A/D converter 2). LPF 1 limits... 

4958311 
Composite finite impulse response digital filter
A composite finite impulse response digital filter for use in an image processing apparatus or the like includes a plurality of subfilters connected in series. In each subfilter, a random access... 

4953118 
Nonrecursive halfband filter
A nonrecursive halfband filter which permits the conversion of a complexvalue input signal into a complexvalue output signal. The pulse response of the filter is modulated onto a complex... 

4953116 
Digital word output highpass filter apparatus
A highpass filter which provides a digital word output indicative of a highpass filter function of the quantity of logic "1" inputs to the counter. The output of a counter is lowpass filtered... 

4947480 
Multichannel signal enhancement
A mixed adaptive filter is formulated for the signal processing problem where desired a priori signal information is not available. The formulation generates a least squares problem which enables... 

4941185 
Image processing
A method and apparatus for processing a first (e.g. halftone) image constituted by a second (e.g. continuous tone) image convolved with a periodic (screen) function, to produce the second image... 

4939576 
Adaptive ringing reducer for television signal processing
A method for reducing ringing artifacts caused by low pass filtering of baseband television signals comprises the steps of: detecting the occurrence of a horizontal transition in the baseband... 

4933978 
Method and apparatus for determining the value of a sample in the mth position of an ordered list of a plurality of samples
A method and apparatus for determining the value of a sample having a particular position in an ordered ranking, by magnitude, of a set of digital samples includes means for truncating the lesser... 

4931972 
Multipleinput digital filter
A multipleinput digital filter capable of filtering a plurality of digital input signals with a single filtering device first latches the input signals and then sequentially selects each of the... 

4908787 
Interpolator/decimator filter structure and a notch filter therefor
A filter structure including a notch filter is designed to have a transmission zero at a frequency slightly displaced from one half of the lower sampling rate of the interpolator/decimator, and... 

4896285 
Calculation of filter factors for digital filter
An apparatus for calculating a filter factor for a digital filter which can be simply constructed and in which the time period for calculation can be shortened as compared with conventional... 

4893316 
Digital radio frequency receiver
A digital radio receiver is described. The digital receiver of the present invention contemplates a digital radio receiver which operates on a received analog signal which has been converted to a... 