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5502277 Filter device and electronic musical instrument using the filter device  
A filter device has a variable frequency cut-off characteristic as well as a variable gain characteristic. To obtain these characteristics, a filtering operation is performed on data input thereto...
5491725 Tracking filter and quadrature-phase reference generator  
A tracking filter has a tunable filter responsive to an input signal for producing a filtered output signal, a Hilbert transformer for producing an in-phase reference signal and a quadrature-phase...
5490169 Decision feedback equalizer method and apparatus  
A decision feedback equalizer is suitable for use with a bipolar return-to-zero receiver. The equalizer determines an output Y(n) (160) based on a compensated received value X(n) (104) and a...
5488635 Low complexity adaptive equalizer radio receiver employing reduced complexity branch metric calculation  
A low complexity adaptive equalizer for use in U.S. digital cellular radios demodulates π/4-shifted differentially encoded quadrature phase shift keyed (DQPSK) encoding in the presence of...
5488576 Amplitude adaptive filter  
A digital filter transfer function is implemented using at least two implementing filters, one of which has a transfer function which guarantees an output which is unconditionally within a...
5475710 Adaptive equalizer and receiver  
A receiver capable of effecting frame synchronization control even at the time of initial acquisition and hand off in the presence of frequency selective fading. The receiver is provided in a...
5450339 Noncanonic fully systolic LMS adaptive architecture  
A noncanonic fully systolic least mean squares adaptive filter architecture encompasses both tap weight updates and filtering and allows cascadability without penalties in speed or accuracy. A...
5432724 Processor for uniform operations on respective series of successive data in respective parallel data streams  
A data processing system for processing parallel first and second sequences of successive first and successive second data, respectively, includes a memory, having a memory input to receive the...
5432725 Self-adapting filter  
The Self-Adapting Filter is an adaptive interference suppression device t can be used to extract bandspread communication signals from a received signal containing significant structured...
5428562 Fast converging adaptive filter  
A fast affine projection adaptive filter capable of frequent parameter updating and fast convergence with low complexity. The invention mitigates affine projection adaptive filter complexity due...
5428644 Adaptive detection method and detector for quantized signals  
The invention relates to an adaptive detection method and detector for detecting signal states of a received quantized signal using a set of reference vectors stored in a memory (11). According to...
5426597 Adaptive infinite impulse response (IIR) filter system  
An adaptive filter system for use in connection with a reference system t receives an input u(s) and generating in response thereto a reference output y(s) defined by a reference transfer function...
5424946 Adaptive angular transmission filter for pet scanner  
A positron emission tomography scanner detects coincident annihilation events occurring in the field of view of a detector array and stores them as a two-dimensional sinogram array. Prior to image...
5420810 Adaptive input/output apparatus using selected sample data according to evaluation quantity  
The adaptive input-output apparatus comprises a data holding portion which holds sample data for determining an input/output function, a data selector which uses a predetermined evaluation...
5420884 Automatic equalizer  
Disclosed is an automatic equalizer which, through a simple and inexpensive arrangement, performs precise equalization irrespective of timing phase error at the time of transmission. Specifically,...
5414732 Adaptive equalizer and method for operation at high symbol rates  
Adaptive equalizers and processing methods wherein data required to implement an adaptation algorithm is sampled at a rate that is significantly lower than the symbol rate. The adaptation...
5400256 Frequency tracking adaptive synchronous vibration suppression apparatus  
A frequency tracking adaptive synchronous vibration suppression apparatus for suppressing vibrations in a dynamic system subject to synchronous disturbance includes calculating the sine and cosine...
5396414 Adaptive noise cancellation  
A compensator that enables an adaptive filter to be placed within a closed loop control system so as to reduce the effects of both measurable and unmeasurable disturbances on the output of the...
5392315 FIR filter coefficient updating system  
A coefficient updating system for a time sampled filter, such as a finite impulse response filter, includes a new coefficient register for updating the coefficients stored in the filter register....
5381359 Adaptation and training of digital finite impulse response filter within PRML sampling data detection channel  
A digital adaptive finite impulse response filter circuit is provided for a PR4,ML sampled data channel including an analog to digital sampler for providing raw digital samples of data to the...
5381357 Complex adaptive fir filter  
A complex adaptive Finite-Impulse-Response filter for processing complex digital data having real and imaginary data portions that includes a first data path for receiving and processing the real...
5371695 Method for automatically controlling the bandwidth of a digital filter and adaptive filter utilizing same  
A method and an adaptive filter are provided wherein the bandwidth of the filter is varied as a function of current and past input signal values based on the amount of noise judged to be present....
5357580 Temporal filtering of color doppler signal data  
An apparatus for temporal filtering in an ultrasonic imaging system. The apparatus has a means for storing previous imaging information from a previous time period and a means for storing current...
5325319 Filtering a signal with the use of approximate arithmetical division  
Filtering a signal with an adaptive digital filter includes updating the filter by performing an approximate division of a constant number by a variable number in binary form. The variable number...
5325204 Narrowband interference cancellation through the use of digital recursive notch filters  
A digital notch filter apparatus for removing narrowband interference signals from a wideband communication signal. The apparatus includes a recursive digital passband interference acquisition...
5319585 High resolution filtering using low resolution processors  
A high-speed digital filter with a large dynamic range is constructed by operating two low-resolution filters in parallel, which is referred to as an "overlap" mode of operation. In this overlap...
5315621 Adaptive nonrecursive digital filter and method for forming filter coefficients therefor  
An adaptive nonrecursive digital filter includes a first filter unit having N controllable filter coefficients. A control unit controls the filter coefficients as a function of an input signal...
5313411 Adaptive receiver capable of achieving both of matched filtering function and carrier recovery function  
In an adaptive receiver comprising a primary transversal filter for filtering an input signal into a filtered signal in accordance with a plurality of tap coefficients and a decision-feedback...
5309378 Multi-channel adaptive canceler  
Disclosed is an adaptive canceler in which a pipelined approach is used wherein reference signals are divided into two or more sections having concurrent weight adjustment. This architecture...
5303173 Adaptive digital filter, and method of renewing coefficients thereof  
An adaptive digital filter has a series of delay elements for imparting a unit delay of one sampling interval to successive input data samples in order to concurrently obtain a set of data samples...
5301135 Adaptive filter based on a recursive delay line  
An adaptive recursive filter for filtering electronic signals is disclosed. The filter comprises a plurality of cells connected sequentially. Each cell comprises a delay element; a means to...
5297071 Arithmetic circuit, and adaptive filter and echo canceler using it  
In the digital signal processor used for realizing application filters, the filter output calculation processing system 5 and the tap coefficient update calculation processing system 6 are...
5282155 Adaptive digital filter architecture for parallel output/update computations  
The disclosed adaptive finite impulse response (FIR) digital filter architecture computes tap coefficient updates in parallel with and simultaneously with the computation of the filter output at...
5278780 System using plurality of adaptive digital filters  
A main adaptive digital filter and a sub adaptive digital filter are provided, and these two adaptive digital filters share a filter coefficient to be controlled. On the side of the main adaptive...
5278777 Efficient cancelling of AC line interference in electronic instrumentation  
Efficient cancellation of AC power line interference from a signal received by electronic instruments, such as biomedical monitors, is obtained by efficiently estimating the magnitude and phase of...
5272656 System and method of producing adaptive FIR digital filter with non-linear frequency resolution  
A filter and method of adapting a digital filter provides a single fixed finite impulse response (FIR) filter adaptively from measured data, in a manner whereby the filter's frequency and time...
5272723 Waveform equalizer using a neural network  
A waveform equalizer for equalizing a distorted signal, contains a sampling unit, a time series generating unit, and an equalization neural network unit. The sampling unit samples the level of a...
5268848 Equalizer adjustment for partial-response maximum-likelihood disk drive systems  
Apparatus and method for providing equalization adjustment for a finite impulse response (FIR) digital filter are provided in a PRML data channel. A plurality of transformations are defined to...
5268927 Digital adaptive transversal filter for spread spectrum receivers  
A digital adaptive transversal filter includes an interface circuit for regulating and digitizing analog input signals, which comprise of multiple spread-spectrum signals, additive thermal noise...
5263099 High speed window and level function modification for real time video processing  
A CT scanner (10) non-invasively examines a region of interest of a patient to create an image representation that is stored in an image memory (14). Each pixel of the image representation has a...
5260896 Adaptive filter and a method of preventing divergent behavior of the adaptive filter  
A method of preventing divergent behavior of a recursively adjusted adaptive filter and an adaptive filter to which the method is applied are disclosed. The adaptive filter is adjusted by...
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...
5247470 Method and apparatus for estimating signal components of a filter output  
An adaptive matched filter is described as a replacement for a signal replica filter of a maximum likelihood (ML) demodulator, the filter normally receiving an input data vector having signal and...
5245561 Adaptive filter capable of quickly identifying an unknown system  
In an adaptive filter formed by first through N-th delay elements connected in series to one another to define first through N-th taps, first through M-th coefficient circuits which are smaller in...
5243624 Method and apparatus for updating coefficients in a complex adaptive equalizer  
Convergence of a complex adaptive equalizer used in digital communications is substantially improved by updating all coefficients of the equalizer during each filter clock cycle. Complex signal...
5237524 Method of low-pass filtering and arrangement for performing said method  
Signal smoothing can be improved without simultaneously obliterating the useful input signal edges by adaptively filtering the signal, in which the averaging interval is corresponding to the...
5233635 Receiving method and receiver for discrete signals  
The invention relates to an adaptive receiving method and a receiver comprising an adaptive equalizing device for processing a received signal. The receiver further comprises an adaptive detector...
5233550 Adaptive balance filter  
In an adaptive balance filter, the coefficients of an adaptive filter are only taken over in a shadow filter, when a digital input signal to be transmitted is recognized as a wide band signal.
5224170 Time domain compensation for transducer mismatch  
A two channel real time octave analyzer is equipped with an adaptive time domain phase compensation filter whose poles and zeros are programmably selected to counteract phase error associated with...
5218560 Circuit for controlling tap gains at rapid speed in an adaptive filter  
In a tap control circuit for use in an adaptive filter for filtering a received signal into a filtered signal in accordance with first through N-th controllable tap gains which are produced by a...