Wilfred Andre Maria Snijders, Nicolaas Alphonsus Maria Verhoeckx, Petrus Josephus VAN Gerwen, Hendrik Arie VAN Essen: Modulation and filtering device. U S Philips Corporation, Frank R Trifari, Simon L Cohen, January 11, 1977: US04003002 (146 worldwide citation)

A digital data transmitter is described, whose line carrier frequency need not be an integral multiple of one half the clock frequency of the digital input signal. Use is made of a digital filter for increasing the sampling frequency to a value which is twice the modulator carrier wave frequency.

John Schwaller: Adaptive distribution system for transmitting wideband video data over narrowband multichannel wireless communication system. December 17, 1996: US05585850 (144 worldwide citation)

A technique for transmitting wideband signals such as video signals over a communication system such as a cellular or Personal Communication System (PCS) which only has narrowband channels. The video signal is first digitized and compressed, and then forwarded to a commutating switch, together with ...

J William Whikehart: Digital quadrature radio receiver with two-step processing. Ford Motor Company, Mark Mollon, Roger L May, June 22, 1993: US05222144 (132 worldwide citation)

A digital signal processing (DSP) radio receiver employs a conventional analog RF tuner to produce an analog intermediate frequency. The receiver performs DSP functions of digitally sampling the analog intermediate frequency at a sampling rate f.sub.s, concurrently mixing, filtering, and sample-rate ...

Masao Kasuga: Sampling frequency converter. Victor Company of Japan, Ladas & Parry, September 18, 1984: US04472785 (132 worldwide citation)

A sampling frequency converter for converting a first signal sampled at a first sampling frequency f1 into a second signal sampled at a second sampling frequency f2 comprising an interpolation device supplied with the first signal, for inserting L-1 zeros (L is an integer) for every sampling time, a ...

Philippe L Jacob, Sharbel E Noujaim, Glenn A Forman, John A Mallick: Subsampling time-domain digital filter using sparsely clocked output latch. General Electric Company, Allen L Limberg, James C Davis Jr, Marvin Snyder, January 1, 1991: US04982353 (130 worldwide citation)

The plural-phase clocking signal used in a subsampling time-domain digital filter is partially blanked to generate a sparse clocking signal for a clocked data latch that decimates the output signal from the digital filter, to supply it at a subsampling rate as compared to the sampling rate of input ...

William J Owen, Robert A Booker: Optimum second order digital filter. Martin Marietta Corporation, Sughrue Mion Zinn Macpeak & Seas, October 26, 1982: US04356558 (126 worldwide citation)

A second order digital filter utilizing six processor operations, two add instructions, two shift instructions and two store instructions. No multipliers are required. The filter is used as a digital filter in a servo loop having a Z transform of, G(Z)=4 (1-Z.sup.-1)+Z.sup.-2.

Mark A Webster, James C Richards: Least-mean squares adaptive digital filter havings variable size loop bandwidth. Harris Corporation, Charles E Wands, February 14, 1995: US05390364 (120 worldwide citation)

An adaptive digital filter uses a weight adjustment unit for adjusting the weights of an adaptive digital filter according to one or more input signals to the digital filter and according to an error signal indicative of the difference between the actual and desired outputs of the digital filter. Th ...

Joseph H Rothweiler: System for digital multiband filtering. RCA Corporation, Clement A Berard Jr, Henry I Schanzer, William H Meise, September 1, 1987: US04691292 (116 worldwide citation)

A digital filter system in which the frequency spectrum of an input signal is divided into M consecutive subbands. Each subband is generated by multiplying the impulse reponse of a low pass filter by a sinusoid (sine or cosine) whose frequency is equal to the center frequency of its respective subba ...

Bruce D Signore, Eric J Swanson: Analog-to-digital converter with a continuously calibrated voltage reference. Crystal Semiconductor, Gregory M Howison, June 7, 1994: US05319370 (116 worldwide citation)

A method and apparatus for calibration of errors in the analog reference voltage input of an analog-to-digital converter. A monolithic reference voltage generator is provided to generate the analog reference which includes a bandgap voltage reference (50) that outputs an untrimmed voltage and a temp ...

Robert Richard Leyendecker: Frequency selective predistortion in a linear transmitter. Glenayre Electronics, Christensen O Connor Johnson & Kindness PLLC, February 2, 1999: US05867065 (112 worldwide citation)

A system for linearly transmitting an amplified output signal using predistortion is disclosed. The system uses a straight inverse modeling scheme to more easily and accurately determine the inverse of the distortion caused by a power amplifier of a RF transmitter. The direct inverse modeling scheme ...

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