Patents Examined by Tesfaldet Bogure
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Patent number: 6201844Abstract: A data stream (DS) comprises a time multiplex of coded data (D) and control data (C). The data stream (DS) may be, for example, of the MPEG type representing a sequence of pictures. The coded data (D) is transcoded (T) so as to obtain transcoded data (DT) which differs in size from the coded data (D). The control data (C) is adapted for the transcoded data (DT) so as to obtain adapted control data (CA) which does not substantially differ in size from the control data (C). The transcoded data (DT) and the adapted control data (CA) are written into a transcoder output buffer (TOB) and read from the transcoder output buffer (TOB) so as to obtain a transcoded data stream (DST). This allows an efficient use of a transmission channel via which the transcoded data stream (DST) is to be transmitted and, consequently, it allows a satisfactory transcoding quality.Type: GrantFiled: April 27, 1999Date of Patent: March 13, 2001Assignee: U.S. Philips CorporationInventor: Nicolas Bailleul
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Patent number: 6034957Abstract: A packet switching device having a central shared memory and a number of medium access controllers each coupled to a communications medium to exchange data packets therewith, and a controller coupled to each medium access controller via a data path to exchange data packets with the media access controller. The controller has a number of data path controllers each connected to each medium access controller via a separate and like portion of the data path to exchange a corresponding portion of the data packets with the medium access controller. The data path controllers each have a number of buffers each connected to one of the medium access controllers to which the data path controller is connected, to hold the portion of the data packets exchanged with the corresponding medium access controller.Type: GrantFiled: February 24, 1998Date of Patent: March 7, 2000Assignee: Extreme Networks, Inc.Inventors: Stephen R. Haddock, David K. Parker, Andrew H. Smith, Erik R. Swenson, Michael Yip
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Patent number: 5917854Abstract: A wireless radio modem for incorporation into a host system includes radio frequency modulation/demodulation circuitry employing electronic device elements that operate in a frequency range that minimize the RF interference between the radio modem and the host system. Radio modem power conservation is further maximized by 1) simplifying signal modulation processing by use of a single sideband suppressed carrier waveform transition table, thereby reducing processing requirements; and 2) incorporating a "sleep mode" feature in which all non-timer circuitry is powered-down when not in use.Type: GrantFiled: August 20, 1997Date of Patent: June 29, 1999Assignee: Research In Motion LimitedInventors: Bryan Taylor, Mihal Lazaridis, Peter Edmonson, Perry Jarmuszewski, Lizhong Zhu, Steven Carkner, Matthias Wandel
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Patent number: 5881103Abstract: An electronic device (110) provides equalization and/or compensation for a coupled audio accessory device (120). The audio accessory device (120) has a memory (220) that contains equalizer parameters (304, 308, 310, 314) which helps in characterizing its audio response or impact on audio signals within the electronic device (110). When the audio accessory device (120) is coupled to the electronic device (110), the electronic device (110) reads the equalizer parameters (304, 308, 310, 314) from the audio accessory's memory (220) and processes audio signals with equalization and/or compensation based at least in part on the equalizer parameters (304, 308, 310, 314).Type: GrantFiled: August 3, 1995Date of Patent: March 9, 1999Assignee: Motorola, Inc.Inventors: Chin Pan Wong, Scott D. Gleason
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Patent number: 5764701Abstract: A VSB modulator receives a stream of data at a 10.76 MHz constant symbol rate and converts it to a 6 MHz bandwidth signal centered at 44.0 MHz. The incoming data is interpolated by three to generate three data images and a digital filter selects the image embracing the range of 5.38 to 10.76 MHz. A sine X/X correction is added to compensate for the loss experienced in the D/A converter. The signal for the D/A converter is filtered and mixed with a 35.93 MHz oscillator output to produce data about the 44.0 MHz IF frequency. A SAW filter rejects all but the desired data.Type: GrantFiled: March 4, 1996Date of Patent: June 9, 1998Assignee: Zenith Electronics CorporationInventor: Thomas P. Horwitz
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Patent number: 5479454Abstract: A digital filter characterized by a plurality of filter coefficients, positive ones of the coefficients being represented by unsigned binary integers and negative ones of the coefficients being represented by 2's complement binary integers, comprising an input for receiving a digital input signal comprising a first predetermined number of bits; means for truncating or rounding at least one leading "0" or trailing "0" of the positive ones of the coefficients and at least one leading "1" or trailing "0" of the negative ones of the coefficients, such that significance of the integers is removed; means for successively delaying the digital input signal to produce successively delayed versions of the digital input signal; means for multiplying the successively delayed versions of the digital input signal by respective ones of the truncated representations of the respective ones of the plurality of filter coefficients and in response generating a plurality of intermediate product integers; means for restoring signiType: GrantFiled: September 21, 1993Date of Patent: December 26, 1995Assignee: Genesis Microchip Inc.Inventors: Lance Greggain, Peter Mandl
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Patent number: 5282226Abstract: A mobile station cellular telephone transmitting system having a digital data source, waveform map, FIR filter with eight taps, a zero force circuit, start/end burst detection circuit, quadrature modulator, upconverter, and power amplifier. The ramping of the power output at the beginning and end of each frame slot or burst is controlled by forcing the first and last symbol of the burst's FIR filter output to zero.Type: GrantFiled: April 27, 1992Date of Patent: January 25, 1994Assignee: Hughes Aircraft CompanyInventor: David N. Critchlow