Abstract: A station to serve as a proxy for responding to a multicast message is selected using dynamically maintained information about other stations communicatively coupled to a shared communications network. The dynamically maintained information is used to select a station having a high probability of replying to the multicast message. Network performance may be further improved by re-selecting proxies when a multicast frame fails to acknowledged.
Abstract: A step-down switching voltage regulator with a push-pull output stage is adapted to provide a voltage converter with an auxiliary voltage rail that supplies an auxiliary voltage that is higher than the input supply voltage. The push-pull output stage of the step-down voltage regulator is used to drive a charge pump voltage-doubler circuit. In this way, a single integrated topology provides a regulated low voltage output as well as an auxiliary high voltage output. The circuit topology enables a low component count resulting in lower component cost and smaller physical size.
Abstract: A step-down switching voltage regulator with a push-pull output stage is adapted to provide a voltage converter with an auxiliary voltage rail that supplies an auxiliary voltage that is higher than the input supply voltage. The push-pull output stage of the step-down voltage regulator is used to drive a charge pump voltage-doubler circuit. In this way, a single integrated topology provides a regulated low voltage output as well as an auxiliary high voltage output. The circuit topology enables a low component count resulting in lower component cost and smaller physical size.
Abstract: A method and apparatus for detecting a channel jammed by narrowband jamming interference in a block oriented digital transmission system such as an orthogonal frequency division multiplexing (OFDM) or discrete multi-tone (DMT) system. A spectrum of a received data bearing signal is examined to identify areas of the spectrum that are likely corrupted by a narrowband jamming interference. The method identifies jammed channels by applying a boxcar filter, in order to identify narrow peaks in the spectrum that are substantially larger in magnitude than adjacent channels. Channels identified as jammed or affected by a jamming signal, are listed in a jam mask used for screening out corrupted channels during data transmission.
Type:
Application
Filed:
June 24, 2002
Publication date:
December 25, 2003
Applicant:
Cogency Semiconductor Inc.
Inventors:
John Louis Fanson, Douglas Hamilton Taylor, Bradley Robert Lynch
Abstract: An analog signal gain control circuit(ASGC) for a digital radio HomePlug orthogonal frequency division multiplexing (OFDM) receiver includes a digital variable gain amplifier (DVGA) to control the gain of a received signal to achieve a desired signal amplitude to match a dynamic range of an analog-to-digital converter (ADC), an inverse scaling stage controlled to inverse-scale the signal output by the ADC, and a two-stage fast attack and slow decay filter that outputs control signals to the DVGA and to the inverse scaling stage. The fast attack and slow decay filter rapidly responds to an increase in signal amplitude and slowly decays the amplitude of the control signal in response to a decrease in input signal amplitude.
Type:
Application
Filed:
May 15, 2002
Publication date:
November 20, 2003
Applicant:
Cogency Semiconductor Inc.
Inventors:
Brian James Langlais, Akrum Elkhazin, John Fanson, Bradley Robert Lynch, Xi Chu
Abstract: A method and system for estimating a time shift required for symbol synchronization in a block oriented digital communication systems such as an orthogonal frequency division multiplexing (OFDM) or a discrete multi-tone (DMT) data transmission system. The method uses an N/d inverse discrete Fourier transform (IDFT), where N is a sample number and d is a decimation factor, or alternatively an N/(2d) inverse fast Fourier transform (IFFT) for a real received signal or an N/d IDFT for a complex received signal.
Type:
Application
Filed:
April 17, 2002
Publication date:
October 23, 2003
Applicant:
COGENCY SEMICONDUCTOR INC.
Inventors:
John Louis Fanson, Douglas Hamilton Taylor