3com Corporation

Other

U.S. Robotics Mobile Communications Corp.

Kevin J Smart

Todor Cooklev

Scott Bevan

Jack Yang

John R Rosenlof

William Kurt Dobson

John Bernard Dougall, Jr

Nathan M Whitney

Peter M Rigstad

Mark W Christiansen

Trenton D Stoddard

Kurt Dobson

Sachindev Shetty

Trent Stoddard

Jiankan J Yang

A sliding-window multi-carrier communication system is described, wherein the carriers are orthogonal in a local sense, but not necessarily in a global sense. In one embodiment, the system allows a reduction of the length of the basis function time as compared to conventional OFDM systems. In some circumstances, the symbol time can be reduced almost to the basis function length even though the delay spread from channel-to-channel is significant. In one embodiment, a discrete Fourier transform DFT is used in the sliding-window receiver. In one embodiment, the DFT produces M outputs (one output for each of M channels) for each time-domain input. In one embodiment, the DFT produces outputs for M channels from N samples, where N is a basis function length. In one embodiment, the sliding-window receiver provides an adjustable basis-function length. In one embodiment, the basis-function length can be separately selected for each channel. In one embodiment, the sliding-window receiver provides independent equalization for each channel by extracting equalization information from a packet header.

Sliding-window multi-carrier frequency division multiplexing system

A correlator for use in a timing recovery apparatus of a receiver in a multicarrier transmission system. The correlator locates the beginning of a data frame and initializes a pointer register with an address to a location within the receive signal buffer. Data is transferred to a signal converter from the receive signal buffer where the samples that are fed into the converter are determined by the address stored in the pointer register.

Correlation based method of determining frame boundaries of data frames that are periodically extended

A communication system configured to transceive a signal along multiple communication media of the communication system thereby increasing the rate at which the signal is transceived. The communication system comprising a source configured to transceive a signal. A communication apparatus configured for decomposing the signal into a plurality of manipulated signals. The number of the plurality of manipulated signals being determined by the number of the multiple communication media in communication with the source and the maximum transceival rate of each communication media. In communication with the communication apparatus is a reconstructing apparatus that is configured for reconstructing the plurality of manipulated signals into the signal, the signal being capable of being transceived by a host.

High-speed MODEM operating over two or more telephone lines

The compression method utilizes a combination of both lossy and lossless compression to achieve significant compression while retaining very high subjective quality of the reconstructed or decompressed signal. Methods and apparatus for compression and decompression of digital audio data are provided. In one preferred embodiment, the compression method or apparatus employs an approximation of a psychoacoustic model for wavelet packet decomposition and has a bit rate control feedback loop particularly well suited to matching the output bit rate of the data compressor to the bandwidth capacity of a communication channel.

Method and apparatus for wavelet based data compression having adaptive

The compression method utilizes a combination of both lossy and lossless compression to achieve significant compression while retaining very high subjective quality of the reconstructed or decompressed signal. Methods and apparatus for compression and decompression of digital audio data are provided. In one preferred embodiment, the compression method or apparatus has a bit rate control feedback loop particularly well suited to matching the output bit rate of the data compressor to the bandwidth capacity of a communication channel. Embodiments trade-off various error sources in order to keep perceptible distortion levels to a minimum for a fixed bit rate. Preferred embodiments also utilize a unique combination of run length and Huffman encoding methods in order to take advantage of both local and global statistics.

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Bountiful, UT, United States of America

Kevin J Smart