Ikanos Communications, Inc.

Rouben Toumani

Sam Heidari

Behrooz Rezvani

Sanjay Bhandari

Robert A Blauschild

Dale Smith

Avadhani Shridhar

Ying Wu

Sushil Agrawal

A multi-tone transceiver including: a channel controller and a plurality of components forming a transmit path and a receive path. The channel controller configured to determine bit-loading for each successive symbol or tone set based on a 1noise margin target for a first subset of tones in each tone set dedicated to transport of a robust communications channel (RCC) and based on a 2noise margin target less than the 1noise margin target for remaining tones in each tone set dedicated to a standard communications channel (SCC). The plurality of components forming the transmit and receive paths are responsive to the channel controller to select for data modulated on a given tone at least one of smaller constellations and higher gain scaling levels when the given tone corresponds to an RCC tone as compared to an SCC tone, whereby the first set of tones dedicated to the RCC exhibit greater immunity to noise variations than the remaining tones dedicated to the SCC.

Method and apparatus for differentiated communication channel robustness in a multi-tone transceiver

A high efficiency line driver is disclosed. The line driver may be applied with equal advantage in wired and wireless communication media to amplify data signals with a minimum of power consumption. In an embodiment of the invention a line driver is disclosed which includes: at least one amplifier, a delay element, a control signal generator and a generator. The at least one amplifier includes at least one bias supply, a signal input and a signal output. The delay element accepts as an input the data signal and delays delivery of the data signal to the at least one line amplifier for amplification. The generator is responsive to a control signal to generate varying voltage levels corresponding thereto on the at least one bias supply of the at least one amplifier. The control signal generator is responsive to the input data signal to detect peaks therein and to generate the control signal corresponding thereto in advance of delivery of the data signal to the amplifier.

Method and apparatus for a high efficiency line driver

An inverse discrete Fourier transform (IDFT) processor processing a lower frequency image of a selected transmit band along with base images of remaining transmit bands called for in a corresponding X-DSL standard. A hybrid upconverter processing the IDFT output by generating a higher frequency replication of the imaged transmit band falling in the standards based frequency range along with the base band images of remaining transmit bands and selectively passing onto the communication medium only images or replications called for by the standards. A hybrid downconverter processing at least one of the received bands at sampling rates below Nyquist thereby creating a lower frequency image within the range of a discrete Fourier transform (DFT) processor. The hybrid downconverter clears the frequency band in which the image processed at sub-Nyquist rates will fold. The DFT then transforms only the images or replications falling within its frequency range.

Method and apparatus for extending the frequency range of multi-tone modems

A method and apparatus for extending existing fiber and local area networks across digital subscriber lines, at matching data rates is disclosed. A DSL transceiver system is disclosed with one or more gateways coupled to at least one digital signal processor (DSP). The DSP in turn couples to a plurality of analog-front-ends (AFE's). Each AFE is coupled via associated hybrid front ends (HFE's) to corresponding subscriber lines. The transceiver or a controller coupled thereto maintains a table of bandwidth requirements and frame types for a variety of sessions. Individual sessions include bandwidth requirements beyond existing XDSL capabilities. The system determines frametype, e.g. 802 and bandwidth requirements, e.g. 100 Mbps for each session and allocates more than one subscriber line accordingly. For each session the divergent bandwidth availability of each of the subscriber lines to which the DSP may be coupled is determined and all or a portion of that bandwidth is allocated to the selected session. Provisioning continues until the allocated bandwidth on each subscriber line equals the session requirements. Next, a pseudo channel identifier is allocated to each physical channel. This along with a session number which is assigned to each pseudo channel allows packet based demultiplexing of a single session across a plurality of subscriber lines. A sequence for processing of pseudo channels is then assigned to all the pseudo channels within each session. This information is then communicated to the remote end and a corresponding provisioning takes place.

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San Jose, CA, United States of America

Rouben Toumani