Texas Instruments Corporation

Thomas N Zogakis

Peter J Melsa

Konrad W Kratochwil

Himamshu Gopalakrishna Khasnis

Brian Robert Wiese

Michael Eugene Locke

Baireddy Vijayavardhan

A method of communicating data across a channel that experiences near-end cross talk (NEXT) interference and far-end cross talk (FEXT) interference in alternate intervals. In one embodiment, a first data rate is determined for a first carrier-number mode that is to utilize a first bit table, a second data rate is determined for a second carrier-number mode that is to utilize dual bit tables, a third data rate is determined for a third carrier-number mode that is to utilize a second bit table during a FEXT interval, and a modem is configured to transmit using the mode having a highest data rate.

Memory-efficient ADSL transmission in the presence of TCM-ISDN interferers

System and method for improving trellis decoding in communications systems with finite constellation boundaries. A preferred embodiment for a received point of a tone when the tone represents a number of bits greater than three comprises determining if a received point lies outside of a specified region, wherein the specified region is dependent upon the number of bits, and transforming the received point if the received point lies outside of the specified region. The transformation moves the received point onto a boundary of the specified region, which can help in the correct decoding of the received point.

Trellis decoding with finite constellation boundaries

A method of communicating data across a channel that experiences near-end cross talk (NEXT) interference and far-end cross talk (FEXT) interference in alternate intervals. In one embodiment, the method comprises: a) determining N, the number of bits per symbol usable in a FEXT-only mode of operation; b) determining N, a number of bits per symbol usable in a single mode of operation; c) determining whether the FEXT-only mode or the single mode provides a higher data rate; and d) configuring a modem to transmit using the mode having a higher data rate. The FEXT-only mode may be determined to have a higher data rate when 126N&#x3e;340N.

A communication device (e.g., a modem) is disclosed as including logic that processes a transmit signal before providing a signal to an echo canceler. The processing may include low pass filtering and decimation of the transmit signal. The low pass filter's cut-off frequency preferably is less than the sampling rate associated with the transmit signal.

Echo cancellation in communication systems with asymmetric data rates

A receiver architecture featuring a decimation filter and a bypass around said decimation filter is disclosed along with a method for optimizing said receiver's sampling phase and programmable gain amplifier. Said method utilizes said receiver architecture to modify said receiver's receive path to simplify optimizations.

Communications receiver architectures and algorithms permitting hardware adjustments for optimizing performance

System and method for a multi-standard sigma-delta modulator. A preferred embodiment comprises an integrator coupled to a signal input, wherein the integrator is configured to sum a difference between an input signal and an output of the sigma-delta modulator. A dithering circuit, also coupled to the signal input, is used to produce a dithering sequence. A summing point combines an output of the integrator and the dithering circuit while a quantizer converts the combined outputs into one of several discrete levels. The sigma-delta modulator further comprises a reset circuit to reset the sigma-delta modulator if the integrator becomes saturated. The sigma-delta modulator, as described, is compatible with G.Lite, ADSL, and ADSL+ variants of the digital subscriber line technical standards.

Growing community of inventors

Mountain View, CA, United States of America

Thomas N Zogakis