Sunrise Telecom, Inc.

Scientific-atlanta, Inc.

James E Barker

Robert L Richards

Richard Charles Jaworski

Herman B Elliott

Scott E Hrastar

David A Sedacca

Roy A Bowcutt

Todd A Merrill

Clifford Brown

Hermann B Elliott

Hermann B Elliot

Richard C Jawaorski

A device and methods for automatically diagnosing impairments in a digital quadrature amplitude modulated signal is disclosed. The impairments include phase noise, compression, coherent interference, and non-coherent interference. The device comprises a phase noise detector, a compression detector, and an interference detector. The phase noise detector detects phase noise by analyzing data points of an amplitude quadrature modulated constellation for orthogonal deviations from ideal points. The compression detector detects compression by analyzing the magnitudes of vectors from the constellation's origin to data points of the constellation. The interference detector detects coherent and non-coherent interference by detecting error signals in the data points and then analyzing the distribution of the error signals.

System and method for automatic diagnosis of impairments in a digital quadrature amplitude modulated signal

A system for testing a portion of a cable network provides a pattern generator, Addresser, forward error corrector, and comparator. The system is particularly adapted to testing the upstream channel in a cable network. The pattern generator generates a test signal. The addresser addresses the signal to a known server and also instructs the known server to return the test signal to the test system. The forward error corrector corrects errors introduced in the test signal in transmission from the known server to the test system. The comparator then compares the returned test signal to the originally transmitted test signal to determine the performance of the back channel. Preferably, the comparator uses a bit error rate test to determine the performance of the back channel.

System for testing the upstream channel of a cable network

A system and method for testing a portion of a cable network provides a pattern generator, addresser, forward error corrector, and comparator. The system and method is particularly adapted to testing the upstream channel in a cable network. The pattern generator generates a test signal. The addresser addresses the signal to a known server and also instructs the known server to return the test signal to the test system. The forward error corrector corrects errors introduced in the test signal in transmission from the known server to the test system. The comparator then compares the returned test signal to the originally transmitted test signal to determine the performance of the back channel. Preferably, the comparator uses a bit error rate test to determine the performance of the back channel.

System and method for testing the upstream channel of a cable network

A method for transporting digital data from a sender to a receiver in a system where the digital data is broken into data packets for transmission over radio frequency channels, each data packet including forward error-correcting code, the method comprising the steps of receiving the data packets at the receiver; reconstructing the data packets to the digital data, the forward error-correcting code for fixing corrupted data packets; and halting the data packet reconstructing step if a data packet is uncorrectable.

System and method for detecting correcting and discarding corrupted data

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Lawrenceville, GA, United States of America

James E Barker