Patent ID: 8306166
Filing Date: 2012-11-06
Classification: H04L

Abstract:
1. A system for detecting burst noise during quadrature amplitude modulation (QAM) communications in a cable modem system, comprising: a cable modem termination system (CMTS) receiver in communication with a plurality of cable modems, the receiver receiving a QAM signal and demodulating the QAM signal to identify a plurality of symbols; and a burst noise detection module in communication with the CMTS receiver for detecting burst noise in QAM signals received by the receiver, the burst noise detection module determining normalized amplitudes for each of the plurality of symbols, comparing the amplitudes to a threshold, and recording information relating to a burst noise event for each absolute amplitude that is greater than the predetermined threshold, wherein the detection module defines boundaries of a QAM constellation using symbols which lie on the perimeter of the constellation, and the detection module detects energy which lies outside of the boundaries of the QAM constellation.