Noise measurement method and a related receiving digital subscriber line modem

摘要

The present invention relates to a Noise measurement method and a related device for noise measurement in a Digital Subscriber Line transmission system. Such a system comprises a transmitting Digital Subscriber Line modem and a receiving Digital Subscriber Line modem where the transmitting Digital Subscriber Line modem is coupled over a communication line to the receiving Digital Subscriber Line modem. The method of the present invention comprises the step the receiving Digital Subscriber Line modem receiving a symbol transmitted by the transmitting modem. Subsequently the receiving Digital Subscriber Line modem demaps the symbol received onto a constellation point. The receiving Digital Subscriber Line modem then performs a noise measurement based on the difference between the received symbol and the determined constellation point. Further, the receiving Digital Subscriber Line modem determines a frequency of the symbols incorrectly demapped and
Subsequently the receiving Digital Subscriber Line modem corrects the noise measurement using the frequency of the symbols incorrectly demapped.