Multi-Carrier Modulation and MIMO Principle Application on Subscriber Lines

Abstract

The multi-carrier modulation is used in many applications, primary for a wireless transmission, for example Wi-Fi and WiMAX networks or DVB-T. But the same physical principle can be used also for metallic lines in access or local networks, for example ADSL and VDSL. The multi-carrier modulation in these cases is called DMT. The dominant source of noise in multi-pair metallic cables is crosstalk when the information capacity is limited dramatically. However, information capacity of metallic lines can be increased, if the system is using MIMO principles, concrete VDMT modulation and line bounding concept. The methods for VDMT modulation and partial crosstalk cancellation are discussed and simulation results are presented.