Discrete Multitone Modulation Using Wavelet

The DMT (discrete multitone modu- lation) technique has been widely applied to data transmission over fading channels of twisted pairs. It has been shown that the DMT system with ideal lters can achieve within 8 to 9 dB of the channel capacity of ADSL. The DFT based DMT system is proposed as a practical DMT implementation but its optimality is never asserted. In this report we will show that the DFT based DMT systems are asymptotically optimal although they are not opti- mal for nite number of channels. The DFT based DMT system and the DMT system with ideal l- ters achieve the same bound. However, for a mod- est number of channels the optimal transceiver can provide substantial gain over the DFT based sys- tem