Method and apparatus for improving data transmission in a digital subscriber line (DSL) system. The transmitter determines whether a spectrum of an inverse Fourier transform (IFT) is periodic with respect to a clock of a predetermined standard-size IFT and communicates this information to the receiver....http://www.google.com.tw/patents/US7061974?utm_source=gb-gplus-share專利 US7061974 - System and method for data transmission in DMT-based DSL modems
