Patent ID: 7796685

Claim:
A method of shaping an outbound signal in a very high bitrate digital subscriber line (VDSL) transceiver comprising: defining, using a leakage power module at the VDSL transceiver, a leakage power function of an N th discrete multi-tone (DMT) sub-channel, where N is an integer between 1 and a maximum number of available sub-channels, wherein defining a leakage power function of an N th DMT sub-channel comprises defining a function [Aw] k , where w is the window function, A is the matrix, A = 2 ⁢ x ⁡ [ 1 1 … 1 cos ⁡ ( π ⁡ ( L - 1 ) N ) cos ⁡ ( π ⁡ ( L - 3 ) N ) … cos ⁡ ( π N ) ⋮ ⋮ ⋰ ⋮ cos ⁡ ( π ⁡ ( N / 2 - 1 ) ⁢ ( L - 1 ) N ) cos ⁡ ( π ⁡ ( N / 2 - 1 ) ⁢ ( L - 3 ) N ) … cos ⁡ ( π ⁡ ( N / 2 - 1 ) N ) ] N 2 × L 2 ⁢ a ⁢ ⁢ n ⁢ ⁢ d ⁢ ⁢ ⁢ ⁢ k = 0 : N 2 - 1 ; minimizing the leakage power function based on the defined leakage power function; generating a transmit window based on the minimized function; and reducing power leakage by windowing the outbound signal transmit window.