Patent ID: 6252911
Filing Date: 2001-06-26
Classification: H04L

Abstract:
A trellis shaping method for use in connection with data communication over a communication channel between a transmitter and a receiver, the method comprising:defining a convolutional code c=b G of size n through a rate k/n code, where b is a binary sequence of length k and G is a variable polynomial code generating matrix G of size k by n;defining a matrix H.sup.T of size n by (n-k) which represents the syndrome-former of the convolutional code defined so that G H.sup.T =0;defining a matrix (H.sup.T).sup.-1 of size (n-k) by n which represents the left inverse of H.sup.T ;at the transmitter:mapping digital data bits into a set of n magnitudes and a set of (n-k) sign bits s;passing the (n-k) sign bits through (H.sup.T).sup.-1 to obtain preliminary sign bits t=s (H.sup.T).sup.-1 of size n; andadding the convolutional code c=b G, through an exclusive OR operation, to the preliminary sign bits t to obtain final sign bits given by s (H.sup.T).sup.-1 +b G.