Patent ID: 7346118

Claim:
A method of encoding Quadrature Amplitude Modulation (QAM) trellis coded data signals, comprising: receiving data bits and inputting into a Trellis encoder; encoding some of the received data bits using a Trellis state machine; employing a 4/5 convolutional encoder to encode the data bits; generating a redundant data bit u 0 using a six stage state machine; mapping all of the data bits onto a constellation according to the equations: v′ 2 =u 5 v′ 1 =u 1 ⊕u 3 v′ 0 =u 3 w′ 2 =u 4 ⊕u 5 w′ 1 =u 0 ⊕u 1 ⊕u 2 ⊕u 3 w′ 0 =u 2 ⊕u 3 wherein u 1 , u 2 , u 3 , u 4 , are the encoded bits; u 5 is an uncoded bit, u 0 is the redundant bit, and wherein v′ 0 , v′ 1 , v′ 2 , w′ 0 , w′ 1 , w′ 2 are input into discrete multi-tone (DMT) bins; and forcing the Trellis state machine to return to zero state.