Patent ID: 7117427

Claim:
A method of TCM decoding, the method comprising the steps of: a) receiving a soft symbol; b) choosing a constellation point closest to the received soft symbol for each TCM subset; c) calculating the metric of each branch based on the distance of the chosen point from the received symbol, wherein the distance is Euclidean distance; d) calculating new state metrics for each trellis state as the minimum of the sums of all possible previous states and appropriate branch that lead to a new state; e) selecting the state with the smallest metric; and f) tracing back from the state with the smallest metric, to determine the state and appropriate transmitted symbol(s) having a delay based on the traceback length, wherein steps b and c together choose between parallel branches between states in the trellis, and assign branch metrics to each branch and each branch metric is calculated by adding the absolute value of the real and imaginary parts of the complex vector resulting from the subtraction of the received symbol and the closest symbol in each subset to implement simplified metric VA decoding.