Patent ID: 8068549
Filing Date: 2011-11-29
Classification: H04L

Abstract:
1. A method of trellis decoding a symbol stream comprising symbols of a first type and symbols of a second type, symbols of the first type are encoded using a first convolutional code and symbols of the second type are encoded using a second convolutional code, the method comprising: for symbols of the first type, storing a plurality of states along each path of a trellis based on a comparison of incremental error metrics and storing an additional plurality of states along each path of a phase inverted trellis; for symbols of the second type, storing a plurality of path indicators along each path of the trellis and storing an additional plurality of path indicators along each path of the phase inverted trellis, wherein path indicators are associated with each leg of each path; and tracing back along a candidate path to decode a symbol according to the plurality of states, the plurality of path indicators, the additional plurality of states and the additional plurality of path indicators.