Patent ID: 6980606
Filing Date: 2005-12-27
Classification: H04L

Abstract:
1. Device for reconstructing a runlength constrained sequence of n-ary digits from an analog input signal representing said sequence, the device comprising an input for receiving said signal, a sampling unit for taking time-discrete samples of the input signal, a branch metric calculation unit for calculating a set of branch metric values for subsequent samples of the sampled input signal, each of the set of branch metric values being an indication for the likelihood that an amplitude value of a sample corresponds to a particular state, a state being defined as a sequence of n-ary digits, a delay unit for delaying metric values, a path metric calculation unit, coupled to the delay unit, for calculating path metric values out of the branch metric values, a path metric value being an indication for the likelihood that a sequence of samples corresponds to a sequence of states, an output for providing the reconstructed runlength constrained sequence of n-ary digits and wherein the delay unit forms part of a delay chain of delay units, a first delay unit of the delay chain being coupled to the branch metric calculation unit, and the path metric calculation unit forms part of a path metric calculation chain of path metric calculation units, the path metric calculation chain comprising one or more path metric calculation units having first inputs coupled to a delay unit and second inputs coupled to a preceding path metric calculation unit.