Patent ID: 7440521
Filing Date: 2008-10-21
Classification: H03M,H04L

Abstract:
1. A method of normalizing alpha (α) values (forward metrics) in a map decoder that is operable to decode a signal, the method comprising: storing the α values for a current decoder cycle, in a register; feeding back the stored α values for use in α update calculation for the current decoder cycle; performing detection of a normalization condition that is indicated when all the stored α values have reached a certain value for the current decoder cycle, wherein the α update calculation and the performing detection of the normalization condition are performed in parallel with one another such that the detection of the normalization condition is performed during a same time period as the α update calculation for the current decoder cycle; subtracting a constant value from all the α values on a next decoder cycle; and employing soft information that is generated, at least in part, from the α values of a most recent decoder cycle, when decoding the signal to make an estimate of an information bit within the signal.