0 in the case of what are known as u201c tailbiting codes u201d no initial state is known at the outset a transient phase of length u03c0 therefore has to be introduced for both directions associated metrics values for the transient phase are indicated as m u03b1 pre and m u03b2 pre respectively fig2 is a diagrammatic representation of a window maxlogmap algorithm for the calculation of soft output values according to the related art the window maxlogmap algorithm which is implemented with the aid of a sliding decoding window is used for long data sequences the particular advantage of the window maxlogmap algorithm is its efficient implementation similarly to fig1 alpha metrics values m u03b1 calc are calculated precisely in a forward direction starting at a trellis segment t 1 by contrast beta metrics values m u03b2 calc 1 of a first decoding window dp 1 and beta metrics values m u03b2 calc 2 of a second decoding window dp 2 are estimated if the two decoding windows dp 1 and dp 2 reach the right hand edge of the trellis diagram trel all the termination information is available the beta metrics values m u03b2 calc 1 and m u03b2 calc 2 are calculated precisely and the corresponding soft output values are formed metrics values m u03b1 pre m u03b2 pre 1 and m u03b2 pre 2 are again assigned to a transient phase the window maxlogmap algorithm is described in detail in the above mentioned publication u201c an intuitive justification and a simplified implementation of the map decoder for convolutional codes u201d for this implementation with a data throughput similar to that of fig1 in total u250c w u03c8 u2510 1 metrics.