Realization 11 also is based on the publication of Forney [7]. In order to eliminate the loops of realization 10, some blocks can be combined to one big block, see the dashed lines of the following diagram:
The two big blocks are realized as the function nodes f. Furthermore, always two bits are combined to one variable with four different values. This combination is done by four function nodes g. Both of these functions are implemented by trellis sections, i.e. instead of programming new function nodes, the very general trellis sections have been "abused" for representing this functions.
The functions f and g are shown in the following trellises:
The realization 11 is shown here:
