Reed-Solomon example in 802.16 standard

The answer is simpler than many did suggest. If you look for generator
polynomials of many RS codes in literature they are given in direct form.
But you also can modify these polynomials -- by applying additional
multipliers in each branch. Say, first (MSByte) encoder's additional
multiple is alpha, second one is alpha^2 and so on. Why they use this
trick? I am not sure. But in my humble opinion is that this is done just
to have some "proprietary" implementation. I encountered this problem (
decoder needs some modification too ;) ) when dealt with DVB-H/ISDB-T
system. I guess this was true and for yours case.