a method for branch metric calculation in a plurality of communications standards is disclosed . the method generally includes steps to . step may calculate a plurality of sum values by adding a plurality of first values related to a plurality of information bits , a plurality of second values related to the information bits and a plurality of third values related to a plurality of parity bits . step may generate a plurality of permutated values by permutating the sum values based on a configuration signal . the configuration signal generally identifies a current one of the communications standards . step may generate a plurality of branch metrics values by adding pairs of the permutated values .