1. A method for maximum-likelihood decoding of convolutional codes for a received code sequence having 2.sup.m states (where m is a whole integer) by a plurality of interconnected processors each of which is normally in communication with all the other processors of said plurality and each provided with a decoding algorithm means for deriving/interchanging decoding parameters including branch metrics, accumulated metrics and survivors in an m-state trellis with each processor fixedly assigned to one state of said trellis, the improvement comprising: connecting each one of a plurality of 2.sup.m processors, equipped with said decoding algorithm means, in an n-cube configuration having bidirectional communication links along the edges only of said cube and certain processors thereof not having a direct communication link between other processors of said n-cube configuration; mapping an equivalent trellis for said n-cube configuration wherein processors represent more than one state and thus have direct communication links between other processors of said n-cube configuration on said equivalent trellis; and deriving/interchanging the branch and accumulated metrics between the processors which represent all of the states in said equivalent trellis in order to select, by said decoding algorithm means, the maximum likelihood path from said equivalent trellis.