1. A method of processing channel values received from a two-dimensional (2-D) inter-symbol interference (ISI) channel to which was provided a plurality input values, the channel values being associated with a plurality of rows that together form a matrix, the method comprising: (a) computing, by way of a processing device, a plurality of sets of combination values respectively based upon a plurality of overlapping subsets of the rows of the channel values; (b) applying an a-postiori probability (app) algorithm to the plurality of sets of combination values; and (c) producing result values that are indicative of the input values that gave rise to the channel values, wherein the result values are produced based upon results from the application of the app algorithm.