Polynomial complexity optimal detection of certain multiple-access systems

It is demonstrated that optimal multiple-user detection in a linear multiple-access system with identical crosscorrelations requires only /spl Oscr/(KlogK) operations instead of the worst case O(2/sup K/). A simple optimal detection algorithm is given, which when generalized has a complexity that is exponential not in the number of users but in the number of unique crosscorrelation values.