1. A method comprising a plurality of activities, comprising: automatically: receiving a signal; and via a plurality of iterations, determining, for the received signal, a provable near-optimal B-term representation formed from a linear combination of a plurality of elements selected from a predetermined redundant &mgr;-coherent dictionary, said determined near-optimal B-term representation corresponding to an error that is a minimum of a set of errors corresponding to all possible B-term representations associated with the predetermined redundant &mgr;-coherent dictionary.