On the equivalence of blind equalizers based on MRE and subspace intersections

Two classes of algorithms for multichannel blind equalization are the mutua lly referenced equalizer (MRE) method by Gesbert et at, and the subspace in tersection (SSI) method by van der Veen et al. Although these methods seem, at first sight, unrelated, we show here that certain variants of the SSI a nd the MRE methods both optimize a new blind criterion, which is referred t o as maximum coherence and, thus, are equivalent.