Polynomial ambiguity resistant precoders: theory and applications in ISI/multipath cancellation

In this paper, precoding techniques are studied for combating the intersymbol interference (ISI)/multipath effects in communication systems. We introduce a new type-precoder which we term the polynomial ambiguity resistant (PAR) precoder for its ability to resist signal distortion induced by finite impulse response (FIR) channels. In particular, the precoder allows a receiver to identify an input signal without knowing the channel characteristics at the expense of a minimum amount of bandwidth increase. A family of such precoders, which is linear (no modulo operations), channel independent, and modulation pattern preserving (except for some occasional 0 symbols), is presented. Also presented is a closed-form algorithm that can simultaneously identify the input signals and zero-forcing equalizers.