A. Scaglione et al., Redundant filterbank preceders and equalizers Part II: Blind channel estimation, synchronization, and direct equalization, IEEE SIGNAL, 47(7), 1999, pp. 2007-2022
Transmitter redundancy introduced using finite impulse response (FIR) filte
rbank precoders offers a unifying framework for single- and multiuser trans
missions. With minimal rate reduction, FIR filterbank transmitters with tra
iling zeros allow for perfect (in the absence of noise) equalization of FIR
channels with FIR zero-forcing equalizer filterbanks, irrespective of the
input color and the channel zero locations. Exploiting this simple form of
redundancy, blind channel estimators, block synchronizers, and direct self-
recovering equalizing filterbanks are derived in this paper, The resulting
algorithms are computationally simple, require small data sizes, can be imp
lemented online, and remain consistent (after appropriate modifications), e
ven at low SNR colored noise. Simulations illustrate applications to blind
equalization of downlink CDMA transmissions, multicarrier modulations throu
gh channels with deep fades, and superior performance relative to CMA and e
xisting output diversity techniques relying on multiple antennas and fracti
onal sampling.