A. Chevreuil et al., Blind channel identification and equalization using periodic modulation precoders: Performance analysis, IEEE SIGNAL, 48(6), 2000, pp. 1570-1586
The present paper deals with blind identification and equalization of commu
nication channels within the so called modulation induced cyclostationarity
(MIC) framework, where the input symbol stream is modulated by a P periodi
c precoder with the purpose of inducing cyclostationarity in the transmit s
equence. By exploiting the cyclostationarity induced by the periodic precod
er, a subspace-based channel identification algorithm that is resilient to
the location of channel zeros, channel order overestimation errors, and col
or of additive stationary noise, is developed, The asymptotic performance o
f the subspace-based identification approach is analyzed and compared with
the asymptotic lower bound provided hy the nonlinear cyclic correlation mat
ching approach. Criteria for optimally designing the periodic precoder are
also presented. The performance of MMSE-FIR and MMSE-DFE equalizers is quan
tified For the proposed cyclostationarity-induced framework in terms of the
MMSE. Although cyclostationarity-inducing transmitters present several adv
antages relative to their stationary counterparts from a channel estimation
viewpoint, it is shown that from an equalization viewpoint, MIG-based syst
ems exhibit a slightly increased MMSE/BER when compared with the stationary
case.