  In doubly selective channels, receiver windowing constitutes an effective
technique for enhancing the banded structure of the frequency-domain channel
matrix, and thus improving the effectiveness of a banded equalizer for
intercarrier interference (ICI) mitigation. A common window design technique,
which performs close to optimal, is based on the criterion of maximum average
signal-to-interference-plus-noise ratio (SINR). The optimality of this
technique has been verified for stationary channels with perfectly known
statistics. However, in cases where this assumption does not hold, a near
optimal performance can be achieved at the expense of high complexity cost. To
overcome these limitations, an adaptive windowing technique is proposed that is
able to track the optimal receiver window offering low-complexity requirements.
Through simulation experiments it has been verified that the proposed technique
is able to adapt to the varying channel statistics with increased robustness to
channel modeling errors.
