A finite interval constant modulus criterion for multicarrier channel shortening

Abstract

This paper considers time-domain equalization of fading channels for multicarrier systems with channels whose delay spread exceeds the length of the cyclic prefix. We propose to apply Regalia's Finite Interval Constant Modulus Algorithm, which directly minimizes the constant modulus criterion for finite data sets, to the output of a single sub-carrier. This results in a blind adaptive channel shortening technique which is used to design a time-domain finite impulse response equalizer or channel shortener, whose goal is to compress the overall channel impulse response to within the length of the cyclic prefix. Simulation results are provided in terms of bit error rate (BER) in the context of wireless systems.