Blind channel estimation for OFDM and multicarrier CDMA systems using frequency-domain oversampling

Abstract

Subspace based blind channel estimation for OFDM systems has received considerable attention. Existing schemes mainly exploit inherent redundancy such as cyclic prefix and virtual subcarriers or artificial redundancy generated by pre-coding. In this paper, OFDM and multicarrier CDMA systems are considered. Frequency-domain oversampling is used at the receiver to perform detection and channel estimation. It turns out that frequency-domain oversampling can enable blind channel estimation for multicarrier systems and improve its performance. For the downlink of MC-CDMA, we show that the proposed estimator's performance can be significantly improved by using spreading code diversity.