Preamble-based channel estimation techniques for OFDM/OQAM over the powerline

OFDM/OQAM is a special type of multi-carrier modulation that can be considered as an alternative to conventional OFDM with cyclic prefix (CP) for transmission over multi-path fading channels. Indeed, as it requires no guard interval, it has the advantage of a theoretical higher spectral efficiency. Furthermore, if the pulse shape is well-localized in frequency, the resulting OFDM/OQAM signal satisfies stringent spectrum requirements. However, the classical channel estimation methods used for OFDM cannot be directly applied to OFDM/OQAM. In this paper we present an analysis of this problem and we describe a method for perfect channel estimation in OFDM/OQAM. Then we introduce two new realistic preamble-based channel estimation methods. The performance results are obtained by considering the transmission of an OFDM/OQAM signal over a multi-path power line communication (PLC) channel model. The proposed channel estimation methods are compared to the ones obtained with CP-OFDM.