2 dB Better Than CP-OFDM with OFDM/OQAM for Preamble-Based Channel Estimation

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 CP, it has the advantage of a theoretically higher spectral efficiency. Furthermore, efficient pulse shaping can also be easily implemented with OFDM/OQAM. 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 introduce a new preamble-based channel estimation method. The performance results are obtained either by considering an IEEE802.22 channel model or regarding to the channel delay spread variation of a two-tap channel. The proposed OFDM/OQAM channel estimation method is evaluated, in both scenarios, using different pulse shaping and taking conventional CP-OFDM as reference.