Channel estimation in MIMO OFDM/OQAM

Multi-carrier modulations such as orthogonal frequency division multiplexing (OFDM) are widely used in radio transmission systems. Among these modulations, OFDM/OQAM is an interesting alternative to the conventional cyclic-prefix, OFDM (CP-OFDM) modulation, as it does not require the use of any guard interval. This specificity allows a better spectral efficiency. In this paper we investigate on channel estimation for OFDM/OQAM modulations in the case of multiple-input multiple-output (MIMO) transmissions over radio channels. We focus on a two transmit antenna spatial data multiplexing (SDM) scheme and on the use of scattered pilots for the channel estimation. We propose a MIMO channel estimation method that copes with the intrinsic interference inherent to OFDM/OQAM and we compare this method to ideal channel estimation methods proposed in previous studies.