Efficient Channel Estimation for FBMC Systems based on Auxiliary Preamble Design

Filter bank-based multicarrier (FBMC) has been considered as an attractive scheme alternative to the conventional OFDM with cyclic prefix (CP), especially in terms of the robustness against frequency offset and Doppler spread. However, due to the real-field orthogonality of FBMC signals, these classical OFDM channel estimation (CE) methods cannot be directly applied to FBMC systems. Focusing on existing preamble-based CE schemes for FBMC systems, all schemes require three real-valued symbol duration to transmit the preamble training symbols, whereas two real-valued symbol duration equivalent to one complex-valued symbol duration is only required in CP-OFDM systems. In this paper, we introduce a preamble design with auxiliary symbols for removing the intrinsic imaginary interference from neighboring data symbols. Compared with existing CE schemes, the superiority of auxiliary preamble method (APM) is with less time-frequency resource consumption of preamble training symbols, meanwhile without losing the accuracy of estimation performance. Numerical simulation and analysis demonstrate that the proposed APM is an efficient CE approach for practical preamble-based FBMC systems.