Preamble Design for Improved Noise Suppression in FBMC-OQAM Channel Estimation

FBMC-OQAM is a promising multi-carrier technique being considered for future wireless communication systems, owing to the flexibility it provides via the choice of prototype filters, robustness against asynchronous transmissions, and the absence of cyclic-prefix requirement. The performance of FBMC-OQAM systems is however limited by the accuracy of channel estimation due to the presence of so-called intrinsic interference. In this letter, we consider two well-known preamble-based channel estimation approaches for FBMC-OQAM, and propose generic preamble structures, followed by formulation of mathematical optimization problems to improve the resilience of both estimation schemes against this intrinsic interference. The proposed preambles, without incurring any additional run-time complexity at transceiver, lead to improved noise suppression, eventually leading to superior channel estimation performance. The benefit of the proposed preambles is shown not only numerically in terms of the relevant performance metrics, but also via link-level simulations under realistic transmission scenarios.