Pilot-Aided Channel Estimation Utilizing Intrinsic Interference for FBMC/OQAM Systems

This paper proposes a novel channel estimation technique for the offset quadrature amplitude modulation based filter bank multi-carrier (FBMC/OQAM) systems. Unlike the conventional approaches, the proposed pilot signals utilize their intrinsic interference for the channel estimation, and provide an improved power efficiency compared to the conventional auxiliary pilot method. However, due to the non-whiteness of the noise components at the output of the analysis filter banks, the power gain obtained by the proposed scheme cannot be maximized. To overcome this difficulty, we propose a semiblind channel estimation by grouping the pilot signals and imposing sign ambiguities to them. Theoretical analysis shows that the proposed semiblind channel estimation remarkably improves the power efficiency of its non-semiblind version. Finally, it is demonstrated that the near optimum detection performance is achieved by the proposed scheme at a reduced complexity.