Frame Repetition: A Solution to Imaginary Interference Cancellation in FBMC/OQAM Systems

In this paper, we propose a complex-valued symbol based FBMC/OQAM (C-FBMC/OQAM) system to achieve the self-cancellation of intrinsic imaginary interference. The key idea is the employment of a well-designed repeated frame, in which complex-valued QAM symbols are transmitted instead of only real-valued symbols in the classical FBMC/OQAM systems. It is proven that, intrinsic interference among symbols can be eliminated in the proposed C-FBMC/OQAM systems, and the spectral efficiency is maintained even in the existence of repeated frame. Simulation results shows that the proposed C-FBMC/OQAM system and preamble structures for channel estimation demonstrate improved robustness against frequency selective fading channels compared to conventional FBMC/OQAM systems due to the intrinsic interference cancellation.