Equalization with Interference Cancellation for Hermitian Symmetric OFDM/OQAM systems

OFDM/OQAM is a multi-carrier modulation scheme that, differently from conventional OFDM, does not require any guard interval. Indeed, the interference that results from a transmission over time and/or frequency selective channels can be partly contained if the pulse shape has been appropriately selected. Nevertheless, for certain transmission conditions, a simple zero forcing (ZF) equalization is not enough to cancel this interference. In this paper, we propose an equalization with interference cancellation (EIC) to counteract the performance floor that characterizes OFDM/OQAM systems using a simple ZF equalization. To fit with the case of a baseband transmission, we use an OFDM/OQAM variant that satisfies Hermitian Symmetry conditions to directly provide a real-valued modulated signal. This modulation is evaluated for the transmission of 64 and 256- QAM over a power line communication (PLC) channel. The simulation results illustrate the efficiency of the EIC method.