A Filtered OFDM Using FIR Filter Based on Window Function Method

Orthogonal Frequency Division Multiplexing (OFDM) is designed to combat the effect of multipath reception, by dividing the wide band frequency selective fading channel into many narrow flat sub-channels, which improves the spectral efficiency and significantly mitigates the intersymbol interference (ISI). However, OFDM can not meet the demand for 5G heterogeneous service scenarios since it has a high out-of-band emission and a large peak-to-average power ratio (PAPR), and it only supports one kind of waveform parameter in the whole bandwidth. The Filtered-OFDM (F-OFDM) is proposed as a candidate technique for 5G high-data rate wireless communication system. This paper proposes a finite impulse response (FIR) digital filter based on window function method to achieve the F-OFDM, and discusses the performance of different window functions implemented in the F-OFDM. Simulation results show that the proposed F-OFDM is easy to be implemented and has a very low out-of-band emission with the same bit error rate (BER) performance compared to the conventional OFDM.