Performance improvement for windowed OFDM using pre-coding and sub-carriers interleaving

This paper discusses the out-of-band emission power reduction technique by window functions and performance improvement scheme for OFDM (Orthogonal Frequency Multiple Access) systems. The windowed OFDM is effective to suppress the out-of-emission band, however, the communication performance is degraded, comparing with the conventional OFDM system. To improve the performance in frequency selective fading channel, the pre-coding using the unitary transform is adopted. Moreover, the performance improvement scheme that data sequence between the unitary transform and IFFT/FFT is interleaved for the pre-coded windowed OFDM system is proposed. The BER (Bit Error Rate) is evaluated to show the effectiveness of the proposed scheme, comparing to the conventional pre-coded windowed schemes and the out-of-band emission power is also reduced.