A new OFDM frame structure in time-varying channel robust to Doppler frequency spread

How to reduce or suppress the intercarrier interference (ICI) is one of the key problems in OFDM systems. In this paper, we propose a new frame structure for OFDM transmission and the corresponding demodulation algorithm in mobile communications. Analysis and simulation results indicate that without-loss of bit rate, this signaling structure can ideally achieve the same BER performance at two times Doppler frequency spread of the classical OFDM in flat fading channels, and it can improve greatly the BER performance of the OFDM system in multipath fading channels.