A precoding and detection scheme for OFDM based wireless communication system in high-speed environment

A loss of subchannel orthogonality due to time variant multipath channels in orthogonal frequency-division multiplexing (OFDM) systems leads to interchannel interference (ICI) which increases the error floor in proportion to the Doppler frequency. This paper proposes a simple precoding and detection scheme which can compensate for the effect of ICI in multipath fading channel. In this scheme, the data symbols modulated in frequency domain are divided into several groups, and the precoding is performed by inserting several redundancy carriers at both sides of each data group. Then the simplified ICI cancelation can be achieved at the receiver through inverse fast Fourier transform (IFFT) of grouped data symbols followed by traditional detection method, such as minimum mean-square error (MMSE) and zero forcing (ZF). The proposed scheme has the robust performance and low complexity. More important it does not require any channel state information. The simulation results show that the proposed scheme keeps good performance in high speed scenario even when the vehicle velocity is over 500km/h.