An improved DCT-based OFDM data transmission scheme

A discrete cosine transform (DCT)-based orthogonal frequency-division multiplexing (OFDM) system is described. The performance of the DCT-OFDM system with a zero-padding guard interval scheme and a minimum mean-square error (MMSE) receiver over time-varying multipath Rayleigh fading channels is investigated. The results show that employing the proposed DCT-OFDM system rather than the conventional DFT-OFDM system can provide better bit error rate performance in practical systems, by as much as 5.5 dB in signal-to-noise ratio (SNR).