An OFDM transmission technique with overlap FDE

This study proposes an orthogonal frequency division multiplexing (OFDM) transmission technique. N samples generated by the N-point inverse discrete Fourier transform at the OFDM transmitter form one transmission block. It is controlled so that the M tail samples of every N-point transmission block have the same pilot sequence. If the maximum delay spread of multipath channel does not exceed M-sample duration, such an operation creates a circular channel under the multipath conditions. If the maximum delay spread exceeds M-sample duration, an overlap frequency domain equalization (FDE) is applied to the discrete Fourier transform input at the OFDM receiver. The overlap FDE is a technique for single-carrier transmission without using cyclic prefix to cope with the multipath channel. Computer simulation shows the effect of the proposed technique over the multipath channels.