New OFDM structure to smooth frequency notches of wireless channel

This paper proposes a new orthogonal frequency-division multiplexing (OFDM) structure to smooth the frequency notches of a wireless fading channel. The proposed system is based on a property that the KN-point inverse fast Fourier transform (IFFT) transmitter of an OFDM system can be realized by utilizing an N-point IFFT transmitter. The proposed OFDM system will generate a filter to smooth the frequency notches of a wireless fading channel, therefore, it will improve the system performance. On the other hand, the proposed structure can be designed to enlarge the bandwidth efficiency of system or improve the performance of the channel estimation.