Polyphase filter-based OFDM transmission system

This paper presents a polyphase filter-based orthogonal frequency division multiplexing (PF-OFDM) technique. The proposed structure makes use of a modified discrete Fourier transform (MDFT) transmultiplexer to achieve better spectral efficiency than the classical OFDM system, while preserving backward compatibility with it. This modulation technique uses a single DFT structure, in contrast to the MDFT transmultiplexer, which requires two DFT polyphase filter banks. The prototype filter,which is split into polyphase filters, is designed to have control over the shape of the magnitude response and stopband attenuation, which make it possible to eliminate a guard interval. The PF-OFDM modulation is justified over multipath Rayleigh fading channels.