Fractional Fourier Transform Based Pilot Symbol Assisted Modulation

In this study, a novel Fractional Fourier transform (FrFT) based pilot symbol assisted modulation (FPSAM) technique for channel estimation has been proposed. In FPSAM, the received pilot symbols are processed in fractional Fourier domain before being used for channel estimation. In practice, the channel estimation is done by sending known training (pilot) symbols along with the information symbols and the quality of Channel State Information (CSI) obtained from the pilot symbols depends on the technique used for channel estimation. The proposed method helps in obtaining accurate channel estimates due to effective removal of noise in the optimum fractional domain. For spline interpolation, FPSAM gives an SNR improvement of 1.90 dB as compared to conventional PSAM for a BER of 10G. It is shown through simulations that the proposed method clearly outperforms the existing method.