An Efficient Layered FFT Approach for Reduction of PAPR, Spectral Re-growth and CFO on the Performance of an OFDM System

Orthogonal frequency division multiplexing (OFDM) is an attractive multi carrier modulation technique for future broadband wireless transmission systems. However, the OFDM system exhibits high peak to average power ratio (PAPR) , large computational complexity by applying discrete Fourier transform (DFT) at the transmitter and inverse DFT (IDFT) at the receiver and sensitivity to carrier frequency offset (CFO), caused by Doppler shift which the carrier frequency difference between the transmitter and receiver. In this paper, we propose a divide & conquer FFT algorithm of an OFDM system to reduce PAPR and also analyze the impact of spectral re-growth and CFO on the performance of an OFDM system with and without D&C FFT approach. Simulation results show that OFDM system based D&C approach can achieve a good balance between complexity and system performance. Key-Words: CCDF, CFO, Divide & Conquer Approach, OFDM, PAPR, Spectral Re-growth