PAPR Reduction Of FrFT-Based MB-OFDM Ultra Wide Band Signals

Multi-band orthogonal frequency division multiplexing (MB-OFDM) is being considered as a promising candidate for UWB systems due to its higher spectral efficiencies and better system performance. The classical Fourier transform scheme may fail when the channel is doubly selective. Chirp-like basis (fractional Fourier transform based) can be used instead of exponential functions to combat this problem. However, just like in the Fourier transform based MB-OFDM, fractional Fourier transform based MB-OFDM (FrFT based MB-OFDM) UWB also suffers from the high peak to average power ratio (PAPR) problem. In this paper, we have analyzed the MB-OFDM UWB signals in the fractional domain, and evaluated the effects of the well-known OFDM PAPR reduction methods such as selected mapping (SLM) and partial transmit sequences (PTS) to FrFT based MB-OFDM UWB through computer simulations.