PAPR approximation of continuous-time WFRFT signals

Recently an coordinated transmission approach to single carrier and multi-carrier convergence was proposed based on the weighted-type fractional Fourier transform (WFRFT). This hybrid carrier scheme also suffers the high peak to average power ratio (PAPR) since it contains the multi-carrier component. There is some research on the PAPR of WFRFT signals, whereas most of which only takes the discrete-time signals into consideration. In practice, the PAPR of continuous-time signals concerns us more than that of discrete-time signals. Therefore, this paper investigates the PAPR approximation of continuous-time WFRFT signals based on baseband discrete-time mapped signals. The PAPR approximation method of continuous-time WFRFT signals is proposed and numerical computations are implemented to show that the proposed approach can make discrete-time signal PAPR converges to continuous-time signal PAPR as the interpolation times L increases. Besides, L ≥ 8 is sufficient to approximate the continuous-time PAPR. Particularly, simulation results also indicate that the proposed approximation method can render clipping technique more efficient for continuous-time signal PAPR reduction.