Waveform design and optimization for OFDM radar signal based on fractional Fourier transform

To gain better performance of the radar based on orthogonal frequency division multiplexing (OFDM), a new radar system based on OFDM using fractional Fourier transform (FRFT) rather than fast Fourier transform (FFT) is proposed in this paper. The expression of OFDM radar signals is given and its wideband ambiguity function (WAF) is derived in detail. Also, the peak to average power ratio (PAPR) of the proposed radar signal is analyzed. The WAF performance of FFT-based and FRFT-based OFDM radar signal with Barker code modulation are both simulated contrastively. It is shown that FRFT-based OFDM radar signal has better WAF with better thumbtack shape. Besides, FRFT-based OFDM radar signal gains higher velocity resolution as well as distance resolution and gets lower PAPR.