Design of OFDM Signal with Good Autocorrelation for Ground Penetrating Radar

Orthogonal frequency division multiplexing (OFDM)-based ground penetrating radar (GPR) has been proved to have a number of advantages. To improve the performance of a GPR system, time domain non-periodic autocorrelation (AC) of the transmitted OFDM signal should be designed to have similar shape to an ideal pulse. Challenge in OFDM signal design for GPR is that there is little pertinent literature and the design should be different from that in communication and air radar fields. In this paper, we propose a design scheme of OFDM signal with good AC for GPR. We divide the AC into main lobe and side lobe with proving that the main lobe is dominated with the functionality of the modulating amplitudes while the side lobe's main function is modulating phases. Thus, modulating amplitudes and phases can be designed, respectively. Performance of this proposed approach is demonstrated by numerical examples. The results show that the designed OFDM signal yields a better AC and fewer false alarms for GPR systems.