The principle of synthesizing HRRP based on a new OFDM phase-coded stepped-frequency radar signal

Orthogonal Frequency-Division Multiplexing (OFDM) phase-coded pulse is a wideband signal, of which the range resolution is inversely proportional to the bandwidth. However, it is a challenge to synthesize large bandwidth for OFDM phase-coded pulse since wide instantaneous bandwidth and high sampling rate requirements. To solve this problem, this paper proposes a new radar signal called OFDM phase-coded stepped-frequency (OFDM-PCSF) signal, of which the pulse train is stepped frequency, and each pulse is implemented with OFDM phase-coded chips. The property of OFDM-PCSF signal is analyzed at first. And then, the mathematical expressions of the high resolution range profiles (HRRP) are derived, assuming an elementary scenario of point-scattering targets. It mainly presents the influence of velocity on HRRP and investigates the parameter design and velocity compensation, which is helpful for the realization of OFDM imaging radar. Finally, the simulation results demonstrate the validity of the conclusions.