Noise Robust High Resolution Range Profile Analysis in OFDM-Based RadCom Systems

Abstract:
The detection of small radar cross section (RCS) unmanned aerial vehicles (UAVs) can be challenging. In this paper, we present a novel signal processing approach for orthogonal frequency division multiplexing (OFDM) signals in integrated radar and communication (RadCom) systems, to improve the detection performance of small targets under low signal-to-noise ratio (SNR) environment. We first design a repeated symbols OFDM (RS-OFDM) signal model, where each OFDM symbol adopts the same sequence. Then, to achieve the high resolution range profile (HRRP) of small targets, a combined modified DFT and compressed sensing algorithm is proposed, in which a sparse representation model for the range profile spectra in all relevant Doppler frequencies by utilizing modified DFT strategy, and the HRRP is achieved via the sparsity adaptive matching pursuit (SAMP) algorithm. The proposed approach overcomes the disadvantages of Doppler sensitivity and robustness against noise and has less computational complexity than full two-dimensional sparse estimation methods. Simulation results validate our analysis.