Super-Resolution Delay-Doppler Estimation for OFDM Passive Radar

摘要

In this paper, we consider the problem of joint delay-Doppler estimation ofmoving targets in a passive radar that makes use of orthogonalfrequency-division multiplexing (OFDM) communication signals. A compressedsensing algorithm is proposed to achieve supper-resolution and better accuracy,using both the atomic norm and the $\ell_1$-norm. The atomic norm is used tomanifest the signal sparsity in the continuous domain. Unlike previous workswhich assume the demodulation to be error free, we explicitly introduce thedemodulation error signal whose sparsity is imposed by the $\ell_1$-norm. Onthis basis, the delays and Doppler frequencies are estimated by solving asemidefinite program (SDP) which is convex. We also develop an iterative methodfor solving this SDP via the alternating direction method of multipliers (ADMM)where each iteration involves closed-form computation. Simulation results arepresented to illustrate the high performance of the proposed algorithm.