Robust Parameter Measurement of PSK Signals Based on FRI Sampling and Structured Sparsity.

Phase-shift keying (PSK) signals exist widely in radar and communications systems. However, in noncooperative scenarios, measuring PSK signals demands a wide range of detection bandwidth, and the measurement schemes using the Nyquist theorem need a relatively high sampling rate. In this article, we propose a two-part cooperative sub-Nyquist sampling (TCSS) system for robust measurement of the discontinuity locations (DLs) and carrier frequency (CF) of PSK signals based on the finite rate of innovation (FRI) sampling and the structured sparsity. The minimum number of samples needed by the TCSS system depends only on the number of estimated parameters but not on the CF and bandwidth. The TCSS system comprises the delayed autocorrelation sampling (DAS) and orthogonal time-staggered sampling (OTS) structures. First, the DLs are measured by the DAS structure using the subspace method. In addition, for binary-PSK signals, a two-stage structured orthogonal matching pursuit (S-OMP) algorithm is used to improve the parameter measurement's robustness based on the DLs' structured sparsity. The within-symbol samples of the OTS structure are obtained based on the estimated DLs, and the CF is calculated using the subspace method and the robust Chinese remainder theorem (R-CRT). Compared with similar measurement schemes, the proposed method has higher robustness for parameter measurements over a wide bandwidth and is easier to implement in engineering. Simulations and hardware results illustrate the efficiency of the TCSS system.