LAUSR

This article introduces a multiemitter 2-D angle-of-arrival (AoA) estimation scheme. It consists of an AoA estimation algorithm based on impinging signal spatial sparsity, Dantzig selector (an l1-norm minimization solution), and a six-element nonuniformly random-spaced 2-D array. The new scheme can identify more signals than the number of sensors without requiring a priori knowledge of signals and in a low signal-to-noise ratio (SNR) environment. It is demonstrated from 2 to 18 GHz with ten simultaneous incoming signals within 500 MHz instantaneous bandwidth. The number of signals, bandwidth, and frequency range are determined by the performance of digital receivers and are not limited by the compressive sensing (CS)-based 2D-AoA estimation scheme. Note that the random selection of element locations plays a vital role in ensuring that the new scheme achieves a highly successful estimation rate (SER). This is because random sensing is one of the key factors in CS. The only constraint of element locations is the spacing between elements, which has to be bigger than the diameter of cavity-backed-spiral-antenna. Simulation results show that the 2D-AoA estimator has more than 69%, 82%, and 90% SER if the measurement error is less than or equal to 1°, 2°, and 4°, respectively, when SNR is between −10 and 10 dB.