New beam-steering algorithms using DELSA for frequency hopping systems

We propose a novel, blind and robust algorithm, DELSA [5], to estimate the azimuthal direction-of-arrival (DOA) of sources impinging an array of antennas. Subsequently, we develop two new beam-steering algorithm for a typical frequency hopping (FH) system [4]. We treat the DOA estimation as an inverse problem of estimating a set of parameters {rho(i)} which explains the received signal for a suitable physical model. We specify a highly underdetermined linear system as the physical model and solve the resulting least squares problem using the well-known Conjugate Gradients (CG) iterations on the Normal Equations (NE). Unlike DOA estimation methods such as MUSIC [1], our method does not require any a priori information concerning the number of sources for the algorithm to perform. It is also independent of the type of modulation employed [6]. Simulation results indicate that our method is robust in the regimes of friendly interferences and low signal-to-noise-ratios (SNRs) of the desired source.