Joint Estimation for Downsampling Structure with Low Complexity

Abstract

Spectrum sensing and direction of arrival (DOA) estimation have both been thoroughly investigated. Estimating spectrum and DOA is important for many signal processing applications, such as cognitive radio (CR). A challenging scenario, faced by CRs, is that of multiband signals, composed of several narrowband transmissions spread over a wide spectrum and each with an unknown carrier frequency and DOA. The Nyquist rate of such signals is high. To overcome the sampling rate issue, several sub-Nyquist sampling methods, such as multicoset or the modulated wideband converter (MWC), have been proposed. In this paper, we use an ULA-based MWC structure to implement joint carrier frequency and DOA estimation at sub-Nyquist sampling rate. Different from other methods, we reduce the complexity of the hardware with fewer antennas and solve the pairing issues compared to other estimation methods.