Joint Spectrum, Carrier, and DOA Estimation With Beamforming MWC Sampling System

The joint estimation of the spectrum, carrier, and direction of arrival (DOA) is significant in radar, sonar, wireless communications, and cognitive radio systems. The traditional parameter measurement methods based on the Shannon–Nyquist theorem require very high sampling rates, which put a lot of pressure on sampling, processing, and storage devices. In this article, novel beamforming modulated wideband converter (BMWC) system for joint estimation of the spectrum, carrier, and DOA is proposed to improve the robustness of estimation and reduce structural complexity. From the spatial signal model of array MWC, combined with the spatial filtering and signal enhancement characteristics of adaptive beamforming, the spatial target signals are focused and separated to enhance the robustness of the system. Due to the spatial filtering of beamforming, the MWC structure only needs to reconstruct one signal at a time. The number of channels of MWC connected to each antenna gets rid of the dependence on the number of signals. We utilize the MWC channel expansion technology, which makes it possible to reconstruct the signal well even when each receiving antenna is only connected to a single MWC channel. Compared with previous works, the proposed system enhances the sparsity property of the signals and greatly simplifies the MWC structure. Simulation and hardware experimental results demonstrate the effectiveness and robustness of the proposed method.