Angle Estimation using Weighted Beampattern in Frequency Diverse Array Radar

Abstract

The frequency diverse array (FDA) radar beampattern is a function of angle, time and range. Therefore, it has more potential applications in target localization. The transmit antenna elements weight design for illumination of a target present in a particular direction and range at a particular instance of time is important for target detection with large probability. In non-uniform weighted FDA radar, a desired transmit beampattern is achieved by using non-uniform weights at the transmit antenna elements using the IFFT algorithm. The IFFT algorithm provides a closed-form solution for transmitting antenna weights. The designed transmit beampattern has a large dwell time and has the potential to illuminate any desired angular region. In this work, a signal model is derived for non-uniform weighting and angle estimation is performed using the minimum-power-distortionless response beamformer at the receiver. The Cramer-Rao lower bound (CRLB) for the FDA radar has been derived. We compared the mean-square-error performance of angle estimation with existing approaches and CRLB.