Joint Estimation of Target's Range and Angle Based on Time-Invariant Spot Beam Optimization

The application of frequency diverse array and multiple-input multiple-output (FDA-MIMO) radar to achieve the joint estimation of target's range and angle is receiving more and more attention. However, its performance is generally affected by the periodicity and time-varying of its beam pattern. Therefore, this paper implements a joint estimation algorithm of target's range and angle based on a new waveform synthesis model of time modulation and range compensation FDA-MIMO (TMRC-FDA-MIMO) radar. At the same time, the multiple signal classification (MUSIC) algorithm is mainly used in FDA-MIMO radar. The huge amount of calculation also brings difficulties to the implementation of the system. Therefore, this paper proposes an improved estimating signal parameters via rotation invariance technique algorithm to solve the problem of large amount of calculation on the basis of ensuring system performance. In addition, the closed form expressions of the Cramer–Rao lower bound and root-mean-squared error of range and angle estimation are derived. Theoretical analysis and simulation verify the effectiveness of the proposed method and demonstrate the excellent performance of the proposed radar system and algorithm.