Efficient and noise-resistant parameter estimation method for maneuvering targets in stepped frequency radar

In this paper, a novel efficient parameter estimation method is proposed for maneuvering targets based on the stepped frequency radar. Since the envelope migration can be represented by the exponential phase variance with respect to range frequency, the received echoes are first converted into the range frequency domain and modeled as cubic phase (CP) signals. Then, a new correlation transform, referred to as recursive delay correlation transform (RDCT), is defined and applied to estimate the parameters of maneuvering targets. Since RDCT is simple and only requires the fast Fourier transform (FFT) and the nonuniform FFT (NUFFT), the searching operation is unnecessary and the computational cost is significantly reduced. Compared to the other four representative methods, the proposed RDCT-based method has no error propagation and can greatly improve the anti-noise performance on the premise of retaining the computational efficiency, achieving a good balance between the computational complexity and estimation performance. Theoretical analyses of anti-noise and anti-aliasing performance, and several simulation results verify the effectiveness of the proposed parameter estimation method.