Accurate Low-Angle Tracking Using Successive Interference Cancelation and Single-Tone Frequency Estimation

다국어 초록 (Multilingual Abstract)

This paper tackles the low-angle target tracking problem caused by surface-reflected multipaths through successive interference cancelation (SIC) and single-tone frequency (STF) estimation. The coherent specular multipath component in the received radar signal is canceled through SIC, after which the angle-of-arrival (AoA) of the direct path is accurately estimated by applying STF estimation to the interference-suppressed signal. To further improve estimation accuracy, we develop an iterative process where SIC and STF are sequentially repeated. Drawing on the AoA of the direct path estimated using STF, a more accurate AoA of the specular path is obtained by exploiting their geometrical relationship between the two paths, which is then used to suppress the specular multipath in the received radar signal more precisely during the next SIC process. Computer simulations verify that the proposed angle estimation method using SIC and STF (AE-SICSTF) outperforms conventional angle estimation methods. Furthermore, while computational complexity analysis shows that the complexity of each iteration in AE-SICSTF is comparable to that in three-dimensional beam-domain maximum likelihood, it is also found that the former requires less than 10 iterations to converge the root mean square error performance, resulting in considerably less computing time than the refined maximum likelihood and root-MUSIC algorithms.