Huang, Chin WeiChin WeiHuangChen, Li FuLi FuChenBORCHING SU2023-09-012023-09-012023-01-011053587Xhttps://scholars.lib.ntu.edu.tw/handle/123456789/63488813 pages, 7 figures. This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibleIn an active sensing system, waveforms with good auto-correlations are preferred for accurate parameter estimation. Furthermore, spectral compatibility is required to avoid mutual interference between devices as the electromagnetic environment becomes increasingly crowded. Waveforms should also be unimodular due to hardware limits. In this article, a new approach to generating a unimodular sequence with an approximately optimal peak side-lobe level (PSL) in auto-correlation and adjustable stopband attenuation is proposed. The proposed method is based on alternating minimization (AM) and numerical results suggest that it outperforms existing methods in terms of PSL. We also develop a theoretical lower bound for the PSL minimization problem under spectral constraints and unimodular constraints, which can be used for the evaluation of the results in various works about this waveform design problem. It is observed in the numerical results that the PSL of the proposed algorithm is close to the derived lower bound.Active sensing system | alternating minimization | dual problem | Lagrangian | lower bound | peak side-lobe level | spectral compatibility | waveform design; eess.SP; eess.SP; Mathematics - Optimization and Controljournal article10.1109/TSP.2023.32914542-s2.0-85164451412https://api.elsevier.com/content/abstract/scopus_id/85164451412