A Design Method of Windows by Spline Functions Based on Weighted Equiripple Approximation
Kazuo Toraichi, Mamoru Iwaki, Masaru Kamada, Rokuya Ishii, Ryuichi Kawamoto · IEEJ Transactions on Electronics Information and Systems · 1993
Improvement is discussed on a method of designing a window with the feature of minimizing the highest sidelobe level under desired mainlobe bandwidth and sidelobe fall-off. A previous paper by one of the authors has proposed a method with the above feature. But it has a problem that designed windows are discrete-time ones defined on a series of sampling points in the observation domain. Discrete-time windows need to be designed whenever the number of the sampling points is changed. The present method employs a C-spline function in expressing a continuous-time window. Experiments result in that the present method can design windows with dimension 30 which are as good as or better than the ones designed by the previous method with dimension 64 or more. It is also shown that the present design examples are superior to the authors' other windows expressed by C-spline functions.