Synchronous acquisition methods with code‐orthogonalizing filters in DS/CDMA over multipath fading channels
Masaaki Tahara, Masanori Hamamura, Shin’ichi Tachikawa · Electronics and Communications in Japan (Part III Fundamental Electronic Science) · 2003
Abstract In this paper, we propose a new method for speeding up synchronous acquisition methods by using code‐orthogonalizing filters in DS/CDMA. In the proposed synchronous acquisition method, the normalized complex LMS algorithm is adopted as an adaptive algorithm with code‐orthogonalizing filters and can be applied to multipath fading transmission paths. To further shorten the synchronous acquisition time, we study the step size, the number of updates of the tap weights of the adaptive algorithm, and multiple‐dwell detection. By simulating these methods on a computer, we evaluated the average synchronous acquisition time as a function of the co‐channel power ratio and the number of users, compared the proposed method to conventional methods, and clearly demonstrated its effectiveness. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 38–47, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/ecjc.10051