Joint Direction Finding and Multipath Delay Estimation in the Presence of Mutual Coupling

• Main Authors: Vu Van Khang, 武文康
• Other Authors: Wen Hsien Fang
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/08070023511903847113

碩士 === 國立臺灣科技大學 === 電子工程系 === 97 === The channel parameters such as directions of arrival (DOAs) or multipath delays are of importance in wireless communication systems. The precise information of these two parameters not only are crucial in the localization of mobil stations, but also enhances the accuracy of channel estimation, which in turn improves the communication link quality. It is thus of interest to simultaneously estimate the DOAs and delays of the impinging rays based on the signals received by an antenna array. However, most of the existing algorithms either do not take the mutual coupling, incurred due to closely spaced antennas, into consideration or are too complicated to admit practical implementations. Since the subspace based algorithms in general strike a better tradeoff between performance and complexity. In this thesis, we extend two widespread Multiple-SIgnal-Classification (MUSIC) based algorithms for joint DOA-delay estimation, namely the JADE-MUSIC and CTST-MUSIC, to the scenarios in the presence of mutual coupling. It is justified that when the mutual coupling is known, the extensions take the same form as the original ones, except a slight modification of the spatial response vectors. Also, with the addition of auxiliary sensors on both sides of the antenna array, it is shown that both algorithms can be extended to the scenarios when the mutual coupling is unknown. Our focus is put on the CTST approach which uses three stages of one-dimensional (1-D) MUSIC algorithms along with a constrained spatial filtering process and a constrained temporal filtering process in between to render high resolution parameter estimates, yet with low computational overhead. Simulations are provided to verify the resilience of the extended algorithms against the mutual coupling and their superiority compared with previous works.