Cumulant-Based Adaptive Blind Beamformer

• Main Authors: Zane E Chou, 冉一喬
• Other Authors: 洪賢昇
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/19636698632395942809

碩士 === 國立海洋大學 === 電機工程學系 === 87 === Abstract A beamformer is a processor used in conjunction with an array of sensors to provide a versatile form of spatial filtering. A beamformer performs spatial filtering to separate signals that have overlapping frequency content but originate different spatial locations .Thus, beamformer has been widely applied in the radar, sonar and communication field. In most optimum beamforming procedure(see Chapter 2), they rely on complete knowledge of response and location or array elements and/or DOA information of the desired signal. If the array manifold is unknown, or they are uncertainities , it is then necessary to calibrate the array. In addition, calibration source may be required. Even small errors in the calibration may considerably degrade the performance. We employ the higher older statistical characteristics of the desired signal to make the discrimination ,without any a-priori knowledge of array manifold and DOA information about desired signal .In a communications environment, multipath propagation almost take place. In this case, most conventional techniques fail ,but cumulant-based beamformer still behave as the optimum beamformer. In our work, we not only describe blind estimation and optimum narrowband/broadband beamforming but have some simulations for different conditions. For real-time operation ( a necessary requirement in communications applications ) we also propose adaptive implementations of the cumulant-based beamformer for narrowband and broadband environment .