Adaptive Broadband Beamforming under Coherent Environments

• Main Authors: Jen-Chiu Hsu, 徐振球
• Other Authors: 李枝宏
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/80865202928766768139

碩士 === 國立臺灣大學 === 電信工程學研究所 === 93 === An adaptive broadband antenna array is a collection of sensor elements and tap delay line whose outputs are combined by an iteratively adjusted combining (or weight) vector so as to pass a desired signal on desired arrival directions with minimum distortion while rejecting interfering signals which makes the maximum output SINR. Here, we use second order auto-regressive model to generate broadband signals, and consider the beamforming technique under coherent environment that cause signal cancellation phenomena. The phenomena can cause signal loss in the case of narrowband signals, or cause significant signal distortion in the case of wideband signals. Traditionally, one method is known as spatial smoothing technique which was proposed by Shan and Kailath, and the derivational methods as weighted spatial smoothing and progressive spatial smoothing. In this paper, we use LCMV structure of Frost, and propose our method TBTAM (Toeplitz–Block-Toeplitz Approximation Method) and I-TBTAM (Iteration-TBTAM) combining with AIC,MDL method as the optimum beamforming technique under coherent environment. Finally, we present broadband general sideband canceller as compared with LCMV.