Adaptive Beam Pattern Diversity and Source Loclization in a Mobile Environment

• Main Authors: Chung-Tze Chen, 陳重志
• Other Authors: Ta-Sung Lee
• Format: Others
• Language: en_US
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/15192680808220629029

碩士 === 國立交通大學 === 電信研究所 === 83 === An adaptive beam pattern diversity scheme for reducing the fading effects in a mobile environment is presented. The main concept of the proposed diversity technique is to form two reception beams encompassing the incoming fading signals. The optimum beamformers are then constructed so as to minimize the crosscorrelation coefficient between two beam outputs. The beam patterns should possess low sidelobes for interference rejection and mutual symmetry for equal power diversity signals. To maintain an accurate look direction, a localization method is also proposed. First, the source angle estimate is obtained by comparing two sets of fixed Chebyshev beams for equal output power. Second, range estimation is accomplished by training a curve fitting unit (CFU) with the data emitted from different subcells in the field of interest. The CFU is constructed to memorize the relationship among various incoming angles, ranges, and the corresponding squared magnitudes of beam space crosscorrelation coefficients (BSCCC). Specifically,it is used as a mapping from the squared magnitude of BSCCC to the range estimate. We demonstrate that the proposed adaptive beam patten diversity scheme working in conjunction with the location estimator provides an appropriate solution for fading phenomenon in the presence of complicated interference.