ADAPTIVE ARRAY ANTENNA BASED ON SPATIAL SPECTRAL ESTIMATION USING MAXIMUM-ENTROPY METHOD

An adaptive array antenna can be considered as a useful tool of combat ing with fading in mobile communications. We can directly obtain the o ptimal weight coefficients without updating in temporal sampling, if t he arrival angles and signal-to-noise ratio (SNR) of the desired and t he undesired signals can be accurately estimated. The Maximum Entropy Method (MEM) can estimate the arrival angles, and the SNR from spatial ly sampled signals by an array antenna more precisely than the Discret e Fourier Transform (DFT). Therefore, this paper proposes and investig ates an adaptive array antenna based on spatial spectral estimation us ing MEM. We call it MEM array. In order to reduce complexity for imple mentation, we also propose a modified algorithm using temporal updatin g as well. Furthermore, we propose a method of both improving estimati on accuracy and reducing the number of antenna elements. In the method , the arrival.angles can be approximately estimated by using temporal sampling instead of spatial sampling. Computer simulations evaluate ME M array in comparison with DFT array and LMS array, and show improveme nt owing to its modified algorithm and performance of the improved met hod.