بررسي همبستگي سيگنال CDMA دريافتي در كانال مخابرات سيار سلولي روي المان هاي آنتن آرايه اي

CORRELATION OF CDMA RECEIVED SIGNALS AT THE ANTENNA ARRAY ELEMENTS IN CELLULAR MOBILE

One of the important matters before using smart antenna in cellular mobile communication systems is to have suitable vector channel modeling. In cellular mobile communications, a vector channel must take into account the delay spread and Doppler shift and direction of arrival (DOA) of received signal. In this paper, a proper vector correlation matrix of the received signal at the array elements is evaluated. Analytic results show that in the CDMA domain, the received signal has a rayleigh behavior in signal is dependent on the array size, direction of arrived, scatterers location and spreading angle, i.e., for law direction of arrival and small spreading angle, increasing the antenna array element would not improve the correlation coefficient appreciably. Therefore, improvement of the fading would not be obtained through the implementation of array processing. Simulation and analytic of correlation of coefficient for specific cases with circular and sectoral distribution of bunches are presented in this paper, based on the channel model simulation of CDMA cellular mobile environment.