Effect of antenna element separation on performance of MAI canceller combined with adaptive array antenna for DS-CDMA systems

In order to increase the capacity of a DS-CDMA system by suppressing multiple access interference (MAI), a receiver cascading an adaptive array antenna and a multistage parallel interference canceller has been studied. The performance of the cascaded receiver has been evaluated by computer simulations assuming that the antenna element separation is half a wavelength. However, the fading correlation among antenna elements gets smaller as the antenna element separation and the angle spread among incident waves become larger. In this paper, the performance of the cascaded receiver is evaluated by computer simulation assuming a two-path Rayleigh fading channel by varying the antenna element separation and the angle spread among the incident waves. As a result, it is shown that the cascaded receiver with the adaptive array antenna based on directivity control is effective when the angle spread is small, and the cascaded receiver with the adaptive array antenna utilizing the difference of fading correlation among antenna elements is effective when the angle spread is large.