The range increase of adaptive versus phased arrays in mobile radio systems

In this paper, we compare the increase in range with multiple-antenna base stations using adaptive array combining to that of phased array combining. With adaptive arrays, the received signals at the antennas are combined to maximize signal-to-interference-plus-noise ratio (SINR) rather than only fo rm a directed beam. Although more complex to implement, adaptive arrays hav e the advantage of higher diversity gain and antenna gain that is not limit ed by the scattering angle of the multipath at the mobile, Here, we use com puter simulation to illustrate these advantages for range increase in both narrow-band and spread-spectrum mobile radio systems. For example, our resu lts show that for a 3 degrees scattering angle (typical in urban areas), a 100-element array base station can increase the range 2.8 and 5.5-fold with a phased array and an adaptive array, respectively. Also, for this scatter ing angle, the range increase of a phased array with 100 elements can be ac hieved by an adaptive array with only ten elements.