Fading channel characterization for oscillating-beam-pattern smart antennas using geometric-based stochastic channel modeling with circular coverage area

Whenever the channel coherence time is less than the symbol duration, a mobile station (MS) receiver can exploit time diversity to enhance its probability of error performance. One way to ensure a channel coherence time less than the symbol duration is by use of a carefully controlled oscillating-beam antenna array at the base station (BS). Here, beam pattern movement creates small coherence times. In this paper, with an oscillating-beam-pattern antenna array at the BS, the time varying channel is modeled to evaluate the channel coherence time and the available diversity in the MS. Here, a geometric-based stochastic channel model (GSCM) is used, and a circular coverage area is assumed. For a mid-sized city center, coherence times are shown to correspond to 1/7^th the symbol duration, suggesting a 7-fold time diversity is available at the MS when the BS´s antenna array pattern is carefully controlled