Semi-elliptic-coverage geometric-based stochastic channel modeling for smart antenna arrays with oscillating beam patterns

In this paper, a smart antenna array is located at the base station (BS). Time-varying delays are applied to the array elements. These time-varying delays create a small oscillation in the beam pattern, which in turn leads to a time-varying channel. At the single-antenna mobile station (MS), the time-varying nature of the channel is exploited to achieve time diversity benefits. In this work, we present a channel model for the time-varying channel, and use our proposed model to evaluate the coherence time at the MS. A so-called geometric-based stochastic channel model (GSCM), with a semi-elliptic coverage area, is presented. This geometric approach allows us to stochastically model the parameters of the time-varying channel impulse response. Simulations based on the GSCM allow for the characterization of coherence time and its relationship to smart antenna control parameters.