Comparison of capacity between adaptive tracking and switched beam smart antenna techniques in TDD-CDMA systems

In this paper, a theoretical analysis of TDD-CDMA capacity constraint is presented firstly when employing the adaptive tracking and switched beam smart antenna techniques in both uplink and downlink. In uplink, the multi-user detection (MUD) technology is utilized and the smart antenna technique is involved, and the corresponding capacity and load evaluation is reinvestigated. Based on the proposed theoretical analysis model, the pole capacity and load estimation formulations are proposed. In downlink, the smart antenna scheme is adopted to suppress the interference, and the smart antenna based load and pole capacity estimation models are presented. Additionally, the performance comparison between the adaptive tracking and switched beam smart antenna techniques is given for both uplink and downlink. The simulation results demonstrate the analytical model is available. The adaptive tracking smart antenna technique can provide better performance than the switched beam does