Evaluation of Dynamic Slot Allocation for Space-Division Multiple Access in a Smart Antenna System

In this paper we evaluate the performance of fixed-user-per-slot and dynamic slot allocation for a smart antenna system using Space-Division Multiple Access. Fixed-user-per-slot allocation is studied with the first-come first-served method for different beamforming algorithms and sorting techniques. Dynamic slot allocation is studied with the first fit and modified first fit (MFF) methods. MFF requires significantly less computational complexity to select sets of users for simultaneous transmission in a frequency band. It is found that sorting by input SNR does not affect the throughput rate, but sorting by data length sharply improves the throughput rate. The tradeoff between capacity and range of a smart antenna system is evaluated. The effect of multipath on system capacity is studied, with results showing that the throughput rate significantly increases when at least one multipath signal is present.