CDMA wireless local loop capacity

A wireless local loop (WLL) system has many inherent advantages over traditional cellular system, such as bigger coverage area, low power, reduced interference, higher capacity, no fast fading, no hand-off, etc. In this paper ideal multiple-tier hexagonal cells are used to derive the capacity of a CDMA WLL system. First, the reverse link interference from each tier to the center cell is calculated separately, Then, interference ratio of reverse links in a WLL system is analytically derived as a function of total tier number. The result shows that interference from other cells is proportional to the beam width of the house antenna. We also found that tier number plays a vital role in system capacity in a free-space propagation (20 dB/dec) environment. A WLL simulator is also built to verify our analytical solution.