Multimedia Hotspots Supporting Wireless LAN and Cellular CDMA Access

Abstract

Recent boom in wireless hot-spots has triggered interest in optical fiber based wireless access schemes. An enhanced hot-spot will support both IEEE 802.11 wireless LAN and cellular radio services. Simultaneous transmission of these radio signals over a single radio-over-fiber (ROF) link is possible in a subcarrier multiplexed manner. However, link design in this multi-system scenario is a complex task. There are number of quality measures such as signal to noise, distortion and interference ratios involved both in the optical link and in the air interface. These are functions of several parameters such as the fiber length, bandwidth, modulation depth, radio cell size and relative RF power of both systems. In this paper we analyze the uplink and show a way to decide the cumulative optical modulation index (mu) and the RF power ratio (T) that will yield the best performance for both systems.