Coexistence of an ultrawideband spread spectrum system with fixed wireless access systems

Ultra Wide Bandwidth (UWB) spread-spectrum techniques are getting an increased importance due to their many desirable features such as high bit rates availability and low power consumption. UWB is now considered an enabling technology for advanced wireless local area networks providing integrated multimedia services to nomadic users over hot-spot areas. The assessment of the possible interference caused by UWB devices on already existing narrowband and wideband systems is fundamental to ensure not conflicting coexistence and, therefore, the acceptance of UWB technology worldwide. In this paper we analyze coexistence issues between an indoor UWB system and an outdoor Fixed Wireless Access (FWA) system operating in the 3.5-5.0 GHz frequency range. By considering an UWB master/slave system architecture and realistic traffic scenarios, we show through computer simulation, that in many practical cases UWB system can coexist with FWA without causing any dangerous interference. Both upstream and downstream communication directions are analyzed.