Coexistence issues for ultra-wideband radio technology

The goal of this Thesis is the assessment of the radio-coexistence between Ultra-wideband radio technology (UWB-RT) and some of the most important legacy narrow-band systems: Fixed Wireless Access (FWA), Point to Point (PP), Fixed Satellite Service (FSS) and Primary Radars operating in the 2.7-2.9 GHz band. UWB-RT is the most promising alternative for current medium-range communications technologies, best suited to short range applications in personal area networking. The versatility of this technology ranges from high data rate applications as USB cable replacement to location and tracking solutions in wireless sensor networks. But UWB concept is significantly different from traditional narrow-band radio systems and spread spectrum technologies: it uses a low peak power spread over an extremely wide bandwidth so overlapping the frequency bands already assigned to other systems. The high likelihood of a wide spreading of UWB devices linked to other properties such as low power consumption, small physical size of chips (requirement for next-generation consumer electronic devices like PDA, cell phone, ...) together with seamless connectivity and the multiple access, makes the UWB interference a big issue for peaceful radio coexistence with present and future narrow-band radiosystems. To make a fair appraisal about the UWB interference effects, this work has considered several facets of this issue starting from analyzing the features of UWB signals up to the integration of these characteristics within a communication system architecture; the requirements on the correct operation of the potential victim systems have been perused basing on ITU documents and detecting a criterion to measure the degradation of the performances due to UWB interference. Two reference scenarios have been identified to measure the UWB aggregate interference received by the generic victim receiver and how this UWB power is dependent on several parameters (some related to the adopted UWB signals and system such as modulation techniques or presence of a power control algorithm, some else linked to the features of the antenna and/or the operative centre frequency of the victim receiver, others associated with the propagation models)