Capacity analysis of UWB systems with transmitter power constraints

Ultra wide bandwidth (UWB) wireless technology plays a key role in future beyond third generation systems guaranteeing very high bit rates availability, low power consumption, low costs and location capabilities. The peaceful acceptance of the UWB technology worldwide is mainly related to coexistence issues with other existing (and future) narrowband and wideband systems sharing the spectrum with UWB. This led regulatory bodies to impose restrictions on UWB transmissions thus implicitly limiting the UWB system capacity intended as the number of users that can be served for a specified outage probability. In this work we provide a methodology to evaluate the UWB system capacity under the Federal Communications Commission (FCC) constraints. UWB networks with power controlled UWB devices are considered. The concept of irreducible outage probability is introduced. Results can be used to analyze the performance of a given network topology and/or to provide useful design hints for an UWB indoor system with devices communicating in accordance to a clustered master-slave network topology.