UWB Technology for WSN Applications

Ultrawide band (UWB) technology has been recognized as a feasible technology for wireless sensor networks (WSNs) applications due to its very good time-domain resolution allowing for precise location, tracking, coexistence with existing narrowband systems (due to the extremely low power spectral density) with low power and low cost on-chip implementation facility. Sensor Nodes (SN) that builds the backbone of such networks is normally micro controller based small devices. As batteries normally supply powers to these nodes that can only provide relatively small and limited processing capabilities. As a result, a number of UWB-based sensor network concepts have been developed both in the industrial and the government domain. For UWB devices, there are three independent bands i.e. the sub-gigahertz band (250–750 MHz), the low band (3.1–5 GHz), and the high band (6–10.6 GHz). Each UWB band has a single mandatory channel and devices that operate independently of the other band. Here, emphasis given on the low band of UWB (3.244-4.742 GHz) that is based on spread spectrum technique for WSN applications. The main feature of the system is the design simplicity having the advantage of using simple binary modulation technique and non-coherent detection scheme. Simulation result shows that, the pulse repetition coder has significant impact on performance as well as controlling data rates and reliable reception. Moreover, data is successfully recovered by an energy detection method (detect and avoid), which facilitates design simplicity at the receiver by avoiding pulse synchronization and coherent detection. We have also analyzed pulse repetition coder in conjunction with spread spectrum technique that facilitates robust and low power transmission system design. The remaining part of this chapter briefly discusses the feasibility of UWB for WSN as a physical layer communication system and then describes the UWB system design, transmission and reception process as well as performance analysis.