**1. Introduction**

Future wireless communication systems have to be realised in a simple and energy efficient manner while guaranteeing sufficient performance. Furthermore, the available frequency resources have to be used flexibly and efficiently. In this context two different approaches have been considered in recent years: On one hand OFDM-based overlay systems in which a primary user dynamically allocates unused frequencies to one or more secondary users [57] and on the other hand unlicensed, easy-to-realise and low-cost ultra-wideband (UWB) systems. This underlying technology operates with an extremely low transmission power over a wide frequency range and does not interfere with existing licensed systems [15].

In order to establish UWB on the consumer market it has to get along with some challenges. Such challenges are, e.g., the realisation of practical, low-complex and energy-efficient transceiver architectures, the investigation of methods for accurate synchronization and channel estimation or the handling of high sample rates. To meet these requirements this chapter considers a non-coherent multiband impulse radio UWB (MIR-UWB) system [11, 45, 46]. The MIR-UWB system focuses on short-range high data rate communication applications. The MIR-UWB system is an alternative to the architectures Multiband OFDM UWB [2] and Direct Sequence UWB [16] which have been proposed within the IEEE 802.15.3a standardization process.

The chapter is organised as follows: Section 2 gives a short introduction into the physical layer architecture of the non-coherent MIR-UWB system. In the following section 3 the performance of the energy detection receiver is analysed with respect to different aspects. In contrast section 4 deals with interference investigations for the non-coherent MIR-UWB system aiming at an efficient and intelligent interference handling. The chapter concludes with section 5 in which a summary is given.

©2013 Dehner et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0),which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©2013 Dehner et al., licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

2 Will-be-set-by-IN-TECH 2 Ultra-Wideband Radio Technologies for Communications, Localization and Sensor Applications MIRA – Physical Layer Optimisation for the Multiband Impulse Radio UWB Architecture <sup>3</sup>
