Assessment of Indoor Propagation and Antenna Performance for Bluetooth Wireless Communication Links
Tommy Hult, Abbas Mohamme · InTech eBooks · 2011
Over the last decade the world has witnessed explosive growth in the use of wireless mobile communications.Looking around we find users with mobile phones, wireless PDAs, MP3 players, keyboards etc. and wireless headphones to connect to these devices -a small testament of the impact of wireless communications on our daily lives.In addition the burst of new technologies such as Bluetooth and other short-range wireless communications are encouraging the further development of a wide variety of distributed wireless devices (Mohammed, 2002).Bluetooth is one of those short range wireless communication technology systems which aims at replacing many proprietary cables that connect one device with another with one universal short-range radio link.Recently, many mobile devices (e.g., mobile phones, PDAs, computer mice) with integrated Bluetooth modules have been introduced.Their wireless technology is used to transfer any kind of data onto these devices.Propagation of radio waves inside buildings is a very complicated issue, and it depends significantly on the indoor environment (home, office, factory) and the topography (LOS: line of sight and NLOS: non-line of sight).The statistics of the indoor channel varies with time due to movements of people and equipment (Obayashi & Zander, 1998).A survey of indoor propagation measurement and models can be found in (Hashemi, 1993), and electromagnetic propagation effects in (Sander & Reed, 1978).There are limited investigations in the open literature on the measurements and simulations of multipath wave propagation effects on the performance of live Bluetooth links.In this chapter we present measurement campaigns (signal power, bit error rate and data rate) in an indoor office building for LOS and NLOS propagation scenarios and assess their effects on the Bluetooth link.These measurements were carried out using various antennas (omni-directional and directive antennas), and we will present comparative analysis to access the potential improvement in system performance gained from the use of directive antennas.We will also show the effect of antenna parameters (gain and efficiency) on the results and the overall impact on the quality and coverage of the Bluetooth link.The organization of this chapter is as follows.In section 2 we provide a brief description of the building in the tested indoor office environment and the various types of antennas used in the measurement trials and their related parameters.In section 3 we present the results of these measurements.Finally, section 4 concludes the chapter. Assessment of Indoor Propagation and AntennaPerformance for Bluetooth Wireless Communication