Positioning in Wireless Communications Systems

Chapter 9Applications

In this chapter, we introduce applications that use the location information obtained from wireless position information. First, in Sections 9.1, 9.2, and 9.3 we consider applications that improve wireless communications systems in terms of macro diversity, radio resource management, and mobility management. A lot more information on these applications can be found at (WHE n.d.). A second major application, which has particularly driven the standardization of wireless positioning in cellular mobile communications systems is emergency calls (see Section 9.4). Finally, we give a brief overview on the wide field of LBS in Section 9.5.

9.1 Macro Diversity

Macro diversity is a spatial diversity scheme with multiple antennas being separated by several orders of wavelengths. In cellular networks or WiFi, macro diversity implies that the antennas are located at different BSs or APs. Examples of macro diversity schemes include the CDMA softhandover in UMTS (ETSI 2010) or cooperative diversity in 3GPP LTE-Advanced (3GPP 2010). In Section 9.1.1, we discuss how to apply spatial diversity schemes and space-time codes in order to provide cellular diversity that outperforms pure macro diversity with the help of location information. Next, we consider location-based synchronization for cellular OFDM in Section 9.1.2, that is, multi-link synchronization, which is a necessary prerequisite for macro diversity schemes. Finally, we investigate position aware adaptive communications ...