Application of sectorised antennas and STBC to increase the capacity of hot spot WLANs in an interworked WLAN/3G network

At present, wireless local area networks (WLANs) supporting broadband multimedia communication are being developed around the world. Standards include HIPERLAN/2 and the IEEE 802.11 family. These systems provide channel adaptive data rates up to 54 Mbps over short ranges up to 200 meters. It is likely that WLANs will become an important complementary technology to 3G cellular systems and will typically be used to provide 'hot-spot' coverage. The complementary use of WLANs with and without sectorised antennas in conjunction with UMTS is presented. Additionally, results are presented for the case where STBC (space time block codes) are considered as a means of enhancing WLAN performance. It is shown that significant enhancements in both coverage and capacity can be achieved in both cases.