Modulation and Equalisation Considerations for High Performance Radio LANs

The European Telecommunications Standards Institute (ETSI) is currently defining a European standard for HIgh PERformance Radio LANs (HIPERLAN). To operate as wired LAN replacements, these systems will need to offer data rates as high as 20 Mb/s. To counteract the time dispersive nature of the indoor radio channel, adaptive equalisation is proposed at the receiver. In this paper a number of possible modulation and equalisation techniques are presented and, in particular, the BER performance of quasi-coherent GMSK detection is investigated. Important issues such as frame and symbol synchronisation, frequency offset correction and equaliser implementation are also addressed from a practical standpoint.