Synchronisation techniques for radio LANs

The High Performance Radio Local Area Network (HIPERLAN) system will operate in the 5 GHz and eventually 17 GHz bands at a data rate of 23.5 Msymbols/s. Access to the radio medium is assumed to be completely asynchronous; the medium itself is assumed to be a Rayleigh fading channel. These two criteria imply a need for a robust synchronisation mechanism, so that both suitable timing instants in the noncoherent receiver can be chosen, and equalisation performed to mitigate the effects of the time dispersive channel. As part of the preliminary design effort for the formation of the HIPERLAN transmission standard, the ESPRIT project 7359 LAURA (Local Area Network User Radio Access) is currently operating as a testbed and technology demonstrator for certain aspects of the HIPERLAN standard. Taking the LAURA system parameters as a baseline, further work has been carried out. Part of this work is concerned with a search for suitable synchronisation codes. It was decided from this work that 26-bit codes would provide adequate processing gain.