Recommendation on Time Varying Radio Propagation Channel Models and Study of System Performance for LMDS
Prathap Soma, M.Y.W. Chia, Lawrence Ong · 2000
Local Multipoint Distribution Service (LMDS) has been recognised as an effective last mile solution to provide broadband wireless access to fixed networks providing services ranging from one-way video distribution and telephony to fully interactive switched broadband multimedia applications for residential and business customers. In this paper, we recommend the realistic and accurate LMDS channel models based on the measurements conducted in urban, suburban and rural environments of Singapore at 27.4 GHz. A generalised tapped delay line model was developed to represent the time varying complex channel impulse response. The propagation characteristics obtained include received signal short-term fluctuations and delay characteristics. Also the system performance was studied using various first-order and second-order statistical characteristics such as cumulative distribution function, level crossing rate and average fade duration of the fading signal. These characteristics provide valuable information on the coverage limitations, choice of suitable data rates, word lengths and modulation and coding schemes in an operational LMDS system.