A wideband channel model applicable to mobile satellite systems at L- and S-band

In the near future, mobile satellite systems (MSS), providing worldwide voice and data communications are to come into service. As the demand for these services and the requirement for higher data rates and quality of service increases, the effects of the wideband mobile satellite propagation channel become more critical with respect to the overall system link budget. There is an increasing need to be able to accurately model the channel in order to optimise the design of radio mobile satellite systems. A wideband channel model has been developed based on the philosophy as the RACE ATDMA model. The model is of the tapped delay type, comprising a transversal filter structure with equidistant time shifted taps. The model parameters have been derived from the measurement campaign, and defined by a small number of discrete taps, where each tap is described by its complex time-varying amplitude including its statistical distribution and corresponding Doppler spectrum. A typical example is included of the tap amplitudes and statistical distributions from the measured data and the respective Doppler spectrum for the first tap (direct path) and the second tap (first multipath echo) in the model for the urban environment at 45° elevation angle. Additionally, the model has been validated against independent results published from the DLR measurement campaign