Measurement and modelling of wideband propagation at L- and S-bands applicable to the LMS channel

摘要

Results of a wideband propagation measurement campaign applicable to mobile satellite communication systems at L- and S-band are presented. First-order statistics, including RMS delay spreads and cumulative probability density functions are presented for elevation angles from 15° to 80°, and for a wide range of propagation surroundings, including urban, wooded and open environments. Typical RMS delay spread values are found to be in the region of 40ns. In open conditions, the statistical analysis of the line-of sight-path signal shows a form close to a Rician distribution, as expected, but, under shadowed conditions, the distribution is closer to Rayleigh. Amplitude and phase measurements are made during the campaign and allow second-order statistics to be evaluated from the data, examples of which are given for the urban/suburban and open environments. The second-order statistics, in the form of level crossing rates, should provide a more accurate characterisation of the channel.