Measurement and modelling of wideband mobile radio channels at 900 MHz

The complex bandpass impulse response of urban mobile radio channels is measured at 900 MHz using a swept time-delay cross-correlator channel sounder. The propagation data are analysed with particular relevance to the development of a representative channel simulation and production of parameters useful to systems engineers. In both cases, a two-stage characterisation of the data is used. A moving average normalisation method is applied to the processing of the simulation data. The wideband propagation path is shown to be well modelled by a tapped-delay line, with each tap comprising an uncorrelated Rayleigh modulator, a partially correlated log-normal modulator and a weighting factor. These results lend support to the Gaussian wide-sense stationary uncorrelated scattering model. The simplicity of using this model is highlighted by way of an example. Gross non-stationarity in the channel impulse responses identifies the need for formulating cumulative distributions of the small-scale systems parameters. It is shown how these results may be used in assessing the performance of existing and future mobile radio systems.<>