Measurements and characterization of the UHF mobile radio channel. Part 1: Measurements over the band 853¿885 MHz

The design of a wideband measuring system using a frequency stepping technique is presented. The system measures the amplitude and differential phase (group delay) variations of a pair of spaced frequencies over the bandwidth 850¿960 MHz. The measurements are made when the vehicle carrying the receiver is stationary. Hence the Doppler shifts and spread of the signal observed by the moving receiver cannot be measured directly. Using the measuring system the complex frequency response of the UHF mobile radio channel has been measured in urban and suburban areas of the city of Leeds, UK. The presented results are classified into appropriate categories in terms of the building density and the natural environment. The preliminary analysis, based on derivations of the complex transfer function of the channel from measured data at a particular location and the corresponding frequency coherence function and power delay profile, is presented. A full discussion is given of the channel behaviour for different areas by interpreting frequency responses over the band 853-885 MHz and the corresponding frequency coherence function and power delay profile over the band 869¿877 MHz.