Envelope, phase and data-transmission characterization for mobile radio channels at UHF frequencies

This paper presents results of envelope, phase and data-transmission measurements for mobile radio transmissions in the 900 MHz band as well as statistical characterization of the channel-envelope and phase behaviour, of the effect of space diversity, and modelling of error sequences experienced with 20 kb/s BPSK and 10 kb/s differential phase-shift keying (DPSK) data transmission. All experiments were conducted in medium-sized cities, namely Quebec City and Ottawa, and the results show evidence in most cases of a main or direct component superimposed on the multipath components, as is typical of a Rice channel, rather than the fully random behaviour of Rayleigh channels. Actual recordings of the error sequences indicate that the error-generation process is well characterized by Fritchman's channel model consisting of two to four error-free states and a single error state, and the paper concludes by presenting typical values of Fritchman parameters as a function of different values of the mean error rate.