Received signal-level characteristics in a wide-band mobile radio channel

A mobile propagation model aimed at clarifying fundamental propagation characteristics in received signal-level variation for wide-band transmission is proposed. On the basis of this model, the author derives an expression for a received signal level in wide-band transmission and examines the fundamental signal-level characteristics by computer simulation and experiment. Both simulation and measurement results agree well and the results follow. For a received signal-level variation in wide-band transmission: first, received signal-level depth becomes shallower with increasing receiver bandwidth 2/spl Delta/f, and the level has no Rayleigh distribution. In an urban area when 2/spl Delta/f is 3 MHz, the level difference between the cumulative probability 50% and 1% values is about 5 dB. Second, received signal-level distribution depends on the number of arriving waves N and path length difference |/spl Delta/L/sub ij/|. The level depth becomes shallower with increasing N and |/spl Delta/L/sub ij/|. Third, received signal-level distribution is almost independent of radio frequency f/sub c/. The author also derives expressions for the autocorrelation coefficient /spl rho/(z) and frequency coefficient /spl rho/(s) of the received signal level. /spl rho/(z) is independent of 2/spl Delta/f, and is about J/sub 0/(Z//spl lambda//sub c/)/sup 2/, which is known as narrow-band reception. The /spl rho/(s) becomes higher with increasing 2/spl Delta/f.<
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