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, we derive an expression for a received signal level in wide-band transmission and examine 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 2DELTAf, and the level has no Rayleigh distribution. In an urban area when 2DELTAf 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 \DELTAL(ij)\. The level depth becomes shallower with increasing N and \DELTAL(ij)\. Third, received signal-level distribution is almost independent of radio frequency f(c). We also derive expressions for the autocorrelation coefficient rho(z) and frequency coefficient rho(s) of the received signal level. Rho(z) is independent of 2DELTAf, and is about J(o)(Z/lambda(c))2, which is known as narrow-band reception. The rho(s) becomes higher with increasing 2DELTAf.