Received signal level characteristics for wideband radio channel in microcells

In multipath mobile propagation, the variation of the received signal level in wideband transmission is entirely different from that in narrowband transmission. Consequently, the wideband propagation characteristics must be clarified to evaluate various digital communication systems and select the system parameters. Currently, a number of efforts are underway to design a wideband mobile communication system. The system is an alternative of the Future Public Land Mobile Telecommunication Systems (FPLMTS). We clarify the received signal level characteristics for wideband mobile radio channels with low antennas. The results from urban-area field experiments, where the received signal levels for various receiver bandwidths form 300 kHz to 30 MHz and power delay profiles were measured, show that the depth of fading of the received signal decreases as the normalized RMS delay spread, defined as the product of the receiver bandwidth and the RMS delay spread, increases. We also discuss the received signal level characteristics as determined by computer simulation. These results agree well with the experimental ones. In addition, we clarify that the depth of fading converges to a constant value when the normalized RMS delay spread is large. The converge value decreases as the number of arriving waves increases. These results are useful in designing wideband microcell systems for urban areas