LOS and NLOS path-loss and delay characteristics at 3.35 GHz in a residential environment

Abstract

Measurement results are discussed for the path loss and delay characteristics of microwave transmissions from a low base station antenna for a LOS and multiple NLOS paths in a suburban residential area. While propagation corner losses of 30 to 35 dB occurred that increased abruptly for the NLOS courses, it was found that the distance path loss coefficient decreased at about the same rate as the LOS course, at a rate of the distance squared (/spl alpha/=2). Allowances must be made for the presence of different topological features such as open spaces or spaces between the rows of houses in the vicinity of the base station, which would cause the distance path loss coefficient to vary as /spl alpha/ becomes small to, for example, about 0.25. The delay spread was dependent on distance, and the NLOS delay spread was found to be several times larger than that of the LOS course. The standard deviation of delay spread for the NLOS courses ranged from 80 to 200 ns, which was an order of magnitude larger than that of the LOS course. The increase in the delay spread as a function of distance for the NLOS course was several ns/m, some one order of magnitude larger than that of the LOS course. The delay profile for the LOS course conformed with the power type model, but the exponents ranging from 1.9 to 2.9 were smaller than those obtained in urban environments. It was found that the models which have been proposed in the past do not account well for the NLOS data obtained in this work.