Measurements and analyses of multipath propagation structure for small-cell digital mobile radio in hilly areas

For research on characterization and reduction of the bit error rate in high‐speed digital mobile communication, the understanding of the multipath propagation structure is indispensable. In this research, a measurement system is developed in which the two sets of directive antennas and the delay time measurement method by TV video signals with a sharp pulse inserted are combined. The multipath propagation structure is measured in detail in hilly small‐cell model areas. In addition to conspicuous reflections from the buildings and hills around the measurement course, the reflected waves from far away buildings and multiple (several times) reflected waves are observed. The power‐delay profiles and the nature of the delay spread of the multipath waves are analyzed so that the effect of the delayed multipath waves on the bit error rate in the digital transmission is found.