Impact of the antenna set-up and arrays on mobile radio systems

This paper outlines the impact of the antenna set-up and antenna array configurations on mobile radio system at millimetre-wave frequencies. Simulations in typical indoor environments using directive antennas have shown a significant reduction in the channel time dispersion and in power requirements. Also in a typical city street, specially when some objects (cars, buses, etc.) are present, it gives significant performance improvements when compared with an omnidirectional antenna. The significant reduction of channel time dispersion achieved with directional antennas, associated to the fact that a mobile terminal must be able to communicate in any direction, indicates that the best performance of a broadband system is obtained with either switchable beams or antenna arrays. The propagation channel is modelled with a ray tracing tool that takes into account the propagation environment and the antennas used