Experimental radio channel measurements.

The undertaken measurements are aimed at validating and refining the developed propagation models and at studying the particularities of the radio channel in every kind of environment (rural, urban, indoor, etc.). Apart from narrow-bandwidth measurementsto estimate the propagation losses, which can find application in the planning of first and second generation mobile communications systems (as GSM), at present, wide-bandwidth measurements as well as MIMO channel measurements are also being carried out. The wide-bandwidth measurements are undertaken in order to evaluate, not only the mentioned propagation losses, but the channel dispersion in time and space, and could be applied in third generation systems such as UMTS. The MIMO channel measurements use multiple antennas in both transmission and reception and significantly succeed in improving the channel capacity. Both kinds of measurements are focused onmicrocellular environments and special ones such as tunnels.