Highlights of the mobile communications channel research

Mobile cellular radio communications is a demanding service. The environment-rich in shadowing or otherwise scattering objects-stresses the performance of the communications systems, which strive to achieve both a high grade of service and a high spectral efficiency. The means of mitigating the impairments of the dispersive and fading channels affect the complexity of the system. A compact characterization of the channels, in terms that are useful to the system designers and performance evaluators, is the objective of the Joint Task Group of URSI (the International Union for Radio Science), chaired by the author. 5 workshops have been held during the last 4 years. A substantial part of the channel characterization effort has shifted from generic statistical models to the underlying physical mechanisms, the deterministic features and the proper interpretation of measurements. A review of the ongoing research, in the community and the author´s contributions, is discussed, to include an analysis of a measurement campaign in the US, providing evidence of the channel structure.