THEORY AND MEASUREMENT OF THE ANGLE-OF-ARRIVAL AND TIME-DELAY OF UHF RADIOWAVES USING A RING ARRAY

The knowledge of directions of arrival (DOA) of waves is fundamental i n understanding the physics of the mobile communications aide-band pro pagation channel. In this paper, we first present a measurement setup able to accurately measure these DOA, It is based on the evaluation of the channel complex impulse response at regularly spaced locations on a circle, We theoretically investigate a new approach for deriving DO A from this ring array, We then describe an experimental campaign, whe re such measurements were done on a building rooftop, We show that all the main paths are clearly retrieved and identified and that the ray theory is valid and applicable, The results emphasise the predominant role of UHF-wave specular reflection by walls in actual urban environm ent.