Influence of diffraction coefficient on ray prediction of power and delay spread in urban microcells

For a low base station antenna located on one street, signals propagate into crossing and parallel streets by reflection and diffraction at corners of the buildings. In order to accurately predict the received signals, it is therefore necessary to properly model the diffraction coefficient at the building edges. This paper presents a new heuristic diffraction coefficient (NHDC), and compares ray tracing predictions to measurements of received power and rms delay spread. The NHDC has higher diffracted field strength in deep shadow than does the commonly used heuristic diffraction coefficient, and shows better agreement with measurements of both received power and delay spread.