Long term fading characteristics of VHF broadcast signals in an urban environment

Spatial long-term fading (SLTF) characteristics of VHF broadcast signals, under urban conditions, in an inner metropolitan micro-neighborhood region (MNR), are described. Understanding of the SLTF behaviour in densely built-up urban areas is considered essential to reliable systems design for land mobile radio communications. Exploratory field-strength measurements of local FM broadcasting stations (88-108 MHz) were made in Montreal, Canada, in two separate MNR surveys. The SLTF behavior is represented by the local mean field strength, estimated by logarithmic signal averaging over twenty wavelengths at the measured frequency. The measurements provide preliminary results showing: (i) the effect of different transmitter locations, (ii) the shadowing effect between different streets for the same transmitters, (iii) the effect of street orientation, and (iv) a comparison of the statistical behavior of the vertical and horizontal polarization components on streets of different orientation. Suggestions for further analysis are made