VHF/ UHF Building Penetration Characteristics When Using Low Antenna Heights

Measurements and propagation models for building penetration are shown for a VHF/ UHF system that uses low antenna height (<3 meters). Measurements show that excess building loss, even when line-of-sight conditions exist, can easily exceed 30 dB. Additionally, variations of the channel frequency response in excess of 20 dB were observed over a 5 MHz bandwidth. Also, paths with maximum excess delays (25 dB) up to 5.2 mu seconds were observed. These factors as well as others presented in detail in this document will have a significant impact on the air interface specification for the cognitive radio in- building communication system.