Performance tests of a low power cellular enhancer in a parking garage

The authors develop engineering criteria for an economical low-power cellular radio-telephone enhancer suitable for parking garages, exhibit halls, offices, etc. Signal propagation measurements were made in a 275´×245´ two-level parking garage using 5 mW input to a 3-dB-gain whip antenna on a ground plane. Signal strength measurements indicated that a few milliwatts of power in each garage would provide excellent coverage. A low-power cellular enhancer, constructed from off-the-shelf components, was installed in the garage. A high-gain antenna on the roof was connected through a low-loss transmission line to a duplexer in the enhancer. Two low-loss distributed antenna systems were used, one for relaying donor cell signals to mobiles and portables, and the other for receiving signals from the mobiles and portables. The enhancer was shown to provide satisfactory service in the garage with approximately 3 mW radiated power per channel