Unformatted text preview: of 4.0, since cellular systems are designed to achieve higher path loss exponent. At 1900 MHz, λ = 3 × 10 8 / 19 × 10 8 = 3 / 19 m. Using a reference distance of 100 m,115(dBm) = 27(dBm) + G t (dB) + G r (dB)20 log 10 4 π 100 m 3 / 19 m40 log 10 d 100 m (1) So 40 log 10 d 100 m = 142 + G t + G r78 . (2) So d = 100 m 10 (64 . 0+ G t + G r ) / 40 (3) For G t = G r = 0 dB, d = 3 . 98 km. For G t = G r = 2 . 15 dB, d = 5 . 10 km. For G t = G r = 7 dB, d = 8 . 91 km. When we go up in center frequency from f old to f new , the path loss at the reference distance Π increases, by a factor of 20 log 10 λ old /λ new , or equivalently 20 log 10 f new /f old . So increasing the center frequency increases the path loss, and thus decreases the range....
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This note was uploaded on 02/25/2011 for the course ECE 5325 taught by Professor Dr.nealpatwari during the Spring '10 term at Utah.
 Spring '10
 Dr.NealPatwari

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