ITT650hw3

ITT650hw3 - Calculate its Doppler shift. = 3 x 108/900MHz=...

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Darrin Wright Due: September 18, 2011 Homework 3 3.2. Consider an antenna transmitting a power of 5W at 900MHz. Calculate the received power of at a distance of 2km if propagation is taking place in free space. P r = (900MHz)(5w) / 4π 2k 2 = 89.52W 3.4. The transmission power is 40W, under a free-space propagation model, (a) What is the transmission power in unit of dBm? dBm = 10 * ( log10 (mW) ) so, 10* (log10(40000m)) = 46.02 dBm (b) The receiver is in a distance of 1000m; what is the received power, assuming that the carrier frequency ƒ = 900MHz and G t = G r = 0dB? = 3 x 10 ʎ 8 /900MHz= .33m P r = 40000m(.33) 2 /(4πx1000) 2 = 4356/157913670 = 2.76 x 10 -5 mW (c) Express the free space path loss in dB. 10log(40000/2.76x10 -5 ) = 91.61 dBm 3.7. Consider an antenna transmitting a 900MHz. The receiver is traveling at a speed of 40km/h.
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Unformatted text preview: Calculate its Doppler shift. = 3 x 108/900MHz= .33m = 40000m/.33(cos ) 3.14 A BS has a 900MHz transmitter and a vehicle is moving at the speed of 50 mph. Compute the received carrier frequency if the vehicle is moving (a) Directly toward the BS. d = /cos = - 22.4m/s /.33m = -67.87 r = c + d (9x10 8 ) + 67.8 = 900000067.8 Hz (b) Directly away from the BS. = c- d (9x10 8 ) 67.8 = 899999932.2Hz (c) In a direction that is 60 degrees to the direction of arrival of the transmitted signal. Cos(60) = 1/2 = .5 Doppler Shift = (22.4/.33)(.5) = 67.87 X .5 = 33.93 Hz (9X10 8 ) 33.93 = 899999966.1...
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This note was uploaded on 11/22/2011 for the course ITT 650 taught by Professor Zeng during the Fall '11 term at N.C. A&T.

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