CS 455/555: Spring 2007. Chapter 2: The Physical Layer. Topics. Theoretical Basis for Data Communication Transmission Media Wireless Transmission Telephone System Narrowband ISDN B-ISDN and ATM Cellular Radio Communication Satellites. Theoretical Basis for Data Communication.
Chapter 2: The Physical Layer
“Any reasonably behaved periodic function, g(t), with period T can be constructed by summing a (possibly infinite) number of sine and cosine functions.”
g(t)=0.5c + ∑an sin(2∏nft) + ∑ bn cos(2 ∏nft) where f =1/T is the fundamental frequency and the a’s and b’s are amplitudes. (See page 86 for more details)
RMS amplitude = Sqrt(an2 + bn2 )
maximum data rate = H log2 (1+S/N)
Shannon’s result is independent of the number of levels in a signal and the rate of sampling of a signal.
10log10(transmitted power/received power)
10log10(1/0.8)=0.969 dB/1 km
0.4845= 10log10(1/x); 1/x=100.04845=1.118; x=0.894 watt;
2* 108 meters/sec