From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 3415/CH11/EX11.1/Ex11_1.sce | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 3415/CH11/EX11.1/Ex11_1.sce (limited to '3415/CH11/EX11.1/Ex11_1.sce') diff --git a/3415/CH11/EX11.1/Ex11_1.sce b/3415/CH11/EX11.1/Ex11_1.sce new file mode 100644 index 000000000..0283fcc9c --- /dev/null +++ b/3415/CH11/EX11.1/Ex11_1.sce @@ -0,0 +1,42 @@ +//fiber optic communications by joseph c. palais +//example 11.1 +//OS=Windows XP sp3 +//Scilab version 5.4.1 +//given +clc +clear all +//given +lambda=0.85e-6//wave length in um +Pi=10*10^-3//led Power in W +L=20//fiber cable loss in dB +Row=0.5//respomsivity in A/W +ID=2*10^-9//Detector dark current in A +RL=50//load resistance in ohm +BW=10*10^6//receiver's bandwidth in Hz +Ta=300//temperature in Kelvin +SCL=14//source coupling loss in dB +CL=10//connector loss in dB +e=1.6*10^-19//charge of electron in columbs +k=1.38e-23//boltzman constant +//to find +TL=SCL+CL+L//total Loss in dB +Tn=10^(-TL/10)//transmission efficiency +PR=Pi*Tn//received power in W +is=Row*PR//photo current in A +PES=is^2*RL//Electrical signal power in W +PNS=2*e*is*BW*RL//shot noise power in W +PNT=4*k*Ta*BW//Thermal noise power in W +SNR=PES/PNT//signal to noise ratio +SNRdB=10*log10(SNR)//signal to noise ratio in dB +SNRQL=is/(2*e*BW)//quantum limited SNR + + +mprintf("Received power =%fuW",PR*10^6)//multiplication by 10^6 to convert the unit from W to uW +mprintf("\nPhoto current=%fnA",is*10^9)//multiplication by 10^9 to convert the unit from A to nA +mprintf("\nElectrical signal power=%f*10^-12W",PES*10^12)//multiplication by 10^12 to convert the unit from W to x10^-12W +mprintf("\nShot noise power=%f*10^-17W",PNS*10^17)//multiplication by 10^17 to convert the unit from W to x10^-17W +mprintf("\nThermal noise power=%f*10^-13W",PNT*10^13)//multiplication by 10^13 to convert the unit from W to x10^-13W +mprintf("\nSignal to noise ratio=%fdB",SNRdB) +mprintf("\nQuantum limited SNR=%f",SNRQL) +//this is the exact answer, book has taken approximated values of parameters and its Quantum limited SNR is 62500 + -- cgit