diff options
Diffstat (limited to '3547/CH7/EX7.2/Ex7_2.sce')
| -rw-r--r-- | 3547/CH7/EX7.2/Ex7_2.sce | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/3547/CH7/EX7.2/Ex7_2.sce b/3547/CH7/EX7.2/Ex7_2.sce new file mode 100644 index 000000000..ebc5cbf47 --- /dev/null +++ b/3547/CH7/EX7.2/Ex7_2.sce @@ -0,0 +1,55 @@ +// Example no. 7.2
+// To calculate exact and approximate Q-factor if the signal is (a)OOK, (b) PSK
+// Page no. 311
+
+clc;
+clear;
+
+// Given data
+lambda=1.55*10^(-6); // Wavelength of given signal
+meanPin=1; // Mean fiber launch power in dBm
+alpha=0.2; // fiber loss in dB/km
+l=240; // fiber length in km
+neta=0.7; // quantum efficiency
+T = 290; // Tempearture in K
+RL=100; // Length resistance in Ω
+PLOdBm = 10; // Power at local oscillator in dBm
+Be = 7.5*10^9; // Efficient bandwidth of filter in Hz
+c=3*10^8; // Speed of ligth in air in m/s
+loss=alpha*l; // Total fiber loss
+q=1.602*10^(-19); // Charge of electron
+h=6.626*10^(-34); // Planck constant
+kB=1.38*10^(-23); // Bolzman constant
+
+f=c/lambda; // mean frequency
+R=(neta*q)/(h*f); // Responsivity
+
+//For OOK
+Pin=10*log10(2)+meanPin; // peak power in dBm
+P1rdBm=Pin-loss; // received peak power in dBm
+P1r=(10^(P1rdBm/10))*10^(-3); // received peak power in W
+PLO=(10^(PLOdBm/10))*10^(-3); // Power at local oscillator in W
+I1=2*R*sqrt(P1r*PLO); // mean of bit 1
+sigma1=2*q*Be*R*(P1r+PLO)+(4*kB*T*Be)/RL; // Square of variance of bit 1
+I0=0; // mean of bit 0
+sigma0=sigma1; // Square of variance of bit 0
+Q1=(I1-I0)/(2*sqrt(sigma1)); // Exact Q-factor
+Q2=sqrt((neta*P1r)/(2*h*f*Be)); // Approximate Q-factor
+
+// Displaying the result in command window
+printf('\n Exact Q-factor if the signal is OOK = %0.1f',Q1);
+printf('\n Approximate Q-factor if the signal is OOK = %0.1f',Q2);
+
+// For PSK
+P1rdBm=meanPin-loss; // received peak power in dBm
+P1r=(10^(P1rdBm/10))*10^(-3); // received peak power in W
+I1=2*R*sqrt(P1r*PLO); // mean of bit 1
+sigma1=2*q*Be*R*(P1r+PLO)+(4*kB*T*Be)/RL; // Square of variance of bit 1
+I0=-I1; // mean of bit 0
+sigma0=sigma1; // Square of variance of bit 0
+Q1=I1/sqrt(sigma1); // Exact Q-factor
+Q2=sqrt((2*neta*P1r)/(h*f*Be)); // Approximate Q-factor
+
+// Displaying the result in command window
+printf('\n Exact Q-factor if the signal is PSK = %0.2f',Q1);
+printf('\n Approximate Q-factor if the signal is PSK = %0.2f',Q2);
|