VLSI homework 10, ECOMMS homework 3

7th-Semester-Fall-2024/ECOMMS/homework/homework-3/problem-1.py

@@ -4,21 +4,41 @@ import matplotlib.pyplot as plt
 
 f_c = 1
 f_m = f_c/4
+f_s = 8E3
+T_s = 1/f_s
+
+A_c = 1
 
 omega_m = 2*np.pi*f_m
 omega_c = 2*np.pi*f_c
 
-T_c = f_c
-
-t = np.arange(0,10,T_c/10)
+# Time samples to 10 seconds at a samplig frequency of 8kHz
+t = np.arange(0,10,T_s)
 m = np.cos(omega_m * t)
 
-plt.plot(t, m)
-plt.show()
+plt.subplot(311)
+plt.plot(t, m, label="$m(t)$")
+plt.ylabel("$m(t)$")
 
 D_p = np.pi
 D_f = np.pi
 
-S_p = np.cos(omega_c + D_p*m)
+# The phase modulated signal
+S_p = np.cos(omega_c*t + D_p*m)
+
+plt.subplot(312)
+plt.ylabel("$S_p(t)$")
+plt.xlabel("t (seconds)")
 plt.plot(t,S_p)
+
+# The time integral of the mesage signal
+M = np.sin(omega_m * t) / omega_m
+
+# The frequency modulated signal
+S_f = np.cos(omega_c*t + D_f*M)
+
+plt.subplot(414)
+plt.ylabel("$S_f(t)$")
+plt.xlabel("t (seconds)")
+plt.plot(t,S_f)
 plt.show()