# Chpater 6: DIGITAL MODULATION TECHNIQUES

## Example 6.5, Page No 327¶

In :
import math
#Symbol rate of transmission and bandwidth

#initialisation of variables
fb=1.0                #MHz
Tb=1/fb               #bit period ms
N=4

#CALCULATIONS
Ts1=Tb
Bw1=2*fb
Ts2=Tb*2
Tr2=(1.0/2)*1000          #Symbols/sec
Bw2=1/Tb
Ts3=N*Tb
Tr3=(1.0/4)*1000
Bw3=(2.0*fb)/N

#RESULTS
print("In BPSK")
print("The symbol rate of transmission is = %.f X 10^6 symbol/sec " %Ts1)
print("The Bandwidth is = %.f MHz " %Bw1)
print("In QPSK")
print("The symbol rate of transmission is = %.f X 10^3 symbol/sec " %Tr2)
print("The Bandwidth is = %.f MHz " %Bw2)
print("In 16-ary PSK")
print("The symbol rate of transmission is = %.f X 10^3 symbol/sec " %Tr3)
print("The Bandwidth is = %.f kHz " %(Bw3*1000))

In BPSK
The symbol rate of transmission is = 1 X 10^6 symbol/sec
The Bandwidth is = 2 MHz
In QPSK
The symbol rate of transmission is = 500 X 10^3 symbol/sec
The Bandwidth is = 1 MHz
In 16-ary PSK
The symbol rate of transmission is = 250 X 10^3 symbol/sec
The Bandwidth is = 500 kHz


## Example 6.6, Page No 328¶

In :
import math

#initialisation of variables
fb=90              #MHz
Bw=20              #Mb/s

#CALCULATIONS
N=(2*fb)/Bw

#RESULTS
print("Number of bits required = %.f " %N)

Number of bits required = 9


## Example 6.12, Page No 357¶

In :
import math

#initialisation of variables
Tb=0.1          #msec

#CALCULATIONS
fb=1/Tb

#RESULTS
print("Transmission bandwidth = %.f kHz" %fb)

Transmission bandwidth = 10 kHz