# Chpater 4: DIGITAL MULTIPLEXERS

## Example 4.4, page no 190¶

In :
#Caption: Sampling Rate

#initialisation of variables
f1=4.0*10**3
f2=4.5*10**3

#CALCULATIONS
fsmin=(2*f2)/1000

#RESULTS
print(" Sampling rate =%.2f kHz" %fsmin)

 Sampling rate =9.00 kHz


## Example 4.5, Page No 190¶

In :
#Caption: Nyquest rate,Signaling rate,bandwidth

#initialisation of variables
f1=3000.0
f4=1000.0
f2=1000.0
f3=1000.0

#CALCULATIONS
#Nyquest rate
nq1=2*f1
nq2=2*f2
nq3=2*f3
nq4=2*f4

#RESULTS
print('i. Nyquest rate of x1 =%.2fkHz' %nq1)
print('ii. Nyquest rate of x2 =%.2fkHz' %nq2)
print('iii. Nyquest rate of x3 =%.2fkHz' %nq3)
print('iv. Nyquest rate of x4 =%.2fkHz' %nq4)

i. Nyquest rate of x1 =6000.00kHz
ii. Nyquest rate of x2 =2000.00kHz
iii. Nyquest rate of x3 =2000.00kHz
iv. Nyquest rate of x4 =2000.00kHz


## Example 4.6, Page No 190¶

In :
#Find The spacing between two successive pules

#initialisation of variables
samplingrate=8000.0
totalsignals=24+1

#CALCULATIONS
t=1/samplingrate
T=t/totalsignals
T=T*10**6            #time is now u sec
space=T-1

#RESULTS
print('The spacing between two successive pules %.f u sec' %space)

The spacing between two successive pules 4 u sec


## Example 4.7, Page No 191¶

In :
#Find signaling rate ,bandwidth

#initialisation of variables
N=6.0
fm=5000.0

#CALCULATIONS
r=2*fm   #sampling rate
sr=N*r   #signalingrate
BW=N*fm  #Bandwith
sr=sr/1000
BW=BW/1000

#RESULTS
print('Signaling rate %.f K bits/sec' %sr)
print('Bandwith to avoid the cross talk in TDM is %.f kHz' %BW)

Signaling rate 60 K bits/sec
Bandwith to avoid the cross talk in TDM is 30 kHz


## Example 4.9, Page No 198¶

In :
#Find signaling rate ,bandwidth

#initialisation of variables
N=4.0
x=24              #bits/frame
D=1152
s=1.0/3
r=1.544*10**6

#CALCULATIONS
r0=N*r*((D+x)/(D-s*N))

#RESULTS
print('Output bit rate %.2f MB/sec' %(r0/(10**6)))

Output bit rate 6.31 MB/sec


## Example 4.10, Page No 198¶

In :
#Find signaling rate ,bandwidth

#initialisation of variables
N=24.0
x=72.0              #bits
D=192             #message and stuff bits
s=1.0/3
r=64              #kb/sec

#CALCULATIONS
r0=N*r*((D+x)/(D-s*N))
r1=((N*r)/r0)*100

#RESULTS
print('i) Output bit rate %.2f MB/sec' %(r0/(10**3)))
print('iI) Throughput efficiency is =  %.2f percent' %r1)

i) Output bit rate 2.20 MB/sec
iI) Throughput efficiency is =  69.70 percent