CHAPTER 5 - Cellular antenna system design considerations

EXAMPLE 5.1 - PG NO.133

In [1]:
#page no.133
op=15.
l=2.
n=2.
l1=n*l#connector loss
l2=3.#coaxial cable loss
tl=l1+l2#total loss
ip=op-tl#input=output-total loss
print '%s %s %d %s' %('signal level at the i/p of the antenna is =','+',ip,'dBm')

signal level at the i/p of the antenna is = + 8 dBm

EXAMPLE 5.2 - PG NO.136

In [2]:
#page no. 136
import math
ci=18.
CI=10.**((ci)/10.)
q=(6*(CI))**0.25
K=math.ceil(q*q/3)#cluster size
print'%s %d' %('minimum cluster size is K =',K)
k=7
q1=math.sqrt(3*k)
c1i1=q1**4/6
C1I1=10*math.log10(c1i1)
if (C1I1<20):
	print('cluster size cannot meet the desired C/I requirement')
	C2I2=10**(20/10)
	q2=(6*C2I2)**0.25
	k1=math.ceil((q2)**2/3)
	print'%s %d' %('nearest valid cluster size is K =',k1)
else: 
	print('cluster size determined is adequate')

minimum cluster size is K = 7
cluster size cannot meet the desired C/I requirement
nearest valid cluster size is K = 9

EXAMPLE 5.4 - PG NO.139

In [3]:
#page no. 139
import math
Y=4.#path loss exponent
N=6.

K=7.
q=math.sqrt(3.*K)
CI=(2.*(q-1.)**(-Y)+2.*q**(-Y)+2.*(q+1.)**(-Y))**(-1.)#C/I for omnidirectional operating cell
CIdB=10.*math.log10(CI)
print'%s %d %s' %('co-channel interfernce ratio C/I for K=7 is =',CIdB,'dB')

K1=9.
q1=math.sqrt(3.*K1)
CI1=(2.*(q1-1.)**(-Y)+2.*q1**(-Y)+2.*(q1+1.)**(-Y))**(-1.)
CI1dB=10.*math.log10(CI1)
print'%s %.1f %s' %('co-channel interfernce ratio C/I for K=9 is =',CI1dB,'dB')

K2=12.
q2=math.sqrt(3.*K2)
CI2=(2.*(q2-1.)**(-Y)+2.*q2**(-Y)+2.*(q2+1.)**(-Y))**(-1.)
CI2dB=10.*math.log10(CI2)
print'%s %.1f %s' %('co-channel interfernce ratio C/I in dB for K=12',CI2dB,'dB')


if (CIdB<18) :
	print('K=7 is imperfect')
else :
	print('K=7 is perfect')
#end

if (CI1dB<18):
	print('K=9 is imperfect')
else: 
	print('K=9 is perfect')
#end

if (CI2dB<18) :
	print('K=12 is imperfect')
else: 
	print('K=12 is perfect')
#end

co-channel interfernce ratio C/I for K=7 is = 17 dB
co-channel interfernce ratio C/I for K=9 is = 19.8 dB
co-channel interfernce ratio C/I in dB for K=12 22.5 dB
K=7 is imperfect
K=9 is perfect
K=12 is perfect

EXAMPLE 5.5 - PG NO.142

In [4]:
#page no.142
import math
N=2.
Y=4.
K=7.
q=math.sqrt(3*K)
CI=((q**(-Y)+(q+0.7)**(-Y)))**(-1)#C/I for 3-sector
CIdB=10*math.log10(CI)
print'%s %.1f %s' %('worst case signal to co-channel interfernce ratio C/I is =',CIdB,'dB')

worst case signal to co-channel interfernce ratio C/I is = 24.5 dB

EXAMPLE 5.6 - PG NO.143

In [5]:
#page no.143
import math
N=2
Y=4
K=4

q=math.sqrt(3*K)
CI=((q**(-Y)+(q+0.7)**(-Y)))**(-1)#C/I for 3-sector
CIdB=10*math.log10(CI)
print'%s %d %s' %('worst case C/I is',round(CIdB),'dB')
if CIdB>18 :
	a= CIdB-6
	if a>18 :
		print('K=4 is adequate system as C/I is still geater than 18dB after considering the practical conditions with reductions of 6dB ')

	else :
		print('K=4 is inadequate system as C/I is smaller than 18dB after considering the practical conditions with reductions of 6dB ')
	#end

else: 
	print('K=4 is inadequate system as C/I is less than the minimum required value of 18dB ')
#end

worst case C/I is 20 dB
K=4 is inadequate system as C/I is smaller than 18dB after considering the practical conditions with reductions of 6dB

EXAMPLE 5.7 - PG NO.145

In [6]:
#page no.145
import math
N=1.
Y=4.
K=7.
q=math.sqrt(3.*K)
CI=((q+0.7)**(-Y))**(-1.)#C/I for 6-sector
CIdB=10.*math.log10(CI)
print'%s %d %s' %('signal to co-channel interfernce ratio C/I is =',round(CIdB),'dB')

signal to co-channel interfernce ratio C/I is = 29 dB

EXAMPLE 5.8 - PG NO.146

In [7]:
#page no. 146
import math
N=1.
Y=4.
K=4.
q=math.sqrt(3.*K)
CI=((q+0.7)**(-Y))**(-1)#C/I for 6-sector
CIdB=10.*math.log10(CI)
print'%s %.2f %s' %('signal to co-channel interfernce ratio C/I is =',CIdB,'dB')

if CIdB>18 :
	a= CIdB-6
	if a>18:
		print('K=4 is adequate system as C/I is still geater than 18dB after considering the practical conditions with reductions of 6dB ')

	else :
		print('K=4 is inadequate system as C/I is smaller than 18dB after considering the practical conditions with reductions of 6dB ')
	#end

else: 
	print('K=4 is inadequate system as C/I is less than the minimum required value of 18dB ')
#end

signal to co-channel interfernce ratio C/I is = 24.78 dB
K=4 is adequate system as C/I is still geater than 18dB after considering the practical conditions with reductions of 6dB

EXAMPLE 5.9 - PG NO.146

In [8]:
#page no.146
CIdB=15.
CI=10.**(CIdB/10.)
q=(6.*(CI))**0.25
K=q*q/3.


if K >4:
    K=7.
print'%s %d' %('optimum value of K for an omnidirectional antenna design is K =',K)
q1=(CI**0.25-0.7)
k=q1*q1/3.


if k<3: 
	k=3
#end
	print'%s %d' %('practical value of K for 6-sector 60deg. directionl antenna design is K =',k)

optimum value of K for an omnidirectional antenna design is K = 7
practical value of K for 6-sector 60deg. directionl antenna design is K = 3

EXAMPLE 5.10 - PG NO.148

In [9]:
#page no. 148
N=312.
K=7.
Nspc=3.
Ntcpc=N/K
Ntcps=Ntcpc/Nspc#number of traffic channels per sector
print'%s %.f' %('number of traffic channels per sector for System A is =',Ntcps)

N1=312.
K1=4.
Nspc1=6.
Ntcpc1=N1/K1
Ntcps1=Ntcpc1/Nspc1#number of traffic channels per sector
print'%s %.f' %('number of traffic channels per sector for System B is =',Ntcps1)

number of traffic channels per sector for System A is = 15
number of traffic channels per sector for System B is = 13