Lab Report on FM-Radio Coverage and Interference Analysis of the Province of Torino

TAMEZANANG TEKEUSSO BORIS (s187464)

FOMETEU TONLEU WILFRIED ROSTOV (s185748)

AWET ABRAHA GIRMAY (s184415)

Radio planningRadio planningRadio planningRadio planning

FMFMFMFM----Radio Coverage and Interference AnalysisRadio Coverage and Interference AnalysisRadio Coverage and Interference AnalysisRadio Coverage and Interference Analysis

Mater 1 In Telecommunications Engineering

Professor:

Lab Instruc

Radio Coverage and Interference Analysis of the Province of Torino

(s187464)

(s185748)

Radio planningRadio planningRadio planningRadio planning / Radio Mobile/ Radio Mobile/ Radio Mobile/ Radio Mobile

Radio Coverage and Interference AnalysisRadio Coverage and Interference AnalysisRadio Coverage and Interference AnalysisRadio Coverage and Interference Analysis of the Province of Torinoof the Province of Torinoof the Province of Torinoof the Province of Torino

Master degree

III Faculty of Engineering

Mater 1 In Telecommunications Engineering Oriented Wireless Systems

Year 2011/2012

Politecnico di Torino

Professor: Prof. Daniele TRINCHERO

Instructor: Dott. Riccardo STEFANELLI

Radio Coverage and Interference Analysis of the Province of Torino

1

of the Province of Torinoof the Province of Torinoof the Province of Torinoof the Province of Torino

Oriented Wireless Systems

Lab Report on FM-Radio Coverage and Interference Analysis of the Province of Torino

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1. Introduction

The purpose of this exercise is to study the FM-radio coverage of the province of Torino which

consists of different communes by a radio transmission center working at 99.000 MHz frequency and

using a Stereo modulation which is located near the vicinity of the city of Turin. Besides to designing

different antenna arrays for varied radiation requirements, studying the effect of radio interference levels

on the specified transmitter from Valcava (BG), Loazzolo (AT), and Frabosa Soprana (CN) as per the

recommendations of ITU-R BS.412-9 is also the main objective of this exercise. Below is depicted the

area over which we studied the radio coverage from the central transmitter and interference analysis from

neighboring interfering transmission unit.

Fig 1: Main Province of Turin

Lab Report on FM-Radio Coverage and Interference Analysis of the Province of Torino

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Fig 2 : Province of Turin and nearest interferer points

Here is tabulated transmission parameters and antenna information we used in this lab exercise.

S/N Name of TX Tx

power

Tower

height

Operating

freq.

Freq.

deviation

Location Orientation/

Tilt

Remark

1

Central TX

1kw

30m

99.000MHz

-

45°01’55.31”N,

7°43’14.22” E

Towards Turin

Azimut=326.60

Eleva=-5.2480

Uses 2,4,8

element

dipole ant

2

Valcava (BG)

5kw

20m

99.050MHz

50KHz

45° 46’ 56” N ,

09° 31’ 12” E

Towards Milan

Azimut=216.20

Eleva=-1.640

Uses 2

element

yagi ant

3 Loazzolo (AT) 2kw 30m 99.150MHz 150KHz 44° 40’ 23” N,

08° 13’ 26” E

Azimut=00

Eleva=00

Uses 4

element

dipole ant

4

Frabosa Soprana

(CN)

1kw

20m

99.000MHz

0

44° 16’ 10” N,

07° 47’ 33” E

Towards Cuneo

Azimut=304.30

Eleva=-2.8490

Uses 8

element

yagi ant

Lab Report on FM-Radio Coverage and Interference Analysis of the Province of Torino

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2. Procedure

Initially we defined an area within the province of Turin over which all the habitants reside and

including all communes. To study the FM radio coverage, we created one network using the network

properties of radio mobile software which includes the central TX, a mobile unit, and three interferers

and setup their memberships. In addition, we created four systems corresponding to the four transmitters

and plugged in the given parameters.

2.1. Antenna’s radiation pattern design

At the very beginning, we choose the parameter � �� to be 0.65 in our AF and antenna array design. We wrote a small Matlab script to realize the array factor (AF) calculation which consists 360 horizontal

and 181vertical pattern values all expressed in dBs. For the central FM radio transmitter we used an

angular tilt of ����� = −5.158� for determining the AF. We used the following expression of the AF:

�� = ��� (��� )

��� (�� )

∗ ����� � !"

We then implemented a Matlab program to perform the point by point addition in dBs of the AF and the

already existed single element dipole and yagi antenna pattern values within the radio mobile software.

The .ant file we generated was placed inside the antenna folder of the radio mobile.

2.2. Gain calculation of Array elements:

To obtain the gain value of the different types of antenna arrays with N elements from a single

element antenna gain, we used the following formula and the outcomes of the manipulation are as

tabulated below:

G$%%$& $�' = 10 ∗ log,� N + G���/01 $�' [dBi]

S/N Number of elements

(N)

789:;<= >9?@<= = A. BC [>D9] 789:;<= EF;9 = G. BH [>D9] Remark

7FIIFJ >9?@<= [>D9] 7FIIFJ JF;9 [>D9]

1 2 5.17 11.16

2 4 8.18

3 8 11.19 17.18

Lab Report on FM-Radio Coverage and Interference Analysis of the Province of Torino

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2.3. Interference analysis:

As per the ITU-R BS.412-9 planning standard for FM sound broadcast recommendations, we took the

minimum usable field strength for stereophonic transmission in urban areas to be 66 �L �MN O� !. Furthermore, we choose the appropriate radio frequency protection ratio levels of the individual

interferers on our transmitter from the table for systems using a maximum frequency deviation of

±50 QRS which is being practiced here in Italy. The protection ratios for the three carrier frequency spacing and for stereophonic steady interferences are tabulated below:

S/N TX Name Freq. deviation from Tx

(KHz)

Radio freq. protection ratio

(S/I in dB)

Remark

1 Valcava (BG) 50KHz 51

2 Loazzolo (AT) 150KHz 18

3 Frabosa Soprana (CN) 0 49

After we selected the appropriate S/I values and using minimum usable field strength we got

before, we did the interference radio coverage analysis using radio mobile for each of the three interferers

to see their effect on the central transmitter comprising of 2, 4, and 8 element arrays as shown below. We

did the same for the remaining two interferers as well. We carried out the interference study using a

dipole antenna mounted on a mobile unit of 10 meters tall.

Fig 3: Radio Mobile, study of interferences

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3. Results

3.1. Antenna’s radiation patterns

Dipole arrays with 2, 4 & 8 vertical elements and Yagi arrays of 4 & 8 vertical elements

that we designed are depicted below: (we used default scale of 20 dB in Radio Mobile)

Fig 3. 1: Horizontal and Vertical pattern for the tilted 2-elements dipole of the central transmitter

Fig 3. 2: Horizontal and Vertical pattern for the tilted 4-elements dipole of the central transmitter

Lab Report on FM-Radio Coverage and Interference Analysis of the Province of Torino

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Fig 3. 3: Horizontal and Vertical pattern for the tilted 8-elements dipole of the central transmitter

Fig 3. 4 : Horizontal and Vertical pattern for the 2-elements Yagi of the Valcava (BG) Interferer

Lab Report on FM-Radio Coverage and Interference Analysis of the Province of Torino

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Fig 3. 5: Horizontal and Vertical pattern for the 4-elements dipole of the Loazzolo (CN) Interferer

Fig 3. 6: Horizontal and Vertical pattern for the 8-elements Yagi of the Frabosa Soprana (CN) Interferer

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3.2. Interference analysis results

Legend: green acceptable & red unacceptable field strength

Fig 3. 7: Interference by Valcava transmitter on the 2-element dipole system central transmitter

Fig 3. 8: Interference by Loazzolo transmitter on the 2-element dipole system central transmitter

Lab Report on FM-Radio Coverage and Interference Analysis of the Province of Torino

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Fig 3. 9: Interference by Frabosa transmitter on the 2-element dipole system central transmitter

Fig 3. 10: Interference by Valcava transmitter on the 4-element dipole system central transmitter

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Fig 3. 11: Interference by Loazzolo transmitter on the 4-element dipole system central transmitter

Fig 3. 12: Interference by Frabosa transmitter on the 4-element dipole system central transmitter

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Fig 3. 13: Interference by Valcava transmitter on the 8-element dipole system central transmitter

Fig 3. 14: Interference by Loazzolo transmitter on the 8-element dipole system central transmitter

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Fig 3. 15: Interference by Frabosa transmitter on the 8-element dipole system central transmitter

4. Conclusion

As can be seen from the interference radio coverage plot results, the interferers almost totally destroy

our transmitted signal from being heard by most of the inhabitants in the province. Hence, designing

sectorial antennas, increasing number of array elements, and increasing the transmission power may lead

us to have a good coverage over the desired area but this may not bring us a complete solution in

combating the effect of the interferers since their effect is always there persistently over the whole

province unless otherwise another solution is found. Since we have no full control over the transmitted

powers and operating frequencies of the interfering units, the best thing that we can do is to alter and play

with the operating frequency of our transmitter and make it quite far away from the frequencies of the

interferers so as to nullify their effects on our transmission.