ART20182892 RS (original) (raw)
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2018
The study investigates the variation of signal strength generated by the 4.3 kW Frequency Modulation (FM) station of the Imo State Broadcasting Corporation (Orient 94.4FM), Owerri, Nigeria, within some selected routes in Imo State. The signal strength meter (SSM) used for this investigation was designed and constructed. The signal strength was measured at a distance of 5 km intervals field of view from the transmitter’s antenna and in places within the selected pathways, till the signal faded totally. A travel distance application which uses global positioning receiver system (GPRS) was used to measure the distances of the study locations from the broadcasting station. The data gotten was plotted graphically to ascertain the difference in signal strength with distance along the routes, where the study was carried out. The results obtained from this study revealed that the strength of signal was stronger in locations close to and in the same direction with the antenna but was relativ...
Measurements of Field Strength and HD Radio Reception Quality at VHF
IEEE Antennas and Wireless Propagation Letters, 2014
This letter presents the results of field trials conducted in Brazil to evaluate the performance of digital broadcasting systems. Analog FM and digital HD Radio signals broadcasting the same content were simultaneously transmitted in the urban and suburban areas of the city of Belo Horizonte in Brazil. A mobile unit recorded the received signal intensity and reception quality along radial routes of up to 24 km from the transmitter, thereby enabling the comparative assessment of the systems performance and the evaluation of the propagation loss. 1
Investigation of Diurnal Variation of Signal Strength Generated by FM Transmitter
This paper focuses on the determination of the diurnal variation of signal strength generated by Orient 94.4 FM transmitter along six (6) selected route in Imo State, Nigeria. This was carried out with the aid of a constructed signal strength meter (SSM). Signal strength measurements were collected at different time, on different days, and in different months. The measurement was carried out at a constant distance of 20 Km. Arrangement was made with the management of the base station to ensure that the transmitting parameters were kept constant throughout the period of signal strength measurement. The average results of these measurements were taken. The data obtained from the measurements was plotted in a graph to establish the diurnal variation in signal strength along the different routes of signal strength measurement. It was observed from this research that transmission and reception of signals are dependent on the time of the day. High signal strength was noted between the hours of 8 am and 11 am, while low signal strength was recorded between the hours of 1 pm and 5 pm. Better signal strengths were recorded at night. The result of this study shows that signal strength generated by FM transmitter vary with time of the day and the prevalent weather conditions. Stronger signals are recorded mostly at night along the different routes of the study. The signal strength consequently drops in the afternoon and recovers in the morning hours.
The ability to predict the minimum power a transmitter must radiate to give an acceptable quality of coverage over a predetermined service area is very imperative. This work adapted some field strength models that are best suitable for Makurdi city in Benue State, Nigeria. Some existing field strength models are optimised to suit Makurdi city using a VHF television signal of Nigeria Television Authority (NTA), Makurdi. The models are free space, Hata, ITU-R P.529-3 and ERC Report 68 models. NTA, Makurdi transmits at a frequency of 210.25 MHz for video signal. Measurement of the video signal levels was done along four radial routes from the transmitting station. A digital signal level meter and Global Positioning System (GPS) was used to measure the signal level of the transmitted signal from the station along these routes and to measure the corresponding distances away from the base of the transmitting antenna respectively. The results obtained, after processing and computation of t...
It is important to understand the impact of physical surroundings on a propagating signal because the propagation characteristics of any radio channel are severely affected by objects that surround the transmitters and the receivers. So, the propagation characteristics limit the performance of in-building high capacity wireless communications. This research work adapted some field strength models that are best suitable for Minna city in Niger State, Nigeria. This is done by optimising some existing field strength models which are: Free space, Hata, ITU-R P.529-3 and ERC Report 68 models to suit Minna city using a VHF television signal of Nigeria Television Authority (NTA), Minna. This station transmits at a frequency of 210.25 MHz for video signal. The signal levels of the transmitted signal were taken along five radial routes from the transmitting station using a digital signal level meter and the corresponding distances were also measured using Global Positioning System (GPS). Data processing and computation were carried out using MATLAB. The results obtained show that the Hata model gives a more accurate prediction for field strength in Minna city after general modification with the correction factor of 3.08 and Root Mean Square Error of 6.35 dBµV/m.
— This work measured experimentally, and calculated theoretically using the existing Friis Fomula, the Attenuation of 92.1 MHz (Ajilete FM) Signals along Gambari(Lat 8 o 29 1 N; Long 4 o 29 1) – Oyo-Road(Lat 7 o 50 1 N; Long 3 o 56 1 E), Oyo State Nigeria. The two results were compared. The experimental Measurement campaign was achieved by using an appropriate design dipole antenna, well matched to (810 GSP Analyser), to determine the attenuation. The calculated results correlated very well with the measurements (Correlation Coefficient Value R 2 =1). But, they are not accurate when compared with the measurements (Chi-square values equal zero for received power, measured attenuation). The inaccuracies of the results for the existing formula with the measurements may be due to hills, valleys, trees and bends along the links. Hence the accuracy of the model used can only be effectively confirmed in areas free of the obstacles mentioned above. By applying LEAST SQUARE fit method to the experimental measured data, the analytical models, P(x)= 0.0154x 2-1.3575x-38.7620 and A(x)= 0132x 2-1.2464x-104.8487, in the form of polynomial of degree two, were obtained respectively for received power and measured attenuation. The analytical model obtained is therefore recommended for use in an area characterised with bends, valleys, hills and trees, since the model has taken into consideration all these factors. In addition, repeater stations should be installed for effective transmission and for wider coverage in forested and valley areas. Moreover, transmitter of higher value like ten kilowatts should be employed for long distance transmission.
The ability to predict the minimum power a transmitter must radiate to give an acceptable quality of coverage over a predetermined service area is very imperative. This work adapted some field strength models that are best suitable for Makurdi city in Benue State, Nigeria. Some existing field strength models are optimised to suit Makurdi city using a VHF television signal of Nigeria Television Authority (NTA), Makurdi. The models are free space, Hata, ITU-R P.529-3 and ERC Report 68 models. NTA, Makurdi transmits at a frequency of 210.25 MHz for video signal. Measurement of the video signal levels was done along four radial routes from the transmitting station. A digital signal level meter and Global Positioning System (GPS) was used to measure the signal level of the transmitted signal from the station along these routes and to measure the corresponding distances away from the base of the transmitting antenna respectively. The results obtained, after processing and computation of the data; show that the free space model gives more accurate prediction for field strength in Makurdi city, after general modification, with the correction factor of -29.85 and Root Mean Square Error of 4.12 dBμV/m.
Conference on Innovation and Application of Science and Technology (CIASTECH), 2020
Prasarana telekomunikasi diperlukan untuk menunjang operasional pertambangan dengan area sangat luas. Sistem komunikasi radio dua-arah yang paling layak dipertimbangkan untuk melayani area tersebut diatas. Agar sistem radio bisa menghasilkan performa yang optimal perlu adanya perencanaan jaringan radio, yang melibatkan penggunaan model propagasi radio. Permasalahan dari penelitian ini adalah cara menentukan model propagasi yang sesuai untuk sistem radio dua-arah pada pita very high frequency dan ultra high frequency (VHF-UHF) pada area pertambangan terbuka dengan kondisi lahan tidak beraturan. Tujuan dari penelitian ini adalah investigasi sejumlah model propagasi radio yang sesuai untuk sistem komunikasi radio dua-arah pada pita VHF-UHF di area pertambangan terbuka dengan kondisi geografis yang tak beraturan untuk daerah tropis, dengan studi kasus di wilayah pulau Kalimantan, Indonesia. Metode yang digunakan adalah penentuan obyek riset, penentuan parameter jaringan radio, investigasi model propagasi, studi literature, analisis dan evaluasi model, klasifikasi model. Hasil analisis menunjukkan Standard Propagation Model memiliki performa terbaik untuk prediksi sistem radio area pertambangan. Namun, metode ini memiliki kekurangan yang memerlukan kalibrasi cukup kompleks. Kata-kunci: sistem radio dua-arah, model propagasi radio, VHF-UHF, pertambangan terbuka, tropis
Investigation of VHF signals in bands I and II in southern India and model comparisons
In order to achieve a highly reliable communication with a simple and small receiver, one requires the knowledge of the spatial and temporal variability of field strength. This assumes greater significance in broadcasting applications where the user expects a very high quality signal. The performance of any communication circuit depends on the models employed to calculate the coverage area and interference problems. The development and identification of models is a continuing and ongoing process and there is always scope for refinement. With this objective some field strength measurements were conducted using Chennai TV and FM stations in several radials. The variability of the path loss as a function of distance has been studied and path loss exponents deduced from the observed values were compared with the model available in literature. The agreement and deviations of the model with the observed results are presented and discussed and two approaches have been proposed to compare the observed results.
UNIOSUN Journal of Engineering and Environmental Sciences
This paper evaluated the coverage and performance of VHF and UHF signal level from two different transmission stations in the urban area of Ilorin, Kwara State, Nigeria. The performance characteristics of the two bands are of special importance regarding coverage and quality requirements. Effective communication links require direct line of sight; however, this cannot be achieved in a build-up areas where obstacles are present along the communication paths, which in turns result in signal strength degradation. In this work, the signal strength and performance of Nigeria Television Authority (NTA), Ilorin, and Kwara State Television (KWTV) were investigated along some six selected routes. The measurement was taken with a spectrum analyzer. Global positioning system (GPS) device was used to measure the coordinates between the transmitter and receiver during measurement. Microsoft Excel software was used to show the graphical variation of the field strength. Furthermore, the result obt...