scholarly journals Analysis of Fade Dynamic at Ku-Band in Malaysia

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Siat Ling Jong ◽  
Michele D’Amico ◽  
Jafri Din ◽  
Hong Yin Lam
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Heavy Rain ◽  
Rain Attenuation ◽  
Time Interval ◽  
Radio Communication ◽  
System Operator ◽  
Typical Day ◽  
One Year ◽  
Ku Band

This work investigates fade dynamics of satellite communication systems in equatorial heavy rain region based on a one year of Ku-band propagation measurement campaign carried out in Universiti Teknologi Malaysia (UTM), Johor, Malaysia. First order statistics of rain attenuation are deduced and the results are found to be in good agreement with those obtained from other beacon measurements gathered within the same area (Kuala Lumpur). Moreover, the fade duration and slope statistics of the satellite signal variations are also carefully derived and subsequently compared with the ITU-R recommendation model. Such information is useful for the system operator and radio communication engineer for the design of appropriate fade mitigation techniques as well as the quality of service that could be offered to the user (according to the time interval for a typical day). Further evaluation on the performances of several ITU-R models in the heavy rain region are needed based on the measurement database available of this climatic region.

scholarly journals Characterization of concurrent ku band tropospheric scintillation and rain attenuation in Malaysia

2019 ◽  
Vol 15 (2) ◽  
pp. 956
Author(s):  
Ibtihal Fawzi Elshami ◽  
Jafri Din ◽  
Lam Hong Yin ◽  
Ali I Elgayar
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Power Spectral Analysis ◽  
Rain Attenuation ◽  
Significant Information ◽  
Tropical Regions ◽  
Significant Impairment ◽  
One Year ◽  
Tropospheric Scintillation ◽  
Ku Band

<span>Tropospheric scintillation in satellite communication systems operating at frequencies over 10 GHz is a significant impairment, especially in tropical regions, as attenuation affects scintillation dramatically. This work concentrates on tropospheric scintillation in equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement study utilising a direct broadcast receiver and an automatic weather station. This study aimed to investigate the relationship between wet scintillation and rain attenuation using experimental measurements. The power spectral analysis has been carried out to determine required cut-off frequency of filtering to separate out rain attenuation and scintillation effects. The results can provide significant information on the fluctuations of wet scintillation at Ku-band earth space link in tropical regions.</span>

Seasonal and Diurnal Variation on Tropospheric Scintillation at Ku-Band in Tropical Climate

2016 ◽  
Vol 6 (4) ◽  
pp. 1710
Author(s):  
Ibtihal Fawzi Elshami ◽  
Jafri Din
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Elevation Angle ◽  
Signal Amplitude ◽  
Clear Sky ◽  
South West Monsoon ◽  
One Year ◽  
Tropospheric Scintillation ◽  
Propagation Measurement ◽  
Ku Band

Tropospheric scintillation is a rapid fluctuation of the received signal amplitude which can cause propagation impairments that affect satellite communication systems operating above 10 GHz. Scintillation data was collected in Equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement campaign, utilizing MEASAT-1 Satellite with an antenna elevation angle of 75.61°. This work concentrates on the probability density function (PDF) of diurnal variations of clear sky scintillation variance analyzed on an hourly basis. Besides, seasonal variation of scintillation amplitude has been presented in this paper. From the results, it is concluded that clear sky scintillation variance is likely to occur during morning and afternoon periods. Moreover, clear sky scintillation amplitude of the South-West monsoon shows a relatively higher comparing with others monsoon seasons. Hence, signal attenuation based on seasonal and diurnal information is of great interest for the system designers to appropriately design fade margin.Tropospheric scintillation is a rapid fluctuation of the received signal amplitude which can cause propagation impairments that affect satellite communication systems operating above 10 GHz. Scintillation data was collected in Equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement campaign, utilizing MEASAT-1 Satellite with an antenna elevation angle of 75.61°. This work concentrates on the probability density function (PDF) of diurnal variations of clear sky scintillation variance analyzed on an hourly basis. Besides, seasonal variation of scintillation amplitude has been presented in this paper. From the results, it is concluded that clear sky scintillation variance is likely to occur during morning and afternoon periods. Moreover, clear sky scintillation amplitude of the South-West monsoon shows a relatively higher comparing with others monsoon seasons. Hence, signal attenuation based on seasonal and diurnal information is of great interest for the system designers to appropriately design fade margin.

scholarly journals Seasonal and Diurnal Variation on Tropospheric Scintillation at Ku-Band in Tropical Climate

2016 ◽  
Vol 6 (4) ◽  
pp. 1710
Author(s):  
Ibtihal Fawzi Elshami ◽  
Jafri Din
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Elevation Angle ◽  
Signal Amplitude ◽  
Clear Sky ◽  
South West Monsoon ◽  
One Year ◽  
Tropospheric Scintillation ◽  
Propagation Measurement ◽  
Ku Band

Tropospheric scintillation is a rapid fluctuation of the received signal amplitude which can cause propagation impairments that affect satellite communication systems operating above 10 GHz. Scintillation data was collected in Equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement campaign, utilizing MEASAT-1 Satellite with an antenna elevation angle of 75.61°. This work concentrates on the probability density function (PDF) of diurnal variations of clear sky scintillation variance analyzed on an hourly basis. Besides, seasonal variation of scintillation amplitude has been presented in this paper. From the results, it is concluded that clear sky scintillation variance is likely to occur during morning and afternoon periods. Moreover, clear sky scintillation amplitude of the South-West monsoon shows a relatively higher comparing with others monsoon seasons. Hence, signal attenuation based on seasonal and diurnal information is of great interest for the system designers to appropriately design fade margin.Tropospheric scintillation is a rapid fluctuation of the received signal amplitude which can cause propagation impairments that affect satellite communication systems operating above 10 GHz. Scintillation data was collected in Equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement campaign, utilizing MEASAT-1 Satellite with an antenna elevation angle of 75.61°. This work concentrates on the probability density function (PDF) of diurnal variations of clear sky scintillation variance analyzed on an hourly basis. Besides, seasonal variation of scintillation amplitude has been presented in this paper. From the results, it is concluded that clear sky scintillation variance is likely to occur during morning and afternoon periods. Moreover, clear sky scintillation amplitude of the South-West monsoon shows a relatively higher comparing with others monsoon seasons. Hence, signal attenuation based on seasonal and diurnal information is of great interest for the system designers to appropriately design fade margin.

scholarly journals Evaluation of Concurrent Variation in Rain Specific Attenuation and Tropospheric Amplitude Scintillation Over Akure, Southwest Nigeria

2021 ◽  
Author(s):  
Ayodeji Gabriel Ashidi ◽  
Joseph Sunday Ojo ◽  
Oluwaseyi Julius Ajayi ◽  
Toluwalope Mary Akinmoladun
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Signal Amplitude ◽  
Rain Attenuation ◽  
Coefficient Of Determination ◽  
Integration Time ◽  
Radio Communication ◽  
Amplitude Scintillation ◽  
Specific Attenuation ◽  
Rain Specific Attenuation

AbstractRain constitutes a major limitation to the performance and use of terrestrial and satellite communication systems with operational frequencies greater than 10 GHz. The situation gets further complicated by fast fluctuations in the received signal amplitude due to in homogeneities in atmospheric weather conditions; a phenomenon known as amplitude scintillation. The concurrent evaluation of the two phenomena guarantees a better fade margin determination for the planning of radio communication over any location. This work employs 3 years of in-situ measurement of temperature, humidity, rainfall rate and rainfall amount for the estimation of tropospheric amplitude scintillation and rain specific attenuation over Akure (7.17° N, 5.18° E, 358 m) South West Nigeria. Davis vantage pro weather station at 1-min integration time was used for the measurement and the ITU models for rain specific attenuation (ITU-R P.838-3) and amplitude scintillation (ITU–R 618-13) were employed for the estimation. Time series and statistical analyses of the phenomena show that rain attenuation is the more prominent cause of signal degradation at Ku-band frequencies. Nevertheless, the need to make an extra fade margin allowance of about 0.25 dB due to amplitude scintillation fade subsists to forestall any loss of synchronization on the link. Also, a 3-parameter power-law expression developed for estimating amplitude scintillation fade from rain attenuation performed excellently well, as indicated by average root mean square error (RMSE) and coefficient of determination (R2) values of 0.002151 and 0.8747, respectively.

scholarly journals Development of software for Ku-Band signal availability due to rain attenuation

2019 ◽  
Vol 13 (3) ◽  
pp. 1252
Author(s):  
Norsuzila Ya’acob ◽  
Noraisyah Tajudin ◽  
Muhammad Rezza Alui ◽  
Nani Fadzlina Naim ◽  
Murizah Kassim ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Rain Rate ◽  
Prediction Models ◽  
Weather Prediction ◽  
Rain Attenuation ◽  
Cumulative Distribution ◽  
One Year ◽  
Satellite Dish ◽  
Band Signal ◽  
Ku Band

<span>Ku-Band signal is often used for satellite communication mainly for direct to home (DTH) broadcasting. One of the major issues using this band is that the signal will be affected by raindrops. Raindrops absorb and scatter signal that operates at a frequency of more than 10 GHz. However, studies have been done to predict and measure the rainfall rate and rain attenuation. The rain attenuation in Ku-Band range and the rain rate were measured at satellite receiving dish, pointed towards the orbital slot 91.5 E over a one-year period in 2013. The cumulative distribution of rain rate obtained as well as a cumulative distribution of rain attenuation obtained are presented and compared with the rain prediction models. The aim is to get the best model to be used for the purpose of software development. It was found out that the DAH prediction model is fairly equitable when compared to direct satellite dish receiving measurements in Malaysia. The model provided a suitable baseline in developing a user interface software for weather prediction.</span>

scholarly journals Modification of ITU-R Rain Fade Slope Prediction Model Based on Satellite Data Measured at High Elevation Angle

2012 ◽  
Vol 12 (5) ◽  
Author(s):  
Hassan Dao ◽  
Md. Rafiqul Islam ◽  
Khalid Al-Khateeb
Keyword(s):  
Prediction Model ◽  
Elevation Angle ◽  
Heavy Rain ◽  
High Elevation ◽  
Time Interval ◽  
Kuala Lumpur ◽  
Tropical Regions ◽  
Mitigation Techniques ◽  
One Year ◽  
Ku Band

Rain fade slope is one of fade dynamics behaviour used by system engineers to design fade mitigation techniques (FMT) for space-earth microwave links. Recent measurements found that fade slope prediction model proposed by ITU-R is unable to predict fade slope distribution accurately in tropical regions. Rain fade measurement was conducted  in Kuala Lumpur (3.3° N, 101.7° E) where located in heavy rain zone by receiving signal at 10.982 GHz (Ku-band) from MEASAT3 (91.5° E) on 77.4° elevation angle. The measurement has been carried out for one year period. Fade slope S parameter on ITU-R prediction model has been investigated. New parameter is proposed for the fade slope prediction modeling based on measured data at high elevation angle, Ku-band. ABSTRAK: Cerun hujan pudar adalah salah satu dinamik tingkah laku pudar yang digunakan oleh jurutera sistem untuk mereka bentuk teknik-teknik pengurangan pudar (FMT) bagi link gelombang mikro ruang bumi. Ukuran baru-baru ini mendapati bahawa cerun pudar ramalan model yang dicadangkan oleh ITU-R tidak mampu untuk meramalkan pengagihan cerun pudar tepat di kawasan tropika. Pengukuran  hujan pudar telah dijalankan di Kuala Lumpur (3.3° N, 101.7° E) yang terletak di kawasan hujan lebat dengan menerima isyarat pada 10,982 GHz (Ku-band) dari MEASAT3 (91.5° E) pada sudut ketinggian 77.4°. Pengukuran telah dijalankan untuk tempoh satu tahun. Parameter cerun pudar S pada model ramalan ITU-R telah disiasat. Parameter baru adalah dicadangkan untuk pemodelan cerun pudar ramalan berdasarkan data yang diukur pada sudut paras ketinggian, Ku-band.KEYWORDS: fade slope; ITU-R; fade mitigation techniques; sampling time interval

scholarly journals Fog and rain attenuation characterization and performance of terrestrial free space optical communication in Akure, Nigeria

2020 ◽  
Vol 4 (3) ◽  
pp. 125-134
Author(s):  
Ajewole M. O ◽  
Owolawi P. A ◽  
Ojo J. S ◽  
Adetunji R. M.
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
Outer Space ◽  
Rain Attenuation ◽  
Integration Time ◽  
Free Space Optical ◽  
High Data ◽  
Space Optical Communication ◽  
And Performance ◽  
One Year

Reliable broadband communication requires secure high data rate and bandwidth links. With the observedincrease in broadband users, known communication systems such as RF and microwave links cannot promise suchrequirements due to link interference and low bandwidth. A current communication system that promises suchrequirements and more is Free Space Optical (FSO) communication. This system basically involves the transmissionof signal-modulated optical radiation from a transmitter to a receiver through the atmosphere or outer space. However,location-variant atmospheric channel degrades the performance of an FSO system under severe atmosphericconditions, thus necessitating local atmospheric attenuation studies.This paper presents the characterization of both fog- and rain-induced attenuation and the performance ofan FSO system in a terrestrial terrain at Akure, Nigeria. One-year archived visibility data and in-situ measured 1-minute integration time rain rate data obtained from Nigerian Meteorological Agency (NIMET) and the Departmentof Physics, Federal University of Technology, Akure were used to compute the fog- and rain-induced specificattenuations using Kruse model and Carboneur model respectively. The performance of the FSO system is analyzedthrough link margin by using the parameters of a commercial optical transceiver, Terescope 5000.

scholarly journals Rain Rate Distributions for Microwave Link Design Based on Long Term Measurement in Malaysia

2018 ◽  
Vol 10 (3) ◽  
pp. 1023 ◽  
Author(s):  
Islam Md Rafiqul ◽  
Md Moktarul Alam ◽  
Ali Kodhim Lwas ◽  
Sarah Yasmin Mohamad
Keyword(s):  
Communication Systems ◽  
Rain Rate ◽  
Prediction Models ◽  
Complex Structure ◽  
Satellite Communications ◽  
Rain Attenuation ◽  
Integration Time ◽  
Radio Link ◽  
Radio Communication ◽  
High Frequency Microwave

Attenuation due to rain is an important constraint in microwave radio link design especially at frequencies above 10 GHz. It restricts the path length of radio communication systems and limits the use of higher frequencies for line-of-sight microwave links and satellite communications. In order to predict the attenuation due to rain accurately rainfall intensity is required with 1-minute integration time. Rainfall is a meteorological phenomenon with complex structure due to its variability in space, duration and occurrence frequency, particularly in tropical and equatorial regions. Since, the statistical distribution of rain attenuation is obtained from the rain rate distribution for the region considered, it should be noted that the accuracy of the rain rate measurement affects the accuracy of the attenuation estimation. This paper presents rain intensity with 1-minute integration time measured for 6 years in Malaysia, it’s distribution, comparison with other prediction models and impact on high frequency microwave links.

A PRIORI ANALYSIS OF RADIATION RESISTANCE OF MULTICHANNEL LOW-NOISE KU-BAND AMPLIFIER

2021 ◽  
Author(s):  
Д.А. ТИТОВ
Keyword(s):  
Radiation Dose ◽  
Radiation Resistance ◽  
Communication Systems ◽  
Satellite Communication ◽  
A Priori ◽  
Low Noise ◽  
A Priori Analysis ◽  
Onboard Equipment ◽  
Ku Band ◽  
Unified Design

Приводится алгоритм расчета накопленной дозы радиационного излучения для унифицированной конструкции бортовой аппаратуры систем спутниковой связи The article presents an algorithm for calculating the accumulated radiation dose for the unified design of onboard equipment of satellite communication systems.

Stochastic Approach to a Rain Attenuation Time Series Synthesizer for Heavy Rain Regions

2016 ◽  
Vol 6 (5) ◽  
pp. 2379
Author(s):  
Masoud Mohebbi Nia ◽  
Jafri Din ◽  
Hong Yin Lam ◽  
Athanasios D. Panagopoulos
Keyword(s):  
Time Series ◽  
Communication Systems ◽  
Measurement Data ◽  
Likelihood Estimation ◽  
Heavy Rain ◽  
Stochastic Approach ◽  
Rain Attenuation ◽  
Least Square ◽  
Model Parameters ◽  
Cir Model

<p>In this work, a new rain attenuation time series synthesizer based on the stochastic approach is presented. The model combines a well-known interest-rate prediction model in finance namely the Cox-Ingersoll-Ross (CIR) model, and a stochastic differential equation approach to generate a long-term gamma distributed rain attenuation time series, particularly appropriate for heavy rain regions. The model parameters were derived from maximum-likelihood estimation (MLE) and Ordinary Least Square (OLS) methods. The predicted statistics from the CIR model with the OLS method are in good agreement with the measurement data collected in equatorial Malaysia while the MLE method overestimated the result. The proposed stochastic model could provide radio engineers an alternative solution for the design of propagation impairment mitigation techniques (PIMTs) to improve the Quality of Service (QoS) of wireless communication systems such as 5G propagation channel, in particular in heavy rain regions.</p>

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