Time diversity as a rain attenuation countermeasure in satellite links in the 10-100 GHz frequency bands

2006 ◽  
Author(s):  
Emilio Matricciani
Keyword(s):  
Rain Attenuation ◽  
Frequency Bands ◽  
Time Diversity ◽  
Satellite Links

scholarly journals Investigation of time diversity gain for earth to satellite link using rain rate gain

2019 ◽  
Vol 8 (3) ◽  
pp. 951-959
Author(s):  
Md. Moktarul Alam ◽  
Islam Md. Rafiqul ◽  
Khairayu Badron ◽  
Farah Dyana A. R. ◽  
Hassaan Dao ◽  
...  
Keyword(s):  
Communication Systems ◽  
Rain Rate ◽  
Satellite Communications ◽  
Rain Attenuation ◽  
Diversity Gain ◽  
Potential Candidate ◽  
Tropical Regions ◽  
Frequency Bands ◽  
Time Diversity ◽  
One Year

The utilization of satellites for communication systems has expanded considerably in recent years. C and Ku-bands of frequencies are already congested because of high demand. Future directions of satellite communications are moving towards Ka and V-bands. Earth to satellite communications are moving towards higher frequency bands in future which are more sensitive to environment. Rain causes severe degradation in performances at higher frequency bands specially in tropical regions. Several mitigation techniques are proposed to design reliable system. Time diversity is one of the potential candidate for it. However, time diversity analysis requires measured rain attenuation data. For future high frequency link design those data are not available at most of the places. This thesis proposes a method to utilize 1-minute rain rate to analyze time diversity technique at any desired frequency. This paper proposes a method to utilize 1-minute rain rate to analyse time diversity rain rate gain. In proposed method, it is assumed that rain rate gain with delay can represent rain attenuation gain with delay for same period of time at same location. The characteristics of rain rate and rain attenuation almost same because the attenuation causes due to rain.  One year measured rain rate in Malaysia is used to predict rain rate gain. The measured gain at 12.225 GHz signal is compared with that predicted by ITU-R based on rain rate measurement and is found good agreement. Hence it is recommended that the time diversity gain can be predicted using measured rain rate for any desired frequencies.

scholarly journals An Analytical Prediction Model of Time Diversity Performance for Earth-Space Fade Mitigation

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Pantelis-Daniel M. Arapoglou ◽  
Athanasios D. Panagopoulos ◽  
Panayotis G. Cottis
Keyword(s):  
Prediction Model ◽  
High Frequency ◽  
Rain Attenuation ◽  
Analytical Prediction ◽  
Time Dynamics ◽  
Time Diversity ◽  
Satellite Applications ◽  
Basic Parameters ◽  
Cost Efficient ◽  
General Prediction

Time diversity (TD) has recently attracted attention as a promising and cost-efficient solution for high-frequency broadcast satellite applications. The present work proposes a general prediction model for the application of TD by approximating the time dynamics of rain attenuation through the use of the joint lognormal distribution. The proposed method is tested against experimental data and its performance is investigated with respect to the basic parameters of a satellite link.

scholarly journals Analysis of Time Diversity Gain for Satellite Communication Link based on Ku-Band Rain Attenuation Data Measured in Malaysia

2018 ◽  
Vol 8 (4) ◽  
pp. 2608
Author(s):  
Islam Md. Rafiqul ◽  
Ali Kadhim Lwas ◽  
Mohamed Hadi Habaebi ◽  
Md Moktarul Alam ◽  
Jalel Chebil ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Satellite Communications ◽  
Earth Satellite ◽  
Rain Attenuation ◽  
Diversity Gain ◽  
Communication Link ◽  
Time Diversity ◽  
Communication Links ◽  
System Time ◽  
Diversity Technique

<p><span>This paper reports a study on mitigation of propagation impairments on Earth–space communication links. The study uses time diversity as a technique for mitigating rain propagation impairment in order to rectify rain fade. Rain attenuation time series along earth-to-satellite link were measured for two years period at 12.255 GHz in Malaysia. The time diversity technique was applied on measured rain fade to investigate the level of possible improvement in system. Time diversity gain from measured one-minute rain attenuation for two years period was estimated and significant improvement was observed with different delays of time. These findings will be utilized as a useful tool for link designers to apply time diversity as a rain fade mitigation technique in Earth-satellite communications systems.</span></p>

scholarly journals Short-term prediction of rain attenuation level and volatility in Earth-to-Satellite links at EHF band

2008 ◽  
Vol 15 (4) ◽  
pp. 631-643 ◽  
Author(s):  
L. de Montera ◽  
C. Mallet ◽  
L. Barthès ◽  
P. Golé
Keyword(s):  
Time Series ◽  
Prediction Error ◽  
Nonlinear Models ◽  
Garch Model ◽  
Rain Attenuation ◽  
Frequency Scaling ◽  
Attenuation Level ◽  
Satellite Links ◽  
Short Term Prediction ◽  
The Cost

Abstract. This paper shows how nonlinear models originally developed in the finance field can be used to predict rain attenuation level and volatility in Earth-to-Satellite links operating at the Extremely High Frequencies band (EHF, 20–50 GHz). A common approach to solving this problem is to consider that the prediction error corresponds only to scintillations, whose variance is assumed to be constant. Nevertheless, this assumption does not seem to be realistic because of the heteroscedasticity of error time series: the variance of the prediction error is found to be time-varying and has to be modeled. Since rain attenuation time series behave similarly to certain stocks or foreign exchange rates, a switching ARIMA/GARCH model was implemented. The originality of this model is that not only the attenuation level, but also the error conditional distribution are predicted. It allows an accurate upper-bound of the future attenuation to be estimated in real time that minimizes the cost of Fade Mitigation Techniques (FMT) and therefore enables the communication system to reach a high percentage of availability. The performance of the switching ARIMA/GARCH model was estimated using a measurement database of the Olympus satellite 20/30 GHz beacons and this model is shown to outperform significantly other existing models. The model also includes frequency scaling from the downlink frequency to the uplink frequency. The attenuation effects (gases, clouds and rain) are first separated with a neural network and then scaled using specific scaling factors. As to the resulting uplink prediction error, the error contribution of the frequency scaling step is shown to be larger than that of the downlink prediction, indicating that further study should focus on improving the accuracy of the scaling factor.

scholarly journals Spectral characteristics of satellite links at ka band in the southern tropical region of India

2017 ◽  
Vol 7 (1.1) ◽  
pp. 631
Author(s):  
Sravya Velaga ◽  
Jagadeesh Korrapati ◽  
Chaithanya Krishna B ◽  
Vandana Matti ◽  
K Ch. Sri Kavya ◽  
...  
Keyword(s):  
High Frequency ◽  
Spectral Characteristics ◽  
Low Frequency ◽  
Radiowave Propagation ◽  
Tropical Region ◽  
Multimedia Services ◽  
System Availability ◽  
Ka Band ◽  
Frequency Bands ◽  
Satellite Links

The objective of this study was to perform a spectral analysis of the Ka band propagation channel. Now a day, because of the expanding interest of the end users for multimedia services which require vast bandwidth, and because of the immersion of low frequency bands, for example, L, S, C bands, and Ku band in close future, satellite media transmission systems are moving to higher frequency bands. In such high frequency bands, the presence of the atmosphere strongly affects radiowave propagation and attenuation effects become so severe that system availability would not be sufficient if systems were designed in a conventional way with a static propagation margin. 

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