scholarly journals Evaluation of Time Diversity Technique for Satellite Mitigation in Tropical Climate

Author(s):  
Mawarni Mohd Yunus ◽  
Nurazriana Samin ◽  
Jafri Din ◽  
Siat Ling Jong
Author(s):  
Islam Md. Rafiqul ◽  
Ali Kadhim Lwas ◽  
Mohamed Hadi Habaebi ◽  
Md Moktarul Alam ◽  
Jalel Chebil ◽  
...  

<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>


2013 ◽  
Vol 1 (4) ◽  
pp. 268-273 ◽  
Author(s):  
Nurul Wahida M Saad@Md Saad ◽  
Ahmad Fadzil Ismail ◽  
Khairayu Badron ◽  
Nuurul Hudaa Mohd Sobli ◽  
Jafri Din ◽  
...  

Inventions ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 46
Author(s):  
Maan A. Yahya ◽  
Omar Ibrahim Alsaif ◽  
Ibrahim Ahmed Saleh ◽  
Ahmed M. Abdulkhaleq ◽  
Naser Ojaroudi Parchin ◽  
...  

A new proposed method is presented, where multiple antennas have been applied into HIPERLAN/2 system in addition to employing space-time diversity technique, especially the Alamouti technique. The suggested approach is used to cancel or reduce the effect of the transmitted power using a feedback signal process within the transceiver unit, especially when the antennas are closely located and working in full-mode duplexing. Several parameters including the transmitted power, the received power, and the feedback accuracy have been considered for testing the performance of the system in term of the signal to noise ratio (SNR) versus bit error rate (BER). A software programme using MATLAB and Simulink is implemented to evaluate the proposed method. The results showed that the system performance is heavily dependent on the amount of the mismatch in the feedback, the received power, and the transmitted power. The performance of the system decreases as the feedback accuracy increases when the transmitted power and the received power are constant. At the same time, the performance of the system decreases as the transmitted power increases when the received power and the mismatch are constant. Finally, the increase in the received power enhances the system performance when the other parameters are constant.


2015 ◽  
Vol 1 (5) ◽  
pp. 235-242
Author(s):  
Édio Damásio da Silva Júnior ◽  
Rogério de Araújo Almeida ◽  
Elisa Rodrigues Siqueira ◽  
Ábio Roduvalho da Silva

2010 ◽  
Vol 32 (4) ◽  
pp. 794-798
Author(s):  
De-sheng Wang ◽  
Hong-zi Lin ◽  
Guang-xi Zhu

Author(s):  
Ricardo Ortiz Ortega ◽  
Alonso Vilches Flores ◽  
Marco Aurelio Rodríguez Monroy ◽  
Patricia Bonilla Lemus

Studies accomplished in freshwater demonstrate the importance of identify the presence of<br />protozoa like free living amoebae (FLA). In particular, the genera Acanthamoeba is associated with<br />severe infections in man, as the Granulomatous Amebic Encephalitis (GAE). The most important<br />factor for the development of these organisms is the high temperature of the water body. The<br />region of the Huasteca Potosina in Mexico, with a tropical climate and great aquatic resorts, like<br />rivers, waterfalls and pools of thermal waters, that allows the development of amoebae. In this<br />study we evaluated the presence of amoebas in the most visited places on the Huasteca Potosina.<br />Samples of a liter were taken in nine sites during the rainy and dry season. 54 strains of amoebas<br />were identify, 46 belong to the genera Acanthamoeba, resulting 30 of them pathogenic in the<br />animal tests. The pathogenic isolated amoebas were present in the most attended resorts by the<br />people in the waterfalls or pools of the places sampling. Temperature turned out to be the most<br />important factor for the presence of amoebae.


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