Site diversity gain at the equator: radar‐derived results modeling in Singapore

Abstract

SUMMARYSite diversity is an effective rain attenuation mitigation technique, especially in the tropical region where high rainfall rates are common. According to our previous study, site diversity gain is found to be dependent on the site separation distance and path elevation angle while it is independent of signal frequency, baseline angle and polarization angle. Therefore, using 28 months of radar data, a simple site diversity gain prediction model is proposed. The proposed model is compared with the existing ITU-R models. The seasonal wind direction, another factor that might affect the site diversity gain prediction model, is shown to have negligible effect on site diversity gain. Triple-site diversity is also investigated, and although it is found to provide gain improvement over dual-site diversity, this gain improvement is too little to justify for the cost of setting up an additional site. This study is useful for the implementation of site diversity as a rain attenuation mitigation technique in the tropical region.

A Comprehensive Review of the Site Diversity Technique in Tropical Region: Evaluation of Prediction Models Using Site Diversity Gain of Greece and India

“…Nonetheless, they clarified the statement later that the wind direction was dependable and limited to the Singapore terrain. The rapid wind movement that brings rain from one place to another could cause the attenuation experienced at an SDS separated by a short distance to resemble each other [36]. The observation of wind movement by Yeo et al appeared to be similar to the conclusion drawn by Pan, Allnutt, and Tsui, but the geographic terrain of a locality differentiates the formation of rain types.…”

Observation of Site Diversity Gain Dependency on Separation Distance Using an Attenuation-Dependent Logarithmic Model in a Tropical Region

“…The reference site was the Nanyang Technological University, Singapore (NTUS), and the diverse site was located approximately southeast of the NTUS (SE). The radar dataset used in this study was collected at the Changi Weather Station and consisted of the whole year of 2003 and 16 months from May 2010 to August 2011 [19]. The SD scheme at Sri Gading, Johor, Malaysia (SGJ), where radar was placed, used a virtual diverse site 8 km away but within the coverage of the radar [29].…”

“…Furthermore, X. Yeo's model was designed with a minimal distance of 5 km from one square grid to another. The details can be referred to in the author's article [19]. Fig.…”

“…Semire et al compared the proposed model with the Hodge, Nagaraja, and Panagopoulos models using tropical data and reported that the proposed model suited the measured data. The model of Yeo et al [19] was developed based on the results of their study in which the frequency and baseline orientation angle did not affect the value [20]. The proposed model was based on 2025 slant path attenuation measurements from 45 sites in Singapore districts.…”

Time diversity evaluation for attenuation mitigation method using attenuation data in Thailand and Japan

“…As a result, numerous researchers in tropical areas have proposed various methods of handling rain attenuation difficulties in their countries. Basic methods, such as site diversity , are well known and widely used but are often difficult to adopt in many cases due to high installation costs. On the other hand, up‐and‐coming technologies such as the adaptive satellite power control method are now being researched but have not yet been deployed because of the numerous technical problem faced, such as phase array antennas, and it remains uncertain whether they will be effective in countering rain attenuation.…”