Prediction of the degradation of the carrier‐to‐noise plus interference ratio concerning a site diversity system suffering from differential rain attenuation

Abstract

[1] Rain-induced attenuation is a factor of utmost importance in designing a satellite link since it can strongly deteriorate the availability and performance of an Earth-space path. Availability and performance are key criteria for the reliable design process. In the present paper the statistics of carrier-to-noise plus interference ratio under rain fade conditions are examined, given that the interference is caused by an adjacent satellite operating at the same frequency, and taking also under consideration double site diversity protection as a countermeasure technique. The method presented herein is based on a model of convective rain cells and the lognormal assumption for the point rainfall statistics. Numerical results have been obtained for heavy rain climatic regions and very large availability times, to examine how effective site diversity can be, not only for lowering fade margins but for compensating severe interference effects. Moreover, the elaboration of the numerical results has revealed how the optimum design of the satellite link can be achieved by selecting proper values for some critical parameters of the system.INDEX TERMS: 6979 Radio Science: Space and satellite communication; 6964 Radio Science: Radio wave propagation; 6914 Radio Science: Electromagnetic noise and interference; 6904 Radio Science: Atmospheric propagation; KEYWORDS: rain attenuation, interference, site diversity Citation: Livieratos, S. N., and J. D. Kanellopoulos, Prediction of the degradation of the carrier-to-noise plus interference ratio concerning a site diversity system suffering from differential rain attenuation,

Causes of degradation of C/N and its mitigation in Satcom

“…More exactly, it is the paths through the rain that are uncorrelated and so the technique is more accurately described as path diversity. The earth stations are connected together so that any one earth station can be used to support the traffic stream while the other(s) is (are) suffering a rain fade [6]. k) Depolarization: Depolarization compensation is a technique whereby the feed system of the antenna is adjusted in such a way as to correct for depolarization in the path.…”

“…Stratiform rain consists of a generally constant rainfall rate over a very large area while convective rain is generally confined to a narrow, but tall, column of rain. The rain attenuation depends on frequency, rain fall rate, diameter and distribution of rain drops [6]. Attenuation (rain) = γ r × L where γ r is the specific rain attenuation in dB / Km and L is the effective path length.…”

Performance of the DBS Satellite Receiver under the Impact of Rainfall and Terrestrial Interference

“…The CNIR is a significant criterion contributing to the much appropriate precise estimation of the entire outage period of satellite link that suffers from interference lacking any condition concerning the thermal noise. This is an unavoidable condition specifically for systems operating within an interference environment as a dominant factor [21,22]. In [22], it is stated that the necessary CNIR is 4.7 dB for DBS to operate with satisfactory performance.…”

“…This is an unavoidable condition specifically for systems operating within an interference environment as a dominant factor [21,22]. In [22], it is stated that the necessary CNIR is 4.7 dB for DBS to operate with satisfactory performance. As a result of both the interference (I) from the FS and the receiver thermal noise power (N) of the DBS receiver, the CNIR (dB) can be estimated by equation (1) [23,24] as follows:…”