Analysis and modeling of the cloud impairments of satellite-to-land mobile channel at Ku and Ka bands Ali M. Al-Saegh, A. Sali, Alyani Ismail Department of Computer and Communication Systems Engineering Universiti Putra Malaysia (UPM) Serdang, Selangor, Malaysia ali.alsaegh84@gmail.com, {aduwati, alyani}@upm.edu.my J. S. Mandeep Department of Electrical, Electronic and Systems Engineering Universiti Kebangsaan Malaysia (UKM) Bangi, Selangor, Malaysia mandeep@eng.ukm.my Abstract—Cloud impairments have significant effect on signal propagated in the satellite to land stationary terminals channel at frequencies above 10 GHz. With the recent satellite to land mobile terminals network technologies and services that use these frequencies, there is a lack of channel impairments modeling and analysis for such type of link. This study presents a reliable channel model of satellite-to-land mobile terminals that consider dynamic cloudy weather impairments. The cloud’s dynamic parameters and their effect on the Rician factor are modeled. The model involves modules that design multipath signals, direct clear line-of-sight (LOS) normalized signals, and cloud impairments. Results show that a considerable change occurs in the performance of the signal propagated through the cloud. The change appears as deviations in the fade depth and the variance of the propagated signal in the link between the satellite and the land mobile terminals. The channel model is a realistic approach to the link characteristics, which satellite systems designers should consider when designing high data rate satellite systems. Keywords—Channel modeling; satellite communications; cloud impairiment; satellite-to-land mobile link; Ku and Ka bands. I. INTRODUCTION Recent developments in satellite-to-land mobile (SLM) communication applications have increased the demand for increasingly high data rate and high transmission frequency that meets user requirements. As a result, impairments occur and exert a serious effect on the received signal level, such as the clouds, at transmission frequencies above 10 GHz [1, 2]. The liquid water content of the cloud absorbs and scatters signal electromagnetic (EM) energy and causes the signal wave energy that penetrates through the cloud to deteriorate to a value that depends on several parameters [3, 4]. These parameters include total columnar content of liquid water in Kg/m 2 (liquid water content, LWC), temperature, elevation angle, and transmission frequency. Clouds can be classified into several types [5, 6]. The characteristics of clouds in tropical regions are different from those of clouds in temperate regions. Clouds in tropical regions are generally thicker and cover more space than clouds in temperate regions, and they lead to higher cloud attenuation in the former than in the latter [7]. Clouds in wet equatorial regions cover 70% of the space for most of the year [6]. Statistical SLM channel modeling with a time-series synthesizer was initially introduced for the L and S bands [8]. However, SLM channel modeling at the Ku and Ka bands has been the focus of much interest recently [9-12]. The receivers at these frequency bands require a high-gain directional antenna [9] to overcome significant impairments, particularly mobility and atmospheric impairments. Several studies have been conducted to design accurate SLM channel models [8, 9, 13-15]. The accuracy of the designs has increased notably over time because of the addition of several features which approximate real-world scenarios with the development of other recent SLM technologies and applications. However, the effects of cloud on mobile scenarios have not been taken into consideration yet in the previous works. Consequently, not considering the cloud effect may cause serious problems related to the accuracy of the model, particularly during cloudy weather. This context is what frames and motivates this study, which presents a model design and analysis of such scenario and considers dynamic atmospheric and transmission parameters. To the best of the authors’ knowledge, this study is the first investigation conducted on the impairments caused by clouds on SLM terminal channels. This paper is organized as follows. The characteristics of cloudy channels for mobile terminals are presented in Section II. An analysis of the proposed channel model and signal performance is introduced in Section III. Section IV presents a discussion of the results, particularly of the generated fading effect caused by dynamic cloudy weather, and an analysis of cloud impairments. The conclusion is given Section V. II. CHANNEL CHARACTERISTICS SLM channel models can be classified into two types: single-state model and multi-state model [16]. This typology involves designing the signal level distribution over time for a specific propagation environment. Clear line-of-sight (LOS), shadowing, and blockage are the typical examples of the mobility state environment. The SLM channel is typically characterized by the Rice factor (K) [9], which is the ratio of the carrier to normalized average multipath power. The work is supported by the Ministry of Higher Education in Malaysia through project grant code ERGS/1-2012/5527096. 2014 7th Advanced Satellite Multimedia Systems Conference and the 13th Signal Processing for Space Communications Workshop (ASMS/SPSC) 978-1-4799-5893-1/14/$31.00 ©2014 IEEE 436