Improvement of QoS of Land Mobile Satellite Systems Using Diversity Techniques (original) (raw)
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IEEE Journal on Selected Areas in Communications, 2001
The paper addresses the exploitation of satellite diversity in a satellite mobile network. In particular, we focus on the impact of diversity on service availability and on system capacity, considering the forward link of a CDMA system with a multisatellite and multibeam architecture. The analysis includes the effects of path blockage, intrabeam and interbeam interference, imperfect power control, and fading correlation in the time domain due to nonideal interleaving. A closed-form solution is given for the estimation of system capacity. We show that satellite diversity is essential in providing service availability in urban and suburban areas, while the impact of satellite diversity on system capacity may be positive or negative, mainly depending on the fading channel characteristics. In particular, diversity becomes more and more beneficial for increasing fading time-domain correlation (i.e., for low mobile speed and/or limited interleaving depth). The analytical results have been validated by means of Monte Carlo simulation.
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This paper addresses the applicability of single-input multiple-output (SIMO) technology to land mobile satellite (LMS) communications and proposes a fully parameterized statistical model, which can be used to accurately characterize SIMO-LMS channels. Specifically, it focuses on the careful consolidation of currently available experimental results for "conventional" SISO-LMS and terrestrial MIMO channels, and on their novel extrapolation to the SIMO-LMS case of interest for the accurate statistical modeling of L/S-band correlated, both spatially and temporarily, SIMO-LMS channels. Moreover, based on the proposed channel model, the channel capacity statistics as well as the error performance of a SIMO-LMS diversity system, assuming both maximal ratio combining (MRC) and selection combining (SC), are evaluated through detailed computer simulations. Useful numerical results on the capacity and diversity gains achieved are also provided taking into account several critical operational system parameters.
Capacity Improvement for a Land Mobile Single Satellite MIMO System
IEEE Antennas and Wireless Propagation Letters, 2006
This letter investigates a land mobile single satellite multiple-input-multiple-output (MIMO) system, polarization-time coded for capacity gain and provides complementary cumulative distribution function capacity predictions using experimental data. Capacity results obtained for a single satellite, single antenna terminal [single-input-single-output (SISO)], and a dual polarized single satellite, dual polarized antenna terminal (2 2 MIMO) system are compared, showing the benefit of satellite-MIMO. Index Terms-Land mobile satellite (LMS), multiple-input-multiple-output (MIMO) capacity, propagation.
IEEE Communications Letters, 2000
To mitigate the main impairments due to the mobile satellite channel, satellite systems adopting code-division multiple access (CDMA) can exploit diversity. Each signal can flow through more than one paths, increasing link availability or improving signal-to-noise ratio (SNR). This letter presents a general mobile satellite channel model for an arbitrary diversity order assuming that all the links are statistically independent. A diversity availability improvement upper bound is calculated.
Performance of SC-FDMA with diversity techniques over land mobile satellite channel
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La demanda de la alta velocidad de datos resulta en una importante interferencia entre simbolos para los sistemas monoportadora en canales de ancho de banda y potencia limitada. Superar la selectividad en el tiempo y la frecuencia del canal de propagacion requiere el uso de potentes tecnicas de procesamiento de senales. Ejemplos recientes incluyen el uso de multiples antenas en el transmisor / receptor, en la tecnica conocida como Multiple-Input Multiple-Output (MIMO). En ciertos entornos (tales como el enlace ascendente de un enlace movil) por lo general solo una antena esta disponible en la transmision. Por lo tanto, solo esquemas con entrada individual y salida unica (Single Input Single Output, SISO) o transmisiones con entrada unica y multiples salidas (Single Input Multiple Output, SIMO) son factibles. La multiplexacion por division ortogonal en frecuencia (Orthogonal Frequency-Division Multiplexing, OFDM) es una tecnica de modulacion ampliamente utilizada por su robustez fren...