The random access channel (RACH) is an uplink shared channel for initial channel access to the network as well as for short data bursts. In this paper, we propose modifications to the RACH preamble for satellite-UMTS using higher order of Hadamard codes, and it is shown that these enhancements have a better performance than that of the current Third Generation Partnership Project (3GPP) specifi...

Remote sensing of cloud and surface properties from different satellites requires consistent calibration of the instruments on each satellite. The unique spectral, spatial, and temporal resolutions of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on the new Meteosat Second Generation, Meteosat-8, give it the potential for providing unprecedented scientific data, especially when com...

The performance of a direct sequence spread-spectrum land-mobile satellite transmission system, using binary phase shift keying (BPSK) modulation, is analyzed. The satellite channel is modeled as having shadowed Rician fading characteristics. The bit error probability is evaluated, considering both the envelope and the phase variation. Assuming a Gaussian approximation for the interference, num...

In order to enhance the availability and the offered Quality of Service (QoS), Land Mobile Satellite Systems (LMSS) will have the option to use simultaneous transmission via two or more satellite as diversity. In this paper the performance of a TDMA and CDMA single user return link employing such a diversity reception is investigated by means of computer simulation using a three state mobile sa...

A high capacity communication satellite interconnects scores of ground stations simultaneously. Under the Satellite-Switched/ Time Division Multiple Access (SS/TDMA.) system, each channel of the satellite is allocated to a pair of ground stations for a certain time period, after which the whole set of allocations (called a switch) is changed simultaneously. The problem we address is to minimize...

The most widely known remote-sensing data are satellite images (typically LANDSAT or other visible imagery), which are used in the geosciences for a multitude of applications, including landuse, urbanization, sea-ice expansion, to name only a few. Commonly, these remote-sensing data are analyzed with the help of commercial software systems (eg. ENVI, ERDAS-IMAGINE). Analysis methods employ the ...

considering a) a) that a number of SCPC (Single Channel Per Carrier) carriers are transmitted via a single satellite transponder in satellite communication systems; b) that, for efficient use of satellite power, the transponder would be operated in the near saturation region, in which case intermodulation noise affects signal quality; c) that the intermodulation products falling into the freque...

Countermeasure for round trip delay which occurs in between satellite and ground with network accelerator is investigated together with operating system dependency on effectiveness of accelerator. Also disaster relief data transmission experiments are conducted for mitigation of disaster together with acceleration of disaster related data transmission between local government and disaster preve...

in this paper, we propose a unified and interactive mobile learning (M-Learning) model to help with expanding and spreading education in the Arab Homeland countries. The model utilizes a new competitive spot beam satellite communication technology, which enables efficient channel allocation, where communication channels can be allocated to specific and precise areas. The proposed model is refer...

The exploitation of fluctuating channel conditions in link adaption techniques for unicast transmission has been shown to provide large system capacity gains. However, the problem of choosing transmission rates for multicast transmission has not been thoroughly investigated. In this paper, we investigate multicast adaptive techniques for reliable data delivery in GEO satellite networks. An opti...