International Journal of Satellite Communications 

About: International Journal of Satellite Communications is an academic journal. The journal publishes majorly in the area(s): Communications satellite & Time division multiple access. It has an ISSN identifier of 0737-2884. Over the lifetime, 600 publications have been published receiving 5011 citations.

Implementation and performance of a turbo/MAP decoder

Abstract: The implementation and performance of a turbo/MAP decoder are described. A serial block MAP decoder operating in the logarithm domain is used to obtain a very-high-performance turbo decoder. Programmable gate arrays and EPROMs allow the decoder to be programmed for almost any code from four to 512 states, rate 1/3 to rate 1/7 (higher rates are achieved with puncturing) and interleaver block sizes to 65,536 bits. Seven decoding stages were implemented in parallel. For rate 1/3 and 1/7 16-state codes with an interleaver size of 65,536 bits and operating at up to 356 kbit/s the codec achieved an Eb/N0 of 0⋅32 and −0⋅30 dB respectively for a BER of 10−5. BERs down to 10−7 were also achieved for a small increase in Eb/N0. An efficient implementation of a continuous MAP decoder is also presented, along with a synchronization technique for turbo decoders. © 1998 John Wiley & Sons, Ltd.

Ip routing issues in satellite constellation networks

Abstract: This paper examines strategies for implementing and operating IP routing effectively within satellite constellation networks, given known constraints on the constellation resulting from satellite mobility, global visibility, routing and addressing.

Modelling of the rainfall rate cumulative distribution for the design of satellite and terrestrial communication systems

Abstract: The design of line of sight (L.O.S.) or satellite links requires annual point rainfall rate statistics for several percentages of time in the locations where the radiocommunication links are planned. Rain rate data within an average year, indeed, allow the estimation of the time percentage during which attenuation due to rain is significant, and consequently the future link margin. To meet ITU Radiocommunication Sector's Recommendations, we propose a probability law model allowing the prediction of the rainfall rate cumulative distribution in temperate and tropical climates. This model, which can be easily used, may serve as a very useful and accurate enough tool for radiocommunication engineers and scientists.

Low earth orbit satellite systems for communications

Abstract: It may be that we are now entering the era of LEO constellation satellite communications after thirty years of domination by the GEO systems. This paper heralds the coming of the new era with a tutorial approach to the system design and trade-offs of LEO constellation system design. It discusses orbital configurations, network topologies and routeing considerations, multiple access schemes and link performance design. In so doing it brings out the major design parameters and how they interact with each other. Also considered are the service applications for the LEO constellation systems, and the important difference between real-time and delayed communication systems is highlighted. Examples of single and multi-beam (cellular) coverage system link designs are presented for L-Ka frequency bands. Future papers will consider aspects of the LEO spacecraft and launchers.

Space Internet architectures and technologies for NASA enterprises

Abstract: NASA's future space communication needs and requirements will be addressed through a space communications network that mirrors the terrestrial Internet in its capabilities and flexibility. NASA's needs and requirements for future data gathering and distribution by this Space Internet have been obtained from NASA's Earth Science Enterprise (ESE), the Human Exploration and Development in Space (HEDS), and the Space Science Enterprise (SSE). To address NASA's future needs, we propose and describe an integrated communications infrastructure based on Internet technologies, the architectures within the infrastructure, and the elements that make up the architectures. The architectures meet the requirements of the enterprises beyond 2010 with Internet compatible technologies and functionality. The elements of an architecture include the backbone, access, inter-spacecraft, and proximity communication parts. From the architectures, technologies have been identified which have the most impact and are critical for the implementation of the architectures. Published in 2002 by John Wiley & Sons, Ltd.