High-speed Satellite Communication System Research Articles

Model of operation of a high-speed satellite communication system for rational distribution of frequency-energy and time resources in the space and ground segment

Model of operation of a high-speed satellite communication system for rational distribution of frequency-energy and time resources in the space and ground segment

A Joint Implementation for Timing Synchronization and Matching Filtering Through the Frequency Domain

In order to reduce the computational complexity of the high-speed satellite communication system, the article proposes an architecture that combined the timing synchronization and the matching filtering without mixing. In the architecture, the filter module and the synchronization module are improved to ensure that the filter operation results could be used in the timing synchronization module. In other words, the architecture can complete signal filtering and synchronization processing through a Fast Fourier Transform. This method can not only reduces system complexity but also reduces the amount of computation. Theoretical analysis and simulation experiments show that the architecture has better estimation performance at low signal to noise ratio and high latency environment. At the same time, this architecture effectively reduces the amount of system calculations by reusing resources between modules. Compared with the Gardner algorithm, the scheme uses in this paper can reduce about 70% of the calculation, which is suitable for high-speed demodulation system.

Presentation, Design and Application of a New Parallel Frame Synchronization Scheme

To solve the problems of frame sync words gotten unstably and short frame synchronization state decision time, a new parallel frame synchronization scheme is presented. The proposed method improves the robustness and state decision performance of the frame synchronization system. The method is implemented and verified in a high-speed satellite communication system. Based on that practical application, a multi-channel parallel frame synchronization design method is given for even higher speed data communication systems.

622 Mbps High-speed satellite communication system for WINDS

WINDS is the experimental communications satellite currently under joint development by Japanese Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). The high-speed satellite communication system is very effective for quick deployment of high-speed networks economically. The WINDS will realize ultra high-speed networking and demonstrate operability of satellite communication systems in high-speed internet. NICT is now developing high-speed satellite communication system for WINDS. High-speed TDMA burst modem with high performance TPC error correction is underdevelopment. Up to the DAC on the transmitter and from the ADC on the receiver, all modem functions are performed in the digital processing technology. Burst modem has been designed for a user data rate up to 1244 Mbps. NICT is developing the digital terminal as a user interface and a network controller for this earth station. High compatibility with the Internet will be provided.

Proton irradiation effects on advanced digital and microwave III-V components

A wide range of advanced III-V components suitable for use in high-speed satellite communication systems were evaluated for displacement damage and single-event effects in high-energy, high-fluence proton environments. Transistors and integrated circuits (both digital and MMIC) were irradiated with protons at energies from 41 to 197 MeV and at fluences from 10/sup 10/ to 2/spl times/10/sup 14/ protons/cm/sup 2/. Large soft-error rates were measured for digital GaAs MESFET (3/spl times/10/sup -5/ errors/bit-day) and heterojunction bipolar circuits (10/sup -5/ errors/bit-day). No transient signals were detected from MMIC circuits. The largest degradation in transistor response caused by displacement damage was observed for 1.0-/spl mu/m depletion- and enhancement-mode MESFET transistors. Shorter gate length MESFET transistors and HEMT transistors exhibited less displacement-induced damage. These results show that memory-intensive GaAs digital circuits may result in significant system degradation due to single-event upset in natural and man-made space environments. However, displacement damage effects should not be a limiting factor for fluence levels up to 10/sup 14/ protons/cm/sup 2/ [equivalent to total doses in excess of 10 Mrad(GaAs)]. >

High rate concatenated coding systems using bandwidth efficient trellis inner codes

High-rate concatenated coding systems with bandwidth-efficient trellis inner codes and Reed-Solomon (RS) outer codes are investigated for application in high-speed satellite communication systems. Two concatenated coding schemes are proposed. In one the inner code is decoded with soft-decision Viterbi decoding, and the outer RS code performs error-correction-only decoding (decoding without side information). In the other the inner code is decoded with a modified Viterbi algorithm, which produces reliability information along with the decoded output. In this algorithm, path metrics are used to estimate the entire information sequence, whereas branch metrics are used to provide reliability information on the decoded sequence. This information is used to erase unreliable bits in the decoded output. An errors-and-erasures RS decoder is then used for the outer code. The two schemes have been proposed for high-speed data communication on NASA satellite channels. The rates considered are at least double those used in current NASA systems, and the results indicate that high system reliability can still be achieved.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The data station controller of the apollo system

AbstractThis paper describes a high speed satellite communication system called APOLLO, designed to allow the transmission of documents across Europe. Emphasis is put on the hardware and software for which Logica is responsible, and the message flow through the system. A review is given of the current position and future plans of the project.

High rate concatenated coding systems using multidimensional bandwidth-efficient trellis inner codes

A concatenated coding system using two-dimensional trellis-coded MPSK inner codes and Reed-Solomon outer codes for application in high-speed satellite communication systems was proposed previously by the authors (ibid., vol.37, no.5, p.420-7, May 1989). The authors extend their results to systems using symbol-oriented, multidimensional, trellis-coded MPSK inner codes. The concatenated coding systems are divided into two classes according to their achievable effective information rates. The first class uses multidimensional trellis-coded 8-PSK inner codes and achieves effective information rates around 1 b/dimension (spectral efficiency 2 b/s/Hz). The second class employs multidimensional trellis-coded 16-PSK inner codes and provides effective information rates around 1.5 b/dimension (spectral efficiency 3 b/s/Hz). Both classes provide significant coding gains over an uncoded reference system with the same effective information rate as the coded system. The results show that the symbol-oriented nature of multidimensional inner codes can provide an improvement of up to 1 dB in the overall performance of a concatenated coding system when these codes replace bit-oriented two-dimensional codes. >