28 research outputs found
A highly efficient receiver for satellite-based automatic identification system signal detection
An innovative receiver architecture for the satellite-based automatic identification system has been recently proposed. In this paper, we describe a few modifications that can be introduced on the algorithms for synchronization and detection, which provide an impressive performance improvement. The receiver architecture has been designed for an on-board implementation, and a prototype has been implemented by the University of Parma and CGS S.p.A. Compagnia Generale per lo Spazio under the European Space Agency project FENICE (Flexible innovative AIS receiver prototype). A few modifications are also here described that could allow a further performance improvement in case of processing moved to ground-based stations, based on a priori information there available
A highly efficient receiver for satellite-based Automatic Identification System signal detection
An innovative receiver architecture for the satellitebased Automatic Identification System (AIS) has been recently proposed. In this paper, we describe a few modifications that can be introduced on the algorithms for synchronization and detection, that provide an impressive performance improvement with respect to the previous system. The receiver architecture has been designed for an on-board implementation, and for this reason all algorithms have been realized keeping the complexity as low as possible. A prototype for the proposed receiver has been implemented by the University of Parma and CGS S.p.A. Compagnia Generale per 10 Spazio under the ESA project FENICE
Physical Layer Performance of Multi-User Detection in Broadband Multi-Beam Systems based on DVB-S2
vIn this paper we investigate the physical layer performance that can be obtained in a DVB-S2-based broadband system when high frequency reuse is applied and Multi-User Detection (MUD) is adopted at the receiver side to cope with the presence of interference. By calculating the Bit Error Rate (BER) which results from the application of MUD in various cases, the sensitivity of the algorithm to the signals' parameters is first assessed. Then, we show that by jointly detecting/decoding the useful signal and the interferers the peak data rate of the users affected by strong co-channel interference can be significantly increased
Exploiting orthogonality in DVB-S2X through time pre-compensation
The superframing option of the recent DVB-S2X standard specifies, for the so-called SF-Pilot fields, the use of the orthogonal set of Walsh-Hadamard (WH) sequences. In order
to exploit this orthogonality, waveforms coming from different beams to the k-th User Terminal (UT) should be quasi perfectly aligned in time. While in the downlink part of a terrestrial system
this is quite straightforward, in satellite system, having a satellite as a relay, this is not the case, especially when large baudrates are considered in the transmission. A procedure to compensate for timing misalignment amongst waveforms is here presented and the advantages are quantified through numerical simulations.In particular, Channel State Information (CSI) estimation errors, which are fundamental for precoding techniques, are evaluated. While the focus of the work is on systems which enable precoding techniques, the procedure can be applied in each scenario which uses the superframing structure of DVB-S2X in an interference
limited scenario
Precoding in multibeam satellite communications: present and future challenges
Whenever multibeam satellite systems target very aggressive frequency reuse in their coverage area, inter-beam interference becomes the major obstacle for increasing the overall system throughput. As a matter of fact, users located at the beam edges suffer from a very large interference for even a moderately aggressive planning of reuse-2. Although solutions for inter-beam interference management have been investigated at the satellite terminal, it turns out that the performance improvement does not justify the increased terminal complexity and cost. In this article, we pay attention to interference mitigation techniques that take place at the transmitter (i.e. the gateway). Based on this understanding, we provide our vision on advanced precoding techniques and user clustering methods for multibeam broadband fixed satellite communications. We also discuss practical challenges to deploy precoding schemes and the support introduced in the recently published DVB-S2X standard. Future challenges for novel configurations employing precoding are also provided
The application of modular coordination in building An assessment of user response
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