Stefan Lipp

Adaptive coding and modulation for satellite broadband networks: From theory to practice

This paper presents the detailed design and the key system performance results of a comprehensive laboratory demonstrator for a broadband Ka-band multi-beam satellite system exploiting the new DVB-S2 standard with adaptive coding and modulation (ACM). This complete demonstrator allows in-depth verification and optimization of the ACM techniques applied to large satellite broadband networks, as well as complementing and confirming the more theoretical or simulation-based findings published so far. It is demonstrated that few ACM configurations (in terms of modulation and coding) are able to efficiently cope with a typical Ka-band multi-beam satellite system with negligible capacity loss. It is also demonstrated that the exploitation of ACM thresholds with hysteresis represents the most reliable way to adapt the physical layer configuration to the spatial and time variability of the channel conditions while avoiding too many physical layer configuration changes. Simple ACM adaptation techniques, readily implementable over large-scale networks, are shown to perform very well, fulfilling the target packet-error rate requirements even in the presence of deep fading conditions. The impact of carrier phase noise and satellite nonlinearity has also been measured. Copyright

Performance Validation of the DVB-SH Standard for Satellite/Terrestrial Hybrid Mobile Broadcasting Networks

The recently introduced Digital Video Broadcasting Satellite to Handheld standard (DVB-SH) allows for digital broadcasting service provision to small mobile terminals in satellite/terrestrial hybrid networks. In this paper, the key results from an in-depth DVB-SH performance assessment campaign lasting two years are reported. The performance results reported encompass simulation, laboratory and field trials key findings and allow deriving recommendations for preferred system parameters and configurations.

Mobile satellite reception with DVB‐SH receiver architecture and performance

SUMMARY Within the Digital Video Broadcasting (DVB) family of standards, DVB-SH (satellite to handheld devices) is the first standard for a hybrid system offering parallel reception of satellite and terrestrial signals. In this paper, we discuss the architecture and implementation of a full-featured DVB-SH receiver. In addition, a laboratory test bed including a DVB-SH signal generator that can be used for DVB-SH system validation and receiver characterization is presented. We provide some key results of receiver performance measurements in typical channel conditions. Finally, we highlight the advantage of a multi-frequency network configuration in case of a hybrid reception scenario. Copyright

In-service SNR estimation without symbol timing recovery for QPSK data transmission systems

In this paper we consider the problem of estimating the signal-to-noise ratio (SNR) of the received signal in a QPSK data transmission system. This estimation must be done in-service (non-data aided), without carrier phase knowledge and without symbol timing phase knowledge. New algorithms with these features are derived from the ratio of two moments. The performance of these algorithms is studied by means of simulations, and it is shown that they are robust against carrier and symbol timing frequency offsets as well. This makes them suitable for a wide range of applications.

On Distributed Resource Allocation in Fully Meshed Satellite Networks

− The national German research project Mobile Satellite communication in Ka-band (MoSaKa) addresses the growing interest in advanced heterogeneous satellite communication in Ka-band frequencies. In the framework of the project, a satellite communication system has been defined and developed which implements fully meshed connectivity among all stationary and mobile terminals and is dedicated to security, crisis, and rescue applications. In this paper we describe the adaptive and flexible resource allocation mechanism of MoSaKa which is distributed among the physical layer, data link layer and network layer.