Showing papers on "DVB-S2 published in 2012"

DVB-S2 full cross-layer design for QoS provision

Abstract: The second generation of the Digital Video Broadcasting standard for Satellite transmission, DVB-S2, is the evolution of the highly successful DVB-S satellite distribution technology. DVB-S2 has benefited from the latest progress in channel coding and modulation such as Low Density Parity Check Codes and higher order constellations to achieve performance that approaches Shannon?s theoretical limit. We present a cross-layer design for Quality-of-Service (QoS) provision of interactive services, which is not specified in the standard. Our cross-layer approach exploits the satellite channel characteristics of space-time correlation via a cross-layer queueing architecture and an adaptive cross-layer scheduling policy. We show that our approach not only allows system load control but also rate adaptation to channel conditions and traffic demands on the coverage area. We also present the extension of our cross-layer design for mobile gateways focusing on the railway scenario. We illustrate the trade-off between system-wide and individual throughput by means of simulation, and that this trade-off could be a key metric in measuring the service level of DVB-S2 Broadband Service.

Initial-Estimation-Based Adaptive Carrier Recovery Scheme for DVB-S2 System

Abstract: A data-aided (DA) carrier recovery (CR) method, which can select different coarse frequency estimation (CFE) paths adaptively according to the initial-estimation of frequency offset, is proposed for the 2nd Generation Digital Video Broadcasting Satellite (DVB-S2) system to accomplish the convergence within at most 400 pilot blocks. The well-known two-step CR scheme is used for the consideration of precision and speed, whereas both the CFE and the fine frequency estimation (FFE) adopt L&R algorithm as their basic frequency estimator so that the same correlation operation can be used by both of them to decrease the realization complexity. Optimum threshold values for different CFE paths are determined by analyzing the ill-selection probability and robust Root Mean Square Error (RMSE) performance has been confirmed by our simulations.

LDPC Coded OFDM And It's Application To DVB-T2, DVB-S2 And IEEE 802.16e

Abstract: Since the invention of Information Theory by Shannon in 1948, coding theorists have been trying to come up with coding schemes that will achieve capacity dictated by Shannon’s Theorem. The most successful two coding schemes among many are the LDPCs and Turbo codes. In this thesis, we focus on LDPC codes and in particular their usage by the second generation terrestrial digital video broadcasting (DVB-T2), second generation satellite digital video broadcasting (DVB-S2) and IEEE 802.16e mobile WiMAX standards. Low Density Parity Check (LDPC) block codes were invented by Gallager in 1962 and they can achieve near Shannon limit performance on a wide variety of fading channels. LDPC codes are included in the DVB-T2 and DVB-S2 standards because of their excellent error-correcting capabilities. LDPC coding has also been adopted as an optional error correcting scheme in IEEE 802.16e mobile WiMAX. This thesis focuses on the bit error rate (BER) and PSNR performance analysis of DVB-T2, DVB-S2 and IEEE 802.16e transmission using LDPC coding under additive white Gaussian noise (AWGN) and Rayleigh Fading channel scenarios.

Configurable M -factor VLSI DVB-S2 LDPC decoder architecture with optimized memory tiling design

Abstract: Semi-parallel architectures for decoding Digital Video Broadcasting-Satellite 2 (DVB-S2) Low-Density Parity-Check (LDPC) codes have improved Very Large Scale Integration (VLSI) solutions, but their design is challenging from several perspectives. In order to conveniently exploit parallelism for obtaining VLSI LDPC decoders that occupy small circuit areas and demand low power consumption, we propose in this article a novel ASIC reconfigurable approach that exploits efficiently the memory block reshaping required to use a reduced number of processor nodes. We exploit different memory tiling configurations to reduce the memory area about 20%. The proposed architecture was synthesized for a 90 nm process design with a variable number of processor nodes and a competitive circuit area of 6.2 mm2 was achieved. The operating frequency simultaneously guarantees throughputs superior to 90 Mbps, as required by DVB-S2, and low levels of power consumption.

Investigation of LDPC code in DVB-S2

Abstract: As one of the most powerful error-correcting codes, Low-density parity check codes are widely used in digital communications. Because of the performance of LDPC codes are capable to close the shann ...

Adaptive Coding and Modulation‐enabled satellite triple play over DVB‐S2 (Digital Video Broadcasting ‐ Satellite ‐ Second Generation): a techno‐economic study

Abstract: SUMMARY This article looks at the techno-economic perspectives of the use of DVB-S2 (Digital Video Broadcasting - Satellite - Second Generation) and its unique feature, Adaptive Coding and Modulation (ACM) in the provision of satellite triple play. For this study, current market economic data were used, in conjunction with technical results derived within the European Union-funded IST IMOSAN project. IMOSAN (Integrated Multi-Layer Optimisation in DVB-S2 Satellite Networks) succeeded in realising the provision of satellite triple play over an interactive DVB-S2/DVB-RCS (Return Channel via Satellite) platform. The ACM feature of DVB-S2 was exploited, yielding increased spectrum efficiency and thus decreasing service cost. One-user-per-terminal scenarios are examined, as well as terrestrial redistribution of satellite services to a group of users via WiMAX. Copyright © 2012 John Wiley & Sons, Ltd.

Performance and improvement of the finite order compensation in a non-linear DVB-S2 communication channel

Abstract: High order modulations defined in the DVB-S2 standard are very sensitive to the non-linear interference induced by the power amplifier combined with the filters present in the channel. Several methods have been proposed to mitigate this interference. The finite order compensation, or order p compensation, is an analytical method to remove non-linear interference. However, it shows poor performance in case of high interference channel. We propose therefore a modification of the finite order compensation in order to minimize the mean square error between the initial input symbols and the received symbols.

GSSTP: a signalling transport protocol for DVB‐S2 GSE‐only transmission systems

Abstract: SUMMARY The current signalling framework for Digital Video Broadcasting systems is based on MPEG-2 encoded Program Specific Information and System Information tables that rely on the transport stream. It is expected that in the near future, this architecture will be replaced by one based on the Generic Stream Encapsulation protocol, paving the way for the convergence of DVB-S2 broadcast transmission networks and IP infrastructure. This paper presents a new lightweight Generic Stream Signalling Transport Protocol, which can be used to realise a transmission system based only on the Generic Stream Encapsulation and that efficiently supports filtering of Program Specific Information and System Information tables. Copyright © 2012 John Wiley & Sons, Ltd.

Frequency Estimation for Non-pilot Mode of DVB-S2 System

Abstract: In this paper, we present a frequency estimation method for non-pilot mode of digital video broadcasting-satellite second generation (DVB-S2) system, which is based on a Rife and Boorstyn (R&B) algorithm. The proposed approach consists of the coarse and fine frequency estimation, which is performed by using a physical layer header (PLHEADER) instead of pilot symbols. In addition, it is required a modulation and code rate (MODCOD) decoding to obtain the PLHEADER. Compared with the other frequency estimation methods, the proposed method is very powerful in terms of both the estimation range and frequency offset sensitivity. The effectiveness of the proposed method is verified by simulation results.

CCSDS Telemetry over DVB-S2: Characteristics, Receiver Implementation and Performances

Abstract: The CNES (French Space Agency) has recently proposed to apply the ETSI DVB-S2 telecom standard onto the CCSDS ones (currently "red book") to cope with the high data rate requirement of Telemetry for Earth Observation Satellites. A very high data rate implementation (up to 400 MBauds) of this recommended standard has been achieved by Zodiac Data Systems onto their Cortex HDR XXL receiver. This paper presents the latest version of that recommended standard as well as results obtained with the Cortex demodulator. A specific focus is done on the extremely low degradation performed at high rate, even with 32APSK modulation.

QoSatAr: a cross-layer architecture for E2E QoS provisioning over DVB-S2 broadband satellite systems

Abstract: This article presents QoSatAr, a cross-layer architecture developed to provide end-to-end quality of service (QoS) guarantees for Internet protocol (IP) traffic over the Digital Video Broadcasting-Second generation (DVB-S2) satellite systems. The architecture design is based on a cross-layer optimization between the physical layer and the network layer to provide QoS provisioning based on the bandwidth availability present in the DVB-S2 satellite channel. Our design is developed at the satellite-independent layers, being in compliance with the ETSI-BSM-QoS standards. The architecture is set up inside the gateway, it includes a Re-Queuing Mechanism (RQM) to enhance the goodput of the EF and AF traffic classes and an adaptive IP scheduler to guarantee the high-priority traffic classes taking into account the channel conditions affected by rain events. One of the most important aspect of the architecture design is that QoSatAr is able to guarantee the QoS requirements for specific traffic flows considering a single parameter: the bandwidth availability which is set at the physical layer (considering adaptive code and modulation adaptation) and sent to the network layer by means of a cross-layer optimization. The architecture has been evaluated using the NS-2 simulator. In this article, we present evaluation metrics, extensive simulations results and conclusions about the performance of the proposed QoSatAr when it is evaluated over a DVB-S2 satellite scenario. The key results show that the implementation of this architecture enables to keep control of the satellite system load while guaranteeing the QoS levels for the high-priority traffic classes even when bandwidth variations due to rain events are experienced. Moreover, using the RQM mechanism the user’s quality of experience is improved while keeping lower delay and jitter values for the high-priority traffic classes. In particular, the AF goodput is enhanced around 33% over the drop tail scheme (on average).

Low complexity encoding and decoding research of DVB-S2 LDPC

Abstract: In view of the structure characteristics of storage of low density parity check codes(LDPC)which are used in the second generation satellite digital video broadcasting standard(DVB-S2),the encoding was finished using the improved codeword construction method,and then the check matrix was deduced using the similar method,the data overflow problem in the simulation process was overcomeThrough comparing different decoding algorithms of LDPC,the reduced complexity Minimum-Sum decoding algorithm was used and the performance of different code rates of LDPC was simulated in softwareFrom the hardware implementation of decoder point of view,fixed-point representation instead of floating-point was proposed,and the effect of the number of iterations and the quantization on the input data and inner variables of decoder on the performance was investigatedSimulation analysis showed that this study reduced the complexity of the decoder hardware implementation with small performance penalty in storage and run time and so on,hence leading to lower delay and power consumption in the whole radio receiverIt provides a theoretical basis for hardware implementation

Compensating the high power amplifier nonlinearity for a DVB-S2 system

Abstract: This paper deals with the compensation of High Power Amplifier induced nonlinear Inter-Symbol Interference (NISI) in a DVB-S2 receiver. The Volterra Canceller is an optimal technique if NISI is perfectly estimated. To reach this ideal case, a linearization of the received signal can be done before memory effects appears. In this work, this is achieved using a Laguerre polynomial linearizer. Computer simulations show that the combination of techniques reduces the average number of LDPC iterations thanks to an SNR improvement of 0.16 dB compare to a simple Volterra Canceller, without significant added complexity.

LDPC coding proposal for pulsed-OFDM modulation for WPAN systems using UWB communication in indoor propagation channels

Abstract: In this paper, we describe a combined approach where low density parity check (LDPC) codes are used to reduce the complexity and power consumption of pulsed orthogonal frequency-division multiplexing (pulsed-OFDM) ultra-wideband (UWB) systems The proposed system will use LDPC codes to achieve higher code rates without using convolution encoding and puncturing thereby reducing the complexity and power consumption of pulsed-OFDM system The LDPC-pulsed-OFDM system will achieve channel capacity with different code rates and will have good performance in different channel fading scenarios The proposals from pulsed OFDM system is used where pulsed signals could spread the frequency spectrum of the OFDM signal The performance of LDPC-pulsed-OFDM system for wireless personal area networks (WPAN) is analysed for different UWB indoor propagation channels (CM3 and CM4) provided by the IEEE 802153a Standard activity committee To establish this, we present a design of LDPC-pulsed-OFDM system using the digital video broadcasting-satellite-second generation (DVB-S2) standard and provide the simulation results for the different code rates supported by LDPC codes

Design and Implementation of DVB-S2 LDPC Encoder

Abstract: In this paper, a DVB-S2 LDPC encoder based on FPGA is proposed after detailed analysis of DVB-S2 LDPC code on the basis of irregular repeat accumulate (IRA) coding algorithm. This method not only uses pipeline technique combined with all parallel structures to improve the coding efficiency, but also makes use of VHDL language to achieve DVB-S2 encoder, which meets the requirements of DVB-S2 standard on the condition of low hardware resources.

Subset Optimization of ACM Schemes Based on DVB-S2 Standard

Abstract: A rain fading mitigation technique, called Adaptive Coding and Modulation (ACM), is supported by the DVB-S2 standard. But the number of Coding and Modulation Schemes is over dimensioned. It is shown that by a careful selection of the ACM schemes, with one fourth of the total number of schemes, it is possible to get performance close to the optimum, but with a much lower terminal complexity.

New Spread Spectrum Technique based on DVB-S2 Waveform

Abstract: Nomenclature ACM = Adaptive Coding and Modulation ACSM = Adaptive Coding Spreading and Modulation AGC = Automatic Gain Control AFC = Automatic Frequency Control DS = Direct Sequence DVB-S2 = Digital Video Broadcasting-Satellite(Second Generation) DVB-RCS = Digital Video Broadcasting-Return Channel System via Satellite EIRP = Effective Isotropic Radiated Power HPA = High Power Amplifier IBO = Input BackOff LDPC = Low Density Parity Check MODCOD = MODulation and CODe rate PLFrame = Physical Layer Frame PLheader = Physical Layer Header PLS = Physical Layer Signalling PSK = Phase Shift Keying SF = Spreading Factor SOF = Start OF Frame SNR = Signal to Noise Ratio STR = Symbol Timing Recovery VCM = Variable Coding and Modulation VSAT = Very Small Aperture Terminal

Nonlinear Equalization and Carrier Recovery for DVB-S2 Using Multilevel Pilots

Abstract: the use of constant energy level pilots for receiver synchronization and equalization algorithms. However, these are unsuitable for APSK modulations due to the nonlinear response of the satellite power amplier. In this paper, we investigate the performance of a low-complexity cluster based sequence equalizer (CBSE) for non-linear compensation in DVB-S2 systems based on multilevel pilots. We also propose how multilevel pilots can be used for carrier frequency and phase recovery. Simulation results are presented in terms of total degradation wherein the CBSE technique is shown to achieve a signicant improvement over the conventional approach.

The Design of Low Complexity Decoder Based on DVB-S2 LDPC

Abstract: An improved codeword construction method was used to encode the BCH code and LDPC code in this paper according to the latest standard defined by digital video broadcasting standard(DVB), and moreover the data overflow problem was solved. The LDPC code was decoded by the reduced complexity Min-Sum decoding algorithm, in which the coefficient was studied. Fixed-point representation and decoder quantization were proposed and simulation results show that 6-bits and 16-bits uniform quantization can make close to the performance of unquantized decoder, which reduces the decoder complexity for hardware implementation.

Carrier recovery and nonlinear compensation for DVB-S2 using multilevel pilots

Abstract: The current DVB-S2 standard specifies the use of constant energy level pilots for receiver synchronization and equalization algorithms. However, these are unsuitable for APSK modulations due to the nonlinear response of the satellite power amplifier. In this paper, we investigate the performance of two low-complexity techniques for nonlinear compensation in DVB-S2 systems, i.e. static predistortion and cluster based sequence equalizer (CBSE). We also propose how multilevel pilot structures, matched to each technique, can be used for carrier recovery. Simulation results are presented in terms of total degradation wherein both techniques are shown to achieve a significant improvement over the conventional system.