Simplified Metrics Calculation for Soft Bit Detection in DVB-T2

The constellation rotation and cyclic quadrature component delay (RQD) technique has been adopted in the second generation terrestrial digital video broadcasting (DVB-T2) standard. It improves the system performance under severe propagation conditions, but introduces serious complexity problems in the hardware implementation of the detection process. In this paper, we present a simplified scheme that greatly reduces the complexity of the demapper by simplifying the soft bit metrics computation having a negligible overall system performance loss

A shuffled iterative bit-interleaved coded modulation receiver for the DVB-T2 standard: Design, implementation and FPGA prototyping

International audienceRotated QAM constellations improve Bit-Interleaved Coded Modulation (BICM) performance over fading channels. Indeed, an increased diversity is obtained by coupling a constellation rotation with interleaving between the real and imaginary components of transmitted symbols either in time or frequency domain. Iterative processing at the receiver side can provide additional improvement in performance. In this paper, an efficient shuffled iterative receiver is investigated for the second generation of the terrestrial digital video broadcasting standard DVB-T2. Scheduling an efficient message passing algorithm with low latency between the demapper and the LDPC decoder represents the main contribution. The design and the FPGA prototyping of the resultant shuffled iterative BICM receiver are then described. Architecture complexity and measured performance validate the potential of iterative receiver as a practical and competitive solution for the DVB-T2 standard

Max-log demapper architecture design for DVB-T2 rotated QAM constellations

International audience— Rotated and cyclic-Q delayed (RCQD) quadrature amplitude modulation (QAM) improve DVB-T2 system performance over highly time-frequency selective channels. However, when compared with conventional QAM demapper, the RCQD demapper requires a higher computational complexity. In this paper, a complexity-reduced max-log demapper is derived and implemented over a FPGA platform. The proposed demapper allows to find the maximum likelihood (ML) point with a search spanning only M signal constellation points and guarantees to obtain the same log-likelihood ratio (LLR) metrics as the optimum max-log soft decision demapper while spanning at most 2 M signal constellation points. The optimized hardware implementation introduces only a slight performance loss compared to the floating-point full complexity max-log performance. Index Terms — DVB-T2, Rotated and Cyclic Q Delayed (RCQD) Constellations, Log-Likelihood Ratio (LLR), Max-Log Demapper

A low-complexity 2D signal space diversity solution for future broadcasting systems

-DVB-T2 was the first industrial standard deploying rotated and cyclic Q delayed (RCQD)modulation to improve performance over fading channels. This enablesimportantgains compared toconventional quadrature amplitude modulations(QAM) under severe channel conditions.However, the corresponding demodulation complexitystill prevents its use forwider applications. This paper proposes several rotation angles for different QAM constellations anda corresponding low-complexity detection method. Results show that the proposed solution simplifies both the transmitter and the receiver with often betterperformancethan the proposed angles in DVB-T2. Compared with the lowest complexity demappers currently used in DVB-T2, the proposed solution achieves an additional reduction bymore than 60%. Index Terms- DVB-T2, Rotated and Cyclic Q Delayed (RCQD) Modulations, Signal Space Diversity (SSD), Fading Channel, Quadrature Amplitude Modulations (QAM), Max-Log, ComputationalComplexity

Unified Satellite and Terrestrial ACM Design

First step towards integrating satellite and terrestrial standards at the physical layer is to design a unified packet frame structure, and in particular, a unified adaptive coding and modulation (ACM) scheme without substantial loss in either of the systems. In this paper we introduce a methodology to design such a set of modulation and coding (MODCOD) combinations. In the first step, we design a set of base MODCODs for the AWGN channel. Then, for any other given channel model, we build a new set of MODCODs through a suitable transformation of the base MODCODs. We mainly focus on two types of channels: (a) non-linear satellite channels, and (b) AWGN channels with fading. We compare our results with latest digital video broadcasting standards, namely, DVB-T2 and DVB-S2X

Tantangan Teknis Implementasi DVB-T2 di Indonesia

Transisi dari penyiaran analog ke digital yang menjanjikan banyak kesempatan baru telah memotivasi Organisasi Telekomunikasi Internasional (International Telecommunication Union atau ITU) untuk memberikan dorongan yang besar kepada Negara-negara di dunia untuk segera mewujudkannya. Sebagian besar Negara-negara di dunia juga sudah menyadari begitu pentingnya transisi tersebut. Akan tetapi, banyak tantangan yang membuat proses transisi berlangsung relatif lambat, termasuk di Indonesia. Penelitian ini memilih Swedia dan Inggris yang sudah terlebih dulu melakukan transisi total ke penyiaran digital untuk menggali tantangan-tantangan teknis dan USAha yang dilakukan untuk menghadapi tantangan tersebut. Penelitian ini menganalisa status transisi Indonesia saat ini dan menghasilkan rekomendasi- rekomendasi

Tantangan Teknis Implementasi DVB-T2 di Indonesia

Transisi dari penyiaran analog ke digital yang menjanjikan banyak kesempatan baru telah memotivasi Organisasi Telekomunikasi Internasional (International Telecommunication Union atau ITU) untuk memberikan dorongan yang besar kepada Negara-negara di dunia untuk segera mewujudkannya. Sebagian besar Negara-negara di dunia juga sudah menyadari begitu pentingnya transisi tersebut. Akan tetapi, banyak tantangan yang membuat proses transisi berlangsung relatif lambat, termasuk di Indonesia. Penelitian ini memilih Swedia dan Inggris yang sudah terlebih dulu melakukan transisi total ke penyiaran digital untuk menggali tantangan-tantangan teknis dan usaha yang dilakukan untuk menghadapi tantangan tersebut. Penelitian  ini  menganalisa status transisi Indonesia saat ini dan menghasilkan rekomendasi- rekomendasi

Design of rotated QAM mapper/demapper for the DVB-T2 standard

International audienceSignal space diversity (SSD) has been lately adopted into the second generation of the terrestrial digital video broadcasting standard DVB-T2. While spectrally efficient, SSD improves the performance of QAM constellations over fading channels thanks to an increased diversity. In this paper, flexible mapper and demapper architectures for DVB-T2 standard are detailed. A detection based on the decomposition of the constellation into two-dimensional sub-regions in signal space associated to an algorithmic simplification constitute the main novelty of this work. They enable to strongly decrease the complexity of the demapper. The design and the FPGA prototyping of the resultant architecture are then described. Low architecture complexity and measured performance demonstrate the efficiency of the detection method

Design of rotated QAM mapper/demapper for the DVB-T2 standard

International audienceSignal space diversity (SSD) has been lately adopted into the second generation of the terrestrial digital video broadcasting standard DVB-T2. While spectrally efficient, SSD improves the performance of QAM constellations over fading channels thanks to an increased diversity. In this paper, flexible mapper and demapper architectures for DVB-T2 standard are detailed. A detection based on the decomposition of the constellation into two-dimensional sub-regions in signal space associated to an algorithmic simplification constitute the main novelty of this work. They enable to strongly decrease the complexity of the demapper. The design and the FPGA prototyping of the resultant architecture are then described. Low architecture complexity and measured performance demonstrate the efficiency of the detection method

Advanced constellation and demapper schemes for next generation digital terrestrial television broadcasting systems

206 p.Esta tesis presenta un nuevo tipo de constelaciones llamadas no uniformes. Estos esquemas presentan una eficacia de hasta 1,8 dB superior a las utilizadas en los últimos sistemas de comunicaciones de televisión digital terrestre y son extrapolables a cualquier otro sistema de comunicaciones (satélite, móvil, cable¿). Además, este trabajo contribuye al diseño de constelaciones con una nueva metodología que reduce el tiempo de optimización de días/horas (metodologías actuales) a horas/minutos con la misma eficiencia. Todas las constelaciones diseñadas se testean bajo una plataforma creada en esta tesis que simula el estándar de radiodifusión terrestre más avanzado hasta la fecha (ATSC 3.0) bajo condiciones reales de funcionamiento.Por otro lado, para disminuir la latencia de decodificación de estas constelaciones esta tesis propone dos técnicas de detección/demapeo. Una es para constelaciones no uniformes de dos dimensiones la cual disminuye hasta en un 99,7% la complejidad del demapeo sin empeorar el funcionamiento del sistema. La segunda técnica de detección se centra en las constelaciones no uniformes de una dimensión y presenta hasta un 87,5% de reducción de la complejidad del receptor sin pérdidas en el rendimiento.Por último, este trabajo expone un completo estado del arte sobre tipos de constelaciones, modelos de sistema, y diseño/demapeo de constelaciones. Este estudio es el primero realizado en este campo