Matthieu Crussiere

Performance of the DVB-T2 system in a Single Frequency Network: Analysis of the distributed alamouti scheme

The last wireless broadcast systems, like DVB-T2, have reached performances close to the Shannon limit and there remain few solutions to further increase them. One of these solutions is the use of Multiple Input Multiple Output (MIMO) techniques. In this article, we evaluate the performances of DVBT2 in a Single Frequency Network (SFN). DVB-T2 is the first broadcast standard which provides the possibility to use some Multiple Input Single Output (MISO) technique. Our study will focus on a system with two transmit antennas and one receive antenna with power imbalance between the two resulting links. We will compare the influence of this power imbalance in two configurations (MISO distributed Alamouti scheme and SISO SFN) and show the benefit brought by the use of a MISO technique in a Single Frequency Network.

GEN01-5: Adaptive Linear Precoded DMT as an Efficient Resource Allocation Scheme for Power-Line Communications

In this paper, we propose to apply adaptive loading principles to linear precoded digital multitone (LP-DMT). This new approach can especially be exploited in the powerline context, since it requires the knowledge of the channel at the transmitter. We first show that maximal waveform capacity is achieved when orthogonal matrices are used to linearly precode the multitone signal. A practical loading algorithm based on tone clustering is then developed to handle the configuration of the system. This algorithm assigns tones, size of preceding matrices, bits and energies in order to maximize the total throughput of the system. The optimization procedure is led under power spectral density (PSD) limitations and finite order modulations constraint. Through simulations over power line channels, it is shown that the new adaptive LP-DMT system takes advantage of the carrier merging effect offered by the precoding function and then outperforms the non-precoded DMT system.

SDRAN-based user association and resource allocation in Heterogeneous Wireless Networks

Integrating different types of wireless access technologies in heterogeneous networks provides flexible choices for users to handover to a more preferable network that satisfies their needs. In this paper, we discuss the recent 802.21.1 Software Defined Radio Access Network (SDRAN) architecture that couples the Software Defined Networking (SDN) mechanisms by the IEEE 802.21 Media Independent Handover Services. Based on this architecture, we propose a centralized handover algorithm that manages user association and downlink capacity resource allocation. The algorithm is formulated as a Generalized Assignment Problem (GAP) which maximizes the overall profit of mobile nodes which is studied in terms of power consumption and Received Signal Strength (RSS). Comprehensive simulation has been conducted; It is shown that the formulated algorithm reduces the overall consumed power and increases the average relative received signal strength while demanding an extra number of HOs.

Improved physical layer for energy-efficient M2M communications over cellular networks

The existing GSM networks are promising candidates to enable the machine-to-machine (M2M) communications due to their global deployment. However, these networks are initially designed for mobile telephony, and need to be renovated to adapt to the new M2M applications. In this paper, we address the perspective of upgrading the channel coding scheme of the GSM networks for the M2M communications. Concretely, we investigate two possible solutions, namely concatenated codes (convolutional and Reed-Solomon) and Turbo codes. It is shown that the Turbo coding scheme can simultaneously improve both the service coverage and the energy efficiency performance, and is therefore suitable for the future M2M applications. Finally, it is demonstrated that the enhanced channel coding scheme leads to the reduced energy consumption, or equivalently a longer battery life, in the typical M2M scenarios.

A low latency algorithm for efficient PAPR reduction for DVB-T2 and ATSC 3.0 broadcast

In this paper, the problem of peak-to-average power ratio (PAPR) reduction of orthogonal frequency division multiplexing (OFDM) signals is investigated in the context of second generation of digital video broadcasting for terrestrial transmission (DVB-T2) and the American digital video broadcasting standard ATSC3.0. As a multicarrier modulation technique is characterized by a high PAPR of the transmitted signal and OFDM is prone to non-linear (NL) effects of power amplifiers. DVB-T2 and ATSC3.0 have adopted a gradient-based tone reservation (TR) PAPR reduction technique which is based on an iterative process where, at each iteration, a predefined kernel is used to reduce one peak in time domain. Recently, a new TR PAPR reduction technique termed individual carrier allocation for multiple peaks (ICMP), based on a novel kernel definition has been proposed. However, it suffers from latency issues in ATSC3.0 and higher modes of DVB-T2. So, we propose another novel TR technique, grouped ICMP (GICMP). The simulation results show that GICMP offers better performance than the gradient-based DVB-T2 algorithm. Furthermore, it not only yields the same performance as ICMP but also has less latency.

Load-aware power efficiency maximization in heterogeneous wireless networks

This paper proposes a solution to maximize the power efficiency, i.e. datarate per power unit, in a heterogeneous wireless system that is based on integrated mobile base stations (BSs) and Wi-Fi access points (APs). In this context, a user association and downlink resource allocation optimization problem is formulated. The formulated problem considers the power consumption at both networks and mobile terminals (MTs), and the data rate requirement, i.e. load, of each MT. Since MTs could only be associated with a single network at a time, the formulated problem is binary with high complexity. Thus, a new sub-optimal solution with polynomial-time complexity is proposed based on the continuous relaxation of the problem. Simulation results show that the proposed sub-optimal solution, when compared to the trivial network selection methodology, remarkably reduces the power consumption of networks and MTs. Moreover, it is shown that the proposed solution performs close to the optimal one.

Modeling BP decoding error events with the LDPC codes of the DVB-S2 standard

In this paper, we focus on the behavior of the Belief Propagation (BP) algorithm when decoding the Low-Density Parity-Check (LDPC) code of rate 3/4 in the DVB-S2 standard. By studying the topological structure of its Tanner graph, we raise properties inherent to the degree distribution that turns out to be strongly correlated with the decoding failures. The irregularity of the degrees seriously damages the performance, visible by an abrupt error floor. We accordingly propose a novel model of the error events based on the degree distribution which helps simulate typical error events and observing the flaws of the DVB-S2 code. This work could be used as a good basis to design future codes with a better decoding behavior, especially in the error floor region.