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Massive MIMO systems are known to be a very promising solution for future 5G systems. The attractiveness of using such a system for millimeter Wave (mmWave) transmissions comes partly from the reduced size of a many antenna base station. Furthermore, the beamforming gains that they allow is highly suited to combat the high path losses experienced at such wavelengths. Unfortunately the complexity to...
Multiple algorithms have been proposed to deal with the high Peak to Average Power Ratio (PAPR) of Orthogonal Frequency Division Multiplexing (OFDM) signals. The second generation of Digital Video Broadcasting for Terrestrial transmission (DVB-T2) has adopted the Tone Reservation (TR) technique. It is based on an iterative process where, at each iteration, a predefined kernel is used to reduce one...
The DVB-S2 standard has been revealed a reliable standard for data transmission thanks to the LDPC codes. The waterfall of the bit-error rate is very abrupt to reach low values of order 10^(-10) in the error floor. In this paper, we propose a novel investigation on the iterative decoding of these codes by the Belief Propagation algorithm on Gaussian channels. Introducing definitions of persistent...
Orthogonal Frequency Division Multiplexing (OFDM) systems are characterized by a high Peak to Average Power Ratio (PAPR), which results in performance degradation due to High Power Amplifiers' nonlinearities. Multiple algorithms have been proposed to deal with this problem, among them the Tone Reservation (TR) technique adopted in the second generation of Digital Video Broadcasting for Terrestrial...
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...
In the last few years, mobile broadband communications operators have been confronted to an exponential growth of the traffic over their networks. Recently, the use of a broadcast component as a solution to face this growth has received a particular attention. In [1], a model for a hybrid network is introduced. This network consists in the inter-operation of a LTE unicast component and a DVB-T2 broadcast...
A novel distributed space-time block code (STBC) for the next generation mobile TV broadcasting is proposed. The new code provides efficient performance within a wide range of power imbalance showing strong adaptivity to the single frequency network broadcasting deployments. The new code outperforms existing STBCs with equivalent decoding complexity and approaches those with much higher complexities.
In this paper, we investigate the use of a channel shortening filter (CSF) for multiband orthogonal frequency division multiplexing ultra wideband (MB-OFDM UWB) communication systems. Indoor wideband channels are known as rich scattering environments resulting in potentially large delay spread. When the delay spread exceeds the guard interval length, intersymbol interference (ISI) and intercarrier...
In this paper, we investigate the resource management and scheduling issues for the future UWB-based high-rate WPAN systems. Based on a distributed management architecture, we propose a novel multiple access scheme in the context of multiuser channel and time allocation for the UWB applications. Using a self-learning and managing approach, the distributed resource allocation is based on the exchange...
In contrast to the classical cyclic prefix (CP)-OFDM, the time domain synchronous (TDS)-OFDM employs a known pseudo noise (PN) sequence as guard interval (GI). Conventional channel estimation methods for TDS-OFDM are only based on the PN sequence and consequently suffer from intersymbol interference. This paper proposes a novel two-stage channel estimation method which combines the estimation results...
The classical channel estimation method in TDS-OFDM is carried out based on the PN sequence in the GI which suffers from the intersymbol interference of the previous OFDM data symbols. This paper presents a novel data-aided channel estimation method to refine the initial channel estimation obtained from PN sequence. The data symbols are rebuilt based on the log-likelihood ratio (LLR) from the output...
The Physical layer (PHY) of both IEEE 802.11p (Wireless Access in Vehicular Environments - WAVE) and European standard for Intelligent Transportation Systems (ITS) operating at 5.9 GHz are derived from the well-known IEEE 802.11a standard. While the performance of the 802.11a PHY layer was intensively evaluated in indoor, almost static environments, the performance of the derived 802.11p PHY layer...
In this paper, we propose a novel and efficient joint carrier and sampling frequency offset estimation algorithm based on 2D spread pilots for digital video broadcasting (DVB) systems. The first advantage of the proposed algorithm is the use of the same pilot symbols for both channel estimation and synchronization. A gain in term of spectral efficiency is obtained compared to the DVB-T/H system for...
In this paper, we investigate a new multiuser cross-layer approach for the resource allocation in the high rate ultra-wideband (UWB) systems. This cross-layer scheme is based on an optimization problem defined for the multiuser resource allocation. The new approach consists in combining information provided by the PHY and MAC layers in order to achieve an efficient and low-complexity sub-band allocation...
This paper considers the dynamic resource allocation in a multiuser context taking into account the quality of service (QoS) requirements for the high-rate ultra-wideband (UWB) systems. The aim of this paper is twofold. First, we exploit the effective SINR method in the multi-band WiMedia solution proposed for UWB systems. This method is based on the exploitation of the characteristics of multiple...
In this paper, we propose a novel and simple MIMO channel estimation technique based on 2D spread pilots. Taking advantage of the simplicity and flexibility of 2D spread pilot channel estimation, we easily combine the Alamouti code with the Walsh-Hadamard codes to obtain a space code block code (SCBC) MIMO scheme. We demonstrate that our proposed system is much more efficient in high mobility scenario...
Orthogonal frequency-division multiplexing (OFDM) is the most popular transmission technology in digital terrestrial broadcasting (DTTB), adopted by many DTTB standards. In this paper, the bit error rate (BER) performance of two DTTB systems, namely cyclic prefix OFDM (CP-OFDM) based DVB-T and time domain synchronous OFDM (TDS-OFDM) based DTMB, is evaluated in different channel conditions. Spectrum...
In this paper, we investigate a cross-layer design for the packet scheduling and the resource allocation in UWB systems. This design considers the combination of queuing and channel state information (CSI) which provides QoS support for multimedia applications in UWB. For the physical layer, the use of a linear precoded orthogonal division multiplexing (LP-OFDM) waveform is proposed because of its...
Bit error rate (BER) prediction over channel realisations has emerged as an active research area. In this paper, we give analytical signal to interference and noise ratio (SINR) evaluation of MIMO-OFDM systems using an iterative receiver. Using this analytical SINR expression, we propose an accurate BER prediction method based on effective exponential SINR mapping (EESM) method. We show by simulations...
This article introduces a 3D space-time-space block code for future terrestrial digital TV in single frequency networks. The proposed 3D code is based on a double layer structure designed for inter-cell and intra-cell space time coded transmissions. We show that this new structure is particularly efficient for SFN environments regardless of the location of the receiver. It is then suitable for fixed,...
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