Samir Saoudi

Samir Saoudi
Institut Mines-Télécom | telecom-sudparis.eu · Département Signal et Communications

Professor

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138
Publications
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773
Citations

Publications

Publications (138)
Conference Paper
In a cost-effective implementation, we address the problem of cross-interference in cognitive multiple-input multiple-output (MIMO) spectrum sharing where mutual co-channel interference (CCI) between the primary and secondary systems is of major concern. First, we propose an optimal transmit-antenna selection (TAS) strategy that instead maximizes t...
Article
The standard Monte Carlo estimations of rare events probabilities suffer from too much computational time. To make estimations faster, kernel-based estimators proved to be more efficient for binary systems whilst appearing to be more suitable in situations where the probability density function of the samples is unknown. We propose a kernel-based B...
Article
Full-text available
In this paper, we thoroughly elaborate on the impact different transmit-antenna selection (TAS) strategies induce in terms of the outage performance of incremental cognitive multiple-input multiple-output (MIMO) relaying systems employing receive maximum-ratio combining (MRC). Our setup consists of three multi-antenna secondary nodes: a transmitter...
Conference Paper
Full-text available
Higher order quadrature amplitude modulation (HOQAM) is one of the keytechnologies usedin advanced mobile communication systems to achieve high data rates. However, in such systems, performance evaluation can be very complicated and time consuming due to the increase of constellation size. As a solution, a QAM scheme is seen as a combination of two...
Article
Full-text available
In this letter, we present an end-to-end performance analysis of dual-hop project-and-forward relaying in a realistic scenario, where the source-relay and the relay-destination links are experiencing MIMO-pinhole and Rayleigh channel conditions, respectively. We derive the probability density function of both the relay post-processing and the end-t...
Preprint
In this letter, we present an end-to-end performance analysis of dual-hop project-and-forward relaying in a realistic scenario, where the source-relay and the relay-destination links are experiencing MIMO-pinhole and Rayleigh channel conditions, respectively. We derive the probability density function of both the relay post-processing and the end-t...
Conference Paper
This paper addresses the problem of the Monte Carlo method complexity reduction regarding bit error probability (BEP) estimation. A kernel-based BEP estimator is designed for coded M-ary quadrature amplitude modulation (QAM) transmissions schemes. The design of the kernel estimator is made in a context where the soft observations are spread along a...
Conference Paper
In this paper, we carry out an exact outage analysis for a secondary (unlicensed) system operating under a strict primary (licensed) system outage constraint. We focus on single-user single-input multiple-output (SIMO) secondary communications where the direct link is being assisted by a cluster of single-antenna decode-and-forward (DF) relay nodes...
Conference Paper
Full-text available
In this article, scheduling method of in-band Device-to-Device (D2D) communication underlaying cellular networks is studied. We address a single cell scenario in which several UEs have buffered data for local UEs in the same cell, and they are considered as potential D2D pairs. We propose an interference coordinated scheme, in which eNB selects D2D...
Conference Paper
In this paper, we investigate practical turbo receiver design for throughput-efficient relay ARQ transmissions over broadband cooperative MIMO channels. Our setup is comprised of three multi-antenna nodes: a source, a destination, and a relay node operating under the amplify-and-forward half-duplex relaying mode. To attain higher system average thr...
Article
Multiuser systems can benefit from multiuser diversity by assigning channels to users with better channel conditions at different time instants. In this paper, we present an opportunistic random-access scheme for orthogonal frequency-division multiple-access-based indoor power-line communication systems, based on time- and frequency-varying channel...
Conference Paper
This paper addresses the problem of unsupervised soft bit error rate (BER) estimation for any communications system, where no prior knowledge either about transmitted information bits, or the transceiver scheme is available. We show that the problem of BER estimation is equivalent to estimating the conditional probability density functions (pdf)s o...
Conference Paper
In a spectrum sharing underlay context, we investigate the exact derivation of the outage probability for relay-aided cognitive radio communications. To give more degrees of freedom to the secondary system in acquiring a targeted quality-of-service (QoS) under the primary system interference constraint, the secondary link is assisted by a set of re...
Article
Full-text available
This paper focuses on turbo packet combining for multirelay systems operating over multiple-input-multiple-output (MIMO) broadband channels. We consider a relaying protocol that represents a generalization of the classical point-to-point hybrid automatic repeat request (ARQ). In this protocol, relays play the role of packet retransmitters instead o...
Conference Paper
Full-text available
Transmit power control (TPC) is used in high speed uplink packet access (HSUPA) to compensate for the near far effect which degrades the system performance. However, the use of power control in joint application with turbo coding, and hybrid automatic repeat request (Hybrid-ARQ) is very prohibitive and time consuming. In this paper, we propose a si...
Conference Paper
In this article ad-hoc communications underlying cellular networks is studied. Two branches of usage cases, which lead to two modes of operation, are analyzed. We propose a coordinated in-band scheme where the ad-hoc communication uses the same licensed band operating the cellular networks and is under the control of cellular network operators. We...
Conference Paper
This paper addresses the problem of unsupervised Bit Error Rate (BER) estimation for communication systems where no prior information about transmitted bits is available at the receiver. We introduce a new technique using kernel probability density function (pdf) estimation together with Maximum Likelihood-based smoothing parameter computation. Per...
Article
Full-text available
Transmit power control (TPC) is used in high speed uplink packet access (HSUPA) to compensate for the near far effect which degrades system performance. However, its use in joint application with turbo coding, and hybrid automatic repeat request (Hybrid-ARQ) is very prohibitive and time consuming. In this article, we propose a simplified simulation...
Article
This paper focuses on turbo packet combining for hybrid AF/DF multi-relay systems operating over multiple-input–multiple-output (MIMO) broadband channels. We con-sider virtual antenna based combining strategy that has been widely studied for the point-to-point hybrid ARQ. However, the extension of this combining strategy to hybrid AF/DF cooperative...
Article
Full-text available
Thème – Communication et codage : Systèmes de communications. Problème traité – Pour estimer les performances d'un système de communications numériques en terme de probabilité d'erreur, on utilise le plus souvent la méthode de Monté Carlo. Malheureusement, le temps de simulation peut devenir assez rapidement un obstacle pour estimer des faibles pro...
Conference Paper
Full-text available
This paper addresses the problem of unsupervised soft BER estimation for digital communications systems, where no prior knowledge about transmitted information bits is available. We show that the problem of BER estimation is equivalent to estimating the conditional probability density functions (pdf)s of soft channel/receiver outputs. We also propo...
Conference Paper
Full-text available
Multichannel systems can benefit from multiuser diversity by assigning channels to users with best channel con- ditions in different time instants. In this paper, a two-dimension opportunistic scheme for OFDMA-based in-home PLC systems with random access is presented in order to exploit multiuser diversity over different subchannels and across diff...
Conference Paper
In this contribution, we present a new class of project-and-forward (PF) relays operating with broadband MIMO hybrid ARQ-aided cooperative systems. Their architecture enables to jointly perform the orthogonal projection over multiple ARQ transmissions, increasing thereby the relay diversity order and achieving an interesting power gain over amplify...
Article
We consider a random scheduling problem for OFDMA-based indoor PLC systems with time- and frequency- varying channel conditions in a multiuser context. In multichan- nel systems, opportunistic scheduling can exploit multiuser diver- sity in both time and frequency domains to improve the system performance. On the other hand, designing a scheduling...
Conference Paper
In this paper, we consider two turbo packet combining schemes for cyclic prefix (CP)-CDMA MIMO with Chase-type ARQ: i) In the first scheme, namely “chip-level turbo packet combining”, minimum-mean-square-error frequency domain equalization (MMSE FDE) and packet combining are jointly performed at the chip-level. ii) In the second scheme, namely “sym...
Article
This paper proposes a signal-level turbo packet combining strategy for multi-antenna multi-rate relay-assisted systems operating over broadband channel.We derive a fixed rate equivalent multi-antenna system communication model where the multi-rate multi-node received signals can be viewed as direct retransmissions from a virtual node with a fixed t...
Conference Paper
This paper investigates throughput-efficient relay ARQ protocols for single carrier MIMO systems with amplify-and-forward relaying. We focus on reducing the multiplexing loss due to the half-duplex operation at the relay. We introduce two new relaying protocols where both ARQ and relaying are jointly targeted. Compared to the conventional relaying...
Article
Full-text available
This paper deals with the presentation of different multiuser detectors in the Universal Mobile Telecommunications System (UMTS) context. The challenge is always to optimize the compromise between performance and complexity. Compared with the solution commonly used today, the rake detector, successive interference cancellation (SIC) detector has be...
Article
Full-text available
We have suggested in a previous publication a method to estimate the Bit Error Rate (BER) of a digital communications system instead of using the famous Monte Carlo (MC) simulation. This method was based on the estimation of the probability density function (pdf) of soft observed samples. The kernel method was used for the pdf estimation. In this p...
Conference Paper
Full-text available
This paper focuses on packet combining for multi-relay systems operating over multiple-input-multiple-output (MIMO) broadband channel. The work presented in this paper is valid for both amplify-and-forward (AF) and decode-and-forward (DF) relaying schemes. First, we drive a communication model in such a way that the destination can see the received...
Article
Full-text available
Performance of communications systems receivers is generally estimated by the bit error rate (BER) which is computed using the Monte Carlo (MC) simulation (Bit Error Counting). In a previous paper, an alternative new method based on an estimation in an iterative and nonparametric way, of the probability density function (pdf) of the soft decision o...
Conference Paper
Full-text available
This paper focuses on turbo packet combining techniques for multi-relay-assisted systems operating over multiple-input multiple-output (MIMO) broadband channel. Two packet combining techniques are studied, signal-level packet combining and soft information-based combining. In this paper, a comparative study, in term of implementation cost and perfo...
Conference Paper
Full-text available
In this paper, we propose a new interference canceller (SIC-HARQ) for the WCDMA enhanced uplink system which is the combination of the hybrid ARQ technique (HARQ) with an improved successive interference canceller (SIC). The proposed SIC detector is an iterative receiver which consists of a multiple stages. It is capable of eliminating multiple use...
Conference Paper
This paper investigates Orthogonal Frequency Division Multiplexing (OFDM) resource allocation schemes in a multiuser home Power Line Communication (PLC) network. The proposed cross-layer maximum weighted throughput scheme consists of two phases: subcarrier allocation at the Physical (PHY) layer and scheduling scheme at the Medium Access Control (MA...
Conference Paper
Full-text available
In this paper, we evaluate by computer simulation the performance of the WCDMA enhanced uplink system with cooperative chip-level hybrid ARQ (HARQ) Chase combining technique over a multi-path Raleigh channels. The fixed relaying protocol used is the amplify-and-forward (AF). At each HARQ retransmission, one relay amplifies and forwards it received...
Conference Paper
Full-text available
This paper focuses on turbo packet combining strategies for multi-relay-assisted systems operating over multiple-input-multiple-output (MIMO) broadband channel. We propose a frequency domain minimum mean square error (MMSE)-based turbo packet combining scheme where all slots received signals and their corresponding channel frequency responses (CFR)...
Conference Paper
This paper investigates resource allocation and scheduling schemes based on utility theory in a multiuser OFDM home power line communication (PLC) network since utility can evaluate network performance in terms of the level of users' satisfaction from network resource provision. The proposed cross-layer scheme consists of two phases: subcarrier all...
Article
The reduction of far-end crosstalk in coordinated digital subscriber line (DSL) systems has been proposed to increase their performance. Joint tone-line selection (JTLS) partial crosstalk cancellation helps reduce drastically the online computational complexity of the transmission. Several algorithms were considered but did not take into account th...
Chapter
Full-text available
In this chapter, we considered the design of efficient iterative turbo packet combining algorithms for broadband MIMO systems with Chase-type ARQ. We derived the structure of the optimal MAP turbo packet combining technique that exploits all the diversities available in the MIMO-ISI ARQ channel to perform packet combining, and analyzed its outage p...
Article
This paper addresses the issue of efficient turbo packet combining techniques for coded transmission with a Chase-type automatic repeat request (ARQ) protocol operating over a multiple-input multiple-output (MIMO) channel with intersymbol interference (ISI). First of all, we investigate the outage probability and the outage-based power loss of the...
Conference Paper
Full-text available
In this paper, we provide a survey of cooperative automatic repeat request (ARQ) protocols for multi-relay systems operating over multiple-input-multiple-output (MIMO) broadband channels. We study three main operating modes: amplify-and-forward (AF), decode-and-forward (DF), and positive/negative acknowledgment (ACK/NACK)-aided DF. We describe effi...
Conference Paper
Full-text available
We address the issue of efficient iterative (turbo) packet combining for broadband space-time coded transmission with hybrid-automatic repeat request (ARQ) over co-channel interference (CCI)-limited multiple-input-multiple-output (MIMO) channel. We introduce a new frequency domain turbo combining scheme where multiple transmissions are combined at...
Article
High Speed Downlink Packet Access (HSDPA) aims to provide peak data rates up to 10.8 Mbps in downlink. This goal is reached by introduction of sophisticated technologies such as adaptative modulation and coding (AMC), Hybrid Automatic Request (HARQ), fast scheduling, and transmit diversity with multiple transmit antennas and receive antennas (MIMO)...
Article
This paper addresses the problem of unsupervised soft bit error rate (BER) estimation for any communications system, where no prior knowledge either about transmitted information bits, or the transceiver scheme is available. We show that the problem of BER estimation is equivalent to estimating the conditional probability density functions (pdf)s o...
Conference Paper
In this paper, we address the problem of the presence of spatial correlated noise in upstream coordinated DSL systems. The performance of a minimum mean-squared-error (MMSE) iterative receiver structure without whitening the noise is evaluated. A simplified MMSE receiver based on the approximation of matrix inversion in the iterative process is pre...
Conference Paper
Full-text available
High Speed Uplink Packet Access (HSUPA) is designed to increase the uplink data rate. To reach this goal, a new uplink transport channel, called enhanced dedicated channel (E-DCH), is introduced to the UMTS physical layer. This channel is used in a multicodes transmission principle with very low spreading factors. Furthermore, it supports Hybrid Au...
Conference Paper
ABSTRACT We propose a single carrier joint frequency domain,equal- ization and interference cancellation (FDE-IC) with diver- sity combining for dierent,relaying schemes. We consider amplify-and-forward (AF) and ACK/NACK-aided decode- and-forward (DF) modes over multiple-input multiple-output (MIMO) frequency selective relay channels. During the,rs...
Conference Paper
Full-text available
Hybrid automatic repeat request (HARQ) is one of the main technologies used in HSUPA system to increase the uplink data throughput. Chase combining (CC) and incremental redundancy (IR) are the most known HARQ algorithms. The first provides a time diversity, while the second offers a coding gain. In this paper, we propose a method to increase the ch...
Preprint
This paper addresses the issue of efficient turbo packet combining techniques for coded transmission with a Chase-type automatic repeat request (ARQ) protocol operating over a multiple-input--multiple-output (MIMO) channel with intersymbol interference (ISI). First of all, we investigate the outage probability and the outage-based power loss of the...
Article
Full-text available
Résumé Dans cet article, nous proposons des nouveaux récepteurs pour le système HSUPA (High Speed Uplink Packet Access). L'architecture de ces récepteurs est basée sur la combinaison de l'égaliseur au niveau chip LMMSE (Linear Minimum Mean Squared Error) et de la technique HARQ (Hybrid Automatic Repeat reQuest) avec la méthode de combinaison de Cha...
Article
Full-text available
In this paper, we consider high-speed wireless packet access using code division multiple access (CDMA) and multiple-input multiple-output (MIMO). Current wireless standards, such as high speed packet access (HSPA), have adopted multi-code transmission and hybrid-automatic repeat request (ARQ) as major technologies for delivering high data rates. T...
Article
In this paper, efficient turbo packet combining for single carrier (SC) broadband multiple-input--multiple-output (MIMO) hybrid--automatic repeat request (ARQ) transmission with unknown co-channel interference (CCI) is studied. We propose a new frequency domain soft minimum mean square error (MMSE)-based signal level combining technique where recei...
Conference Paper
The power control and the Hybrid Automatic Repeat Request (HARQ) are important techniques in Wideband Code Division Multiple Access (WCDMA) systems. The joint use of these two mechanisms can enable wireless systems to increase throughput and spectral efficiency. In this paper, we will evaluate the performance of the SIR-based power control in a WCD...
Article
Full-text available
Hybrid automatic repeat request (HARQ) is used in high-speed uplink packet access (HSUPA) to increase the data rate. Chase combining is the simplest of HARQ algorithms. It provides a time diversity and requires a small memory. In this paper, we propose a technique to increase the chase combining efficiency. In this method, HARQ transmissions are se...
Article
Full-text available
In general, performance of communication system receivers cannot be calculated analytically. The bit error rate (BER) is thus computed using the Monte Carlo (MC) simulation (Bit Error Counting). It is shown that if we wish to have reliable results with good precision, the total number of transmitted data must be conversely proportional to the produ...
Article
Full-text available
As a part of the EU-FP7 R&D programme, the OMEGA project (hOME Gigabit Access) aims at bridging the gap between wireless terminals and wired backbone network in homes, providing high bit rate connectivity to users. Beside radio frequencies, the wireless links will use Optical Wireless (OW) communications. To guarantee high performance and quality o...
Conference Paper
Full-text available
This work focuses on signal-level packet combining techniques for coded transmission over co-channel interference (CCI)-limited multiple input multiple output (MIMO) channels with intersymbol interference (ISI). A turbo packet combining algorithm that jointly equalizes multiple transmissions using the concept of virtual antennas is proposed. Block...
Conference Paper
This paper presents a comparative investigation of different channel estimation methods for pilot based coherent RAKE combining in DS-CDMA transmission systems. The channel estimation algorithms are based on interpolation of the channel statistics from pilot symbols. The methods for channel estimation are analyzed and compared in terms of BER perfo...
Article
This paper addresses the issue of iterative space-time equalization for multiple-input-multiple-output (MIMO) frequency-selective fading channels. A new soft equalization concept based on successive interference cancellation (SIC) is introduced for a space-time bit-interleaved coded modulation (STBICM) transmission. The proposed equalizer allows us...
Conference Paper
In this paper, a very low complexity packet combining approach for single user multi-code CDMA transmission over a broadband multiple input multiple output (MIMO) channel is presented. This new approach involves a simple modification to the traditional packet combining algorithms by introducing new variables recursively computed. This modification...
Conference Paper
Full-text available
In this paper, we introduce two packet combining schemes with low complexity minimum mean square error (MMSE) turbo equalization for single user multi-code CDMA transmission over a broadband multiple input multiple output (MIMO) channel. The first scheme considers each transmission as an additional set of virtual receive antennas and combines multi...
Article
Full-text available
The plug-in method enables optimization of the bandwidth of the kernel density estimator in order to estimate probability density functions (pdfs). Here, a faster procedure than that of the common plug-in method is proposed. The mean integrated square error (MISE) depends directly upon J(f) which is linked to the second-order derivative of the pdf....
Conference Paper
Full-text available
This paper extends the geometrical one-ring multi- input multi output (MIMO) channel model for a frequency flat fading process in a land mobile radio system with respect to frequency-selectivity. Our approach enables the design of efficient simulation models for space-time MIMO channels under isotropic scattering conditions for any numbers of trans...
Conference Paper
In this paper a novel channel estimation scheme is proposed for a RAKE receiver operating in a time varying multi-path channel. The approach is an extension of the well known linear interpolation channel estimator, which is based on interpolating the channel estimates from pilot symbol sequence. In this paper parallel pilot-symbol aided channel est...
Article
This article presents a novel iterative technique for joint detection and decoding of direct sequence-code division multiple access (DS-CDMA) systems. A turbo-CDMA successive interference cancellation structure is proposed with complexity in O(K), where K is the number of users. The structure can be implemented easily and converges rapidly to the s...
Conference Paper
Full-text available
This paper focuses on the problem of efficient packet combining techniques for coded systems with hybrid automatic repeat request (ARQ) protocols operating over the frequency selective fading multiple input multiple output (MIMO) channel. We introduce a receiver scheme where space-time soft equalization is integrated into the packet combiner. This...
Article
Full-text available
We investigate the scenario of an upstream coordinated DSL transmission in presence of spatial-correlated noise. Joint signal processing helps mitigate this noise and reduce internal interference effects between coordinated users. We propose to couple noise whitening with a mean-squared error iterative receiver in order to approach the matched filt...
Conference Paper
Crosstalk is the major source of performance limitation in the current short range DSL systems. Coordination between users in the downstream and in the upstream directions has been recently proposed in order to overcome the effects of FEXT in DSL transmissions. In this paper, we study a new low complexity precompensation solution for FEXT reduction...
Conference Paper
Full-text available
In order to compute an optimal Kernel probability density function estimator (KDE), the plug-in method is considered in this paper. Such algorithm gives a way to optimize both the kernel and the bandwidth. Here, we propose a new procedure witch is faster than the common plug-in one. For each time, a factor J(f), which is linked to the second order...
Article
Full-text available
Dans cet article, nous proposons une nouvelle technique de sélection spatio-fréquentielle des interférents dans un système DSL (Digital Subscriber Line) pour une annulation ou précompensation partielle de la diaphonie. L'originalité d'une telle technique est qu'elle est basée sur un critère de performance permettant ainsi un meilleur contrôle de dé...
Conference Paper
Recently, multiuser underwater communication become a research area receiving rising attention by both industrials and researchers. Direct sequence spread spectrum (DS/SS) techniques seem to have gained particular attention since it provide improved performance on time varying multipath channels, through the use of coherent-detection based receiver...
Conference Paper
This paper focuses on the problem of detecting multiuser coded space-time signals transmitted over multi-antenna multipath channel, with imprecise channel knowledge in reception. Computationally efficient methods combining soft multiuser interference (MUI) cancellation and minimum mean square error (MMSE) processing are developed for both channel e...
Conference Paper
Full-text available
High speed downlink packet access (HSDPA) is the major evolution of UMTS downlink. It provides peak data rates up to 10.8 Mbps. This is reached by radio link adaptivity, which includes fast scheduling, adaptive modulation and coding (AMC), and hybrid automatic repeat request (HARQ). The performance of AMC suffers from multipath interference introdu...
Conference Paper
This paper focuses on the problem of turbo equalization for MIMO frequency selective fading channels under the presence of unknown co-channel interference (UCCI). We develop an approach where paths' gains computation, UCCI plus noise covariance matrix estimation, signals equalization and detection, and channel decoding are performed in an iterative...
Conference Paper
This paper addresses the issue of advanced multiuser detection and equalization for multiuser space-time transmission over multipath multiple input multiple output (MIMO) fading channel. Instead of resorting to the straightforward analogy between users and antennas, we introduce a low-complexity approach where multiuser interference (MUI) cancellat...