Wireless local area networks (WLAN) and recent Wi-Fi standards, are used since a few decades for a large variety of network applications. Since a few years, the $5^{\text {th }}$ generation wireless cellular networks (5 G) are being deployed and used, most of the time for similar applications. Both technologies and their evolution, are expected to be deployed within the wireless ecosystem by 2030 and for decades beyond. The Wi-FIP project invokes these two wireless networking solutions and their evolution, to further enhance the wireless data networks regarding sustainable and scalable quality of hybrid network services. This paper presents the visions and objectives of the Wi-FIP project, targeting to enhance synergies and integration of Wi-Fi in 5G/beyond 5G networks, through the convergent B2B/B2C usage model concept, sustainable multi-connectivity, hierarchical Software Defined Networking (SDN) and orchestration. The paper analyzes the functionalities to develop for sustainable, secure and hybrid WLAN/cellular networking.

In this paper, we provide a theoretical analysis on the performance of the famous Gradient-based Tone-Reservation PAPR reduction algorithm. To that end, we study the amplitude statistical distribution of the time domain OFDM signals to which PAPR reduction has been applied. Such distribution is then integrated into a generic EVM expression in order to provide a closed form expression of this latter, which is validated and analyzed through numerical simulations. Thanks to this work, we provide theoretical tools to analytically assess the performance of the Gradient method relatively to the optimal TR algorithm, and hence allow further analysis about the complexity-PAPR reduction efficiency trade-off of TR PAPR reduction algorithms, which could be useful for the optimization of the power efficiency of any multicarrier system.

Peak to average power ratio (PAPR) reduction of OFDM signals has extensively been studied in the literature. Tone Reservation (TR) is one of the most famous algorithms and has already been included in some digital television standards such as DVB-T2 and ASTC3.0. However, the literature is still lacking theoretical analysis and performance bounds for the PAPR reduction of OFDM signals, especially using TR algorithms. For the first time, this paper provides fundamental results establishing the links between TR-PAPR reduction and the remaining signal distortions at the output of a non-linear high power amplifier (HPA) with and without memory effects. We first derive a generic EVM expression relying on the statistical characteristics of the samples composing the time domain signal and for any PAPR reduction technique. Computing these moments in the case of the quadratically constrained quadratic problem (QCQP) algorithm known as the optimal solution to the TR-PAPR reduction problem allows us to get the lower bound of the EVM of OFDM signals after TR-PAPR reduction and non-linear HPA. As a reference, we also provide the EVM expression using a clipping-based PAPR reduction method. The obtained EVM expressions have direct practical meaning since they are in function of the input power back-off (IBO) applied to the signal before the HPA. They also consist in a general analytical framework for OFDM PAPR reduction since they can be further exploited to analyze the performance of sub-optimal TR-based PAPR reduction algorithms.

In this paper, a simple and accurate analytical framework for the duplex mode selection and the power allocation scheme for full duplex (FD) device-to-device (D2D) communications underlaying wireless cellular network is proposed. We first aim at maximizing the D2D links rate by properly selecting the duplex mode of the D2D pairs and allocating the power of the users while fulfilling the quality-of-service (QoS) of the cellular users (CUEs). Since the resulting optimization problem is non-convex, we derive a first-order optimal solution by leveraging an interesting optimization tool named as sequential convex optimization theory. We also discuss how to obtain an efficient sub-optimal solution in term of complexity and accuracy by deriving the optimal power ratio between the D2D devices assuming an interference limited system. The simulations have shown more than 95% accuracy of the proposed approaches and provided great insights on the solution design parameters taking into account the CU location and the self-interference threshold.

This paper studies the rate maximization problem of a Full duplex(FD) D2D underlaying cellular network. In the considered scenario, multiple FD-D2D pairs coexist with multiple cellular users which generate mutual interference between the two communication types. The complicated interference environment makes the optimization problem a non-concave problem. To solve this problem, we discuss how to leverage the monotonic optimization theory to obtain the global optimal solution at the cost of high complexity. We also derive a geometric based optimization framework, denoted as GALEN, that achieves the global optimality with much lower complexity, and also it provides a closed form expression for the solution. The simulation results show the importance of the proposed solution.

Video streaming and mobile TV services have recently gained great research interest with the advances in mobile hardware technologies and the development of single frequency networks (SFN). However, the analysis of the coverage probability of these services in SFN has been and remains a complicated task due to the specific behavior of the received SFN signal and its effect on the useful signal. In this framework, we propose a new approach to model and evaluate the coverage probability for such network configuration. More particularly, using stochastic geometry, we propose a suitable approximation of the problem based on the closest SFN base stations. The resulted expressions represent a lower bound for the probability of coverage of the SFN. The proposed approximation leads to a good trade-off between accuracy and tractability. Numerical simulation results prove the validity of the proposed approach and related theoretical results, especially in a high path loss environment.

In this paper, we provide closed form expressions for the probability density functions (PDF) of the interference power in a network whose transmitters are arranged according to the Poisson Point Process (PPP). These expressions apply for any integer path loss exponent η greater than 2. Using the stretched exponential or Kohlrausch function, we show that the PDF formulas can be obtained as long as the Laplace transform (LT) for the PDF follows a specific common (exponential) formulation. Moreover, we show that such closed form expressions can be useful in deriving performance metrics for the network for any fading type experienced by the signals. Finally, using Monte-Carlo simulations and numerical analysis, we validate the accuracy of the proposed analytical derivations.

In this paper, we study the statistical distribution of the OFDM time-domain signal amplitude to which the optimal tone reservation (TR) PAPR reduction solution is applied. This study comes as a major step towards the derivation of the analytical expression of the error vector magnitude (EVM) metric on OFDM waveforms when non-linear amplification is used. We demonstrate through simulations that this distribution has a bimodal behavior and can be tightly modeled as a superposition of two probability density functions whose expressions are given and whose parameters are obtained through proper estimation. From such analysis, we provide the complete distribution expression of the PAPR-reduced OFDM signal, which can be further exploited for the derivation of performance bounds of the TR PAPR reduction strategy.

Linear services such as mobile TV are witnessing an increasing demand, creating challenges for conventional delivery methods in both broadcast and broadband networks. To overcome this problem, a hybrid delivery approach combining both networks has recently emerged. Using stochastic geometry and a Poisson point process distribution of the users and access points, this paper discusses a hybrid broadcast/unicast network model where an analytical approach was undertaken, deriving a new expression for the probability of coverage. The model is then used to assess the feasibility of the proposed hybrid scheme and then extended to numerically find the optimal operation point in terms of key design parameters including user density in the network.

In this paper, we introduce Drizzle, a new algorithm for maintaining routing information in the low-power and lossy networks. The aim is to address the limitations of the currently standardized routing maintenance (i.e., Trickle algorithm) in such networks. Unlike Trickle, Drizzle has an adaptive suppression mechanism that assigns the nodes different transmission probabilities based on their transmission history so to boost the fairness in the network. In addition, Drizzle removes the listen-only period presented in Trickle intervals leading to faster convergence time. Furthermore, a new scheme for setting the redundancy counter has been introduced with the goal to mitigate the negative side effect of the short-listen problem presented when removing the listen-only period and boost further the fairness in the network. The performance of the proposed algorithm is validated through extensive simulation experiments under different scenarios and operation conditions. In particular, Drizzle is compared to four routing maintenance algorithms in terms of control-plane overhead, power consumption, convergence time, and packet delivery ratio (PDR) under uniform and random distributions and with lossless and lossy links. The results indicated that Drizzle reduces the control-plane overhead, power consumption and the convergence time by up to 76%, 20%, and 34%, respectively, while maintaining approximately the same PDR rates.

Low-power and Lossy Networks (LLNs) have been a key component in the Internet of Things (IoT) paradigm. Recently, a standardized algorithm, namely Trickle algorithm, is adopted for routing information maintenance in such networks. This algorithm is originally designed for disseminating code updates through a wireless sensor network. Thus, when it comes to routing maintenance in LLNs, Trickle suffers from some issues related to power, convergence time, network overhead and load-distribution. In this paper, a new algorithm for maintaining the network topology in LLNs is developed motivated by Trickle weaknesses, namely, Drizzle algorithm. Unlike Trickle, Drizzle uses an adaptive suppression mechanism that permits the nodes to have different transmission probabilities consistent with their transmission history. Another distinctive feature of Drizzle in comparison with Trickle, is the absence of the listen-only period from Drizzle's intervals, thus, leading to faster convergence time. Furthermore, a new policy for setting the redundancy coefficient has been used to mitigate the negative effect of the short-listen problem presented when removing the listen-only period and to further boost the fairness in the network. Our extensive simulation experiments confirm the superiority of the proposed algorithm over Trickle under different operating conditions.

Wireless body area networks (WBANs) facilitate efficient and cost-effective e-health care and well-being applications. The WBAN has unique challenges and features compared to other wireless sensor networks. In addition to battery power consumption, the vulnerability and the unpredicted channel behaviour of the MAC layer make channel access a serious problem. Time Division Multiple Access (TDMA) Medium Access Control (MAC) protocols can help in achieving a reliable and energy efficient WBAN. However, traditional TDMA techniques adopted by WBAN legacy standards, such as IEEE 802.15.4 and the IEEE 802.15.6 do not consider sufficiently the channel status or the reliability of nodes. Thus, this paper presents two new TDMA based techniques to improve WBAN reliability and energy efficiency. Both techniques synchronise nodes adaptively whilst tackling their channel link status. The proposed techniques are evaluated within various traffic rates and time slot lengths. In addition, their performance is compared with the IEEE 802.15.4 and IEEE 802.15.6 MAC. The results confirm that the proposed techniques have the potential to improve WBAN reliability and energy efficiency.

We introduce in this paper two main approaches, Triangulateration (TL) and Angle-Difference-of-Arrival (ADoA) for indoor localization and mapping using single-anchor and millimeter wave (MMW) propagation characteristics. Then, we perform context inference through obstacle localization. To do so, we first include and estimate the positions of virtual anchor nodes (VANs), known as mirrors of the real anchor with respect to obstacle. Then, it is followed by estimating the obstacle position and its dimensions. We assess the performance of each technique via cumulative distribution function (CDF) for the location estimation root mean square error (RMSE). Simulations confirm that localization of the receiver relying on a single anchor and the localization of obstacles in MMW achieves a few centimeters accuracy.

Carrier Aggregation started to appear since release 10 of LTE, and offers higher data rates, but at the cost of increased Peak-to-Average-Power-Ratio (PAPR). This paper studies the distribution of PAPR through analyzing the Crest Factor (CF) which is the square root of the PAPR of the Carrier Aggregated OFDM (CA-OFDM) signals used in the downlink of LTE-A. Although the base station is not power constrained, the increased PAPR can adversely affect performance in terms of energy efficiency and coverage. We model the distribution of the CF by adopting the Level Crossing Rate analysis to approximate the peak distribution of the CA-OFDM signal which can be characterized as a bandlimited complex Gaussian process. The expression of the distribution is derived for an arbitrary number of component carriers for both contiguous and non-contiguous aggregation, where simulations show good agreement with the derived analytical expressions. The derived expression is applied to model the Selective Mapping technique used for PAPR reduction.

In this study, the authors consider the standard condition number (SCN) detector for a cognitive radio with finite number of cooperative sensors. They derive an exact nested form of the distribution of the SCN for the central uncorrelated, non‐central uncorrelated and central semi‐correlated Wishart matrices under and hypotheses. Due to the complexity of these expressions, the authors approximate the distribution of the SCN by the generalised extreme value distribution using moment matching. They derive the exact form of the p th moment of the SCN for these cases. Consequently, the performance probabilities are approximated and a simple decision threshold formula is provided. In addition, a similar approximation for the detection probability is provided using non‐central/central approximation. They show that the proposed analytical approximations provide high accuracy using Monte‐Carlo simulations.

Device-to-Device (D2D) communication has gained a lot of interest in the last years. Recently, it has been accepted as a promising concept as part of the third generation partnership project (3GPP) standard in the LTE-A release 12 and release 13 under the name of Proximity-Based Services (ProSe). However, the proposed solutions to integrate the D2D in the cellular network require added functionalities on the network resources, mainly in the discovery process. In this paper, we mitigate the requirement of additional resources in the LTE-A network by proposing a novel D2D discovery protocol. Specifically, we propose to offload the D2D discovery onto the Vehicular Ad-hoc Networks (VANETs) by using the inherent knowledge of the Road Side Unit (RSU) about the users in its coverage area. In addition, we propose a framework to model and analyze the duration of our discovery through mathematical derivations. Then, all the results are validated through extensive simulations on both Network Simulator 3 (NS3) and Matlab.

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 peak in time domain. In this paper, we first assess the performance of the power control schemes adopted by TR algorithms. Then, we analyze their complexity and show that their kernels are complex to generate, hence practically, difficult to implement. Secondly, we propose a novel kernel signal, simple to implement yet compatible with the DVB-T2 standard to reduce the PAPR value. The proposed kernel is defined to deal with the reduction of multiple peaks at a time. We show that the proposed PAPR reduction outperforms the TR algorithm adopted in DVB-T2 in terms of CCDF and Modulation Error Rate (MER) and then offers a better performance-complexity tradeoff.

In this paper, we introduce a scheme of caching requested data in LTE networks. After data (eg., web pages) is cached after its first request, the subsequent requests of the same data are served from the network's caching memory directly. The idea in this scheme is new in that the caching memory is at the level of the mobile devices themselves and not in the LTE core network, as in other proposed schemes. Our approach aims to minimize the required changes in the functions of the various elements of the LTE network core for supporting the caching operations. As we illustrate in the results section, the proposed system results in lower overall data access delays, which are attributed to retrieving some of the requested data from Internet servers when such data are not found in the network.

In 3GPP LTE-Advanced standard forum, Mobile Relay Node (MRN) occupies an important place. It is well known that cell-edge users suffer from bad Signal Level strength. To improve the signal quality and network coverage at the cell-edge it is proposed to use Mobile Relay Node. For the moment, MRN communicates to the UE devices in the vehicle. In this paper, we propose to implement MRN on the top of public transportation having known path and low speed to serve data hungry users outside the vehicles.

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 transmission (DVB-T2). In this paper we analyze the power control schemes used in TR algorithms by assessing both their performance and complexity. We then propose two novel solutions to improve the performance without requiring additional complexity. The first is based on an enhanced selection of the peaks to be processed by the TR algorithm, and the second is based on a dynamic computation of the threshold used. We show that the proposed techniques outperform the TR algorithm adopted in DVB-T2 by 0.77 dB in terms of CCDF gain at 10-3and by 0.33 dB in terms of Input Back Off (IBO) gain for an MER of -40dB.

In this paper, we analyze the problem of deploying small cellular cells into a large broadcast cell in the framework of the convergence between the Long Term Evolution (LTE) and the Digital Broadcasting Video (DVB) technologies. In this work, a non- cooperative deployment of these technologies is considered in the sense that cellular and broadcast networks interfere on each other. In literature, there is no work dealing with the ergodic capacity of full cross-interfering links in a DVB-LTE convergence scenario. Our contribution lies in two folds: i) the global ergodic capacity is derived in closed-form with Rayleigh fading channel on each link. This derivation allows us to evaluate the global data rate of the DVB and LTE in a spectral overlap scenario. ii) The analytical forms allow the evaluation of the influence of system parameters on the global and broadcast data rate, e. g. mobile and broadcast power, distance between the broadcast receiver and the LTE base station.

This paper investigates the distributed space-time (ST) coding proposals for the future Digital Video Broadcasting-Next Generation Handheld (DVB-NGH) standard. We first theoretically show that the distributed MIMO scheme is the best broadcasting scenario in terms of channel capacity. Consequently we evaluate the performance of several ST coding proposals for DVB-NGH with practical system specifications and channel conditions. Simulation results demonstrate that the 3D code is the best ST coding solution for broadcasting in the distributed MIMO scenario.

The cooperative techniques have recently taken a lot of attention in the recent few years due to their efficiency in radio mobile networks specially when the direct link between the source and the destination is lost. However, their combination with the multiple input multiple output (MIMO) schemes requires further study since new strategies of cooperation are expected when the MIMO component is added to the cooperation scheme construction. In this paper, we propose a double-layer space-time (DLST) code in a distributed way between the relays in order to emulate the MIMO transmission scheme between the relays. The DLST is compared with some of the most promising codes found in the literature. We show that the proposed code is very efficient whatever the transmitted powers by the relays are. This efficiency is verified in both amplify and forward (AF) and decode and forward (DF) algorithms. We show that a gain of at least 1 dB is obtained through DLST compared to conventional MIMO schemes in cooperative communications whatever the transmission scenario is.

This paper analyzes the outage probability of cooperative communications over asymmetric fading environments. This work investigates the scenario where cooperative nodes are located at different geographical locations. Some cooperative nodes experience line of sight (LOS) signals and some nodes may experience non-LOS (NLOS) signals. As a result, signals in different links are affected by different fading distributions, one link may undergo Rician fading distribution and others links may undergo Rayleigh fading distribution. Such scenario is referred to as asymmetric fading channel. Assuming decode-and-forward, we provide an analytical model of outage probability for repetition-based relaying over different asymmetric fading channels. We show that the outage performance is better when the relays are in LOS situation with respect to the source rather than to the destination for the large number of relay nodes regime. The conclusions are verified through analytical and Monte-Carlo simulation studies.

The paper analyzes power spectral density (PSD) of orthogonal pulse-based signals for time hopping ultra wideband (TH-UWB) systems. Our extensive studies show that the PSD of these signals not only depends on the time dithering code and the modulation schemes, but also on the energy spectral density (ESD) of orthogonal pulses. The different order orthogonal pulses provide different ESD which changes the shape of continuous spectral component with symbols. We show that orthogonal pulse-based signals reduce the dynamic range of amplitude of discrete spectral components. Further, we reduce the dynamic range by adopting longer TH code over orthogonal pulse-based signals. As a result, UWB system performance improves with average transmitted power. The theoretical analysis of PSD of orthogonal pulse-based TH-UWB signal is provided in details and verified through simulation results.

Phase noise is a topic of theoretical and practical interest in electronic circuits. Although progress has been made in the characterization of its description, there are still considerable gaps in its effects especially on multi-carrier spreading systems. In this paper, we investigate the impact of a local oscillator phase noise on the multi-carrier 2 dimensional (2D) spreading systems based on a combination of orthogonal frequency division multiplexing (OFDM) and code division multiple access (CDMA) and known as OFDM-CDMA. The contribution of this paper is multifold. First, we use some properties of random matrix and free probability theory to give a simplified expression of signal to interference and noise ratio (SINR) obtained after equalization and despreading. This expression is independent of the actual value of the spreading codes and depends mainly on the complex amplitudes of estimated channel coefficients. Secondly, we use this expression to derive new weighting functions which are very interesting for the radio frequency (RF) engineers when they design the frequency synthesizer. Therefore, based on these asymptotic results, we adapt a new method to predict the bit error rate (BER) at the output of the channel decoder by using an effective SINR value. We show by simulations the validity of our models and that at a given BER, the required signal to noise ratio (SNR) may easily increase due to the carrier phase noise.

Future Communication networks are tending towards a diverse wireless networking world where the positioning information (PI) could be helpful in different techniques like the dynamic resource allocation. On the other hand, the PI could be widely used for cooperative techniques in the relay and/or routing selection process. In this paper, we propose to use the PI in the selection of the relays and then to apply an efficient double layer distributed space time block code (DLSTBC) scheme between the different relays. Using the amplify and forward (AF) technique, we show that the proposed code is very efficient whatever the transmitted power is. Moreover, we show that the relay selection process based on PI yields very powerful results when compared to the random relay selection (RS) process.

Multiple Input Multiple Output (MIMO) is a topic of high interest for the next generation of broadcasting systems. However, their deployment in single frequency networks (SFN) becomes more critical when they are used in hybrid satellite-terrestrial transmission due to the different aspects of the respective transmission links. In this paper, we propose to apply a double layer space time block code (DLSTBC) for MIMO schemes in this hybrid transmission. The proposed scheme is based on a layered construction designed to be efficient in line of sight (LOS) situation but also in deep shadowing. It is then a very promising candidate for next generation handheld broadcasting systems and SFN architecture.

In this paper, we propose a bit error rate (BER) based algorithm for decode and forward (DF) in cooperative orthogonal frequency division multiplexing (OFDM) systems. The proposed algorithm is issued from the prediction of the BER at the output of the channel decoder using an effective exponential signal to noise ratio (SNR). This approach offers a gain of about 2.5 dB in the single-relay case and 16-QAM modulation compared to the SNR based approach and about 0.35 dB in the case of 3 relays. The proposed technique is then a very promising candidate for DF in cooperative networks.

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 than the classical STBC scheme. The performance evaluated over a realistic channel model shows the efficiency of this technique which turns out to be a promising MIMO channel estimation technique for the future mobile video broadcasting systems.

This article investigates the effect of equal and unequal received powers on the performances of different MIMO-OFDM schemes for terrestrial digital TV. More precisely, we focus on three types of non-orthogonal schemes: the BLAST scheme, the linear dispersion (LD) code and the Golden code, and we compare their performances to that of Alamouti scheme. Using two receiving antennas, we show that for moderate attenuation on the second antenna and high spectral efficiency, Golden code outperforms other schemes. However, Alamouti scheme presents the best performance for low spectral efficiency and equal received powers or when one antenna is dramatically damaged. When three antennas are used, we show that Golden code offers the highest robustness to power unbalance at the receiving side.

This paper presents the impact of a carrier frequency offset on the performance of 2 dimensional spreading OFDM-CDMA systems. This is measured by the degradation of the Signal to Interference plus Noise Ratio (SINR) obtained after despreading and equalization. Using some properties of random matrix and free probability theories, a new expression of the SINR is derived. It is independent of the actual value of the spreading codes while still accounting for the orthogonality between codes. This model is validated by means of Monte-Carlo simulations. It is also exploited to compare the sensitivities of MC-CDMA and MC-DS-CDMA systems to carrier offset in a frequency selective channel. This work is carried out for zero forcing (ZF) and minimum mean square error (MMSE) equalizers.

This article presents the impact of a constant timing error on the performance of a downlink 2 dimensional spreading OFDM-CDMA system. This impact is measured by the Signal to Interference plus Noise Ratio (SINR) degradation after equalization and despreading. Using random matrix theory, an asymptotic evaluation of the SINR is obtained. It is independent of the value of users' spreading code while taking into account their orthogonality. Simulation results are provided to evaluate and discuss the validity of this model.