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This study presents a novel approach to enhancing the design and performance of OFDMA (Orthogonal Frequency Division Multiple Access) networks, with a particular focus on WiMAX (Worldwide Interoperability for Microwave Access) for Best Effort (BE) services. The proposed method integrates a robust Markovian analytical model with four advanced scheduling algorithms: throughput fairness, resource fairness, opportunistic scheduling, and throttling. A sophisticated simulator was developed, incorporating an ON/OFF traffic generator, user-specific wireless channels, and a dynamic central scheduler to validate the model's accuracy and evaluate its robustness by dynamically allocating radio resources per frame. The validation study showed that the proposed model reduced simulation time by over 90%, completing analytical calculations in just 15 min, compared to nearly 2 days for simulations using conventional scheduling algorithms. Performance metrics such as the average number of active users and resource utilization closely matched those from the validation study, confirming the model's accuracy. In the robustness study, the model consistently performed well across diverse traffic distributions (exponential and Pareto) and channel conditions. The proposed architecture increased network throughput by up to 25% and reduced latency under dynamic conditions, demonstrating its scalability, adaptability, and efficiency as a crucial solution for next-generation wireless communication systems. [ABSTRACT FROM AUTHOR]

In wireless communication, small cells are low-powered cellular base stations that can be used to enhance the coverage and capacity of wireless networks in areas where traditional cell towers may not be practical or cost-effective. Unmanned aerial vehicles (UAVs) can be used to quickly deploy and position small cells in areas that are difficult to access or where traditional infrastructure is not feasible. UAVs are deployed by telecommunication service providers to provide aerial network access in remote rural areas, disaster-affected areas, or massive-attendance events. In this paper, we focus on the scheduling of beaconing periods as an efficient means of energy consumption optimization. The conducted study provides a sub-modular game perspective of the problem and investigates its structural properties. We also provide a learning algorithm that ensures convergence of the considered UAV network to a Nash equilibrium operating point. Finally, we conduct extensive numerical investigations to assist our claims about the energy and data rate efficiency of the strategic beaconing policy (at Nash equilibrium). [ABSTRACT FROM AUTHOR]

This paper deals with the equalization of rectilinear and quasi-rectilinear modulated signals over frequency selective channels. This study is motivated by the fact that offset quadrature amplitude modulation based filter bank multi-carrier, one of the most prominent post orthogonal frequency division multiplexing contenders for beyond 5G wireless communication systems, employs offset quadrature modulation. This modulation is known to be cyclo-stationary and non-second order circular. Three minimum mean squared error based equalizing structures have been developed, referred to as linear (LE), widely linear (WLE) and widely linear Fresh (WL Fresh) equalizers. For the proposed equalizers, both symbol spaced and fractionally spaced processing have been evaluated, in synchronous DL/UL and asynchronous UL scenarios, with mixed numerologies transmissions. The simulation results show the ability of WL Fresh equalizer to suppress inter-numerology and inter-symbol interferences over frequency selective channels, outperforming the WLE and LE equalization schemes. [ABSTRACT FROM AUTHOR]

The wireless communication for rotating electrical machines is beneficial for diagnosis purposes as well as real-time monitoring. The electromagnetic waves propagation characteristics inside electrical machine is rather delicate. So it will be interesting to find a dynamic tool adapted to our problem. The idea is to validate these propagation concepts with real signatures. The tool must then analyze the signatures of the received signal strength indication. These experiments have shown that the antenna rotation is a disturbance-causing factor of the signal transmission. Thus, in this paper, our aim is to analyze the electromagnetic wave propagation characteristics in rotating environments in order to obtain the optimum parameters and providing a strong theoretical support for radio monitoring system performance improvement. Therefore, our work will process the important parameter which is the path loss variation in rotating environments. [ABSTRACT FROM AUTHOR]

Multiple-input multiple-output is being considered as a highly interesting topic for the new generation of wireless communication systems. The major challenge is how to enhance the link reliability while neither affecting the spectral efficiency nor the quality of service. To reduce the complexity of the maximum likelihood (ML) receiver, efforts have been focused on zero forcing (ZF) decoder using lattice reduction-aided (LRA) techniques. In this study, the authors propose a method that improves performance using the LRA-based precoding technique without increasing the decoder complexity. Their approach is to exploit the channel matrix to generate matrices for both the precoding and LRA detection technique. This makes it possible to achieve maximum orthogonality for the generated channel matrices while reducing considerably the noise effect. They focus on the use of the LRA-ZF for the ease of its implementation and low complexity. The proposed method outperforms LRA-minimum mean square error-based receiver and gets closer to ML receiver performance. The performance and complexity of the proposed scheme are discussed. [ABSTRACT FROM AUTHOR]

Green communication has become the main concern of many researchers according to the quick evolution of wireless communication applications. For this, in this correspondence we develop a cross-layer framework based on the joint association between Modulation and Coding Scheme together with truncated Selective Repeat Hybrid Automatic Repeat Request type I to examine the global energy consumption per bit of Multiband Orthogonal Frequency Division Multiplexing Ultra Wideband (MB-OFDM UWB) systems. Indeed, we examine a theoretical analysis based on throughput performance investigation when mode selection is performed which is dynamically selected following the Channel State Information. Next, we prove that cross-layer design outperforms the mode selection behavior in terms of outage probability. Then, based on the features of cross-layer MB-OFDM UWB (MB-UWB) design a theoretical framework is derived in terms of Packet Error Rate and overall energy expenditure per bit. Specifically, the closed form relation of energy per bit is determined by exploiting the proprieties of the two link adaptation tools. Correspondingly, since the purpose behind cross-layer design adoption into MB-UWB system is EE improvement, we have compared the impact of different M-QAM modulations into energy consumption per useful bit at various range of distances. The obtained results reveal that cross-layer design is a powerful solution in terms of EE enhancement. [ABSTRACT FROM AUTHOR]

Wireless communication can be a useful method to monitor the electrical machine as it provides the main characteristics of online signal processing. Our contribution in this current paper consists in studying a new system to monitor the rotating electrical machines based on wireless communication. The main objective of this system is to detect the temperature value of the squirrel cage induction machine's rotor, using the IEEE 802.11 protocol. However, the application of wireless communication inside the rotating electrical machines is not self-evident due to the fact that the electromagnetic compatibility problems between devices isn't obviously guaranteed. So, in order to obtain a good reliability for wireless communication, the study of the electromagnetic field inside rotating electrical machine is essential. As a first step in this paper, we are going to focus mainly on the flux effect of the rotating electrical machine through the finite element method which offers so much information on the phenomena characterizing the electrical machine operation. This method proves that the high frequency domain transmitter won't be disturbed by the low frequency existing flux inside the machine. As a second step in this study, the proposed network system design is presented. Then, the communication protocol, the hardware design based on the transmitting chip Roving Networks (RN-171) as well as the software design are illustrated. Finally, the experimental results of the proposed system are investigated to validate its feasibility. [ABSTRACT FROM AUTHOR]

Indoor localization in wireless sensor networks is a challenging task. Static localization and moving target monitoring are addressed using ensemble learning method and received signal strength indicator. The suggested strategy combines several regression trees to have better performance. This solution has been experimentally evaluated using real measurements in an office room. The performance results have been analyzed through a comparison with learning-based localization algorithms currently available in the literature. The analysis shows that the adopted solution is simple in term of computation, accurate and robust to environmental variation. [ABSTRACT FROM AUTHOR]

Cooperative relaying is an important feature for the fourth generation wireless system to upgrade system performance. Mobile relays can offer better results than fixed relays without any additional infrastructure cost. However, efficient cooperation decision as well as resource allocation are critical to satisfy model constraints as required quality of service (QoS). In this work, simple mobile users with advantageous channels can act as potential relays for cell edge users for an uplink transmission. They multiplex, in the frequency domain, their own data to that of the relayed sources, with the objective for both relay and sources to reach a target data rate. An optimal joint resource blocks (RB) allocation and power allocation scheme under a required data rate constraint per user is proposed. The optimization problem is formulated to minimize the total system power. Dual decomposition and subgradient method are used to solve the optimization problem after dividing it into independent subproblems with less complexity to find the optimal solution. The cooperation decision and the sources-relays association is either performed as a first step of resource allocation, or jointly optimized with RB and power allocation. Simulation results show that these proposed algorithms both reduce system's power consumption while ensuring the required QoS. Joint optimization of relay selection, RB and power allocation provides a higher power consumption decrease, but requires higher complexity and overhead. [ABSTRACT FROM AUTHOR]

This paper introduces a power controller method for Ad Hoc On-Demand Distance Vector (AODV) reactive routing protocol. The proposed algorithm uses adaptive HELLO messages where their transmit periods are adapted according to the instantaneous energy level of the battery. By transmitting HELLO messages at calculated instant, each node stores its neighborhood energy information. The valid(safest) path between sources and destinations is calculated using route request messages. Indeed, the safest path is defined as the route with the maximum energy levels. However, the collision probability occurred by two nodes having very close energy levels is very hight. Then, we investigate, firstly, the collision occurrence probability using Markov Chain modelling of the battery discharge process. After, we introduce a collision avoidance process to a Power Controller and Reactive Routing Protocol (PC-AODV). The performance of the proposed protocol is theoretically canalised and validated by simulation. [ABSTRACT FROM AUTHOR]

This paper presents a new algebraic carrier frequency offset (CFO) estimation technique for multiple-input–multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) system, to overcome the sensitivity of algebraic space–time codes (ASTCs) to frequency synchronization in quasi-static correlated Rayleigh frequency-selective fading channels. The technique uses a preamble and is thus particularly suitable for burst-mode communications. The preamble consists of orthogonal training sequences that are simultaneously transmitted from the various transmit antennas. The proposed system exploits all subcarriers in the frequency domain, which provides a remarkable performance improvement, and reaches the Cramer–Rao lower bound (CRLB) at a high signal-to-noise ratio. The proposed method is compared with three known CFO estimators in the literature: Cyclic-Prefix-based (CP), Moose, and Classen techniques that show clear advantages. [ABSTRACT FROM PUBLISHER]

This letter deals with a hybrid time-of-arrival/angle-of-arrival (TOA/AOA) approximate maximum likelihood (AML) wireless location algorithm. Thanks to the use of both TOA/AOA measurements, the proposed technique can rely on two base stations (BS) only and achieves better performance compared to the original approximate maximum likelihood (AML) method. The use of two BSs is an important advantage in wireless cellular communication systems because it avoids hearability problems and reduces network signaling burden. Simulation results show that, for certain scenarios, the proposed hybrid TOA/AOA AML with two BSs can outperform the AML with up to six BSs. [ABSTRACT FROM AUTHOR]