Joint power control and beamforming schemes are proposed for cellular systems where adaptive arrays used only at base stations. In the uplink, mobile receiver diversity combining vectors stations calculated jointly. The transmitted is minimized, while signal-to-interference-and-noise ratio (SINR) each link maintained above a threshold. A transmit scheme downlink also weight allocations jointly such that SINR target value. algorithm achieves feasible solution if there one minimizes total in...

The performance of ad hoc networks depends on cooperation and trust among distributed nodes. To enhance security in networks, it is important to evaluate trustworthiness other nodes without centralized authorities. In this paper, we present an information theoretic framework quantitatively measure model propagation networks. the proposed framework, a uncertainty with its value represented by entropy. We develop four Axioms that address basic understanding rules for propagation. Based these...

Wireless positioning has attracted much research attention and become increasingly important in recent years. been found very useful for other applications besides E911 service, ranging from vehicle navigation network optimization to resource management automated billing. Although many devices services are currently available, it is necessary develop an integrated seamless platform provide a uniform solution different configurations. This article surveys the state-of-the-art designs,...

Recent emphasis on green communications has generated great interest in the investigations of energy harvesting and networking. Energy from ambient sources can potentially reduce dependence supply grid or battery energy, providing many attractive benefits to environment deployment. However, unlike conventional stable intermittent random nature renewable makes it challenging realization transmission schemes. Extensive research studies have been carried out recent years address this inherent...

In this paper, a fair scheme to allocate subcarrier, rate, and power for multiuser orthogonal frequency-division multiple-access systems is proposed. The problem maximize the overall system under each user's maximal minimal rate constraints, while considering fairness among users. approach considers new criterion, which generalized proportional based on Nash bargaining solutions coalitions. First, two-user algorithm developed bargain subcarrier usage between two Then optimal coalition pairs...

The interference reduction capability of antenna arrays and the power control algorithms have been considered separately as means to increase capacity in wireless communication networks. minimum variance distortionless response beamformer maximizes signal-to-interference-and-noise ratio (SINR) when it is employed receiver a link. In system with omnidirectional antennas, are used maximize SINR well. We consider beamforming capabilities receiver, control. An iterative algorithm proposed...

In this paper; we propose a new cooperative communication protocol, which achieves higher bandwidth efficiency while guaranteeing the same diversity order as that of conventional schemes. The proposed scheme considers <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">relay</i> xmlns:xlink="http://www.w3.org/1999/xlink">selection</i> via available partial channel state information (CSI) at source and relays. particular, discuss multi-node...

The performance in cooperative communication depends on careful resource allocation such as relay selection and power control, but the traditional centralized requires precise measurements of channel state information (CSI). In this paper, we propose a distributed game-theoretical framework over multiuser networks to achieve optimal without knowledge CSI. A two-level Stackelberg game is employed jointly consider benefits source node nodes which modeled buyer are sellers, respectively....

In recent decades, we have witnessed the evolution of information technologies from development VLSI technologies, to communication and networking infrastructure, standardization multimedia compression coding schemes, effective content search retrieval. As a result, devices digital become ubiquitous. This path technological has naturally led critical issue that must be addressed next, namely, ensure content, devices, intellectual property are being used by authorized users for legitimate...

In order to fully utilize the scarce spectrum resources, with development of cognitive radio technologies, dynamic sharing becomes a promising approach increase efficiency usage. Game theoretical has been extensively studied for more flexible, efficient, and fair usage through analyzing intelligent behaviors network users equipped devices. This article provides game overview from several aspects: analysis users' behaviors, efficient distributed design, optimality

The performance of distributed networks depends on collaboration among entities. To enhance security in networks, such as ad hoc it is important to evaluate the trustworthiness participating entities since trust major driving force for collaboration. In this paper, we present a framework quantitatively measure trust, model propagation, and defend evaluation systems against malicious attacks. particular, address fundamental understanding quantitative metrics, mathematical properties dynamic...

In this paper, a novel cognitive multiple-access strategy in the presence of cooperating relay is proposed. Exploiting an important phenomenon wireless networks, source burstiness, utilizes periods silence terminals to enable cooperation. Therefore, no extra channel resources are allocated for cooperation and system encounters bandwidth losses. Two protocols developed implement proposed strategy. The maximum stable throughput region delay performance characterized. results reveal that...

Digital imaging has experienced tremendous growth in recent decades, and digital camera images have been used a growing number of applications. With such increasing popularity the availability low-cost image editing software, integrity content can no longer be taken for granted. This paper introduces new methodology forensic analysis images. The proposed method is based on observation that many processing operations, both inside outside acquisition devices, leave distinct intrinsic traces...

Crucial to the successful deployment of cognitive radio networks, security issues have begun receive research interests recently. In this paper, we focus on defending against jamming attack, one major threats networks. Secondary users can exploit flexible access multiple channels as means anti-jamming defense. We first investigate situation where a secondary user only channel at time and hop among different channels, model it an game. Analyzing interaction between attackers, derive hopping...

This paper explores the rate-energy (R-E) region of simultaneous wireless information and power transfer for MIMO broadcasting channel under nonlinear radio frequency energy harvesting (EH) model. The goal is to characterize tradeoff between maximal versus rate. separated EH decoding (ID) receivers co-located ID scenarios are considered. For scenario, both time switching (TS) splitting (PS) receiver architectures investigated. Optimization problems formulated derive boundaries R-E s...

In order to verify the authenticity of digital images, researchers have begun developing forensic techniques identify image editing. One editing operation that has recently received increased attention is median filtering. While several filtering detection been developed, their performance degraded by JPEG compression. These suffer similar degradations in when a small window analyzed, as done localized or cut-and-paste detection, rather than whole. this paper, we propose new, robust...

Many forensic techniques have recently been developed to determine whether an image has undergone a specific manipulation operation. When multiple consecutive operations are applied images, analysts not only need identify the existence of each operation, but also distinguish order involved operations. However, operator chain detection is still challenging problem. In this paper, forensics framework for detecting based on convolutional neural network (CNN) presented. Two-stream CNN...

Establishing trust among distributed network entities has been recognized as a powerful tool to secure networks such MANETs and sensor networks. Similar most security schemes, establishment methods themselves can be vulnerable attacks. In this article we investigate the benefits of introducing into networks, vulnerabilities in methods, defense mechanisms. Five attacks against are identified, techniques developed. Effectiveness is demonstrated scenarios securing routing protocols detecting...

A general space-frequency (SF) block code structure is proposed that can guarantee full-rate (one channel symbol per subcarrier) and full-diversity transmission in multiple-input multiple-output-orthogonal frequency-division multiplexing (MIMO-OFDM) systems. The method be used to construct SF codes for an arbitrary number of transmit antennas, any memoryless modulation power-delay profiles. Moreover, assuming the profile known at transmitter, we devise interleaving maximize overall...

Cooperative spectrum sensing has been shown to be able greatly improve the performance in cognitive radio networks. However, if users belong different service providers, they tend contribute less order increase their own throughput. In this paper, we propose an evolutionary game framework answer question of "how collaborate" multiuser de-centralized cooperative sensing, because theory provides excellent means address strategic uncertainty that a user/player may face by exploring actions,...

In this paper, a distributive non-cooperative game is proposed to perform sub-channel assignment, adaptive modulation, and power control for multi-cell multi-user Orthogonal Frequency Division Multiplexing Access (OFDMA) networks.Each individual user's goal minimize his/her own transmitted in distributed manner under the constraints that desirable rate achieved bounded.The pure may result non-convergence or some undesirable Nash Equilibriums with low system performances.To enhance...

Green wireless communications have received considerable attention recently in hope of finding novel solutions to improve energy efficiency for the ubiquity applications. In this paper, we argue and show that time-reversal (TR) signal transmission is an ideal paradigm green because its inherent nature fully harvest from surrounding environment by exploiting multi-path propagation re-collect all would otherwise been lost most existing communication paradigms. A technology must ensure low...