The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper investigates secrecy efficiency (SE) optimization in a friendly full-duplex (FD) decode- and-forward (DF) relay network with a passive eavesdropper. Targeting on SE maximization, the power allocation is optimized subject to the total power and minimum secrecy rate constraints adapting to the assumption of unknown eavesdropper's channel state information (CSI). By exploiting the properties...
The cloud radio access network (C-RAN), which is a novel technology in 5G wireless architecture, has been recently proposed. Resource allocation can utilize resources more efficiently, which generates a lot of researches in C-RAN architecture. In this paper, we deeply investigate the resource allocation in C-RAN with fronthaul capacity constraints, the concept of deploying cache on RRHs in the traditional...
This paper addresses the energy-efficient resource allocation problem in downlink Orthogonal Frequency Division Multiple Access (OFDMA) networks with multiple users. The joint optimization of power and subcarrier allocation to maximize bits-per-Joule is formulated constrained by the maximum transmit power and the minimum required system data rate. Due to the prohibitive computational complexity, this...
This paper considers the use of energy harvesters for cooperative relaying in a large relay network, which consists of N energy-harvesting (EH) relays and one source-destination pair. In particular, a threshold-based “save-then-transmit” scheme is employed at the relays, where each relay transmits only when both the backward and forward link channel coefficients are above certain thresholds. We assume...
We propose decentralized relay coordination algorithms and corresponding channel state information (CSI) signaling concepts for weighted sum rate maximization, via linear downlink transceiver optimization in multiuser multi-relay MIMO network. Two decentralized algorithms are developed with the local CSI requirements at the base station and the relay nodes. In the first proposed algorithm, the generalized...
Besides energy-efficient technologies, increasing attention is paid on powering cellular networks with renewable energy sources, concerning climate change, fossil fuel prices and energy security. In this paper, we not only aim to reduce the absolute energy consumption of cellular networks, but also provide a guideline to utilize the renewable energy efficiently in cellular networks. The renewable...
To successfully deploy multi femtocells in public places, the interference between femtocells must be mitigated. However, some unique features of femtocells present a challenge in interference mitigation, such as complex indoor wireless environment and short distance between femtocells. In this paper, a novel low cost cognitive enabled multi-element antenna solution is proposed to reduce the intra-tier...
As one of the essential characteristics for CRN, the cognitive reconfiguration can automatically adjust the cross-layer parameters to meet the user requirements, realize interoperability between heterogeneous networks and adapt to the time-varying environment. However, the cross-layer parameters reconfiguration implementation is still challenging due to its need for complex environment cognition and...
In this paper, A Modified Differential Algorithm (MDE) developed to solve unconstrained problems. The MDE algorithm use pitch adjustment replaces the traditional mutation operation and design a dynamic method to adjust the crossover rate (CR). The former can enhance the convergence of the MDE, and the latter can effectively prevent the MDE from being trapped into the local optimum. Based on several...
This paper presents a modified harmony search (MHS) algorithm for solving 0-1 knapsack problems. MHS employs position update strategy for generating new solution vectors that enhances accuracy and convergence rate of harmony search (HS) algorithm. Besides, the harmony memory consideration rate (HMCR) is dynamically adapted to the changing of objective function value in the current harmony memory....
We propose a new low complexity direction-of-arrival (DOA) estimation method based on sparse variable projection (SVP) optimization. This method estimates an indicative sparse vector that indicates the locations of DOA from each visual sources corresponding to DOA sampling space and is particular useful to simplify the multiple measurement vector (MMV) problem as a single indicative sparse vector...
In cognitive radio (CR) systems, efficient spectrum sensing ensures secondary users (SUs) to successfully access the spectrum hole. Typically, the detection problem has been studied separately from the optimization of throughput of secondary network. However, due to non-zero probabilities of miss detection and false alarm, the sensing phase has an impact on the throughput of CR networks as well as...
In this paper, we study the cross-layer resource allocation for the secondary users (SUs) supporting heterogeneous services in interference-limited spectrum sharing system. Two classes of SUs are considered: delay-tolerant SUs (DT-SUs) and delay- sensitive SUs (DS-SUs). With the queue theory, the delay requirements of DS-SUs are transformed into constant rate requirements. Unlike most previous works,...
With the increasing demands for high data rate applications with high quality of service in the next generation networks, OFDMA based femtocell technology is a promising solution for indoor coverage extension and network capacity boosting with its automatic and easy deployment features in contrast to the high CAPital EXpenditure (CAPEX) and OPerating EXpense (OPEX) investments for macrocell deployments...
The 3-D substantial model is built for the bushing end of an ultra-high voltage transformer high-voltage coil and the surrounding of the equipotential shielding. This model is properly simplified according to the symmetrical structure of the coil. The electric field intensity nearby the transformer's high-intense coil and the surrounding of the equipotential shielding are calculated on the basis of...
Affinity propagation (AP) is a new powerful clustering algorithm based message passing between data points. One of the major problems in clustering is the determination of the optimal number of clusters. In this paper, we propose a new approach called Affinity Propagation Clustering based Particle Swarm Optimization (PSO-AP), which using Particle Swarm Optimization (PSO) algorithm to determination...
The problem of resource allocation in multiuser OFDM system is a combinatorial optimization problem, difficult to solve in polynomial time. For the sake of reducing complexity, it can be solved either by relaxing constraints and making use of linear algorithms or by metaheuristic methods. In this paper, ant colony optimization, a typical algorithm of metaheuristic methods, is applied to solve the...
The improved fuzzy comprehensive evaluation model of construction diversion schemes is established in the paper by introducing Vague set theory, which considers various technical conditions and economic indexes. The method overcomes the limitation that the traditional fuzzy sets can not reflect the hesitating information between positive and negative. The model is applied to the diversion schemes...
This paper reports an effective optimization procedure for designing no-moving part microvalves where the diodicity of the optimized valves has better performance when compared with the typical Tesla valve. The detailed layout of microvalves is obtained by minimizing the fluidic resistance of fluidic channels for the forward flow under a user-specified design constraint about the fluidic work diodicity...
Bionic evolution is an adaptive artificial intelligence technique; it mimics natural evolution process to solve optimization problems. In the paper, we present an improved proxy signature scheme based on bionic evolution. In the scheme, the original private key is generated with bionic evolution algorithm by a successive optimizing process. The optimizing selection algorithm renders effective protection...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.