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In this paper, a new joint symbol detection and channel tracking algorithm is proposed for the coded MIMO-OFDM systems over time-varying frequency-selective fading channels. The iterative detection/decoding and channel estimation are iteratively employed based on the Variational Bayes expectation-maximization (VBEM) algorithm to improve the system performance. A modified list sphere decoder (LSD)...
Barrage relay networks (BRNs) are mobile ad hoc networks designed from the ground up to meet the demands of tactical edge communications. The fundamental building block of BRNs is not a point-to-point wireless link, but rather a rapid and robust broadcast mechanism that employs an autonomous cooperative communications scheme. Following a summary of basic BRN concepts, this paper demonstrates how the...
Recently, the concept of self-organization has drawn considerable attention for its possible use in distributed interference management. To realize self-organized interference management, a minority game (MG) is a promising tool because it facilitates self-organized decision-making. Although the existing interference management scheme that involves the use of an MG achieves transmission control aware...
Spectrum sensing is a critical step in cognitive radio to learn the radio environment. Despite its long history, in recent years spectrum sensing has attracted substantial interests from the cognitive radio community as well as other areas. Although there have been many methods, most of them need some idealistic assumptions and are hardly applicable in real cognitive radio practice. In this paper,...
Allpass transformed filter banks provide a nonuniform frequency resolution and can be used in mobile speech processing systems, e.g., cellular phones or digital hearing aids. The nominal design of such an allpass transformed analysis-synthesis filter bank (AS FB) with near perfect reconstruction (NPR) is achieved by numerical optimization of finite-impulse response (FIR) equalizers in each subchannel...
Video transmission on wireless links usually requires some frame aggregation, so that the overhead due to the headers is not a too large percentage of the bit-stream. In such a situation, header error detection is essential, because any error in the header may cause a loss of several consecutive frames. The contributions of this paper are (i) an improved reception of the length field of the header...
We propose a scheme for maintaining the requested SIR of each user under uncertainty of system parameters in the power control of interference limited wireless networks. In doing so, we keep the outage probability of users below their predefined threshold with minimal power consumption. To reduce the complexity, we apply the notion of chance constraint robust optimization to the outage probability...
This paper proposes a precoding scheme for downlink multiuser MIMO-OFDM systems. The proposed precoding employs the minimum bit error rate (BER) criterion and estimates precoding matrices to minimize total BER of mobile stations by the steepest descent algorithm. As the cost function of the proposed scheme, an upper bound of the total BER is derived from the pairwise error probability (PEP) and is...
It is proposed in this paper a methodology to obtain optimal controllers gains for the rotor-side converter of doubly fed induction generators (DFIGs) using a genetic algorithm approach. The main objective is to enhance the operational security and robustness of the power system, by a more effective contribution of the DFIG controllers to the system controllability. To reach this goal, the crow-bar...
This paper investigates dynamic stability and control design of modern electric energy systems as many MW-scale distributed generators (DG) of various types are deployed in the distribution side of electric systems. The paper is mainly concerned about small-signal frequency stability of distribution systems with decentralized or centralized control systems. The Gerschgorin Circle Theory and Hicks...
Cloud computing, a new thing which is only three years old, becomes the most fashionable technology and developing trend in IT industry now. People say “X as a service” in the cloud computing, which means that everything including software and hardware can be taken as a service for consumers in the cloud. Meanwhile, a high quality multimedia conferencing has been an urgent requirement these years...
A tension adaptive variable-structure control system was designed for constant tension of electric cable plastic wrapping automatic production process. This system contains two inner loops for current and velocity control using PI regulators; its outer loop is for tension control using model reference adaptive controller. Simulation results indicate that the adaptive variable-structure controller...
HVS theory plays important role in the application of digital image watermarking technique. When inserting watermarking, the visual masking feature of HVS could be fully used to design digital watermarking algorithm with good perceived performance. When extracting watermarking from the damaged image, human's visual feature could be combined to recover the damaged image so as to obtain better effect...
This article use intelligent method based on fuzzy neural network for real-time robot path planning. The constructed fuzzy neural network has six inputs and two outputs. The six inputs are the obstacle distance information detected by the five sonar sensors installed on the robot and the target point relative to the robot orientation information; Obstacle information obtained from the five sensors...
During operation, due to changes of temperature, magnetic field, frequency and other factors, electrical and mechanical parameters of induction motor will change. It will affect controlled plant model accordingly bring badly control accuracy directly. In order to obtain better dynamic performance and steady state accuracy, this paper proposes a combination method of online identification and online...
Proactive traffic control systems based on short term traffic condition forecasting hold great promise in combating degenerating network congestion in urban areas. However, a gap persists between the theory and practice of traffic condition forecasting hindering the development of such systems and delaying the benefits they will provide. Therefore, a framework is proposed in this paper, for facilitating...
In order to overcome the shortcomings of BP neural network, the golden section theory was used to get the reasonable number of Back Propagation (BP) neural network's hidden nodes. By using Genetic Algorithm (GA) to optimize the initial weights and threshold value of BP neural network, the network converged quickly and the recognition precision was increased. The GA-BP neural network model was utilized...
Video-on-Demand (VoD) is a typical human-to-machine communication system, in which the application server resources are typically shared by multiple end users and are designed to satisfy normal peak traffic volume based on time-of-day effect. However, the event that catches the attention of a large number of people will trigger flash crowd, which causes unexpected and overloading surge of traffic...
This paper focus on continuous K-nearest neighbor (CKNN for short) query and propose a query method based on R-Tree and Quad Tree (QR-Tree) to support continuous K-nearest neighbor query for moving objects, in which the main idea is to use a QR-Tree to divide the static spatial space for the moving objects. In the interested region, it uses the QR-Tree and hash tables as an index to store the moving...
Adapting resource management, for vague environments, in wireless communication proved to be a measure point of research recently. In this paper we present a system that is capable of adapting some important resources (type of modulation, code rate and number of subcarriers) for blurred channel conditions. The system in this work is mainly designed for WiMAX, which proved to be one of the prominent...
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