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Orbital angular momentum (OAM) provides extra degrees of freedom to improve spectrum efficiency. However, the harsh requirement that transmit antenna(s) and receive antenna(s) need aligning throws out a great challenge to its application. To investigate the reason of performance degradation caused by misalignment, we first consider uniform circular array (UCA) based OAM system and set up two free...
Energy harvesting wireless network is an emerging paradigm where the wireless nodes harvest energy to increase their lifetime. Due to high potential for a large variety of applications, such networks have drawn considerable attention in both industry and academia. In this paper, we consider the energy replenishment problem when the wireless nodes not only harvest energy from the ambient environment...
In this paper, we propose CGM-PS, a partial-decentralized, un-starving, work-conservative, and preemptive coflow scheduling scheme to shorten the Coflow Completion Time (CCT) for TCP flows in data center networks (DCNs). In CGMPS, we propose both inter- and intra- coflow scheduling policies. In inter-coflow scheduling, we present P-SEBF, which adopts a connected-graph model based novel concept Partialcoflow,...
We investigate the local connectivity of cognitive radio ad hoc networks (CRAHNs), i.e., node degree and probability of node isolation. The local connectivity of CRAHNs depends on not only its own network parameters but also the primary networks. To analyze the local connectivity, we use stochastic geometry and probability theory to derive the distribution of node degree, probability of available...
In this paper, we propose a two-stage interference alignment (IA) scheme for the downlink of partially connected heterogeneity networks (HetNets), where the partial connectivity is induced by the path loss and the low transmission power of small cells. Particularly, in the first stage, the macro cell carries out conventional IA with a set of fully connected small cells. We derive the maximum number...
The influence of emitter layer thickness and interface defect states on the photovoltaic performance of bifacial HIT solar cell was simulated by the program of AMPS-1D developed by the Pennsylvania State University. The simulation results indicate that the conversion efficiency of the solar cell reduces with increasing the emission layer thickness. However, the influence of the emission layer thickness...
The temperature control of the rectification column is an important part of distillation process control system. For the time-delay and parameter time-varying characteristics in rectification column temperature control system, it puts forward neural network self-tuning PID controller method which combines the advantages of traditional PID control and neural network radial basis function (RBF). From...
An improved normalized min-sum (IN-MS) algorithm is proposed for decoding low-density parity-check (LDPC) codes. In this algorithm, two normalized factors are used in check node computing, one for the minimum data and another for the second minimum data, and this algorithm achieves a better approximation to the BP algorithm. Simulation results show that the decoding performance of IN-MS algorithm...
A novel configurable systolic array for Discrete Hilbert Transform (DHT) with any number of sample points is proposed for the applications, which have distinct number of the samples in different cases such as filter in Katsevich formula for cone-beam computed tomography (CBCT). The proposed array is based on the configurable matrix formulation of DHT, and it performs different procedure by the configurable...
A non-binary LDPC codes whose parity check matrix has uniform column weight 2 is constructed in this paper. The approach derives a non-binary LDPC codes from a column-weight 2 binary LDPC codes which is designed according to a all one (2, k) matrix, We proposed a search algorithm for constructing a (2, k) LDPC codes with desired girth, and in this paper, we use the search algorithm twice to obtain...
The stochastic state of the network should be given full consideration when a QoS routing algorithm is designed. This paper proposed an improved ant colony algorithm with multi-strategies for solving QoS routing problems by changing pheromone update rule and substituting the piecewise function for the probability constant which is chosen by ants when a route is selected. By instance simulation the...
Localization is a vital foundation in Wireless Sensor Networks (WSNs). However, most previous localization methods assume an idealistic radio propagation model that is far from reality. This will lead to inaccurate localization, since unknown nodes cannot receive enough location messages under the radio irregularity model. In our previous work “LMAT”, we solved the path planning problem of the mobile...
In this paper, a modified a posteriori probability (APP) based algorithm for the decoding of low- density parity-check (LDPC) codes is proposed. The modified APP-based algorithm utilizes an additional processing in the bit nodes to improve the accuracy instead of the check nodes normalization performed in normalized APP-based algorithm. The modified APP- based algorithm yields desirable trade-off between...
in this paper, we theoretically derive the suitable normalized factor of normalized BP-based algorithm of LDPC decoding in 802.11n system. To be specific, we compute 1.15, 1.25, 1.3, 1.35 as the suitable normalized factors with regard to R=1/2, R=2/3, R=3/4, R=5/6 code in 802.11n system respectively. These factors can compensate for the performance loss in UMP BP-based algorithm. By analyzing the...
In mobile P2P systems over 3G cellular networks, traditional peer selection algorithms with the idea of traffic localization are not suitable due to the architecture and characteristics of 3G cellular networks. In this paper we propose a novel peer selection algorithm named CFPL for mobile P2P systems over 3G cellular networks. By taking not only the available uplink bandwidth of peers but also the...
Through sensing and utilizing available network resources, cognitive network can obviously increase network performance. In this paper, a distributed on-demand routing protocol with traffic awareness (TACR) is proposed for cognitive wireless network. This routing protocol establishes the path based on the cognition and reasoning of traffic loads in a network and it also meet quality of service (QoS)...
A new LDPC decoding design aimed for a reduced finite word-length hardware implementation is proposed for WiMAX LDPC codes. In this design, normalized BP-based decoding method and layered decoding scheme are employed. The correction factor of the decoding method is chosen to simplify the multiplication. By analyzing the statistical distribution of variable node message, the word-length of bit node...
In this paper, we present simulation results evaluating the throughput performances of several high speed TCPs over OBS networks. We find that, among the five high speed TCPs including HSTCP, STCP, H-TCP, BIC, and CUBIC, in most cases BIC achieves the best throughput performances while STCP achieves the worst, and CUBIC will achieve throughputs remarkably lower than those of others when the burst...
In the fields of mobile phone and satellite communications, the quality of data transmission is required highly. In view of the hard space environment of high radiation for satellite, the hardening of anti-radiation must be considered during satellite communications for avoiding the phenomenon which influences communication or error, such as the SEU. Response to the request of the Consultative Committee...
To study the voltage transient process of the wind farm when there is fault in the power system on which the wind farm connected, constant speed wind machine with squirrel cage induction generator and variable speed wind machine with double fed induction generator were discussed based on their operation principle and structure. Two kinds of wind farms built by only one of the two kinds wind machines...
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