As the number of mobile devices accessing large-scale WLANs such as campus and metropolitan area networks increases, the need for load balancing among the cells becomes crucial. In addition, the network must also supp...
详细信息
As the number of mobile devices accessing large-scale WLANs such as campus and metropolitan area networks increases, the need for load balancing among the cells becomes crucial. In addition, the network must also support some minimum handoff tolerance defined by an application. This paper proposes a new metric that provides load balance as well as timely handoffs for WLANs by taking into account both direct and hidden node collisions.
Abstract: We study $H(\mathrm {div})$ preconditioning for the saddle-point systems that arise in a stochastic Galerkin mixed formulation of the steady-state diffusion problem with random data. The key ingredie...
Abstract: We study $H(\mathrm {div})$ preconditioning for the saddle-point systems that arise in a stochastic Galerkin mixed formulation of the steady-state diffusion problem with random data. The key ingredient is a multigrid V-cycle for an $H(\mathrm {div})$ operator with random weight function acting on a certain tensor product space of random fields with finite variance. We build on the Arnold-Falk-Winther multigrid algorithm presented in 1997 by varying the spatial discretization from grid to grid whilst keeping the stochastic discretization fixed. We extend the deterministic analysis to accommodate the modified $H(\mathrm {div})$ operator and establish spectral equivalence bounds with a new multigrid V-cycle operator that are independent of the spatial and stochastic discretization parameters. We implement multigrid within a block-diagonal preconditioner for the full saddle-point problem, derive eigenvalue bounds for the preconditioned system matrices and investigate the impact of all the discretization parameters on the convergence rate of preconditioned minres.
In this paper, we present simulation results for the bit error rate (BER) performance and the fading penalty of a BPSK subcarrier intensity modulation (BPSK-SIM) free-space optical (FSO) communication link in a log-no...
详细信息
ISBN:
(纸本)9781424449637
In this paper, we present simulation results for the bit error rate (BER) performance and the fading penalty of a BPSK subcarrier intensity modulation (BPSK-SIM) free-space optical (FSO) communication link in a log-normal atmospheric turbulence model. The results obtained are based on the Monte-Carlo simulation. Multiple subcarrier modulation schemes offer increased system throughput and require no knowledge of the channel fading in deciding what symbol has been received. In an atmospheric channel with a fading strength σ l 2 of 0.1 obtaining a BER of 10 -6 using a 2-subcarrier system will require a signal-tonoise (SNR) of 23.1 dB. The required SNR increases with the fading strength and at a BER of 10 -9 the fading penalty due to the atmospheric turbulence is ~ 41 dB for σ l 2 = 0.9. The comparative studies of the OOK and BPSK-SIM schemes showed that for similar electrical SNR, BPSK-SIM offered improved performance across all range of turbulence variance.
A DSP method based on sub-sampling followed by M-point FFT of the sub-sampled signal is used to reduce the phase-locked loop's reference spur. To validate the system's effectiveness a digital calibration loop ...
详细信息
This paper describes a 65nm 16-bit parallel transceiver IP macro, whose bandwidth is 4.8GByte/s with 5pf load including the HBM: 2000v ESD protection. Equalizers and CDR modules, CRC checkers and 8b/10b encoders are n...
详细信息
Applications performance is a criterion for system evaluation, and hence performance tuning for these applications is of great interest. One such benchmark application is High Performance Linpack (HPL). Although guide...
详细信息
Helping teachers in their activities has been an issue more and more explored in computerscience. However, in order to support teachers effectively, it is necessary to understand their needs and to design tools that ...
详细信息
A concept lattice based approach for analysis of class cohesion is presented. The approach facilitates rapid identification of less cohesive classes. It also helps identify less cohesive methods, attributes and classe...
详细信息
A concept lattice based approach for analysis of class cohesion is presented. The approach facilitates rapid identification of less cohesive classes. It also helps identify less cohesive methods, attributes and classes in one go. Further, the approach guides refactorings such as extract class, move method, localize attributes and remove unused *** effectiveness of the technique is demonstrated through examples.
暂无评论