In this paper, we propose a novel cooperative transmission scheme based on a symbol constellation expansion over Rayleigh and Rician multipath fading channels. The proposed scheme expands the symbol constellation through a unique combination of the original symbols, thus increasing the minimum distance among the single points. We also analyze the bit error rate (BER) performance showing that th...

A fractional trapezoidal rule type difference scheme for fractional order integro-differential equation is considered. The equation is discretized in time by means of a method based on the trapezoidal rule: while the time derivative is approximated by the standard trapezoidal rule, the integral term is discretized by means of a fractional quadrature rule constructed again from the trapezoidal r...

A fourth-order compact nite diierence scheme is employed with the multigrid algorithm to obtain highly accurate numerical solution of the convection-diiusion equation with very high Reynolds number and variable coeecients. The multigrid solution process is accelerated by a minimal residual smoothing (MRS) technique. Numerical experiments are employed to show that the proposed multigrid solver i...

A fourth-order compact nite diierence scheme is employed with the multigrid algorithm to obtain highly accurate numerical solution of the convection-diiusion equation with very high Reynolds number and variable coeecients. The multigrid solution process is accelerated by a minimal residual smoothing (MRS) technique. Numerical experiments are employed to show that the proposed multigrid solver i...

In this paper, we present a study of some high-order compact difference schemes for solving the Fitzhugh-Nagumo equations governed by two coupled time-dependent nonlinear reaction diffusion equations in two variables. Solving the Fitzhugh-Nagumo equations is quite challenging, since the equations involve spatial and temporal dynamics in two different scales and the solutions exhibit shock-like ...