Implementation and optimization of GPU-based parallel one-step leapfrog ADI-FDTD for far-field scattering problems

The one-step leapfrog alternative-direction-implicit finite-difference time-domain (ADI-FDTD), free from the Courant-Friedrichs-Lewy (CFL) stability condition and sub-step computations, is efficient when dealing with fine grid problems. However, solution of the numerous tridiagonal systems still imposes a great computational burden and makes the method hard to execute in parallel. In this paper, we proposed an efficient graphic processing unit (GPU)-based parallel implementation of the one-step leapfrog ADI-FDTD for the far-field EM scattering simulation of objects, in which we present and analyze the manners of calculation area division and thread allocation and a data layout transformation of z components is proposed to achieve better memory access mode, which is a key factor affecting GPU execution efficiency. The simulation experiment is carried out to verify the accuracy and efficiency of the GPU-based implementation. The simulation results show that there is a good agreement between the proposed one-step leapfrog ADI-FDTD method and Yee's FDTD in solving the far-field scattering problem and huge benefits in performance were encountered when the method was accelerated using GPU technology.