Efficient iterative solution of problems using characteristic basis function method combined with multilevel fast multipole algorithm

This paper presents an efficient technique to speed up the Characteristics Basis Function Method (CBFM) combined with Multilevel Fast Multipole Algorithm (MLFMA) by means of reducing the CPU-Time spent in the iterative resolution of the system. The combination of these techniques avoids the need of computing and storing many terms of the reduced coupling matrix that are not in or close to the diagonal, optimizing the CPU-time and the memory storage requirements.