A fast algorithm based on MEI and FMM for field prediction in urban mobile communications

To meet the growing demand for high-capacity mobile communication services, micro-cell and pico-cell are now introduced. The prediction of the wave propagation in urban micro- and pico-cells is becoming very important in the design of a mobile communication system. In urban environments with many high buildings, the antenna height at the base station is usually below the level of the building roofs, and the wave diffraction at the top of buildings can be ignored. So these buildings can be modeled as parallel infinitely long conducting cylinders coated with lossy media, and the prediction of the wave propagation in the cell can be achieved by solving a two-dimensional scattering problem of multi-cylinders. We present a novel fast iterative algorithm (FAST-MEI+FMM) based on the combination of the FAST-MEI and the fast multipole method (FMM) for the prediction of wave propagation in urban micro-cells. By using the FMM in both calculating the MEI coefficients and the multiple scattering by multi-cylinders, the computing time is then down to O(N/sup 15/logN).