Modal decomposition and modal cluster decomposition on two-dimensional frequency domain (real-time filtering of each modal cluster)

This paper examines a method for the design of a real-time filter for extrcating a desired modal cluster, which is decomposed on a two-dimensional frequency domain. At first, the realization method of modal cluster decomposition was revisited. Then, in order to extract the desired modal cluster on real-time, we derived a design method of a time domain filter based on a theory for two-dimensional FIR filter. This filter computes the simple summation of current signals for a spatial direction, and hence there is no time delay to extract the signal of a desired modal cluster. As a numerical example, it was shown that the real-time filtering of the desired modal cluster can be successfully realized with low computational cost and without time delay.