Patent ID: 7933558

Claim:
A method of estimating an arrival state of a radio wave at a plurality of reception points without pre-specifying a diffraction-considering reception point, the method comprising: a non-diffracted wave estimation operation of estimating an arrival state at each reception point of a radio wave other than a diffracted wave out of the radio waves transmitted from a transmission source by employing a first technique of estimating a radio wave propagation state, the first technique being a deterministic technique taking no diffraction effect into consideration; a diffraction-considering reception point choice operation of choosing one or a plurality of diffraction-considering reception points to be a point, at which the diffracted wave arrives, from among the plurality of reception points based upon the arrival state at each reception point of the radio wave other than the diffracted wave estimated in said non-diffracted wave estimation operation; a diffracted wave arrival state estimation operation of estimating an arrival state of the diffracted wave at the diffraction-considering reception point chosen in said diffraction-considering reception point choice operation by employing a second technique of estimating a radio wave propagation state, the second technique being different from said first technique of estimating a radio wave propagation state and the second technique including estimating a diffractive wave component; an operation of estimating the arrival state of the radio wave at said diffraction-considering reception point based upon the arrival state of the radio wave other than the diffracted wave estimated in said non-diffracted wave estimation operation and the arrival state of the diffracted wave estimated in said diffracted wave arrival state estimation operation; and an operation of defining the arrival state of the radio wave at each reception point other than said diffraction-considering reception point as the respective arrival state of the radio wave estimated in said non-diffracted wave estimation operation.