A communication base station includes a propagation time evaluation section which determines whether or not a propagation time required for a communication radio wave to propagate between the communication base station and a positioning device is within a predetermined allowable time range, a code phase calculation section which calculates a code phase of each satellite signal, a difference calculation section which calculates a difference between the code phase calculated by the communication base station and a positioning-side code phase, a difference evaluation section which determines whether or not the difference is within a multipath range which is a difference range when the positioning-side code phase is affected by a multipath, a correction value transmission section which transmits the code phase calculated by the communication base station to the positioning device when the difference evaluation section has determined that the difference is within the multipath range, and the like.