COMMUNICATION SYSTEM, COMMUNICATION METHOD, MOBILE STATION, AND BASE STATION

PROBLEM TO BE SOLVED: To make it possible for switching of a resource block (RB) mapping method to accurately follow a change in a delay spread and to realize high communication quality.SOLUTION: A mobile station comprises: downlink signal receiving means for receiving a downlink signal from a base station; first extracting means for extracting a downlink reference signal from the received downlink signal; calculation means for calculating a change occurred in the delay spread of the downlink signal from the extracted downlink reference signal; delay spread information generation means for generating delay spread information indicating whether or not the calculated change is equal to or more than a predetermined threshold value; and an uplink signal transmission means for transmitting the delay spread information as an uplink signal to the base station. The base station comprises: uplink signal receiving means for receiving an uplink signal; second extracting means for extracting delay spread information from the uplink signal; and resource block mapping method determination means for determining a mapping method of a resource block to be transmitted to the mobile station based on the extracted delay spread information.