Communication system, communication method for the same and mobile station and base station used for the same

A communication system, in which a mobile station measures a communication channel quality of each of a plurality of bands obtained by dividing a communication band of a downlink and transmits, a result of the measurement to a base station via an uplink, wherein said mobile station comprises:

• first means for selecting one of said plurality of bands, setting a measured value of the selected band to a restored value, obtaining relative value information of each adjacent band by comparing said restored value and measured values of both of the adjacent bands in a higher and lower directions of said one band respectively, and generating said relative value information as a bitmap by performing the same procedure as obtaining a restored value of said each adjacent band by increasing or decreasing by a predetermined step size according to said relative value information also for the adjacent bands thereafter;
• and
• second means for transmitting at least the communication channel quality information of said one band and said bitmap.