A communication method applied to a mobile station in a code division multiple access system transmitting uncompressed frames and compressed frames, the method including: receiving transmission power control information indicating an increase or decrease in power and a compressed frame including a transmission gap from a base station; adjusting transmission power on the uncompressed and the compressed frames in accordance with the transmission power control information, by increasing or decreasing current power with a first power control step size for the uncompressed frames, and with a plurality of power control step sizes for the compressed frames, the plurality including at least one power control step size larger than the first power control step size; and transmitting the uncompressed and the compressed frames in accordance with the adjusted transmission power, wherein the transmission gap included in the compressed frame transmitted from the base station is used to observe other frequency carrier.