Transmission Power Control Method and Transmission Power Control Apparatus

摘要

A transmission power control method of a mobile station in a CDMA (Code Division Multiple Access) system which primarily controls transmission power of the mobile station by using a closed loop control which enables high accuracy power control. When the received power at the base station of a signal from the mobile station suddenly increases owing to the state of buildings surrounding the mobile station, the transmission power of the mobile station must be quickly reduced to prevent the interference to other mobile stations. The mobile station measures an average value of the received power per transmission power control period of a desired signal from the base station, and detects the difference DELTA RSSI between the current average value and that of one of the previous transmission power control periods. If DELTA RSSI exceeds a reference power difference DELTA Pth, transmission power PT corresponding to DELTA RSSI is set by using an open loop transmission power control to quickly reduce the transmission power of the mobile station. If DELTA RSSI is lower than DELTA Pth, the transmission power PT is determined in accordance with the transmission power control bit sent from the base station.