Patent ID: 6035210
Filing Date: 2000-03-07
Classification: H04W

Abstract:
A transmission power control apparatus provided in a radio base station of a mobile communication system, adopting a CDMA system, in which there exist a plurality of mobile terminals, each including a radio signal reception and transmission device for radio communication with the radio base station, and a forward channel error measuring device for measuring a frame error rate of the forward channel radio signals from the radio base station so as to report it as a forward channel frame error rate to the radio base station, and the radio base station including a radio signal transmission and reception device for radio communication with the mobile terminal, a reverse channel error detecting device for detecting received data errors of the reverse channel radio signals from the mobile terminal, and a reception field strength measuring device for measuring a reception field strength of the reverse channel radio signals, the transmission power control apparatus comprising:the forward channel judging part for verifying communication quality of the forward channel based on the forward channel frame error rate reported from the mobile terminal, and judging a communication quality degradation when the forward channel frame error rate reported being worse than a predetermined threshold value with expecting no improvement; anda transmission power control part for controlling the transmission power of the forward channel based on the forward channel frame error rate reported, and controlling the transmission power of the reverse channel by providing instruction information of a transmission power increase to the mobile terminal when the reception field strength value actually having been measured being lower than an expected reception field strength value, based on the reverse channel frame error rate calculated, as the result of comparison, and providing instruction information of a transmission power decrease to the mobile terminal when the reception field strength value actually having been measured being higher than the expected reception field strength value, wherein the expected reception field strength value being set to a lower value than usual when having received the information of communication quality degradation of the forward channel from the communication quality of the forward channel judging part.