A power-control method base on Downlink Piloting Time Slot (DwPTS) in a mobile communication
system. While a terminal is being accessed randomly, the terminal determines the transmitting
signal power at Uplink Piloting Time Slot (UpPTS) for open-loop
power control by using broadcast information and the measured DwPTS power. While the communications are being maintained, the
base station notifies the terminal of the required receiving power, the terminal then calculates the transmitting power for open-loop
power control by using the measured DwPTS power, which is taken as the reference transmission power of the
uplink channel and compared with the actual transmitting power required by the
base station for closed-loop
power control; the difference of the comparison is in turn compared with a threshold, if the difference is larger than the threshold, sum of the reference transmission power and the threshold is used as the power to perform transmission, otherwise, the closed-loop power control command is keeping executed. By taking the
advantage of the TDD mode in which the uplink and downlink transmissions are, carried out in the same conditions, the method makes full use of open-loop power control which has the merits of being simple and accurate so that complex outer-loop power control is not needed in closed-loop power control, making the RNC simpler and the
system more stable. hi addition, since it is the DwPTS power that is measured in the power control, the accuracy of power control is greatly improved.