Patent ID: 6944469

Claim:
A transmission power controlling apparatus in a mobile communication system supporting a single FA (Frequency Allocation), comprising: a channel device group for generating an I (In phase) channel baseband signal and a Q (Quadrature phase) channel baseband signal from channel data; a pulse shaping filter for pulse-shape-filtering the baseband signals; a power controller for controlling the PAPRs (Peak-to-Average power Ratio) of the pulse-shape-filtered signals according to a threshold power required for linear power amplification; and a frequency converter for upconverting the power-controlled signals to RF (Radio Frequency) signals and outputting the RF signals, wherein the power controller comprises: a scale determiner for receiving original I and Q channel signals from the pulse shaping filter, measuring the instant power of the original I and Q channel signals at each sampling period, comparing the instant power with the threshold power, and determining scale values according to the comparison result; a cancellation signal calculator for calculating target signals by multiplying the original I and Q channel signals by the scale values and calculating cancellation signals by subtracting the original I and Q channel signals from the target signals; a signal delay for delaying the original I and Q channel signals by a time required for the operations of the cancellation signal calculator and the scale determiner and a summer for adding the delayed signals to the pulse-shape-filtered signals.