DEVICE AND METHOD FOR REDUCING THE PEAK-TO-AVERAGE POWER RATIO OF A MOBILE STATION'S TRANSMIT POWER

摘要

A device and method are provided for reducing the peak-to-average power ratio of a mobile station's transmit power in a mobile communication system by spreading and modulating the transmission data by a complex spreading sequence. The complex spreading sequence is generated to have a plurality of chips and a phase difference of 90~ between every two successive complex chips in response to each chip of a PN (Pseudo Noise) sequence. The device and method flexibly control the mobile transmit power by limiting its peak-to-average power ratio to a specific range and thus confining the mobile transmit power to a linear characteristic portion in a characteristic curve of a power amplifier. The phase of the complex spreading sequence is prevented from shifting by 180~ (i.e., .pi.) to maintain the mobile transmit power in the linear portion of the power amplifier characteristic curve.