SPREADING MODULATION METHOD FOR REDUCING PEAK TO AVERAGE POWER RATIO IN TRANSMISSION POWER OF TERMINAL, AND APPARATUS THEREFOR

摘要

PURPOSE: A spreading modulation method for reducing a peak to average power ratio in transmission power of a terminal, and an apparatus therefor are provided to flexibly control transmission power of a terminal and control a cell area by limiting a range of a peak to average power ratio in the transmission power, and improve auto-correlation and cross-correlation characteristics. CONSTITUTION: A complex signal comprised of in-phase data I-data and quardrature- phase data Q-data is inputted to a complex spreader as a first input signal. A PN(Pseudo Noise)_1 generator(4) generates PN_1 sequence to a π/2 DPSK(Differential Phase Shift Keying) generator(6). The π/2 DPSK generator(6) generates complex spreading sequences PN_I and PN_Q by using the generated PN_1 sequence, where a phase change between complex spreading sequences PN_I and PN_Q is π/2, thereby removing zero-crossing. The generated complex spreading sequences PN_I and PN_Q are inputted to the complex spreader as second input signals. The complex signal is complex-spreaded by using the P_1 sequence and is respreaded by P_2 sequence.