中文摘要：

为了有效减小SC？FDMA系统的高峰值平均功率比（PAPR），采用DFT扩频技术对单载波频分多址（SC？FDMA）和正交频分多址（OFDMA）上行系统的PAPR性能进行比较与仿真分析。结果表明，这里采用DFT扩频方法能有效减小SC？FDMA系统PAPR，且明显优于OFDMA系统。

英文摘要：

In order to reduce the high peak average power ratio（PAPR）of the SC？FDMA system,the DFT spread spec？trum technology is adopted in this paper to perform comparison and simulation analysis for PAPR performances of single carrier frequency division multiple access （SC？FDMA） and orthogonal frequency division multiple access （OFDMA） uplink systems. The results show that DFT spread spectrum method adopted in this paper can effectively reduce PAPR of the SC？FDMA system, and is superior to the OFDMA system.