LTE-A上行链路子载波分配及PAPR性能的研究

Research on Sub-carriers Allocation and PAPR of LTE-A Uplink

LTE-A系统已经成为4G最具有竞争力的候选方案。LTE-A系统中多址技术上行采用具有单载波特性的DFT-S-OFDM(包括集中式资源分配和分布式资源分配,是单载波频分多址接入方式(SC-FDMA)的频域实现形式)和OFDMA的混合技术,下行采用OFDMA技术。文章着重研究了DFT-S-OFDM的子载波分配方式,进行理论分析推导,仿真出在不同调制方式下,SC-FDMA系统和OFDMA系统的PAPR(Peak-to-AveragePowerRatio)性能,分析得出OFDMA系统较SC-FDMA系统有大的PAPR值,且随着带宽的增大而增大;SC-FDMA系统的PA-PR不但与带宽有关,而且与调制方式和子载波映射方式有关。带宽越宽,PAPR越大;QPSK调制PAPR最小;集中式映射的PAPR比分布式映射的PAPR大。

LTE- A system has become the most competitive candidate of the 4G.In LTE- A, using DFT- S- OFDM technology,is the re- alization of the form of a single- carrier frequency division multiple access（SC- FDMA） in frequency- domain, including localized alloca- tion and distributed allocation with single- carrier character,and OFDMA technology in uplink,and in downlink, using OFDMA technolo- gy. In this paper, study the DFT- S- OFDM sub- carrier allocation principle. Simulation the PAPR performance of SC- FDMA system and the OFDMA system in different modulation mode, concluded that OFDMA system have the larger PAPR than SC- FDMA, and with the increasing of the bandwidth PAPR become larger,the PAPR of SC- FDMA not only reletent with bandwidth but alse with modulation and subcarriers mapping.The larger bandwidth the larger PAPR,QPSK has the smaller PAPR and localized mapping has larger PAPR than distributed mapping.