Filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) is an alternative to OFDM for enhanced spectrum flexible usage. To reduce the peak-to-average power ratio (PAPR), DFT spreading is usually adopted in OFDM systems. However, in FBMC-OQAM systems, because the OQAM pre-processing splits the spread data into the real and imaginary parts, the DFT spreading can result in only marginal PAPR reduction. This letter proposes a novel map-DFT-spread FBMC-OQAM scheme. In this scheme, the transmitting data symbols are first mapped with a conjugate symmetry rule and then coded by the DFT. According to this method, the OQAM pre-processing can be avoided. Compared with the simple DFT-spread scheme, the proposed scheme achieves a better PAPR reduction. In addition, the effect of the prototype filter on the PAPR is studied via numerical simulation and a trade-off exists between the PAPR and out-of-band performances.

翻译：偏移正交幅度调制的滤波器组多载波（FBMC-OQAM）是OFDM的一种替代方案，可增强灵活频谱使用。为降低峰均功率比（PAPR），OFDM系统中通常采用DFT扩展。然而，在FBMC-OQAM系统中，由于OQAM预处理将扩展数据拆分为实部和虚部，DFT扩展仅能实现微小的PAPR降低。本文提出一种新颖的map-DFT扩展FBMC-OQAM方案。该方案中，传输数据符号首先通过共轭对称规则进行映射，然后由DFT编码。这种方法可避免OQAM预处理。与简单DFT扩展方案相比，所提方案实现了更好的PAPR降低。此外，通过数值仿真研究了原型滤波器对PAPR的影响，发现PAPR与带外性能之间存在权衡。