一种基于PTS方法降低FBMC系统PAPR的新方法

A New Method of Reducing PAPR in FBMC System Based on PTS Method

在滤波器组多载波(Filter Bank Multicarrier,FBMC)系统中,通常采用部分传输序列(Partial Transfer Sequence,PTS)方法来降低系统的峰均功率比(Peak-to-Average Power Ratio,PAPR),然而该方法在传输过程中需要携带边带信息,会降低频谱利用率.对此提出了两点改进:在搜索最佳相位因子时,提出了新多层搜索方法,避免了相位因子的重复搜索,降低了计算复杂度;通过加入改进星座映射(Active Constellation Extension,ACE)方法,在接收端可以不需要边带信息即可快速解调出原始数据,虽然PAPR有所增加,但却显著提高了频谱利用率.通过计算和仿真验证了两个改进方案的有效性.

FBMC technology has become an effective technology for 5G networks, because it does not require a cyclic prefix, has less out-of-band energy leakage, and can flexibly utilize spectrum fragmentation and other advantages. However, an important issue in the FBMC system is the peak to average power ratio (PAPR). In a filter bank multicarrier system, the partial transfer sequence (PTS) method is usually used to reduce the peak-to-average power ratio (PAPR). Since this method needs to carry side band information in the transmission process, it may reduce the spectrum utilization. Aiming at the above problem, this paper makes some improvements in two aspects based on the PTS method. The first one is on the searching for the best phase factor and propose a new multi-loop search method such that it can avoid the repeated search and reduce the computational complexity. The second one is to introduce an improved constellation extension (ACE) method, by which the receiver can quickly demodulate the original data without the need for side band information, thereby improving the spectrum utilization and sacrificing a small amount of PAPR. Finally, the effectiveness of the two improved schemes is verified by calculations and simulations.