NC-OFDM系统基于DFT-DCB降PAPR研究

Research of PAPR reduction based on DFT-DCB for NC-OFDM system

针对非连续正交频分复用调制信号高峰均比特点,提出了一种新的降峰均比方法。首先,将符号序列进行离散傅里叶变换;接着,将变换之后的数据按照当前的频谱空洞分布以及后续旁瓣抑制处理,划分成一个或多个最小子载波数受限的数据载波块,并在数据载波块之间插入合适的零数据块予以扩展;最后,将扩展后的数据通过快速傅里叶逆变换实现调制。以闭式表达式的形式给出了原始符号和经过扩展调制之后的信号之间的关系,从理论推导和仿真分析验证了该技术的有效性和可行性。

A novel technique is proposed to reduce the high peak-to-average power ratio（ PAPR） of the non-continuous orthogonal frequency-division multiplexing（ NC-OFDM） signals. Firstly,the symbols are transformed into frequency domain through discrete Fourier transform（ DFT）.Then,the frequency domain signals are divided into one or more data carrier blocks（ DCB） in accordance with the spectral distribution of current white space. The size of the DCB is not less than a certain number for the subsequent processes of the sidelobe suppression. Some zero data blocks are inserted into adjacent DCBs to get the expanded data. Finally,the expanded data are modulated by the inverse fast Fourier transform（ IFFT）. The closed-form expressions are presented to show the relationship between the original symbols and the modulated data. Theoretical analysis and experiment study show the effectiveness and feasibility of this technique.