有效降低系统PAPR的低复杂度SLM方案

Low-complexity SLM scheme for PAPR reduction in OFDM systems

为了降低正交频分复用系统的峰均功率比(peak-to-average power ratio,PAPR),提出了一种基于分块思想的低复杂度PAPR抑制方案。该方案首先将原始信号等分为两个子块,然后将每个子块数据通过快速傅里叶逆变换处理后,与转换向量进行循环卷积生成备选子块序列,同时引入随机相位序列生成更多的备选子块序列。最后,从两个备选子块序列中分别挑选出PAPR最小的子块序列,合并成最优信号进行传输。性能分析表明,当每个转换向量模块生成的备选子块数量大于等于5时,提出的方案可以在保持较低计算复杂度的同时,实现PAPR性能的大幅度改善。

In order to reduce the peak-to-average power ratio（PAPR）of orthogonal frequency division multiplexing systems,a low-complexity scheme based on partition is proposed.In this scheme,the original signal is first equally divided into two sub-blocks.Each sub-block data is processed by inverse fast Fourier transform and circular convolution with the conversion vector to generate candidate sub-block sequences.At the same time,a random phase sequence is used to generate more candidate sub-block sequences.Finally,from two candidate sub-block sequences,two sub-block sequences with the smallest PAPR are selected separately and combined into the optimal signal for transmission.Performance analysis shows that when the number of candidate subblocks generated by each conversion vector is greater than or equal to 5,the proposed scheme can greatly improve PAPR performance while maintaining low computational complexity.