An Enhanced Iterative Clipping and Filtering Method Using Time-Domain Kernel Matrix for PAPR Reduction in OFDM Systems
An Enhanced Iterative Clipping and Filtering Method Using Time-Domain Kernel Matrix for PAPR Reduction in OFDM Systems
复制标题
一种使用时域核矩阵降低 OFDM 系统 PAPR 的增强型迭代限幅和滤波方法
DOI：
10.1109/access.2019.2915354
复制
发表时间：
2019-01-01
期刊：
影响因子：
3.9
通讯作者：
Wei, Jibo
中科院分区：
文献类型：
--
作者：
Liu, Xiaoran;Zhang, Xiaoying;Wei, Jibo
在正交频分复用（OFDM）系统中，迭代裁剪滤波（ICF）是一种降低信号峰均功率比（PAPR）的直接方法。近年来，凸优化被用于寻找使误差矢量大小（EVM）最小并满足PAPR约束的最优滤波器系数。然而，在求解凸优化问题时，可能会产生很高的计算复杂度。因此，我们开发了一种有效的PAPR减少方法，该方法使用时域核矩阵来产生PAPR减少信号。此外，我们还放宽了对剪切噪声是一系列不相关抛物脉冲的假设，并将所提出的方法应用于更一般的情况。该方法基于对裁剪噪声的瞬时观测，构造一个简单的时域核矩阵，并采用曲线拟合的方法优化相应的比例因子。仿真结果表明，该方法在PAPR减小和EVM方面都能达到与凸优化方法非常接近的性能，同时大大降低了计算量。此外，由于减少了迭代次数和计算复杂度，该方法比现有的一些裁剪和滤波方法效率更高。
Iterative clipping and filtering (ICF) is a straight-forward method for reducing the peak-to-average power ratio (PAPR) of signals in orthogonal frequency-division multiplexing (OFDM) system. Recently, convex optimization has been used to find the optimal filter coefficients that minimize the error vector magnitude (EVM) and meet the PAPR constraint. However, high-computation complexity may be incurred when solving the convex optimization problem. Therefore, we develop an efficient PAPR reduction method that uses the time-domain kernel matrix to generate the PAPR-reduction signal. Besides, we relax the assumption that the clipping noise is a series of uncorrelated parabolic pulses and apply the proposed method to more general cases. Based on the instantaneous observation of clipping noise, the proposed method constructs a simple time-domain kernel matrix and employs the curve fitting approach to optimize the corresponding scaling factors. The simulation results show that the proposed method can achieve very close performance to that using convex optimization in terms of both the PAPR reduction and EVM while the computational cost is reduced greatly. In addition, due to the decrease of iteration numbers and computational complexity, the proposed method is more efficient than some existing clipping and filtering methods.