一种降低Flip-OFDM系统LED非线性失真的动态补偿算法

发布时间：2018-04-26 23:17

本文选题：可见光通信 + 翻转正交频分复用　；参考：《计算机应用研究》2014年11期

【摘要】：针对可见光通信系统中翻转正交频分复用(Flip-OFDM)信号峰均较高导致LED非线性失真严重的问题,根据Flip-OFDM信号的单极性提出一种基于动态补偿的LED非线性失真抑制算法。首先通过最小化FlipOFDM负信号幅值确定部分传输序列(PTS)的加权系数,并对Flip-OFDM信号进行限幅(clipping),保证信号处于LED的准线性安全工作区域;然后根据正信号序列动态计算补偿信号,并承载到负信号对应的零信号位;最后接收端采用最大似然和门限判决联合检测方法,根据接收到的补偿信号恢复正信号,以降低限幅噪声。性能分析和仿真结果表明,与PTS-Clipping算法相比,动态补偿算法抑制峰均比和限幅噪声的性能更优,在误比特率为10-3处信噪比最多可有约5 dB的改进,可有效降低LED非线性失真,提高系统性能。
[Abstract]:Aiming at the problem that the high peaks of flipped quadrature frequency division multiplexing (OFDM) signals lead to serious nonlinear distortion of LED, a novel LED nonlinear distortion suppression algorithm based on the unipolarity of Flip-OFDM signals is proposed. Firstly, the weighting coefficient of partial transmission sequence is determined by minimizing the amplitude of FlipOFDM negative signal, and the amplitude of Flip-OFDM signal is limited to ensure that the signal is in the quasilinear safe working area of LED, and then the compensation signal is calculated dynamically according to the positive signal sequence. Finally, the receiver adopts the joint detection method of maximum likelihood and threshold decision to recover the positive signal according to the received compensation signal, so as to reduce the amplitude limiting noise. The performance analysis and simulation results show that compared with PTS-Clipping algorithm, the dynamic compensation algorithm has better performance in suppressing peak-to-average ratio and amplitude limiting noise, and the SNR can be improved by about 5 dB at the error bit rate of 10 ~ (-3), which can effectively reduce the nonlinear distortion of LED. Improve system performance.
【作者单位】：国家数字交换系统工程技术研究中心;东南大学移动通信国家重点实验室;
【基金】：国家“863”计划资助项目(2013AA013603) 东南大学移动通信国家重点实验室开放研究基金资助课题(2013D09)
【分类号】：TN919.3

【相似文献】