降低可见光DCO-OFDM系统峰均比的DCT-GCS方法  

PAPR Reduction by DCT-GCS Method in Visible Light Communication DCO-OFDM System

作　　者：张俊[1] 张剑[1] 王道岷 

机构地区：[1]解放军信息工程大学信息系统工程学院 [2]66403部队

出　　处：《信号处理》2015年第1期39-44,共6页Journal of Signal Processing

基　　金：国家自然科学基金(61271253)资助项目;国家863计划(2013AA013603)资助项目

摘　　要：为了克服现有降低OFDM峰值平均功率比的方法在可见光通信中效果不好的问题,通过分析发现DCOOFDM系统输入序列的共轭对称形式增强了序列的相关性,使传统方法的PAPR抑制性能有明显下降,所以提出了离散余弦变换(DCT)与分组循环移位(GCS)结合的降低系统PAPR的方法。该方法中的分组循环移位能够在DCT的基础上降低输入序列的相关性,使系统输出信号具有更低的PAPR。仿真结果表明:提出的方法比仅采用DCT或者GCS能够更好地抑制系统的PAPR。在CCDF=10-4时,DCT-GCS方法使系统的PAPR下降了5.4d B。DCT-GCS具有较低的PAPR,且计算复杂度要远远低于PTS和SLM方法。In order to overcome the problem that the existing methods have a poor effect to reduce the Peak-to-Average Power Ratio （PAPR）of Orthogonal Frequency Division Multiplexing （OFDM）system in visible light communication.The analysis shows that the conjugate symmetry property enhances the correlation of the input sequence so that the PAPR per-formance of conventional methods significantly decreased in the Direct Current-biased Optical-Orthogonal Frequency Divi-sion Multiplexing （DCO-OFDM）system.A novel method of combining Discrete Cosine Transform （DCT）and Grouping Cyclic Shift （GCS）to decrease the PAPR is proposed.Based on DCT,GCS of the proposed method could decrease the correlation of input sequence.So the system output signal would have a lower PAPR.Simulation results show that the pro-posed method is better to suppress the PAPR than when only using the DCT or GCS method.When the value of Comple-mentary Cumulative Distribution Function is equal to 1 0-4 ,the PAPR has decreased 5.4dB.DCT-GCS method has a low PAPR and the calculation complexity is much lower than the PTS and the SLMmethod.

关 键 词：可见光通信 峰值平均功率比 直流偏置光正交频分复用 离散余弦变换 分组循环移位 

分 类 号：TN911.7[电子电信—通信与信息系统]