机载PLC非充分循环前缀加窗OFDM容量优化  

Optimizing airborne PLC capacity through insufficient CP and window in OFDM-based communication

作　　者：刘才艺 严若文 王彤[1] 李峭[1] LIU Caiyi;YAN Ruowen;WANG Tong;LI Qiao(School of Electronics and Information Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191

出　　处：《北京航空航天大学学报》2024年第8期2557-2564,共8页Journal of Beijing University of Aeronautics and Astronautics

基　　金：载人航天领域预先研究项目(060301)。

摘　　要：机载电源线通信(PLC)技术可以减少机载设备间布线的数量和复杂度,但电源线中多径分量衰减小,信道持续时间长,采用常规循环前缀(CP)设计方法,使用长度不小于信道最大多径时延扩展的CP,会导致容量非最优,可通过选择非充分CP,并结合加窗技术进行优化。基于此,采用对内外侧的子载波施加不同长度CP的边窗技术,以提高通信容量为优化目标,提出一种综合分析通信窗函数和内外侧子载波CP长度的参数设计方法。根据分段机载PLC通信的互连拓扑和频变阻抗,利用传输线理论,建立PLC信道衰落模型;分三阶段调整CP和窗函数参数,进行设计优化,第1阶段得到满足邻道干扰(ACI)约束下的最小加窗扩展长度,第2阶段在该窗函数条件下,调整CP长度增大系统容量,第3阶段通过边窗技术分别优化内外侧子载波,得到最终的优选参数。仿真实验分析表明:所提方法能够在减小ACI的同时避免正交频分复用(OFDM)符号的过度时域扩展,使保守的CP和窗函数选择导致的波特率损失得到改善,最终提高OFDM系统容量;同时,所提方法可以接近或达到全空间枚举的优化效果,且使计算量可接受。Power line communication(PLC)decreases cabling volume and reduces wiring harness complexity.Therefore,capacity is not optimal if sufficient cyclic prefix(CP)that is no shorter than the channel duration is employed.Multipath components,on the other hand,suffer modest attenuation in PLC channels,creating extended channel duration.Therefore,it is reasonable to adopt insufficient CP combined with a windowing scheme to maximize capacity.A comprehensive approach to jointly adapt window and CP parameters is proposed,using the edge-window method which applies different windows to inner and edge subcarriers.Using frequency-selective impedances and airborne PLC topologies,one can first simulate PLC channels in accordance with transmission line theory.The CP and window settings should then be adjusted in three phases.In the first stage,obtain the minimum window overhead under the restriction of adjacent channel interference(ACI).In the second stage,adjust CP length to optimize capacity with the window obtained in the first stage.In the third stage,using edge-window,optimize inner and edge subcarriers separately and finally obtain optimal parameters.The results of the simulation indicate that the suggested strategy might approach or meet the maximum capacity achieved by full space enumeration,avoid excessive time growth of orthogonal frequency division multiplexing(OFDM)symbols while lowering ACI,and make the computation volume acceptable.

关 键 词：电源线通信 信道建模 非充分循环前缀 边窗 容量优化 

分 类 号：N945.15[自然科学总论—系统科学] U283[交通运输工程—交通信息工程及控制] V21[交通运输工程—道路与铁道工程]