宽带卫星移动信道中的OFDM与CI-OFDM性能比较  

Comparisons between OFDM and CI-OFDM over Wideband Satellite Mobile Channel

作　　者：程磊[1] 童新海[2] 吴久银 王庚润[4] 孔博[1] 

机构地区：[1]解放军理工大学通信工程学院研究生3队,江苏南京210007 [2]解放军理工大学通信工程学院 [3]南京6902科技有限公司,江苏南京210009 [4]解放军理工大学通信工程学院研究生4队

出　　处：《军事通信技术》2013年第2期39-44,56,共7页Journal of Military Communications Technology

基　　金：国家高技术研究发展计划(863计划)资助项目(2012AA01A505;2012AA01A508)

摘　　要：近年来,载波干涉正交频分复用(CI-OFDM)作为一种非传统的OFDM改进技术受到众多关注。相比OFDM系统,CI-OFDM系统在发送端IFFT之前增加了一个CI码扩展模块,在接收端FFT之后增加了CI码解扩和均衡模块,这些模块可使得CI-OFDM系统在不降低系统传输率的同时获得频率分集增益,有效克服无线通信中的多径衰落。另外,CI码的存在可以均匀错开调制信号时域波形的峰值,有效降低信号的峰均比(PAPR)。研究人员大多关注CI-OFDM技术的理论研究,少有学者研究其在宽带卫星移动通信中的应用。因此,文章重点将CI-OFDM技术应用在关注功率效率和多径传播以及星上高功放的宽带卫星移动通信中。仿真结果表明,除以上优点外,在宽带卫星移动信道中CI-OFDM比传统的OFDM误码率更低,抗非线性性能更强。Recently, Carrier Interferometry Orthogonal Frequency Division Multiplexing （CI-OFDM） has attracted significant interest as an alternative technique to OFDM. Compared with an OFDM system, a CI-OFDM System adds a CI spreading module before the Inverse Fast Fourier Transform（IFFT） module at the transmitter and a CI de-spreading module with an equal- izer after the FFT at the receiver, which can get frequency diversity gain and combat the undesir- able effects of the frequency selective channel in a simple and an efficient way while remaining spectral efficiency of the system. In addition, each individual CI-OFDM symbol has its peak when all the other symbols are at their minimum, avoiding the constructive addition of the subcarrier peaks that leads to a high Peak-to-Average Power Ratio（PAPR）. While many researchers cared about the theoretical research of CI-OFDM, few people applied it to Wideband Mobile Satellite Communications （WMSC）. Accordingly, the paper bears down on the application of CI-OFDM in WSMC. Simulation results show that bit error rate performance of CI-OFDM is lower than that of the conventional OFDM in a wideband channel model and its ability of anti-nonlinearity outper- forms OFDM, while remaining its coherent advantages mentioned above.

关 键 词：载波干涉 正交频分复用 宽带卫星移动信道 峰均比 误码率 

分 类 号：TN927.23[电子电信—通信与信息系统]