摘要
准正交空时分组编码(QOSTBC)是一种正交空时编码的变换编码结构,将时间分集和空间分集相结合,具有高效的分集利用率和编码效率。QOSTBC是解决大气湍流对光通信影响的有效手段之一。在研究了大气信道特性的基础上,提出一种基于QOSTBC结构和空间分集光通信系统的信道模型;介绍了QOSTBC原理,分析了系统的信道容量和误码率(BER);利用蒙特卡罗仿真比较了采用空时分集编码与未使用分集编码系统的容量及BER的情况。结果表明,使用QOSTBC系统的信道容量随发射天线数增加而递增,误码性能得到有效改善。QOSTBC与Alamouti编码系统相比系统信噪比节省约9dB,说明该系统具有编码所提供的良好信道容量和误码性能,能够有效地抑制大气湍流对光通信所产生的光强起伏影响。
Quasi-orthogonal space-time block coding（QOSTBC） is a transformational structure of orthogonal space-time coding.It is a time and space diversity technique.It has a highly efficient diversity utilization and coding efficiency.Over atmospheric turbulence channels,QOSTBC is an optical communication solution.By the study of the atmospheric channel characteristics,a QOSTBC model based on spatial diversity optical communication is proposed.The principle of QOSTBC is introduced.The channel capacity and bit error rate（BER） are analyzed.Using Monte Carlo simulation method,the channel capacity and the BER between diversity and no diversity coding system are compared.The results show that by using of QOSTBC the system′s channel capacity increases with the number of transmit antennas.The error performance is improved effectively.The system signal noise ratio（SNR） reduces 9 dB comparing QOSTBC and Alamouti coding system,which indicates that the coding system has provided a well channel capacity and error performance.The coding system can effectively inhibit optical intensity fluctuation of optical communication affected by atomspheric turbulance.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2012年第5期156-162,共7页
Chinese Journal of Lasers
基金
国家863计划(2008AA01Z225)
吉林省自然科学基金(20092DGG007)资助课题
关键词
光通信
空时分组编码
多发多收
大气信道
蒙特卡罗仿真
optical communications
space-time block coding
multi-input multi-output
atmospheric channel
Monte Carlo simulation
