自由空间光通信中的CRC-LT编码性能研究  

Research on CRC-LT coding performance in free space optical communication

作　　者：曹阳 任发韬 彭小峰 张勋 陈果 Cao Yang;Ren Fatao;Peng Xiaofeng;Zhang Xun;Chen Guo(School of Electrical and Electronic Engineering,Chongqing University of Technology,Chongqing 400054,China)

机构地区：[1]重庆理工大学电气与电子工程学院,重庆400054

出　　处：《红外与激光工程》2018年第11期401-407,共7页Infrared and Laser Engineering

基　　金：国家自然科学基金(61205106);博士后科学基金(2014M552329);重庆市教委基金(KJ120827);重庆市教委科学技术研究项目(KJ1500934;KJ1709205)

摘　　要：LT码是一种无码率的线性分组码,具有很强的信道适应性和低复杂度。文中提出一种CRC码与LT码级联的编码方案(CRC-LT码),CRC-LT码通过调整译码开销来保证FSO系统的可通率和使LT码在FSO系统中获得的编码增益。通过建立分析模型,推导出在给定信道条件下的数据恢复率。最后,利用Gamma-Gamma信道模型进行CRC-LT码的编译码过程仿真,并给出数据恢复率与信道条件、信噪比和译码开销的关系,以及FSO系统的误码率。仿真结果表明,CRC-LT码在牺牲一定译码开销后能够获得更高的编码增益,有效保证FSO系统的可通率。Luby transform(LT)code is a rateless linear code,which has good channel adaptability and low complexity.A concatenated coding scheme of CRC code and LT code(CRC-LT code)was proposed to ensure the reliability of FSO system and improve the coding gain of LT code in FSO system by adjusting overhead.A new analytic model was developed to derive the data restoration probability with given conditions of channel.Finally,simulation experiments were performed over Gamma-Gamma channel model,and the relationships among data restoration probability,channel condition,SNR and overhead were given.The results show that CRC-LT code has better coding gain and can effectively enhance the reliability of the FSO system by increasing overhead.

关 键 词：LT码 CRC-LT码 FSO 可通率 数据恢复率 

分 类 号：TN911.22[电子电信—通信与信息系统]