自由空间光通信中LT码的编码技术研究

Research on Coding Technology of LT Code in Free Space Optical Communication

摘要:

为了克服大气湍流对自由空间光通信（FSO）链路的影响，将LT码应用到FSO系统中，并结合基于部分信息LT码的修正转移鲁棒孤子分布(ISRSD)，模拟了不同大气湍流强度信道，采用不同的编码方案进行模拟比较，结果表明：与RS码相比，误码率为10-4时，LT码获得大约2dB的编码增益；相比于RSD，ISRSD能使译码开销降低1%~2%，且LT码采用ISRSD后，误码率为10-7时，系统获得0.2~0.5dB的编码增益。

Abstract:

Free space optical communication (FSO) is susceptible to the effects of atmospheric turbulence effect. In order to overcome the influence of atmospheric turbulence on the FSO link, the LT code combined with the improved shifted robust soliton distribution (ISRSD) based on the partial information is applied to the FSO system. Different atmospheric turbulence intensity channels are simulated and different coding schemes are also used for simulation comparsion, the simulation results show that compared with RS code, the LT code obtains a coding gain of about 2dB when the bit error rate (BER) is 10-4. Compared with RSD, ISRSD can reduce the decoding overhead by 1% to 2%, and the system further obtains a coding gain of 0.2~0.5dB when the bit error rate (BER) is 10-7 after the LT code is using ISRSD.