无线光通信系统中极化码编译码技术

Encoding and Decoding of Polar Code in Free Space Optical System

摘要:

大气无线光通信系统中的湍流运动会降低系统误码性能。为此,将 Polar编译码技术引入无线光通信系统中,研究了极化码编码方法及其加入循环冗余校验的列表连续消除(Cyclic Redundancy Check-Successive Cancella. tion List,CRC-SCL)译码原理,并分别在高斯和湍流信道条件下进行了误码性能的蒙特卡洛仿真。结果分析表明, Polar编码对大气湍流信道的无线光通信系统可靠性有明显改善,在误码率为 10-3时,相较于未编码系统,基于 CRC-SCL译码的 Polar编码技术可获得约 6.3dB的编码增益。同时,码长越长,码率越低,编码系统误码性能越佳。

Abstract:

In an effort to improve bit error rate (BER) performance on the issue of light intensity fluctuation generated by at.mospheric turbulences, Polar encoding technique was invoked in free space optical (FSO) system. The improved Polar en.coding and decoding technique, as well as CRC-SCL technique were demonstrated based on the construction of free spaceoptical communication system. Meanwhile, the bit-error-rate (BER) performance in both Gaussian channel and turbu.lence channel was simulated based on Monte Carlo method. Theory analysis and simulation results show that the substan.tial improvement of BER performance is obtained with the aid of CRC-SCL decoding based Polar coding technique. Whenthe BER is 0.02, 2.5 dB coding gain is obtained compared with the performance of FSO system without coding. Additional.ly,it can be observed that, the BER performance is able to be improved as the length of code increases while the code ratedecreases.