Research On Polar Codes And Its Applications In FSO Systems

Channel coding technology can bring coding gain, which can improve the performanceof digital communication systems. For a long time, in order to find a coding scheme that canachieve the shannon limit in channel capacity, researchers have put forward a lot of codingtheory, constructed a lot of coding schemes with good performance, but unfortunately none ofthem could achieve the shannon channel capacity limit theoretically. Until2007, Erdal Arikanproposed a new channel coding scheme based on the channel polarization theory, called thepolar code. In theory, the polar code can achieve the shannon channel capacity, and has lowercomplexity of the encoding and decoding algorithm. In this paper, the coding theory of polarcode and its applications in the free space optical communication system are studied.At first, this paper systematically expounds the basic principle of polar code, andanalyzes the encoding and decoding process of polar code and the performance of polar code.Then the basic theory of the laser transmission through the atmosphere in the links of the freespace optical communications is introduced, the influence of the atmospheric attenuation andatmospheric turbulence effects to the laser transmission is analyzed, and the channel model oflaser transmission through the atmosphere is given. Finally, the applications of polar code inthe free space optical communication system are studied. In order to study the performance ofthe applications of polar code in the FSO communication system, polar codes with differentcode length, code rate and under different turbulence intensities are simulated and analyzedrespectively.