The Research Of Atmospheric Laser Communication In RS Concatenated Code

Since the wave length and high frequency of light waves, optical communication compared to traditional large capacity microwave communication with the advantage of large communication bandwidth, security, and the characteristics of strong anti-interference. The light transmitted in the atmosphere suffers from atmospheric disturb- ances will make error. Error control coding technique is to ensure reliable communication an effective means of transmission, concatenated codes of the channel coding has strong error control capabilities, and therefore the study of atmospheric laser communication channel coding technology is of great significance.This paper first describes the background of space optical communications technology development and research status, and then introduces some domestic research on the status of the concatenated codes, the paper studies provide some reference. The transmission of the laser in the atmosphere by the impact of atmospheric turbulence, this effect mainly caused by random variation of the refractive index of air molecules and the formation of a beam drift, such as point of jitter, beam expansion, light intensity fluctuations, phase fluctuations and other phenomena, These factors make the signal generating random errors and burst errors, concatenated code to correct not only random errors but also correct the burst error can be very effective in improving the quality of communication channel.This paper describes the basic concepts of error control coding and concatenated codes, analyzed the impact of atmospheric laser transmission, increasing flash intensity considered channel model is established. Simulation results show that concatenated codes with RS + BCH encoding on the channel capacity has been significantly improved than with a single error control, but also verify that the error rate increased as the flash intensity blinking, which is consistent with the theory.In order to further verify the improvement of the role of the channel coding, this paper built experimental system platform, comparing the experimental data and simulation data, it is more convincing to demonstrate the excellent performance of RS concatenated code. The experimental data and simulation data are basically the same, from the experiment demonstrated the superior characteristics of RS concatenated codes.Hardware encoding and high-speed data acquisition card can be used to improve the experiment.