The Simulation And Software&Hardware Implementation Of RS Coder&Encoder In Atmospheric Laser Communication System

Along with rapid development of shooting range’s constructing, requirement for self-propelled flexible embattling naval vessel carrier and long-distant manipulation is increasingly boosting up. Immense expansive application space for laser communication technology is provided with high-speed mutual coupling among equipments of shooting range, improvement on rapid communication link inside measure and control facilities and so on.As far as shooting range’s practical application, it has important realistic signification to resolve actual use demand of shooting range by adopting laser communication technology. Laser communication owns a good many excellency of high bandwidth, far communication distance, fine real time character, agile span, etc. However, it possesses disadvantage that laser communication channel is badly affected by weather factor such as brume and subaerial overfall. Therefore, it is signality for normal credible work of laser communication system to research channel error correcting coding technique and enhance the system’s error checking and correcting capability.In atmospheric laser communication system, Reed-Solomon code which has the capability to correct both random error and burst error is used to reduce BER (Bit Error Rate) to improve communication quality and meet the reliability requirement of data transmission. BER performance of RS codes is analyzed, and RS (15,9) hardware decoder based on RiBM (reformulated inversionless Berlekamp-Massey) algorithm is proposed. Decoder operates in pipeline architecture, and key equation is resolved by RiBM algorithm. Atmospheric laser communication system is simulated by adding AWGN (Additive White Gaussian Noise) in fiber, which is tested on FPGA (Field Programmable Gate Array) platform. The experimental result shows that decoding speed can be up to1.94Gbit/s, as3.54times over Altera’s IP core. RiBM algorithm has an advantage of low hardware complexity and short critical path delay, meeting the demands of the system.This article focuses on:1. Analyzing the influence of atmosphere channel on laser transmission, and studying thoroughly atmosphere channel model. Analyzing comparatively three codes of RS、Turbo、LDPC, combining the requirement of project and need in reality, ultimately drawing up design scheme based on RS codes as channel coding of atmospheric laser communication system.2. Analyzing the BER performance of RS codes utilizing Simulink modeling, and getting rid of blemish of images. MATLAB program’s software realization is presented based on expatiating RS coder and encoder theory.3. Designing RS(15,9) decoder hardware circuit based on RiBM algorithm using Quartus Ⅱ, besides FPGA implementation on fiber communication receiving and sending PCB(Printed Circuit Board) empoldered and self-made by Altium Designer. Through validating, RiBM algorithm can satisfy communication transmission demands of high velocity、high reliability and high real-time character in atmospheric laser communication system.