The RS(Reed-Solomon) code is an important linear block and used for solving the problem of serious distortion and
BER(Bit Error Rate) in the atmospheric laser communication system. RS (255,223) code are selected as channel code.
Meanwhile, technologies for the laser communication system such as encode, interleaving, decode have been discussed
in details. In this paper, an improved RiBM algorithm is adopted in the key equations solver of decoding algorithm. In
the Forney's algorithm, inversion circuit in finite field is adopted. Then, division operation in the error value is
realization by subtraction of power exponent. As a result, the whole decoding chip obtains the optimization in the speed
and the usage resources. The hardware structure design and algorithms program have been finished on FPGA according
to CCSDS specification. The BER performance verification has been applied in Visual C language. The experiment
results show that coded data can obtain SNR (Signal-to-Noise Ratio) gain of 3-5dB when BER requirement of 10<sup>-5</sup> is
satisfied in this system.