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Space laser communication is researched by more and more countries. Space laser communication deserves to be
researched. We can acquire higher transmission speed and better transmission quality between satellite and satellite,
satellite and earth by setting up laser link. But in the space laser communication system，the reliability is under
influences of many factors of atmosphere，detector noise, optical platform jitter and other factors. The intensity of the
signal which is attenuated because of the long transmission distance is demanded to have higher intensity to acquire low
BER. The channel code technology can enhance the anti-interference ability of the system. The theory of channel coding
technology is that some redundancies is added to information codes. So it can make use of the checkout polynomial to
correct errors at the sink port. It help the system to get low BER rate and coding gain. Reed-Solomon (RS) code is one of
the channel code, and it is one kind of multi-ary BCH code, and it can correct both burst errors and random errors, and it
is widely used in the error-control schemes. The new method of the RS encoder and interleaving based on the FPGA is
proposed, aiming at satisfying the needs of the widely-used error control technology in the space laser communication field.
An improved method for Finite Galois Field multiplier of encoding is proposed, and it is suitable for FPGA
implementation. Comparison of the XOR gates cost between the optimization and original, the number of XOR gates is
lessen more than 40% .Then give a new structure of interleaving by using the FPGA. By controlling the in-data stream and
out-data stream of encoder, the asynchronous process of the whole frame is accomplished, while by using multi-level
pipeline, the real-time transfer of the data is achieved. By controlling the read-address and write-address of the block
RAM, the interleaving operation of the arbitrary depth is synchronously implemented. Compared with the normal
method, it could reduce the complexity of the channel encoder and the hardware requirement effectively.
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