The Implementation Of The Hardware Decoder Of The Rs Code

The technology of error-correcting code has been widely used in the modern digital electrical area. As one kind of error-correcting code, RS code has been having a desired effect on many digital electrical applications. So this paper is contributed to the detailed discussion about the efficient algorithms of RS hardware decoder and the implementation of those algorithms in VHDL language that is easy to be transplanted. During the research, two different types of RS code are selected as the studying objects. They are [256,252] RS code and [255,223] RS code which has been adopted in the CCSDS Standard. And the main differences between them are: [256,252] RS code can correct two symbol errors and it is usually used to protect the stored data in the memory organization; [255,223] RS code can correct sixteen symbol errors and it is usually used to protect the transmitted data. Thus it can be seen that the two kinds of RS code is greatly different in the error-correcting ability and they have been used in different applications. Therefore, the studying of these two different RS hardware decoder has to be based on different decoding ideas. The decoding idea of [256,252] RS code is that considering the ability of [256,252] RS code and according to whether the supplement redundancy is true or not, the decoder makes out the error location and error value directly. The decoding idea of [255,223] RS code is that the errors of the received code is represented by two polynomials which have limited degrees, and then those errors is made out by the relationship between the two polynomials and those errors. Consequently, the two RS decoders are implemented by VHDL language in the direction of their decoding ideas and the throughput of each decoder is above 400Mbits/s within the timing constraints. And those decoders have their applications: [256,252] RS hardware decoder has been used in the solid-state recorder during the first Moon Exploration in my country; [255,223] RS hardware decoder can be used in the ground receiver system.