Concatenated coding on a spacecraft-to-ground telemetry channel: Method

Techniques for encoding and decoding in a concatenated coding scheme consisting of a convolutional inner code and a Reed-Solomon outer code were evaluated. The Reed-Solomon code has length 256, dimension 224, and is defined over an alphabet of 257 elements. Fermat number transform, long division, Berlekamp's algorithm, Euclidean algorithm, continued fraction expansion, and Chien search are discussed. A combination of techniques that meets the operational constraints, and that is best suited for the code under consideration in terms of logical and computational complexity is presented.