Abstract:

We present sparse factor graph representations of Reed-Solomon codes based on a fast Fourier transform. Similar "fast" transform factor graph representations are also presented for some extended Reed-Solomon codes. These representations can be used to create encoders, or message-passing decoders that use soft input information. We discuss various simplifications and transformations of the factor graphs that may be useful. Finally, we show that other interesting codes can be represented using sparse fast transform factor graphs.