Impact of LLR saturation and quantization on LDPC min-sum decoders

In this paper we quantify the power of noise due to quantization and saturation of the LLRs. Subsequently a model is constructed using the obtained noise power expressions that can be used to estimate the performance of various LLR quantization schemes. The model is validated by comparing the estimation with experimental BER results for an LDPC-based system that uses the min-sum layered decoding algorithm.