Propagation of LLR Saturation and Quantization Error in LDPC Min-Sum Iterative Decoding

In this paper we investigate the propagation in the decoding procedure of the error due to the finite-word-length representation of the LLRs, for the case of LDPC codes. A model is developed that quantifies the impact of the quantization error of the LLRs on the decoding performance, in case of iterative decoding using the Min-Sum algorithm. An older model, also developed by the authors, exploits the new one in order to estimate the performance of various LLR quantization schemes. Proposed model estimation is compared with experimental BER results, in order to be validated.