The effect of noise estimation error in the LDPC decoding performance

Abstract

The number of quantization bits of the input signals rn needs to be optimally determined through the trade-off between the H/W complexity and the BER performance in LDPC codes applications. Also, an effective means to incorporate a channel reliability Lc in the log-MAP based LDPC decoding is highly required, because it has a major effect on both the complexity and performance. In this paper so as to effectively incorporate Lc in LDPC decoding. The optimal number of quantization bits of rn is investigated through Monte-Carlo simulations assuming that bit-shifting approach is adopted. In addition, the effects of an incorrect estimation of noise variance on the performance of LDPC codes are investigated. There is a confined range in which the effects of an in correct estimation can be ignored