A Measure of the Girth Histogram for Improved Girth-Conditioning Construction of LDPC Codes

In this letter, we present a general quantitative measure of the girth histogram of low-density parity-check (LDPC) codes with joint consideration of the degrees and local girths of symbol nodes. We then propose a further girth-conditioning algorithm to optimize such a measure during the construction of LDPC codes. We show by simulation results that the algorithm improves not only the performance of irregular codes at high signal-to-noise ratios (SNR) considerably, but also the rates of regular codes