关于LDPC密度进化理论分析不规则码字阈值，合理优化度分布，构造优异性能的LDPC码。以及高斯近似分析阈值的比较-Analysis of Density Evolution on the irregular LDPC code word threshold, optimize the degree distribution, excellent performance of the LDPC codes constructed. And the Gaussian approximation th

描述光强分布比，提高光强的辐射强度、描绘光强的幅强度-Describe the light intensity distribution, increase the intensity of the radiation intensity, depicting light intensity amplitude intensity