摘要
DVB-S2的核心编码LDPC码采用不同的码率来适应不同的信道条件,阈值分析是信道条件和码率选择的关键,介绍了用EXIT曲线图法来进行阈值分析,该方法比密度进化法计算量大大减少,使得阈值分析变得更加简单,还介绍了可变码率信道编码在DVB中的应用。
The LDPC code, which is the core channel coding in DVB-S2, takes variable rate to adapt to variable channel conditions. Threshold is an important parameter to decide which rate is the best for special channel conditions. In this paper, we present a new way to get the threshold of LDPC codes, i.e. we use EXIT chart to gain it. After lots of numerical simulations, we find that the thresholds got from EXIT chart are very close to those obtained from density evolution. And this method can reduce the amount of calculation. At the end of the paper, we introduce the application of variable channel coding used in DVB.
出处
《电视技术》
北大核心
2005年第1期76-78,共3页
Video Engineering
