码率自适应QC-LDPC码的研究

采用码率自适应分割和部分行合并2种方法来构造码率自适应准循环低密度奇偶校验（QC-LDPC）码，将一定码率的QC-LDPC码作为母码，得到一系列不同码率的子码。仿真结果表明，2种方法构造的码率自适应QC-LDPC码均表现出良好的性能，与基于有限几何直接构造出来的单个码率QC-LDPC；码相比，性能并没有损失。

Design of rate compatible QC LDPC codes

Rate-compatible quasi-cyclic low density parity-check (QC-LDPC) codes were designed with two construction methods. The first technique is based on code division, where a high-rate mother code is progressively divided into lower and lower rates; the other one adopts fractional row combination to yield a range of higher and higher rates form a relative low rate mother code. The two methods cover different ranges of rates. Simulation result shows that the performance of these constructed rate compatible QC-LDPC codes is as good as that of single rate codes which is straightly constructed based on the primitive elements of finite fields.