CAJ | 학술논문

考虑到围长(girth)对低密度奇偶校验(LDPC)码的影响,提出了一种利用遗传算法构造大girth的准循环LDPC( QC-LDPC)码的新方法。该方法借助于计算机搜索,多次运用遗传算法,分步提高girth,在得到大girth 的同时,构造出具有准循环结构的LDPC码。分析发现,该构造方法的复杂度与码长成线性关系。仿真结果表明：在误码率( BER)为10-6时,新方法构造的QC-LDPC码比基于欧式几何构造方法、Gallager和Mackay构造法分别获得约0.15 dB、0.5 dB和0.2 dB的净编码增益( NCG),且因具有准循环结构更易于存储和硬件实现。
고필도위장(girth)대저밀도기우교험(LDPC)마적영향,제출료일충이용유전산법구조대girth적준순배LDPC( QC-LDPC)마적신방법。해방법차조우계산궤수색,다차운용유전산법,분보제고girth,재득도대girth 적동시,구조출구유준순배결구적LDPC마。분석발현,해구조방법적복잡도여마장성선성관계。방진결과표명：재오마솔( BER)위10-6시,신방법구조적QC-LDPC마비기우구식궤하구조방법、Gallager화Mackay구조법분별획득약0.15 dB、0.5 dB화0.2 dB적정편마증익( NCG),차인구유준순배결구경역우존저화경건실현。
A new method is proposed to construct a large girth quasi-cyclic low density parity check( QC-LDPC) code with Genetic Algorithm( GA) by consideration of LDPC codes under the influence of girth. This method depends on computer search,uses GA repeatedly,improves girth step by step. A large girth is obtained,at the same time LDPC codes with a quasi-cyclic structure is constructed. Analysis shows its complexity has a linear relationship with code length. Simulation results illustrate that when the bit error rate(BER) is 10-6 QC-LDPC codes constructed with the new method has net coding gain(NCG) of 0. 15 dB,0. 5 dB,0. 2 dB over LDPC code based on Euclidean Geometry,Gallager random codes and Mackay random codes,respectively,and it is easy to restore and be implemented in hardware because of quasi-cy-clic structure.