【摘要】 基于光正交码构造了一类新的不规则OOC LDPC码.新的LDPC码是准循环码,其编码复杂度与码长成线性关系,具有编码复杂度低的特点,它所对应的双向图中没有四线循环.用和积译码算法对新的码字进行了仿真,结果表明,与具有类似参数的随机码和规则OOC LDPC码相比,当信道误码率为10-5时,译码增益分别为0.3和0.15dB.更多还原

【Abstract】 Based on the optical orthogonal codes, a method for constructing irregular LDPC （low-density parity check） codes was presented. These LDPC codes are quasi-cyclic codes and can be encoded with low complexity with a linear relationship to code length. These codes have Tanner graphs free of 4-cycles. They perform well with the sum-product iterative decoding. Compared with random codes and regular LDPC codes based on the optical orthogonal codes with similar parameters, they have decoding performance gains respectively about 0.3 and 0.15 dB when bit error rate is 10^-5.更多还原