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排列与置换的一个注记
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作者 潘庆年 《惠州学院学报》 1998年第4期58-61,共4页
本文讨论了置换与排列之间的区别与联系,给出了行列式定义的两种等价描述,并使用它来简化行列式性质的证明。
关键词 排列 置换 ()排列 ()置换
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Performance analysis of coded OFDM systems using a novel class of LDPC codes
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作者 何善宝 张立 赵春明 《Journal of Southeast University(English Edition)》 EI CAS 2004年第4期401-404,共4页
A new method of constructing regular low-density parity-check (LDPC) codes was proposed. And the novel class of LDPC codes was applied in a coded orthogonal frequency division multiplexing (OFDM) system. This method e... A new method of constructing regular low-density parity-check (LDPC) codes was proposed. And the novel class of LDPC codes was applied in a coded orthogonal frequency division multiplexing (OFDM) system. This method extended the class of LDPC codes which could be constructed from shifted identity matrices. The method could avoid short cycles in Tanner graphs with simple inequation in the construction of shifting identity matrices, which made the girth of Tanner graphs 8. Because of the quasicyclic structure and the inherent block configuration of parity-check matrices, the encoders and the decoders were practically feasible. They were linear-time encodable and decodable. The LDPC codes proposed had various code rates, ranging from low to high. They performed excellently with iterative decoding and demonstrate better performance than other regular LDPC codes in OFDM systems. 展开更多
关键词 Computer simulation Iterative methods Mobile telecommunication systems QUASICRYSTALS Turbo codes
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对置换群教学的新处理 被引量:1
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作者 杜海霞 潘燕玲 《价值工程》 2016年第7期186-187,共2页
讨论在教学中处理置换群的一种新的处理方法,以利于学生更好地理解教材内容。
关键词 置换 k-轮换 ()置换
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