低压电力线信道编码技术的研究

发布时间：2018-02-28 19:12

本文关键词： 电力线通信 LDPC码欧式几何(EG) 循环置换矩阵错误平台　出处：《中国石油大学(华东)》2014年硕士论文　论文类型：学位论文

【摘要】：电力线通信(Power Line Communication,PLC)作为我国智能电网重要的支撑技术得到了越来越多的重视,其分布广泛、连接方便、成本低廉,应用到数据通信系统中有着巨大的发展潜力。与无线通信信道相比,电力线噪声干扰强、阻抗变化大、信号衰减剧烈。选择合适的信道编码方案可以有效的增强信号抗干扰能力,降低系统的误码率,提高通信系统的可靠性,因此对电力线通信信道编码方法的研究具有十分重要的意义。LDPC码编码方法是由信息序列与生成矩阵相乘,尽管LDPC校验矩阵非常稀疏,但是生成矩阵并不稀疏,编码复杂度与码长的平方成正比关系,不能够满足处理能力相对较低的低压电力载波通信系统要求。因此系统采用基于欧式几何构造编码方法进行编码,以提高生成矩阵的稀疏性,降低编码复杂度,易于电力载波系统硬件实现,满足电力线载波通信系统对编码性能的要求。基于伽罗华域的欧式几何(EG)中,相交于同一点的两条直线和它们的交点可以构造出一个矩阵,然后用循环置换矩阵(CPM)替换该矩阵中的元素,这样就可以得到一类准循环的LDPC码,这类码的周长至少为8,与周长为6的LDPC码相比较,这类码的编码复杂度较低,且具有准循环结构。在搭建的电力线信道系统中仿真结果表明,与随机构造的经典码Gallager、Mackay码相比较,构造的LDPC码具有相当好的误码性能,更低的错误平台和快速的译码收敛速度。
[Abstract]:Power Line Communication (PLC), as an important supporting technology of smart grid in China, has been paid more and more attention. It is widely distributed, convenient to connect and low in cost. Compared with the wireless communication channel, the power line noise interference is strong, and the impedance changes greatly. The signal attenuation is severe. Choosing the appropriate channel coding scheme can effectively enhance the signal anti-jamming ability, reduce the bit error rate of the system, and improve the reliability of the communication system. Therefore, it is very important to study the channel coding method of power line communication. LDPC code coding method is multiplied by information sequence and generation matrix. Although the LDPC checksum matrix is very sparse, the generation matrix is not sparse. Because the coding complexity is proportional to the square of code length, it can not meet the requirements of low-voltage power carrier communication systems with relatively low processing power. Therefore, the coding method based on Euclidean geometry structure is adopted in the system. In order to improve the sparsity of generation matrix, reduce coding complexity, easy to realize power carrier system hardware, and meet the requirements of power line carrier communication system for coding performance, in Galois domain based Euclidean geometry EGG, Two straight lines intersecting at the same point and their intersection points can construct a matrix, and then replace the elements of the matrix with cyclic permutation matrix, so that a class of quasi-cyclic LDPC codes can be obtained. The length of the codes is at least 8. Compared with the LDPC codes with a perimeter of 6, the codes have a lower coding complexity and a quasi-cyclic structure. The simulation results in the constructed power line channel system show that the codes are compared with the randomly constructed classical code Gallagern Mackay code. The constructed LDPC codes have fairly good error performance, lower error platforms and fast decoding convergence speed.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.22

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