Joint Optimization Of LDPC Based On SDN Technology

The Internet is of great research significance in the aspects of transmission security,transmission efficiency and transmission quality,when it's used for wireless communication transmission.In order to improve the transmission performance of wireless communication,the thesis focused mainly on the joint optimization of LDPC based on SDN technology.The specific job content and research results are as follows:(1)After the study and research based on the traditional LDPC check matrix construction algorithm,an improved PEG algorithm combined with matrix shift algorithm has proposed to realize the construction of check matrix.Above all,the nodes added to the tree were selected according to the number of each node in the check matrix and the current row/column of the shift matrix to be constructed to obtain the shift matrix.Next,a shift initial matrix with the same row/column weight as the shift matrix was constructed.The shift magnitude of the shift matrix elements constructed by the above method was set,and the shift matrix was obtained by cyclic shift processing of the initial shift matrix.Then,the shift matrix and the shift matrix were calculated and processed to get the check matrix.In the end,the performance simulation of the improved algorithm and the traditional algorithm was compared and analyzed.(2)The logarithmic domain BP decoding algorithm improvement scheme was put forward through the study and research of LDPC decoding algorithm principle.This thesis mainly contains two improvement points: First,the tangent/arc tangent function involved in the iterative process of decoding algorithm is approximated by linear fitting,and the linear function after processing is obtained;Second,a correction factor is introduced to correct the updated node information to reduce the error generated by the linear fitting function.The performance of the improved logarithmic domain BP decoding algorithm is compared with other algorithms.(3)On account of the advantages of SDN and LDPC,a new joint design architecture of LDPC based on SDN technology was proposed.First of all,LDPC codec function module and algorithm were designed in the controller of SDN network architecture,and the improved LDPC related algorithm was added to this module.In the next place,the packet header of Open Flow switch in SDN technology was designed.Finally,through the platform simulation,the new LDPC architecture based on SDN technology was analyzed and verified experimentally.