Research On Blind Recognition Technology Of Channel Coding

In the field of intelligent communication and communication detection,blind identification of channel coding plays an important role.In the intelligent communication system based on adaptive coding,how to quickly and accurately identify the coding parameters at the receiving end will greatly improve the flexibility and adaptability of the system,ensure the communication data transmission rate and spectrum resource utilization;Communication investigation must first complete the work of identifying the channel coding system,in order to carry out information level analysis and achieve source recovery.With the development of communication technology and the richness of channel coding theory,the demand for channel coding blind identification technology will become increasingly urgent.The reliability and real-time performance of identification analysis is a problem that the blind recognition theory of channel coding needs to solve.Although there are a large number of blind identification methods.However,these methods still have much room for improvement in terms of computational complexity and low signal-to-noise ratio.This paper focuses on the above two aspects and conducts in-depth research and discussion.The convolutional code can realize good fault-tolerant performance by Walsh-Hadamard transform method.However,the algorithm constructs a Hadamard matrix with high dimensionality and faces the problem of excessive computational storage when identifying high-rate convolutional codes.Aiming at reducing the computational storage of Walsh-Hadamard transform method,from the perspective of matrix dimension reduction,a method based on block Hadamard matrix for high rate punctured convolutional codes is proposed.The soft decision method makes full use of the reliability information in the coding sequence,and the recognition of the LDPC code by this method can obtain better recognition performance.With the decrease of signal-to-noise ratio,the correct recognition rate is greatly reduced.By analyzing the relevant parameters affecting the correct recognition rate,It is proposed to use the weighted log-likelihood ratio as the statistic to improve the recognition performance of LDPC codes in the case of low SNR.