The Research&Realization On Blind Identification Of Linear Block Codes

The recognition of linear codes is very significant in the field of digital communication.Under the basis of little or no prior condition,the system can recover the original information only according to the intercepted code information.The paper focuses on the blind identification of binary linear block codes.In this paper,the advantages and disadvantages of the existing algorithms are summarized.Based on the code weight distribution characteristics of block codes,this paper presents a recognition algorithm that combines code weight,Hamming distance and depth distribution.When the code length and starting point for traversing are correct,the weight similarity between coding sequence and random sequence code is minimum,which is firstly used to complete the identification of code length and the rough identification of starting point.The minimum Hamming distance of linear block code is not less than 3,which is then used to determine the roughly identified starting point.The characteristic that the nonzero depth value of (n,k) linear code is k is used to recognize the bit rate.Finally,the codes of nonzero depth value position are combined to be generation matrix.The experimental results show that the presented algorithm can solve the problem of blind identification.Compared with the existing partial algorithm,the recognition accuracy and the error adaptation of starting point recognition of the presented algorithm is obviously better.It has good engineering practicality.