Research On Parameter Identification Technology For Turbo Code

Modern warfare is an information warfare,if we want to win modern warfare,we must take the initiative,communication information reconnaissance plays a vital role in electronics warfare.In the field of non-cooperative communication,most parameters of intercepted information are unknown,and it is necessary to decipher the modulation and encoding schemes and corresponding parameters of the communication signal.This thesis investigates the technology of error correction coding identification,which is to perform bit level recognition on communication signals,carry out estimation and identification of coding parameters without little prior information,and obtain the intercepted original information.As a widely used communication coding scheme,the importance of Turbo code identification and analysis cannot be replaced in the field of communication reconnaissance.The commonly used Turbo codes are cascaded in parallel with two encoders and an interleaver.The coding identification analysis of Turbo codes is mainly on the generated polynomial coefficients of the encoder and the interleaving pattern of the interleaver,but with low signal-to-noise ratio and insufficient effective information,the correct rate of coding identification is very low.Therefore,in order to solve the problem of poor fault-tolerance of the algorithm,it is necessary to find a new solution to ensure that the fault-tolerance performance of the algorithm is stronger on the basis of a small increase in the amount of computation.This thesis aims to enhance the fault tolerance of Turbo coding identification.Firstly,it provides a brief overview of the background and significance of the topic is given,as well as the current research status of Turbo codes;The commonly used encoding and interleaving methods for Turbo codes are introduced;Finally,a new solution for recognizing interleaver patterns and encoder generated polynomials is proposed,which effectively solve the problem of poor fault tolerance and improve the identification rate under low signal-to-noise ratio conditions.The main research contents are summarized as follows:The encoding check function for the encoder generating polynomial is constructed,and the problem of solving the generating polynomial is transformed into a maximum value solution problem.The gradient of the generating polynomial parameters is obtained by using the function,and the generating polynomial parameters are updated iteratively according to the gradient ascent method to complete the identification of the encoder generating matrix.The simulation analysis verifies that the algorithm has better fault tolerant than traditional algorithms under the same conditions.The coding recognition equation is constructed to identify the interleaving relations.Based on the traditional conformity of the check equation,Gibbs algorithm is applied to correct and update the interleaving information each time so that the reliability of the information is enhanced in order to raise the fault tolerance of the algorithm,and the fault tolerance performance of the algorithm is verified by simulation analysis in dealing with the interleaving recognition problem of censored Turbo codes and non-censored Turbo codes.