Research On Blind Recognition Of Linear Block Code And Binary Pseudo Random Sequence

Blind identification of channel coding parameters is mainly through the known intercepted data,in a small amount of even without any prior knowledge of the coding parameters of the intercepted data to identify.With the application of channel coding technology in the field of digital communication more and more widely,the blind identification of channel coding parameters is becoming more and more important in the field of intelligent communication,military reconnaissance and interception and cooperative communication.This article focuses on linear block codes,cyclic codes and binary pseudo-random sequence identification methods,the main work is as follows:(1)Aiming at the problem of poor fault-tolerance performance of the current linear block code parameter blind identification method,the blind block identification method based on block matrix transformation is studied.The method firstly constructs an analysis matrix according to the estimated code length for the intercepted sequence,and performs a block matrix transformation on the analysis matrix.Then,the column weight of each column of the transformed matrix is used as a measure to set an adaptive threshold and counts the number of columns satisfying the threshold.The maximum number of related columns is the estimated code length.And the method can also identify the starting point of the code word.(2)Aiming at the problem that the fault-tolerant performance is poor in the blind identification algorithm of cyclic code parameters,a blind identification algorithm for cyclic code parameters based on generator polynomial reconstruction is proposed.First,the intercepted data is divided into the code word polynomial set according to the estimated code length and the estimated synchronization point,and the irreversible polynomial set is obtained by factorizing the corresponding xn+1 of the estimated code length n.Then,all code words polynomials are Mode 2 operation by each irreversible polynomial.The number of zero remainders is used as an object to determine whether the reduced polynomial is a generator polynomial according to a set threshold.The position parameter at the maximum of the common factor is the correct code length and the synchronization point,and the product of all the factors is the generator polynomial of the cyclic code.(3)For the existing binary pseudo-random sequence blind identification methods,there is a problem that needs to predict certain prior knowledge,poor fault-tolerance performance,and high algorithm complexity.A binary pseudo-random sequence blind recognition method based on polynomial library search algorithm is studied.Firstly,the Galois field Gaussian elimination is used to identify the order of the generator polynomial of the received sequence.Then the received sequence is divided into analysis matrices according to the order of the generator polynomial.In order to reduce the computational complexity of the algorithm,the search is performed in a limited polynomial library.The polynomial that can be matched with the analysis matrix is the generator polynomial of the received sequence identified by this method.