A blind recognition algorithm for the component encoder of punctured turbo code

To solve the problem of blind identification for the punctured Turbo code component encoder, this paper proposes an improved check matrix matching algorithm for this code. Due to the puncturing operation in the encoding process of the Turbo code, the receiver cannot obtain a complete recursive system convolutional code, the traditional blind recognition method is not suitable for the identification of punctured Turbo codes. Therefore, this algorithm has improved the structure of the recognition sequence, for the case where the code words of the Turbo code in the punctured bits is different from the corresponding RSC code, treat these bits as an error code with the same probability of "0" and "1", thereby returing those bits to zero and contrusting appropriate interception sequence to calculate the matching degree, according to the total distribution of the final matching degree, the parameters of punctured turbo code component encoder are identified. Simulation results show that for a punctured turbo code with a code length of 256 and a code rate of 1/2, the correct recognition rate can be maintained above 80% when the maximum bit error rate does not exceed 0.033.