Research On The Identification Method For LDPC Codes

In order to improve the spectrum efficiency of cooperative communication and meet the requirement in communication reconnaissance, we need to analyze the channel code type and parameters of the received data so that the receiver can react effectively, in which the channel encoding identification technology is used. This technology can identify the parameter of the received data without or with a little prior knowledge and will have a very broad prospects.In this paper, we studied the identification method of LDPC codes and solved the identification of its code parameters and starting point. The length of LDPC code is larger than the ordinary channel code, and the data size of the check matrix and generator matrix is relatively large. Most of the existing algorithms are based on the hard decision data to identify the probability of the parity relationship. Because of discarding the soft information, the recognition performance is still to be improved when SNR is very low. Therefore, it has been studied to use the soft information of the channel output to map the parity relationship to the LLR domain, and then identify the encoding parameter set, which increases the computational quantity in the process.In order to improve the recognition performance, this paper proposed a method of LDPC code recognition based on extraction of peak feature. Theoretical analysis and computer simulation results show that the proposed algorithm can maintain good recognition performance in the case of low SNR and reduce the computation of the algorithm to more than half of the algorithm, which can meet the real-time requirements of the actual project.The method in this paper has been tested by the test platform and met the requirements of the project indicators.