Blind Recognition of 5G LDPC Codes Over a Candidate Set

Blind recognition of channel codes is an important technology in Adaptive Modulation and Coding (AMC) systems. Shortening and puncturing have been adopted to achieve flexible code rates and code lengths for different application scenarios in 5G Low Density Parity Check (LDPC) codes, which leads to a challenge for their blind recognition. In this letter, a novel Extended Exponent Matrix (EEM) reconstruction method is proposed to find complete parity checks for punctured codes, which offers the feasibility of Log-Likelihood Ratio (LLR) based blind recognition of punctured linear block codes over a candidate set. Simultaneously, a lifting size parallel operation via the quasi-cyclic property of 5G LDPC codes and limited weights of parity checks are employed in our proposed algorithm to efficiently reduce the reconstruction complexity. At last, simulation results are presented to show the effectiveness of our reconstruction algorithm.