Research On Encoding Structure And Decoding Algorithm Of Polar Code

Since Shannon created information theory,channel coding technology has played an important role in the development of modern communication technology.Scholars from various countries have proposed many coding methods based on channel coding technology.Among them,the Polar Code proposed by Professor Erdal.Ar?kan in 2007 is the only coding technology that has been proved to reach the Shannon limit theoretically.Moreover,the coding structure and decoding of polarization codes have lower computational complexity.Therefore the polar codes have attracted the attention and research of many scholars.Based on the principle of channel polarization,the polar codes make the difference of channel capacity,and then the reliability of the channel is estimated.The information bits are transmitted in the channel with better reliability,while the frozen bits are transmitted in the channel with worse reliability.Then the coding structure is completed by combining the generated matrix.In terms of decoding,The Successive Cancellation Decoding(SC)algorithm is the most basic decoding algorithm for polar codes.The decoding algorithm always decodes bit by bit on a single path.When a bit is erroneously decoded,subsequent decoding will continue to decode in this error path,resulting in an unsatisfactory actual decoding performance.The Successive Cancellation List Decoding(SCL)algorithm is an improved algorithm of the SC decoding algorithm.This decoding algorithm keeps as many decoding paths as possible in the decoding process.The decoding performance of the polar code is improved at the cost of a certain decoding complexity.The combination of SCL decoding algorithm and Cyclic Redundancy Check which called Cyclic Redundancy Check-Successive Cancellation List Decoding(CRC-SCL decoding algorithm)can further reduce the probability of missing correct decoding while retaining multiple paths in SCL decoding without increasing the computational complexity of SCL decoding algorithm.Because of the excellent performance of polar codes in theory,the channel polarization principle of polar codes and the corresponding channel selection methods in different channels will be discussed and simulated in this paper;the coding process of polar codes based on channel polarization principle will be elaborated;the SC decoding algorithm,SCL decoding algorithm and CRC-SCL decoding algorithm of polar codes will be emphatically studied and simulated.Moreover,different CRC check codes are improved on the SCL decoding algorithm,and the performance differences they may produce are simulated and analyzed,so that a suitable combination of CRC codes and polar codes can be obtained.