Research And Implementation Of Encoding And Decoding For Polar Codes

With the rapid development of wireless communication technology,people's requirements for communication systems' reliability are getting higher and higher.Error correcting coding plays an important role in wireless communication,The use of superior performance coding technology is an effective way to improve system performance.Polar codes are an exciting new class of error correcting codes that achieve the symmetric capacity of memoryless channels,and the coding and decoding complexity is low,has become a hot topic in the field of coding.In this paper,we focus on decoding algorithm development and implementation.First of all,this paper expounds the causes and properties of channel polarization phenomenon,deduces the formula of polar code encoding and decoding,and analyzes the performance of polar code.Secondly,we studied and simulated the Successive Cancellation List(SCL)and the CRC Aided Successive Cancellation List(CA-SCL)algorithm for polar codes,compared with the decoding performance of low-density parity-check codes.Aiming at the poor performance of SC decoding algorithm and the high complexity of SCL algorithm decoding,we propose an improved low complexity decoding algorithm based on SC algorithm.By initially making the sequence fail CRC in the case of verification,the decoding information bits of the least reliable channel are reversed and the SC decoding is continued so that the decoding sequence is verified by CRC to obtain the decoding result.Finally,this paper introduces the software defined radio platform,designs SC decoder for polar codes,and builds a complete communication link based on the software radio platform,including polar codes encoding,BPSK modulation,framing,synchronization,BPSK demodulation,polar codes decoding.The final communication system was verified and tested.