Improved Adaptive Successive Cancellation List Decoding of Polar Codes

Although the adaptive successive cancellation list (AD-SCL) algorithm and the segmented-CRC adaptive successive cancellation list ( SCAD-SCL) algorithm based on the cyclic redundancy check(CRC) can greatly reduce the computational complexity of the successive cancellation list (SCL) algorithm, these two algorithms discard the previous decodingresult and re- decodeby increasing L, where L is the size of list. When CRC fails, these two algorithms waste useful information from the previous decoding. In this paper, a simplified adaptive successive cancellation list ( SAD-SCL) is proposed. Before the re- decodingof updating value L each time, SAD-SCL uses the existing log likelihood ratio (LLR) information to locate the range of burst errorbits, and then re- decodingstarts at the incorrect bit with the smallest index in this range. Moreover, when the segmented information sequence cannot get the correct result of decoding, the SAD-SCL algorithm uses SC decodingto complete the decodingof the subsequent segmentation information sequence. Furthermore, its decodingperformance is almost the same as that of the subsequent segmentation information sequence using the AD-SCL algorithm. The simulation results show that the SAD-SCL algorithm has lower computational complexity than AD-SCL and SCAD-SCL with negligible loss of performance.