Significance of Pre-freezing and Extra-freezing in 3GPP Standardized Punctured Polar Codes

• Main Authors: Chen, Ting-Ying, 陳亭穎
• Other Authors: Chen, Po-Ning
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/7m74z7

碩士 === 國立交通大學 === 電信工程研究所 === 108 === Polar coding is an innovative technology that was adopted by 3GPP as the error protection scheme for control channel in 2016. Its traditional structure, however, limits its code length to be a product of powers of primes. A solution is to introduce puncturing and shortening to adjust the code length to a desired arbitrary value. In this thesis, the puncturing scheme, together with the frozen set construction, standardized in 3GPP is studied. According to 3GPP standard, the frozen bits are selected in three steps: pre-freezing, extra-freezing, and reliability freezing. Evidences for the significance of pre-freezing and extra-freezing are then provided via extensive simulations. Our results indicate that a catastrophic error floor phenomenon may occur without pre-freezing even if the successive cancellation list (SCL) decoder is employed, and the absence of extra-freezing will induce a considerable performance degradation.