Hard decision of the zero a posteriori LLR in 5G NR. Issue 2 (17th January 2020)

• Record Type: Journal Article
• Authors: Wu, Hao
• Is Part Of: Internet technology letters. Volume 3:Issue 2(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-01-17
• Subjects: a posteriori log likelihood ratio -- hard decision -- undetected error probability -- 5G NR; Internet -- Periodicals; 004.67805
• DOI: 10.1002/itl2.146
• Languages: English
• ISSNs: 2476-1508

Abstract

Abstract : The a posteriori log likelihood ratios (LLRs) have three kinds of values: negative, zero and positive. For the binary code, the hard decision is 1 when the a posteriori LLR is negative and is 0 when the a posteriori LLR is positive. To simplify the implementation of the decoder, the hard decision is usually 0 when the a posteriori LLR is zero since sign bits of zero and positive are the same. In 5G NR, this scheme increases the undetected error probability and the hard decision should be 1 when the a posteriori LLR is zero.