发明申请
US20090323846A1 METHOD AND APPARATUS FOR COMPUTING SOFT DECISION INPUT METRICS TO A TURBO DECODER
有权
用于计算软件决策输入度量到涡轮解码器的方法和装置
- 专利标题: METHOD AND APPARATUS FOR COMPUTING SOFT DECISION INPUT METRICS TO A TURBO DECODER
- 专利标题(中): 用于计算软件决策输入度量到涡轮解码器的方法和装置
-
申请号: US12111513申请日: 2008-04-29
-
公开(公告)号: US20090323846A1公开(公告)日: 2009-12-31
- 发明人: Nagabhushana Sindhushayana
- 申请人: Nagabhushana Sindhushayana
- 申请人地址: US CA San Diego
- 专利权人: QUALCOMM INCORPORATED
- 当前专利权人: QUALCOMM INCORPORATED
- 当前专利权人地址: US CA San Diego
- 主分类号: H04L5/12
- IPC分类号: H04L5/12
摘要:
A method and apparatus for computing soft decision input metrics to a turbo decoder includes circuits associated with eight-ary phase shift keyed (8PSK) modulation and sixteen-ary quadrature amplitude modulation (16QAM). In both implementations log-likelihood ratio (LLR) metrics on code symbols are estimated as products of various constant values and various combinations of the in-phase and quadrature components of a demodulated soft decision. In the implementation associated with the 16QAM modulation scheme, an estimate of the carrier-signal-to-interference (C/I) ratio is also used to estimate some of the LLR metrics. Estimates of the LLR metrics may also be obtained in association with generalized square QAM and M-ary PSK modulation schemes including, e.g., 64QAM, 256QAM, and 16PSK.