Invention Grant
- Patent Title: Soft-demapping of QAM signals
- Patent Title (中): QAM信号的软解映射
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Application No.: US13384932Application Date: 2010-08-06
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Publication No.: US08879653B2Publication Date: 2014-11-04
- Inventor: Yunxin Li
- Applicant: Yunxin Li
- Applicant Address: AU Fitzroy
- Assignee: Nitero Pty Limited
- Current Assignee: Nitero Pty Limited
- Current Assignee Address: AU Fitzroy
- Agency: Hickman Palermo Truong Becker Bingham Wong LLP
- Priority: AU2009903716 20090807
- International Application: PCT/AU2010/000996 WO 20100806
- International Announcement: WO2011/014926 WO 20110210
- Main IPC: H04L27/22
- IPC: H04L27/22 ; H04L27/38 ; H04L27/34 ; H04L25/06 ; H04L25/02 ; H04L25/03 ; H04L27/26

Abstract:
This invention concerns soft-decision demapping of Quadrature Amplitude Modulation (QAM) signals to enable soft-decision channel decoding in a communications system. In a first aspect the invention is a method for performing the soft-decision demapping of Quadrature Amplitude Modulation (QAM) signals to enable soft-decision channel decoding in a communications system. The method comprises the steps of Extracting baseband signals from both I-and-Q channels. Sampling the baseband signals to extract a stream of complex numbers. Converting the stream of complex numbers to frequency domain vectors with components for each subcarrier frequency. Approximating bit log-likelihood ratios for each symbol directly from the real and imaginary parts of the corresponding frequency vector, without equalization by the estimated channel. And, soft-decoding of the channel codes using the approximated log-likelihood ratios. In other aspects the invention concerns a device for performing the method and software for performing the method.
Public/Granted literature
- US20120134452A1 SOFT-DEMAPPING OF QAM SIGNALS Public/Granted day:2012-05-31
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