Methods and apparatus for providing a maximum likelihood (ML) decoding pipeline for quadruture phase-shift keying (QPSK) multiple-input-multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) receivers
US8817916B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2013 |
| Grant date | Aug 26, 2014 |
| Priority date | — |
| Expiry date | Oct 28, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03286
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus are provided for performing log-likelihood ratio (LLR) computations in a pipeline. Portions of a metric used to compute LLR values are computed in one pipeline part. The portions correspond to all permutations of some received signal streams. The portions are combined with one permutation x2 of the received signal stream that was not included in the previous pipeline computation in a subsequent pipeline part to produce M values associated with a particular bit position. At each subsequent clock cycle, a different permutation of x2 is combined with the previously computed portions producing different M values. State values corresponding to different values of bit positions of the received stream are computed by finding the minimum among the M values, in each clock cycle, that affect a particular bit position. The state values are combined to compute the LLR values for the bit position in a final pipeline part.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.