Method for generating constant modulus multi-dimensional modulations for coherent optical communications
US9621275B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 2014 |
| Grant date | Apr 11, 2017 |
| Priority date | — |
| Expiry date | Jun 12, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/34
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method generates constant modulus multi-dimensional modulations for coherent optical communications by first projecting points in a constellation of the code onto a Poincare sphere or its higher-dimensional hyper-sphere. By using meta-heuristic procedures, nonlinear programming and gradient search methods, constellation points in the hyper-sphere are optimized in certain criteria, such as maximizing the minimum Euclidean distance, minimizing the union bound, minimizing the bit-error rate, minimizing the required signal-to-noise ratio, maximizing the nonlinear fiber reach, maximizing the phase noise tolerance, and maximizing the mutual information. Some methods use parametric unitary space-time block codes such as Grassmannian packing, and filter impulse response as well as unitary rotation over adjacent code blocks to generate near-constant modulus waveform, not only at the symbol timing, but also over the entire time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.