Method and apparatus for high-speed data transfer employing self-synchronizing quadrature amplitude modulation
US9571326B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2010 |
| Grant date | Feb 14, 2017 |
| Priority date | — |
| Expiry date | Nov 29, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3818
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A Quadrature Amplitude Modulation (QAM) method and apparatus including a QAM transmit modulator with at least one unbalanced mixer, which creates an asymmetric two-dimensional (2-D) QAM symbol constellation. The asymmetrical symbol constellation provides baseband symbol clock signal leakage sufficient to facilitate quick and simple baseband symbol clock recovery and signal channel compensation at the QAM receiver without significantly degrading the system bit-error rate (BER). While slightly degrading static BER, overall system performance is improved when considering baseband symbol clock recovery and received signal compensation for an imperfect signal channel. This allows QAM to be deployed in systems where QAM is otherwise prohibitively expensive and improves overall system performance for any existing QAM system application without additional bandwidth, cost or complexity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.