Quasi-orthogonal space-time codes
US7184488B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 15, 2002 |
| Grant date | Feb 27, 2007 |
| Priority date | — |
| Expiry date | May 13, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/0618
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for reducing the bit rate of multi-input systems that employ space-time coding by displacing in signal space the derivatives of a symbol. A mapped particular symbol is space-time coded to generate transmit-sequences having a phase-shifted version of the particular symbol, the phase-shifted version and the particular symbol differing in phase by an amount other than by 90°, 180°, and 270°. In one embodiment, the particular symbol represents a point in a first symbol constellation and the derivatives of the particular symbol represent points in a displaced symbol constellation. In another embodiment, the particular symbol and another symbol are space-time coded to form the transmit-sequences. The derivatives of the particular symbol represent points in a first symbol constellation and derivatives of the other symbol represent points of a second symbol constellation. The two constellations are displaced versions of each other. The displacement can be a phase shift and/or a change in amplitude. Illustratively, the two symbols are ones whose received versions interfere with each other after the two transmit-sequences are space-time decoded at the receiver. Displac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.