Methods and systems for OFDM using code division multiplexing
US8111763B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2006 |
| Grant date | Feb 7, 2012 |
| Priority date | — |
| Expiry date | Aug 2, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/26134
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.