Data transmission via multi-path channels using orthogonal multi-frequency signals with differential phase shift keying modulation
US9197470B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 6, 2008 |
| Grant date | Nov 24, 2015 |
| Priority date | — |
| Expiry date | Mar 24, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2697
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and an apparatus relating to an OFDM data communications system where the sub-carriers are modulated using differential quadrature phase-shift keying (DQPSK). The multi-carrier transmitted signal is directly generated using a summation of pre-computed sample points. As part of the multi-carrier signal generation, a signal for the guard interval is established. In an acoustic application of this approach, direct radiation of the sub-carrier approach is facilitated. Symbol synchronization in the receiver is based on signal correlation with the missed sub-carrier. Separation of the sub-carriers in the receiver uses a correlation of the received signal and reference signals that are derived from a table of pre-computed values. Optimal non-coherent processing of the sub-carriers without any phase tracking procedures is achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.