Non-coherent sequence estimation receiver for digital modulations
US6389079B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1999 |
| Grant date | May 14, 2002 |
| Priority date | — |
| Expiry date | Nov 10, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03337
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A non-coherent receiver for digitally modulated signals, linearly or not, possibly combined with channel coding, is described. In the case of M-PSK, or M-QAM modulations, the received signal is demodulated and filtered by a filter matched to the transmitted pulse. In the case of linear modulations in presence of intersymbol interference, and non-linear M-CPM modulations, the reception filter is of the whitened matched type. The signal is filtered and sampled and the samples are accumulated in a relevant memory containing N-1 samples preceding the current one. These samples are processed by a Viterbi processor estimating the sequence of transmitted symbols according to a maximum likelihood criteria. A first embodiment calculates suitable trellis branch metrics using an implicit estimation of the carrier phase in PSP mode (Per- Survivor-Processing). In a second embodiment, suitable trellis branch metrics are obtained from the expression of the maximum likelihood non-coherent sequence metric by proper truncation of their inherent memory to finite values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.