Method and an arrangement of estimating transmitted symbols at a receiver in digital signal transmission
US5596607A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1993 |
| Grant date | Jan 21, 1997 |
| Priority date | — |
| Expiry date | Jun 23, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03324
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a digital time-shared transmission system, a receiver receives a signal whose symbol rate is lower than the channel bandwidth of the system. A correlating and sampling circuit receives a baseband signal, samples the signal a number of times with each symbol time, performs channel correlation, generates a channel estimate and samples down the once sampled signal to an observed signal with two values for each symbol time. A channel equalizer executes a fractional viterbi algorithm which utilizes two delta-metric values for each state transition and generates estimated symbols. A channel estimating filter receives a symbol sequence of alternating zero-value symbols and the estimated symbols and generates an estimated signal. The channel estimating filter is adapted with the aid of an error signal and the filter delivers a channel estimate to the channel equalizer. Weighting factors are generated with the aid of the error signal and the two aforementioned delta-metric values are co-weighted to a common delta-metric value with the aid of weighting factors, this common delta-metric value being used to generate the estimated symbols. The use of the weighting factors improves the metric…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.