Method and apparatus for encoding/decoding QAM trellis coded data
US6118826A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1997 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Jul 16, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/41
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for encoding and decoding QAM trellis modulated data. In the transmitter, a subset of bits of an input bit set are convolutionally encoded based upon a punctured convolutional code of a lower data rate to provide a set of coded symbols. The coded symbols and the uncoded bits of the input bit set are provided to a QAM modulator to provide a QAM modulation signal indicative of the values of coded symbols and the uncoded bits. In the receiver a QAM demodulator converts the received QAM signal to QAM signal space coordinates. A decoder employing the Viterbi algorithm is used to reconstruct a corrected estimate of the values of the coded data bits from the received signal coordinates. The corrected estimate of the values of the coded data bits are then used in conjunction with the received signal coordinates to provide corrected estimates of the values of the uncoded input bits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.