Adaptive modulation method
US6452964B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 23, 1999 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Mar 23, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/0026
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In the present invention, a modulation level estimation unit calculates the square error of the minimum value of distances between each signal point received at a modulation level ML and the signal point of a received signal at each modulation level ML. A received power measurement unit measures the received power level of the received signal. A modulation level estimation unit calculates the value obtained by multiplying the square error calculated at each modulation level ML, by a weighted calculation from both a threshold power level for switching the modulation level ML and the received power level as a likelihood value at each modulation level ML. Then, the modulation level estimation unit estimates a modulation level ML corresponding to the maximum likelihood value of all the likelihood values at the modulation level ML as a modulation level ML of the received signal, without transmitting any codewords on the used modulation level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.