Method of an apparatus for demodulating amplitude-modulated signals in an amplitude phase shift keying (APSK) system
US6046629A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1998 |
| Grant date | Apr 4, 2000 |
| Priority date | — |
| Expiry date | Jun 11, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/389
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a demodulating method of demodulating amplitude-demodulated signals in an amplitude phase shift keying system for conducting an amplitude modulation by setting signal points as information codes on a complex plane representing a signal space of transmission signals onto circumferences of two concentric circles including a first circle having a first diameter and a second circle having a second diameter smaller than the first diameter on the complex plane, there are obtained, in accordance with an amplitude value of an amplitude component of each symbol of a received amplitude-modulated signal, a first threshold value and a second threshold value having a predetermined relationship with the amplitude value. Next, the amplitude value the an amplitude component of each symbol of the successively received amplitude-modulated signal is compared with the first and second first threshold values to determine an amplitude variation in the amplitude component of each symbol in accordance with a result from the comparison so as to output therefrom a signal representing the determination result as a code obtained by demodulating the amplitude component.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.