Modulation method and apparatus for multicarrier data transmission
US5128964A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 10, 1990 |
| Grant date | Jul 7, 1992 |
| Priority date | — |
| Expiry date | Oct 10, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2614
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A high speed modem system which utilizes multiple carriers to successively transmit frames containing data such that the frames are transmitted so that the level of the signal is minimized, and is preferably zero, at the borders between individual frames thus, reducing or eliminating interframe discontinuities and the accompanying distortion and interframe interference. The modem system includes a circuit to successively combine together the modulated carrier signals of each set to produce a frame waveform which includes an inphase signal and a quadrature signal for each carrier signal as is known in the art. The components of the inphase signal and the quadrature signal are grouped to form an I odd/Q even group and an I even/Q odd group. In order to restore the missing components in the I odd/Q even group, the I odd and the Q even components are duplicated and combined with the I odd/Q even group. In order to restore the missing components in the I even/Q odd group, the I even component is negated and used to form the next higher numbered I component and the Q odd component is negated and used to form the next higher numbered Q component. The resulting waveforms are subjected to a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.