Cosine segment communications system
US5864585A · kind A · utility
Inventor
Key dates
| Filing date | Oct 7, 1996 |
| Grant date | Jan 26, 1999 |
| Priority date | — |
| Expiry date | Oct 7, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/18
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digital communication system is disclosed which is unique in that it modulates a sinusoidal carrier with a discrete cosine segment, a zero slope level segment, and combinations thereof. The discrete cosine segments may contain different time and amplitude values. The discrete cosine segments may be combined with each other or with zero slope level segments in order to effectively modulate the sinusoidal carrier. Rather than employing the use of filters for controlling instantaneous voltage changes, the present communication system forces the bit edges of the discrete cosine segments to occur at the zero slope points of a cosine wave, where no voltage changes occur. The communication system utilizes direct digital synthesis in order to create a carrier signal which closely represents sinusoidal carrier signal. The present communication system may be used in conjunction with various conventional methods such as phase-shift keying and amplitude-shift keying. A demodulator device is also disclosed for demodulating the carrier signal in order to recover the original base band signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.