Spread spectrum communication system
US5825805A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 26, 1994 |
| Grant date | Oct 20, 1998 |
| Priority date | — |
| Expiry date | May 26, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J13/10
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Digital data for generating a signal having a prescribed waveform is stored beforehand in the memory on the transmitting side of a communication system. The prescribed waveform is one obtained by combining signals having mutually different frequencies corresponding to the digits of a spread-spectrum code comprising a plurality of digits. When transmission data is inputted, the system generates, for every bit of data, a signal waveform corresponding to the value of the bit, based upon the data stored in the memory. The generated signal is a signal which has undergone spreading. This signal is placed upon a carrier wave and then sent to a transmission line. Like the transmitting side, the receiving side possesses digital data for generating a signal having a prescribed waveform. When a signal is received, the system generates a signal based upon the data possessed, multiplies this by the received signal and effects a conversion into a signal having an intermediate frequency. Signals in a prescribed frequency band are filtered out of the intermediate frequency and data is demodulated from the filtered signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.