Digital radio modulator
US5425055A · kind A · utility
12Cited by
6References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 23, 1992 |
| Grant date | Jun 13, 1995 |
| Priority date | — |
| Expiry date | Nov 23, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2092
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A radio modulator/demodulator particularly suitable for TDMA mobile telephone use employs digital techniques for GMSK phase modulation. Phase numbers representative respectively of an intermediate frequency carrier and modulation symbols are combined digitally to combination phase numbers which are subjected to a single folded cosine table to produce a digital trignometric sequence of numbers for modulating the transmitter. Economy of components and memory is achieved and some of the modulator components are used in demodulation which is effected by the single look-up table used in sine and cosine mode alternately.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.