Single-channel and multi-channel coherent demodulation devices with no pilot signal, and corresponding receiving system using a plurality of diversity paths
US6028888A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 6, 1998 |
| Grant date | Feb 22, 2000 |
| Priority date | — |
| Expiry date | Aug 6, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0057
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Coherent demodulation is effected in single-channel and multi-channel coherent demodulation devices without any knowledge of the transmitted signal (i.e. without any pilot signal). The phase shift is estimated by applying a predetermined function to produce a signed value from the argument of a summed signal, the summed signal being itself obtained from the received signal (by quadrature demodulation, complex despreading and summing over N samples). The phase shift estimate is used in a phase-locked loop so that the system converges towards a null error. The residual static phase ambiguity introduced by application of the predetermined function is resolved. A plurality of such single-channel and multi-channel coherent demodulation devices is used in a receiving system using a plurality of diversity paths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.