Digital transmitter with constrained envelope and spectral regrowth over a plurality of carriers
US6928121B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2001 |
| Grant date | Aug 9, 2005 |
| Priority date | — |
| Expiry date | Jan 31, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3411
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A constrained-envelope digital communications transmitter (10) places constraints on the envelope of spectrally constrained, digitally modulated communication signals (46) converted into diverse frequency channels (54) and combined into a composite signal (58). The envelope constraints achieve lower peak-to-average power ratio without allowing significant spectral regrowth. The composite signal (58) is applied to a plurality of cascade-coupled constrained-envelope generators (64). Each constrained-envelope generator (64) detects overpeak events (66) and configures corrective impulses (68) for the overpeak events (66). The corrective impulses (68) are distributed to the respective frequency channels (54) in accordance with a predetermined distribution profile (102) and are filtered into allocated shaped pulses (120) that exhibit a constrained spectrum. The allocated shaped pulses (120) are coherently converted into the respective frequency channels (54) and combined with the composite signal (58) to reduce an unwanted signal peak.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.