Constrained-envelope transmitter and method therefor
US6366619B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 2000 |
| Grant date | Apr 2, 2002 |
| Priority date | — |
| Expiry date | Aug 9, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2627
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A constrained-envelope digital-communications transmitter circuit (22) includes a binary data source (32) that provides an input signal stream (34) to a modulator (77,77′). The modulator (77,77′) includes a pulse-spreading filter (76) that filters a phase-point signal stream (50) or a composite signal stream (168) into a modulated signal (74). A constrained-envelope generator (106) generates a constrained-bandwidth error signal stream (108) from the modulated signal (74), and a delay element (138) delays the modulated signal (74) into a delayed modulated signal (140) synchronized with the constrained-bandwidth error signal stream (108). A complex summing circuit (110) sums the delayed modulated signal (140) and the constrained-bandwidth error signal stream (108) into an altered modulated signal (112), and a substantially linear amplifier (146) amplifies the altered modulated signal (112) and transmits it as a radio-frequency broadcast signal (26).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.