Apparatus, methods and articles of manufacture for pre-emphasis filtering of a modulated signal
US7340007B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 16, 2003 |
| Grant date | Mar 4, 2008 |
| Priority date | — |
| Expiry date | Sep 20, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/361
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The invention is directed to a system for determining a transfer function for emphasizing an electromagnetic signal prior to being processed by determining a discrete transfer function for a processing system, such as a wideband phase modulator; determining a target transfer function such that the target transfer function multiplied by the inverse of the discrete transfer function produces a discrete pre-emphasis transfer function; and transforming any unstable poles and/or zeros in the pre-emphasis transfer function to stable poles and/or zeros. The discrete transfer function may be determined, for example, by using an S-function, input and output signals, the inverse-invariant method, and/or the Steiglitz-McBride algorithm. The transformation of the unstable poles and/or zeros may be accomplished using an all pass filter. The target transfer function may be a low pass FIR filter having a gain of about unity across substantially all of the frequency range of said FIR filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.