Data communication modulation with managed intersymbol interference
US5386202A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1993 |
| Grant date | Jan 31, 1995 |
| Priority date | — |
| Expiry date | Nov 3, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/20
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A communication system (10) includes a modulation section (12) and a demodulation section (14). The modulation section (12) performs frequency modulation in accordance with a frequency trajectory signal (28, 30, 32). An intersymbol interference (ISI) prediction filter (20) adjusts the amplitude of the frequency trajectory signal (28, 30, 32) in response to data code (16) sequences being conveyed over a plurality of symbols (18). More frequent data changes in the sequence of the data codes (16) lead to greater amplitudes in the frequency trajectory signal. The demodulation section (14) applies a distorted phase signal to a decision circuit (38). The distorted phase signal conveys a received phase (46) that includes ISI. Due to the equalization applied by the ISI prediction filter (20), the received phase (46) approximates a target phase (40, 42) in spite of the ISI.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.