Methods and apparatus for estimating and adjusting the frequency response of telecommunications channels
US5577117A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1994 |
| Grant date | Nov 19, 1996 |
| Priority date | — |
| Expiry date | Jun 9, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03885
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In methods and apparatus for estimating the frequency response of telecommunications channels, signals carried on the channels are divided into pluralities of signal segments of limited duration, unvoiced signal segments are identified, and spectral components of the unvoiced signal segments are measured. The measured spectral components may be integrated over time to derive time-averaged measurements of the spectral components. The time-averaged measurements may be compared to corresponding components of expected unvoiced signal spectra to improve the accuracy of the frequency response estimates. Filters may be inserted in the channels to adjust the frequency responses, the filters having filter characteristics selected in response to the measured spectral components. The methods and apparatus can be used to compensate for poor bass frequency response in voice channels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.