Apparatus and method for substantially eliminating noise in an audible output signal
US5678221A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 9, 1995 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Jan 9, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/1027
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus, performed by a communication unit (101), for substantially eliminating undesired noise in an audible output signal (113) while a determined quality measure (114) of a received signal (107) is below a predetermined threshold (201). At least a portion the received signal (107) is stored for a predetermined period of time to produce a stored signal (109). A measure of pitch period (111) of the stored signal (109) is determined. When the determined quality measure (114) of the received signal (107) drops below the predetermined threshold (201), a portion of the stored signal (109) is used, responsive to the determined measure of the pitch period (111), to produce the audible output signal (113). To match a boundary between an end of the received signal (107) and an end of the portion of the stored signal (109) a discontinuity between the end of the received signal (107) and the end of the portion of the stored signal (109) at the boundary is determined. Values for a predetermined correction function responsive to the measured discontinuity are determined. The predetermined correction function is applied to the end of the portion of the stored signal (109) to ali…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.