Bad frame indicator for radio-telephone receivers in GSM mobile systems
US7127663B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2003 |
| Grant date | Oct 24, 2006 |
| Priority date | — |
| Expiry date | Aug 19, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B17/336
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system and method for bad frame indication of a speech frame includes estimating a signal-to-noise ratio (SNR) and checking a cyclic redundancy code (CRC) value of the speech frame. When the speech frame fails CRC error detection or the SNR is below a pre-specified value, a bad frame indication (BFI) flag is set. When the speech frame passes CRC error detection and the SNR is above the pre-specified value, a receive signal quality metric of the speech frame is checked against a high threshold and, if need be, a low threshold. The BFI flag and the receive signal quality metric for the previous speech frame is checked when the current receive signal quality metric is between the high and low thresholds. The BFI flag is set according to the value of the SNR, the CRC value, the current and previous receive signal quality metrics, and the previous BFI flag.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.