System and method for measuring channel quality information
US6108374A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1997 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Aug 25, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W72/54
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system and method to measure channel quality in terms of signal to noise ratio for the transmission of coded signals over fading channels. A Viterbi decoder metric for the Maximum Likelihood path is used as a channel quality measure. This Euclidean distance metric is filtered in order to smooth out short term variations. The filtered or averaged metric is a reliable channel quality measure which remains consistent across different coded modulation schemes and at different mobile speeds. The filtered metric is mapped to the signal to noise ratio per symbol using a threshold based scheme. Use of this implicit signal to noise ratio estimate is used for the mobile assisted handoff and data rate adaptation in the transmitter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.