Apparatus and method for measuring signal quality of a wireless communications link
US7016651B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 17, 2002 |
| Grant date | Mar 21, 2006 |
| Priority date | — |
| Expiry date | Aug 26, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2647
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Techniques for measuring signal quality in a communications link supporting OFDM symbol transfer across plural sub-carriers are disclosed. These techniques employ a link interface receiving OFDM symbol(s) from the link, and a signal-to-noise ratio (SNR) estimation unit generating an estimate of a geometric SNR (SNRgeo) for the received symbols based on an average of the logrithmic difference between soft decision and hard decisions for the received symbol. SNRgeo here defines a scalar measure of the link signal quality, which results in a computationally efficient yet accurate link signal quality assessment, and thereby permit selective link characteristic alteration. Only sub-carrier subsets need be used to derive a relatively an accurate SNRgeo estimate. Sharing calculation resources between SNR estimation and soft decision units further reduce implementation complexity. Hard decision generation may use a relatively quick slicer or more accurate viterbi decoder/OFDM re-coder combination, as design goals dictate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.