Apparatus and method for determining carrier frequency offset and timing frequency offset for data transmission and reception
US5654982A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1995 |
| Grant date | Aug 5, 1997 |
| Priority date | — |
| Expiry date | Jun 29, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for a data communications device such as a modem (100, 101) to determine carrier frequency offset and timing frequency offset, from a received probe signal. The various embodiments utilizing a processor (108) or digital signal processor (106) receive first and second sets of a transmitted probe signal having known characteristics, and determine a set of phase differences for the tones comprising the probe signal (702, 703, 704, 705). The various method and apparatus embodiments then form a linear approximation from the set of phase differences to determine the carrier frequency offset and the timing frequency offset (706). In the preferred embodiments, the linear approximation is formed from a minimization of a least square error estimate proportionally weighted by either signal to noise ratios or normalized, average amplitudes of the set of tones of the received probe signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.