Synchronizer for TDMA acquisition signal having an unknown frequency
US5383225A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1992 |
| Grant date | Jan 17, 1995 |
| Priority date | — |
| Expiry date | Dec 17, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/2125
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A synchronizer operates to achieve initial synchronization with a TDMA acquisition signal exhibiting a potentially large Doppler. The synchronizer collects samples of a baseband signal during a timing window. A fast Fourier transform (FFT) is performed on the samples to generate a set of spectral data. The window is moved to an identical point in a subsequent frame and the FFT repeated until a high-confidence spectral data set is obtained. If the spectral data set indicates energy concentrated around a discrete frequency, then that discrete frequency represents an estimate of the acquisition signal's frequency. The timing window's timing parameters represent a time slot estimate of the acquisition signal. If the spectral data set indicates energy spread more or less uniformly over the spectrum, then no estimates are indicated and a new window is positioned at a different point in subsequent frames.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.