This paper presents a frequency offset estimation scheme for Orthogonal Frequency Division Multiplex (OFDM) direct conversion receivers. The key idea is to use a differential filter for reduction of DC offset. Frequency offset is estimated in the presence of time-varying DC offset. In order to overcome the varying DC levels under automatic gain control (AGC) circuits, a threshold level is set for the output of the differential filter. The proposed compensation scheme offers superior frequency offset estimation when compared with a conventional scheme with a high pass filter.
- DC offset
- Direct conversion
- Frequency offset
- Training sequence
ASJC Scopus subject areas
- Computer Networks and Communications
- Electrical and Electronic Engineering