Software radio implementation of carrier offset estimation for OFDM communications

The main objective of this paper is to describe the implementation of a robust and computationally inexpensive orthogonal frequency division multiplexing (OFDM) scheme on a fading channel. While channel-induced intersymbol interference can be eliminated by dividing the data stream into parallel bit sequences in OFDM communications, the loss of orthogonality due to the carrier frequency offset must be compensated before DFT-based demodulation can be performed. A new solution to the carrier offset estimation problem was developed without using reference symbols. The technique provides a high accuracy carrier estimate by taking advantage of the inherent orthogonality among OFDM subchannels. The authors show that this algorithm can be used to perform offset estimation and compensation in a practical system.