A low-cost blind carrier offset estimator for MIMO-OFDM systems

Orthogonal frequency division multiplexing (OFDM) has been adopted by many standards (e.g., IEEE 802.11a, IEEE 802.11g) because it offers high data-rates and low decoding complexity. Because of its high data-rate capability, OFDM is highly suitable for short range military applications. On the other hand, space-division multiplexing and multi-antenna transmissions over multi-input multi-output (MIMO) channels, has been recently proved effective in combating fading, and enhancing the data rate. Therefore, MIMO-OFDM is a potential candidate for future military wireless applications. The main problem in OFDM systems is the carrier frequency offset (CFO). It causes the loss of orthogonality between the subcarriers. Numerous methods have been proposed for single-input single-output (SISO) OFDM systems. In this paper, we present a low-cost blind CFO estimation approach for MIMO-OFDM systems. We have shown that the computational cost can be reduced significantly while the performance of our algorithm is good enough compared with some available approaches in the literature