Algebraic carrier frequency offset estimator for ASTC-MIMO-OFDM systems over correlated frequency selective channel

Abstract

This work presents a new Algebraic Carrier Frequency Offset (CFO) estimation technique for multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems employing Algebraic Space Time Coding (ASTC), in channels time-varying correlated Rayleigh frequency-selective fading. The technique uses a preamble and is thus especially suitable for burst mode communication. The preamble consists of orthogonal training sequences simultaneously transmitted from the various transmit antennas. The proposed system exploits all subcarriers in frequency domain, which provides a remarkable performance improvement, and reach the Cramer-Rao Lower Bound (CRLB). A new algebraic estimation method is proposed, in order to exploit the powerful algebraic ASTC technique in wide-band systems, when the CFOs occur with small variation and to overcome the sensitivity of the ASTC codes in frequency synchronization problemof OFDM system.