Blind Cyclic Prefix-based CFO Estimation in MIMO-OFDM Systems

TL;DR

This paper introduces a low-overhead, blind CFO estimation method for MIMO-OFDM systems using cyclic prefix and antenna diversity, improving accuracy with minimal complexity increase.

Contribution

It presents a novel CFO estimation technique leveraging antenna and time diversity with a closed-form solution, enhancing performance in MIMO-OFDM systems.

Findings

Effective CFO estimation with low overhead

Performance improvement validated through numerical analysis

Linear complexity increase with enhanced accuracy

Abstract

Low-complexity estimation and correction of carrier frequency offset (CFO) are essential in orthogonal frequency division multiplexing (OFDM). In this paper, we propose a low-overhead blind CFO estimation technique based on cyclic prefix (CP), in multi-input multi-output (MIMO)-OFDM systems. We propose to use antenna diversity for CFO estimation. Given that the RF chains for all antenna elements at a communication node share the same clock, the carrier frequency offset (CFO) between two points may be estimated by using the combination of the received signal at all antennas. We improve our method by combining the antenna diversity with time diversity by considering the CP for multiple OFDM symbols. We provide a closed-form expression for CFO estimation and present algorithms that can considerably improve the CFO estimation performance at the expense of a linear increase in computational complexity. We validate the effectiveness of our estimation scheme via extensive numerical analysis.