Mitigating CFO in OFDM systems by exploring the symbol structure

Abstract

In this paper we revisit the carrier frequency offset (CFO) estimation and removal for broadband orthogonal frequency division multiplexing (OFDM) systems. We propose an algorithm that explores the time-domain (TD) properties of transmitted symbols carrying pilots and data. A careful examination of the components that constitute the TD received symbols leads to the definition of a simple, yet effective, cost function. In a real scenario, the cost function presents a bowl shape with a single global minimum easily identifiable (no local minima). The proposed method is independent of the channel estimation and decision, presenting a very low computational load. The feasibility of the investigated method is substantiated by system simulation using BRAN-A broadband wireless channel model. Simulation results show that the impact of the residual CFO in the system¿s performance is minimal.