Joint Channel Equalization and Tracking for V2X Communications Using SC-FDE Schemes

In this paper we consider the use of a single- carrier with frequency-domain equalization (SC-FDE) scheme for vehicle-to-everything (V2X) communications. To cope with the doubly-selective nature of the V2X channel we propose a receiver structure for the joint channel equalization and tracking. We use a low-complexity iterative frequency-domain equalizer based on the iterative block decision-feedback equalization (IB-DFE) concept for the channel equalization and an extended Kalman filter (EKF) for the channel tracking. The tracking procedure works by, first, observing (estimating) the channel state using training symbols and then predicting the channel state using a state-transition model during the transmission of the data symbols. Alternatively, decision-directed channel estimation also can be used, resulting in improved performance.