Low-Complexity Complexity OSIC Equalization for OFDM-Based OFDM Based Vehicular Communications
Abstract: Vehicular communication systems are usually equipped with orthogonal frequency division multiplexing (OFDM) transceivers that operate on rapidly changing radio propagation environments, which results in high Doppler and delay spreads. More specifically, in these environments, the experienced channels are doubly selective and introduce severe intercarrier interference (ICI) at the receiver. An effective ICI mitigation technique is desired as a constituent part of an ordered successive interference cancellation cancellation (OSIC) architecture, which turns out to be computationally efficient, since it may require the solution of linear systems with multiple right right-hand hand sides. To decrease the complexity, several techniques suggest mitigating the ICI by considering only a sma small number of adjacent subcarriers. However, this approximation introduces an error floor, which may result in unacceptable bit error rates (BER) at high signal signal-to-noise ratio regimes. In this paper, we propose a new OSIC equalization technique based on an iterative Galerkin projection projection-based based algorithm that reduces the computational cost without sacrificing the performance gains of the OSIC architecture. Furthermore, we suggest a new serial/parallel cancellation architecture that extends the OSIC and has the potential to completely cancel the experienced ICI introduced in high-mobility mobility scenarios. Extensive Monte Carlo experiments have been carried out to validate the accuracy of our framework, revealing intriguing tradeoffs between achieved BER and complexity, and highlighting the importance