A Two-Dimensional FFT Precoded Filter Bank Scheme

TL;DR

This paper introduces a novel 2D FFT precoded filter bank system that enhances spectral efficiency and performance by integrating a 2D-FFT with FBMC, inspired by OTFS, and demonstrates its effectiveness through simulations.

Contribution

It presents a new 2D FFT precoded filter bank scheme with a hybrid receiver, improving spectral efficiency and error performance over existing FBMC and OTFS systems.

Findings

Achieves error performance comparable to OTFS systems.

Outperforms existing precoded FBMC systems in simulations.

Reduces out-of-band emissions with the new filter bank design.

Abstract

This work proposes a new precoded filter bank (FB) system via a two-dimensional (2D) fast Fourier transform (2D-FFT). Its structure is similar to Orthogonal Time Frequency Space (OTFS) systems, where the OFDM transmitter is changed to a filter bank multi-carrier (FBMC) one, thus obtaining a lower out-of-band emission. The complex orthogonality of the FBMC transmission is guaranteed by using precoding based on a discrete Fourier transform, which is also used to implement the two-dimensional fast Fourier transform. Through the use of a global transmission matrix, we propose a hybrid receiver for the new system. First, a frequency domain equalization is performed, followed by an interference cancellation on the delay-Doppler domain. The simulation results show that the proposed system obtains an error performance similar to other OTFS systems, and superior performance as compared to other precoded FBMC systems.