FBMC Receiver Design and Analysis for Medium and Large Scale Antenna Systems

TL;DR

This paper develops and analyzes a practical FBMC-based massive MIMO receiver with advanced channel estimation and equalization techniques, improving spectral efficiency and robustness in large-scale antenna systems.

Contribution

It introduces a spectrally efficient pilot structure, a joint channel estimation method, and an FSE-based equalizer tailored for practical FBMC massive MIMO scenarios.

Findings

Proposed a new channel estimator with known error statistics.

Designed an FSE for residual channel distortion correction.

Validated the receiver's performance through numerical simulations.

Abstract

In this paper, we design receivers for filter bank multicarrier-based (FBMC-based) massive MIMO considering practical aspects such as channel estimation and equalization. In particular, we propose a spectrally efficient pilot structure and a channel estimation technique in the uplink to jointly estimate all the users' channel impulse responses. We mathematically analyze our proposed channel estimator and find the statistics of the channel estimation errors. These statistics are incorporated into our proposed equalizers to deal with the imperfect channel state information (CSI) effect. We revisit the channel equalization problem for FBMC-based massive MIMO, address the shortcomings of the existing equalizers in the literature, and make them more applicable to practical scenarios. The proposed receiver in this paper consists of two stages. In the first stage, a linear combining of the received signals at the base station (BS) antennas provides a coarse channel equalization and removes any multiuser interference. In the second stage, a per subcarrier fractionally spaced equalizer (FSE) takes care of any residual distortion of the channel for the user of interest. We propose an FSE design based on the equivalent channel at the linear combiner output. This enables the applicability of our proposed technique to small and/or distributed antenna setups such as cell-free massive MIMO. Finally, the efficacy of the proposed techniques is corroborated through numerical analysis.