# Jamming Suppression in Massive MIMO Systems

## TL;DR

This paper introduces a practical framework combining MMSE-based jamming suppression and zero-forcing detection to protect massive MIMO uplink transmissions from jamming attacks, demonstrating robustness and feasibility.

## Contribution

It proposes a novel, computationally efficient jamming suppression method using unused pilots and linear detection tailored for massive MIMO systems.

## Key findings

- The framework effectively reduces jamming impact in massive MIMO uplink.
- The proposed methods are computationally feasible with linear complexity.
- Numerical results confirm the robustness of the approach against jamming.

## Abstract

In this paper, we propose a framework for protecting the uplink transmission of a massive multiple-input multiple-output (mMIMO) system from a jamming attack. Our framework includes a novel minimum mean-squared error based jamming suppression (MMSE-JS) estimator for channel training and a linear zero-forcing jamming suppression (ZFJS) detector for uplink combining. The MMSE-JS exploits some intentionally unused pilots to reduce the pilot contamination caused by the jammer. The ZFJS suppresses the jamming interference during the detection of the legitimate users' data symbols. The implementation of the proposed framework is practical, since the complexities of computing the MMSE-JS and the ZFJS are linear (not exponential) with respect to the number of antennas at the base station and linear detectors with the same complexities as the ZFJS have been already fabricated using 28 nm FD-SOI (Fully Depleted Silicon On Insulator) technology in [12] and Xilinx Virtex-7 XC7VX690T FPGA in [13] for the mMIMO systems. Our analysis shows that the jammer cannot dramatically affect the performance of a mMIMO system equipped with the combination of MMSE-JS and ZFJS. Numerical results confirm our analysis.