2x2 MIMO Prototype for BER and EVM Measurements in Metal Enclosure

TL;DR

This paper presents a 2x2 MIMO prototype using SDRs for BER and EVM measurements inside a metal enclosure, exploring static, dynamic, and interfered channel conditions.

Contribution

It introduces a near-field MIMO measurement setup with real-time BER and EVM analysis in challenging metal enclosure environments.

Findings

BER and EVM vary with channel conditions and interference levels.

The prototype effectively characterizes MIMO performance in metal enclosures.

Dynamic channel conditions impact signal quality and measurement accuracy.

Abstract

In this work, we present a 2x2 near-field multi-input multiple-output (MIMO) prototype for bit-error-rate (BER) and error vector magnitude (EVM) measurements in a metal enclosure. The near-field MIMO prototype is developed using software-defined-radios (SDRs) for over-the-air transmission of QPSK modulated baseband waveforms. We check the near-field MIMO BER and EVM measurements in three different scenarios in a highly reflecting metal enclosure environment. In the first scenario, the line-of-sight (LOS) communication link is investigated when the mode-stirrer is stationary. In stationary channel conditions near-field MIMO BER and EVM measurements are performed. In the second scenario, BER and EVM measurements are performed in dynamic channel conditions when the mode-stirrer is set to move continuously. In the third scenario, LOS communication near-field MIMO BER and EVM measurements are performed in stationary channel conditions but now in the presence of MIMO interference. In three different scenarios, near-field MIMO BER and EVM measurements are investigated at different Tx USRP gain values and in the presence of varying levels of MIMO interference.