MD-OFDM: An Energy-Efficient and Low-PAPR MIMO-OFDM Variant for Resource-Constrained Applications

TL;DR

This paper introduces MD-OFDM, a low-PAPR, energy-efficient MIMO-OFDM variant that uses antenna selection per subcarrier to reduce power consumption and improve BER, suitable for IoT and LPWAN applications.

Contribution

It proposes a novel MD-OFDM system employing per-subcarrier antenna selection, reducing PAPR and power consumption while maintaining good BER performance.

Findings

MD-OFDM achieves lower PAPR than traditional MMSE MIMO.

MD-OFDM demonstrates improved BER performance.

Energy efficiency is enhanced in energy-constrained scenarios.

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) combined with Multiple-Input Multiple-Output (MIMO) techniques forms the backbone of modern wireless communication systems. While offering high spectral efficiency and robustness, conventional MIMO-OFDM, especially with complex equalizers like Minimum Mean Square Error (MMSE), suffers from high Peak-to-Average Power Ratio (PAPR) and significant power consumption due to multiple active Radio Frequency (RF) chains. This paper proposes and mathematically models an alternative system, termed Multi-Dimensional OFDM (MD-OFDM), which employs a per-subcarrier transmit antenna selection strategy. By activating only one transmit antenna for each subcarrier, MD-OFDM aims to reduce PAPR, lower power consumption, and improve Bit Error Rate (BER) performance. We provide detailed mathematical formulations for BER, Energy Efficiency (EE), and PAPR, and discuss the suitability of MD-OFDM for various applications, particularly in energy-constrained and cost-sensitive scenarios such as the Internet of Things (IoT) and Low-Power Wide Area Networks (LPWAN). Simulation results demonstrate that MD-OFDM achieves superior BER and significantly lower PAPR compared to MMSE MIMO, albeit with a trade-off in peak overall energy efficiency due to reduced spectral multiplexing.