Energy-Efficient MIMO-OFDM Transceiver Design for Next-Generation Wireless IoT Systems

Abstract

The superlinear spread of wireless devices in the Internet of Things (IoT), in particular, and the appearance of 6G communication networks, in general, have created urging requirements of the high-performance transceiver design that offer both spectral efficiency and energy savings. In such a circumstance, Multiple-Input Multiple-Output Orthogonal Frequency-Division Multiplexing (MIMO-OFDM) has been found as the core technology as it has the unique capability of chasing the multipath fading and capable of high data throughput. Nevertheless, conventional MIMO-OFDM systems are normally limited by the high complexity of their hardware, and high power requirement, therefore, they cannot be applicable in the limited resource edge devices of the IoT. A new energy efficient MIMO-OFDM transceiver architecture is proposed in this paper and tailored to next generation wireless IoT system. The hybrid analog-digital beam former scheme proposed in the system has the scope to decrease the active radio-frequency (RF) chains in use by a large margin, leading to significant savings in energy usage without demining adaptation in the signal quality. Moreover, real time channel state information (CSI) based adaptive subcarrier power allocation algorithm dynamically assigns transmission power to OFDM subcarriers to prioritize energy efficiency in heterogeneous channel conditions. Simplified baseband signal processing blocks, and low-resolution analog-to-digital converters (ADCs) are also used in order to reduce computational overhead. To authenticate the proposed design, the simulation is carried out at the system-level under demanding tests in MATLAB, and the valuable performance metrics like Bit Error Rate (BER), energy efficiency, power consumption and spectral utilization are measured. Results show that it consumes power significantly, up to 45 percent less, than conventional full-digital transceivers, and they also show enhanced BER and energy-per-bit performance over a broad signal-to-noise ratio (SNR) range. The study presents a practical and scalable alternative to the way low-power, high-capacity wireless communication will be implemented in dense and heterogeneous IoT. The suggested design passes through the expectations of the 6G enabled smart environments of the future where energy efficiency, low latency, and ubiquitous access is prioritized. In future effort, this design will be scaled up to the implementation area and field verification in real-time IoT test beds.