Ris-enhanced 6g mmwave communications: Capacity analysis and optimization

Abstract

The advent of 6G mobile networks promises unprecedented data rates, ultra-low latency, and massive connectivity. However, the utilization of millimeter-wave (mmWave) frequencies, such as 28 GHz, introduces significant challenges regarding path loss and signal blockage. Reconfigurable Intelligent Surfaces (RIS) have emerged as a key enabling technology to overcome these propagation limitations by intelligently reflecting signals. This paper presents a performance analysis of an RIS-assisted Orthogonal Frequency Division Multiplexing (OFDM) system tailored for 6G mmWave networks. We derive the transmission capacity relations based on the impulse response method in the complex baseband, and describe an optimization algorithm based on the power iteration method to maximize the system capacity by configuring RIS phase shifts. Simulation results for the 28 GHz band demonstrate significant gains in transmission capacity and Bit Error Rate (BER) performance compared to systems without RIS or with random configurations.