🤖 AI Summary
To address the 6G requirements of low power consumption and high spectral efficiency, this paper tackles the limitations of conventional spatial modulation—namely, high transmitter-side power consumption and poor flexibility due to hardware-intensive antenna activation at the transmitter. We propose, for the first time, Reconfigurable Intelligent Surface (RIS)-assisted Adaptive Spatial Modulation at the receiver (RASM). RASM leverages an RIS to dynamically tailor the wireless channel and enables joint, adaptive selection of the optimal antenna subset at the receiver. This simultaneously enhances the signal-to-noise ratio (SNR) of target antennas and implicitly encodes extra information in the selected antenna indices. Theoretical bit error rate (BER) analysis and simulations consistently demonstrate that RASM achieves superior BER performance while significantly improving spectral efficiency—without requiring any transmitter hardware modifications and with substantially lower power consumption than transmitter-based schemes. This work establishes a novel paradigm for integrating RIS with spatial modulation, exhibiting strong practical potential for 6G systems.
📝 Abstract
A novel wireless transmission scheme, as named the reconfigurable intelligent surface (RIS)-assisted received adaptive spatial modulation (RASM) scheme, is proposed in this paper. In this scheme, the adaptive spatial modulation (ASM)-based antennas selection works at the receiver by employing the characteristics of the RIS in each time slot, where the signal-to-noise ratio at specific selected antennas can be further enhanced with near few powers. Besides for the bits from constellation symbols, the extra bits can be mapped into the indices of receive antenna combinations and conveyed to the receiver through the ASM-based antenna-combination selection, thus providing higher spectral efficiency. To explicitly present the RASM scheme, the analytical performance of bit error rate of it is discussed in this paper. As a trade-off selection, the proposed scheme shows higher spectral efficiency and remains the satisfactory error performance. Simulation and analytical results demonstrate the better performance and exhibit more potential to apply in practical wireless communication.