AFDM-Enabled Spatial Modulation for A-RoF Optical Fronthaul Networks

Abstract

Fiber-wireless integrated networks are emerging as a key enabler for next-generation high-capacity access, where centralized architectures demand both efficient signal transmission and low-complexity remote units. This paper presents an AFDM-enabled analogue radio-over-fiber (A-RoF) aided spatial modulation (SM) architecture for optical fronthaul systems. By exploiting the chirp-domain parameterization of AFDM waveforms, antenna index information is inherently embedded into the signal and jointly transmitted with communication data over a hybrid fiber-wireless link. The proposed system enables spatial modulation with reduced hardware complexity at the remote radio unit, eliminating the need for multiple photodetectors and parallel RF chains in contrast to our baseline. Simulation results show that the proposed scheme preserves communication performance while introducing a flexible trade-off between index detection and data transmission.