Collaborative Research: VINES: Track 1: Photonics-Enabled Energy-Efficient Radio Architecture With In-Line Signal Processing for Massive MIMO (PRISM)

The rapid growth of wireless traffic and scaling of massive multiple-input multiple-output (MIMO) radios have pushed existing fronthaul technologies to their limits. Today’s mobile fronthaul based on digital radio-over-fiber (RoF) requires extensive analog/digital conversion at the radio unit (RU) and high-bandwidth digital data transfer. This results in significant energy overhead, costly high-speed electronics, and scalability bottlenecks, hindering dense, energy-efficient, and cost-effective RU deployments. This collaborative project brings together investigators from Duke University and the University of California, Berkeley to develop a new approach to replace conventional massive MIMO RUs and DRoF-based mobile fronthaul with photonics-enabled massive MIMO RUs connected over a wavelength-division multiplexing (WDM) fronthaul through the co-design of network architecture, RF/photonic circuits, and signal processing. The proposed research is organized around three interrelated thrusts. (i) Development of a unified modeling and calibration framework for electrical to optical to electrical (E/O/E) signal transmission over the RF-photonic WDM fronthaul, enabling accurate characterization and compensation of impairments across photonic and wireless domains. (ii) Investigation of novel integrated photonic and RF circuits based on microring modulators (MRMs) and photodetectors, including techniques for efficient modulation, demodulation, and local oscillator distribution across WDM channels. (iii) Design of in-line analog signal processing architectures that perform matrix-vector multiplication directly within the RF-photonic fronthaul, transforming it from a communication medium into a computing substrate. The project will advance knowledge at the intersection of wireless communications, signal processing, integrated photonic and RF circuits, and optical networking. The developed technologies will help reduce the energy footprint of next-generation (NextG) networks, improve the utilization of existing fiber-optic infrastructure, and facilitate the use of RF-photonics for both the transport and processing of massive MIMO systems. The project will also provide a platform to engage graduate, undergraduate, and high-school students through research experiences and outreach activities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.