Research & Development
INNOVATE
UD-WiSE develops photonically-enabled system technologies that enhance hardware scalability of Next-Generation (NextG) wireless networks. A NextG network is expected to span a wide geographic area, accommodate a large mix of heterogenous agents, and operate in a highly congested (often contested) spectral environment. It is required to provide ubiquitous access to the maximal number of subscribers, at the same time suppress the maximal number of interferers. To achieve meaningful quality of service, the network must sense the spatial-spectral aspects of ambient RF emissions in real time. Service waveforms in a distributed network can be utilized for multi-static sensing. Furthermore, distributed radio access points allow coherent localization of active emitters and imaging of passive objects. The codependence between sensing (active and passive) and communication is embodied in a distributed integrated sensing and communication (D-ISAC) network that consists of spatially coherent radios acting in synchrony as communicators, sensors and/or illuminators. The expansion of radio spectrums into millimeter wave (mmW) and above increases the number of spatial-spectral degrees of freedom, resulting in improved sensing fidelity and data throughput, but requires massive beam-bandwidth-product processing capability that RF-photonic devices are well suited to provide. Moreover, in a centralized radio access network (C-RAN) architecture, waveform transmission and reception are carried out on the access points (AP’s), whereas waveform synthesis and machine learning are carried out at a central processing unit (CPU), necessitating a proper balance between computational partition and fronthaul capacity. A D-ISAC network is illustrated below.
Photonically-Enabled D-ISAC Network
Photonic innovations provide orders-of-magnitude performance-to-cost gain to the entire D-ISAC network: (1) access points (APs) each employing RF-photonic phased arrays or holographic apertures capable of intra-AP multibeam and multiband operation; (2) an RF-photonic beamspace processor unit (BPU) that carries out centralized beamspace processing across multiple APs, and (3) an analog RF-over-fiber distribution network capable of full-dimensional beamspace transportation between the BPU and the APs while preserving the spatial and temporal coherence between the access points, due to the phase-preserving low-loss transport of a common optical carrier over tens of thousands of meters. The coherence of RF carrier frequency and phase between widely distributed apertures, especially at high carrier frequencies. Photonic manipulation and transportation of radio waves allow low-latency coherent distribution of multifunction, multibeam and multiband wavefronts over a large geographic area, providing a novel means of implementing the Extremely Large-Scale MIMO (XL-MIMO) and the Platform Is The Antenna (PITA) concepts. Applications include collaborative jamming-resistant communication over a larger area, and collaborative localization at a fractional-wavelength precision. Moreover, RF-photonic integrated circuits (RF-PIC) is forging a path for reduction in size, weight, power and cost (SWAP-C) of the entire system on a scale reminiscent of that of CMOS IC for the last half century.
To this end, UD-WiSE research aims to leapfrog on distributed ISAC network performance by concurrent optimization within the hitherto separate fields of RF-PIC nanofabrication, adaptive signal processing, and computational scalability of large networks. Accordingly, the solution space can be divided into three interlocked areas of focus.
- Devices fabrication and system integration
- Intelligent adaptation algorithms
- Network architectures
The solution space can be divided into three interlocked areas of focus.
RF-photonic devices fabrication and system integration
(a) Imaging receiver sees two incoming waves. The PIC in (d) implements the Fourier lens; (b) PIC output for one wave; (c) PIC output for the other wave; (d) PIC; (e) PIC in package.
3D heterogenous integration between electronic and photonic components
- Create a critical mass in RF photonic devices and systems technology, including photonic integrated circuits and thin-film lithium-niobate material platform
- Build a comprehensive infrastructure for design, fabrication, integration, and characterization of RF photonic integrated circuits (RF-PIC), including design tools and multi-project wafer (MPW) submissions through suitable foundries
- Explore modular architectures for large arrays, for heterogenous electronic-photonic integration, as well as for photonic multi-chip-modules (pMCMs)
- Establish a new, state-of-the-art co-packaging facility for pMCMs, only the second in the nation
Signal processing algorithms demonstration
Illustration of distributed coherent beamforming across distributed arrays
RF-photonic test bed for over-the-air (OTA) demonstration of communication at high frequency
- Develop analog and digital adaptation algorithms to maintain optimal sensing and communication performance in a dynamic congested radio environment, e.g.,
- Multi-user, jamming-resistant communication
- Multistatic sensing
- Phase-coherent localization
- Leverage distinct RF-photonic device capabilities for performance leapfrog, e.g.,
- Beamspace adaptation guided by live RF scene from RF-photonic imager
- Simultaneous spatial-spectral sensing via array waveguide grating (AWG)
- Adapt techniques from adjacent fields, e.g.,
- Machine learning
- Computational imaging
- Build over-the-air (OTA) testbed for real-world demonstration of coherent distributed beam adaptation algorithms
RF-photonic network architecture
Full-beamspace analog RF-over-fiber feed network
A RF photonic coherent distributed aperture for multiuser communication
- Quantify the effect of spatial distribution pattern of multibeam apertures on network performance and cost/power of large-scale deployment
- Explore implementation for full-beamspace analog RF-over-fiber (ARoF) fronthaul that employs optical array waveguide grating (AWG)
The Center for Wireless Intelligent Systems Engineering at the University of Delaware
(UD-WiSE) is a research center within the Department of Electrical and Computer Engineering.
research activities
- Fabricate Devices and Test Subsystems
- Design and Validate Algorithms
- Analyze and Simulate Network Performance
- Specify, Design and Integrate Demo Platform
UNIVERSITY of DELAWARE
Department of Electrical and Computer Engineering
140 Evans Hall
Newark, DE 19716
P: (302) 831-2405
F: (302) 831-4375
E: ece-info@udel.edu