Realization and Application of Full-Duplex Transceivers in Millimeter-Wave Links for Small-Cell Wireless Backhaul Networks

• Applicant: Professor Dr.-Ing. Slawomir Stanczak, since 8/2019
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2018 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 409528830

The research and realization of full-duplex transceivers for the application in wireless communication networks is the goal of the requested project. A main focus of the investigations is dedicated to backhaul networks (BHN) which primary are used to enable high-speed data transmission between small-cells. Data transmission is usually performed in half-duplex mode by point-to-point links within the micro-wave bands (6–100 GHz). Since a massive deployment of small-cells for 5G is discussed, a strong demand for more efficient and flexible BHNs is just around the corner.At the moment, the extension of point-to-point links to the more complicated point-to-multipoint links, to multi-hop links over additional relay stations, or to mesh architectures entails high planning effort as well as the provision of multiple frequency channels to reduce interferences between the radio waves. Unfortunately, the congestion of small-cells inevitably leads to more complicated network architectures and in turn to the mentioned increased challenges. It is obvious that the actual half-duplex BHNs will attain their technical and economical limits soon.The considered full-duplex technology in the requested project is a worthy alternative to tackle the mentioned problematic and will significantly help to achieve adaptivity and efficiency in BHNs. Since full-duplex transceivers are able to suppress their self-interference and to work on the same channel for transmission and reception, building a mesh network will be a simple task without using multiple frequency channels. In addition, it is well-known that full-duplex systems achieve a higher spectral efficiency compared to usual half-duplex systems. Moreover, a full-duplex system is more secure against eavesdropper which is a further advantage in comparison to the actual BHNs.In the present project, we first create mathematical models for both the full-duplex transceiver and the associated communication network. These models will make an analytical framework available to evaluate and optimize mesh networks with full-duplex capability. The outcome will be a concept for realizing BHNs in mm-wave bands.Different interdisciplinary methods will be used to achieve the project goals. On the one hand, analytical methods will be utilized to describe the self-interference subject to constraints in real hardware development. On the other hand, numerical and simulative methods will be applied to investigate and model larger radio networks under realistic constraints on the wave propagation. Furthermore, a general quantification of performance limitations of such networks should be elaborated mathematically with the aid of simple assumptions. At the end, real transceivers and antennas will be developed for which high-frequency (RF) measuring instruments and numerical field theory methods will be used. The entire project is accompanied by experimental investigations with prototype implementations of full-duplex transceivers.

• DFG Programme: Research Grants
• Co-Investigators: Privatdozent Dr.-Ing. Gholamreza Alirezaei; Professor Dr.-Ing. Wilhelm Keusgen
• Ehemaliger Antragsteller: Professor Dr. Rudolf Mathar, until 7/2019