Project Details
Projekt
Ultra Wideband Communications based on Massive MIMO and Multi-mode Antennas Suitable for Mobile Handheld Devices
Subject Area
Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
Term
from 2013 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 235628299
The DFG priority program 1655 (SPP 1655) targets at peak data rates of 100 Gbps and beyond for mobile internet access. In our contribution to SPP 1655, we focus on the indoor scenario with limited mobility, where low-cost low-complexity miniature consumer electronic devices like tablets and smartphones are deployed. In the context of ultra-high data rates for wireless communications, ultra-wideband technology is the most promising technique to achieve the target data rate. When considering only the frequency range from 6-8.5 GHz, where the EIRP mask defined for EU countries has a significant maximum, a spectral efficiency of at least 40 bps/Hz is necessary. In our interdisciplinary (microwave engineering/baseband processing) approach we combine our expertise in the following areas: System architectures enabling extremely high throughput, realization of paradigms for complexity reduction and energy saving of gigabit wireless systems, algorithms for baseband processing in ultra-wideband systems, and investigation of performance parameters of wireless 100 Gbps systems.The key concept introduced in the first phase of SPP 1655 is a multi-mode antenna design in conjunction with advanced baseband processing, dubbed multi-mode massive MIMO. This concept is suitable for miniature devices, as well as for access point arrays. In the first phase, both a user terminal multi-mode antenna with up to five ports based on the rectangular shape of a typical chassis as well as an antenna array with 11x11x4=484 ports suitable for access points has been implemented and characterized. One important outcome is that the feasibility of our system proposal could be proven, both from a microwave engineering as well as from a baseband processing point of view. However, also some bottlenecks could be observed: The limited number of modes that is available over the full ultra-wide bandwidth restricts the number of streams on the uplink and hence limits the data rate.In the second phase, we aim at extensions and optimizations of the proposed concept. This work is motivated by insights obtained during the first phase. Notably, multi-user scenarios will be explored to determine the required hardware to serve a given number of users with a given data rate. Concerning the user terminal, in a joint microwave/baseband optimization approach the possible improvements w.r.t. throughput will be investigated when the restriction that all modes must serve the entire bandwidth is dropped. Particularly, the effect of the additional modes on the channel capacity will be studied. Concerning the access point, a reduction of the size of the antenna elements as well as their spacing is of main concern. For typical channel conditions, this shall enable pre-defined analogue beamforming patterns in order to reduce the processing complexity of the digital beamforming optimization. Furthermore, multi-user multi-stream transmit beamforming will be studied in this context.
DFG Programme
Priority Programmes
