Periodic Reporting for period 2 - SILIKA (Silicon-based Ka-band massive MIMO antenna systems for new telecommunication services)
Reporting period: 2018-09-01 to 2020-08-31
The continuously growing need in wireless communications for higher data rates necessitates more wireless spectrum to be made available for new applications. For the next generation of mobile communication, called 5G, licenses in the millimeter-wave (mm-wave) spectrum, i.e. starting around 30 GHz, are going to be issued on top of the current sub-6 GHz bands to meet this demand. Since higher frequencies experience a larger free space attenuation, large-scale multi-antenna massive MIMO (multiple-input multiple-output) base-stations with hundreds or thousands of active antenna elements are needed.
To offer mm-wave 5G technology at affordable prices to the end-user, these base-stations have to make use of reliable, low-cost antenna architectures and technologies. The fact that RF power generation is distributed over a large number of active antenna elements allows the use of highly integrated and cost-effective (Bi-)CMOS technologies. In combination with novel massive MIMO signal processing techniques, this approach can achieve a high-performance system at low costs. However, Europe requires specialists in this area that are trained to develop such multi-disciplinary systems. These experts can take leading roles within the EU ecosystem and maintain European leadership in the domain of wireless communications. Due to the novelty of these base-stations, these specialists have to be trained first. Therefore, SILIKA aims at educating 12 early-stage researchers (ESRs) to develop low-power, low-cost, silicon-based massive MIMO solutions and equip them with a comprehensive set of transferable skills relevant for long-term innovation and long-term employability. Working on different aspects throughout the entire system value chain and in cooperation with leading European industry, the ESRs will build a solid, multi-disciplinary and intra-European network that will fuel innovation and excellence in the EU for the coming decades.
To offer mm-wave 5G technology at affordable prices to the end-user, these base-stations have to make use of reliable, low-cost antenna architectures and technologies. The fact that RF power generation is distributed over a large number of active antenna elements allows the use of highly integrated and cost-effective (Bi-)CMOS technologies. In combination with novel massive MIMO signal processing techniques, this approach can achieve a high-performance system at low costs. However, Europe requires specialists in this area that are trained to develop such multi-disciplinary systems. These experts can take leading roles within the EU ecosystem and maintain European leadership in the domain of wireless communications. Due to the novelty of these base-stations, these specialists have to be trained first. Therefore, SILIKA aims at educating 12 early-stage researchers (ESRs) to develop low-power, low-cost, silicon-based massive MIMO solutions and equip them with a comprehensive set of transferable skills relevant for long-term innovation and long-term employability. Working on different aspects throughout the entire system value chain and in cooperation with leading European industry, the ESRs will build a solid, multi-disciplinary and intra-European network that will fuel innovation and excellence in the EU for the coming decades.
During the project, the ESRs have elaborated on the state-of-the art of multi-antenna systems, nowadays mainly used in defence and radio astronomy. The courses and workshops of the training programme equipped them with the necessary theoretical background as well as currently used technologies, system trade-offs and typical application implementations. Based on this foundation, the ESRs developed a modular antenna system demonstrator that allows experimental verification of different antenna topologies. For this, the ESRs first developed a core module, consisting of an active 2x2 sub-array based on an NXP analogue beamforming chip. It is designed to directly interface with the mm-wave communications test-bench “MATE” at Chalmers University. MATE allows the implementation of real-time signal processing algorithms, such that all aspects covered by the project can be tested in a single system demonstrator. Using the core module, the antenna system can be configured as a pure analogue beamforming array as well as a hybrid beamforming array. Array sizes from 2x2 elements (single tile) of up to 4x8 or 2x16 elements (16 tiles) can be mounted on a 3D-printed holder that was also developed by the ESRs. The fabricated prototypes of the modules have been extensively tested by the ESRs using different testing platform across the consortium. The system-level tests using MATE are currently underway with the first results expected by the end of 2020.
Thanks to the good collaboration of the ESRs, their radically new base-station concept and the active involvement of the industrial hosts, the ESRs were able to achieve several results that are beyond state-of-the-art. These results were published at internationally renowned journals and conferences. During the project, 15 journal articles were accepted and another 4 journal papers have been submitted, 45 conference articles were accepted and another 4 conference articles were submitted. The team, with now well-trained experts, successfully presented their innovative base-station concept. The gained insights will support a successful roll-out of mm-wave 5G technology and, for example, aid consortium member Ericsson with the decision making in their own mm-wave base-station development and consortium member NXP with the improvement of their beamforming chips for base-station applications. Both members have also already indicated their interest to hire ESRs, expanding the intra-European network that will fuel further innovation.