New Waveforms and Applications in Multicarrier Communications
Filter Bank Multicarrier (FBMC) is a group of multicarrier modulations employing waveforms optimized in time and frequency domain. In contrary to the broadly used OFDM modulation (LTE Standard, 802.11a/n Wireless LAN), FBMC waveforms are shaped using filter banks and do not employ Cyclic Delay Diversity, thus reducing communication overhead. Furthermore, they exhibit significantly reduced out-of-band/-carrier leakage, making them a promising concept for future cognitive radio and cooperative multi-point concepts. Asides from that, they offer an increased robustness in doubly (time and frequency) dispersive channels.
A major downside is the increased complexity of the communication scheme, which is shifted towards the receiver side. Many aspects of this multicarrier modulation, as e.g. channel estimation, MIMO aspects, detection, interference mitigation and synchronization, require more complex schemes, algorithms and architectures, which conflict with the power-efficient implementation in e.g. mobile end-user devices. Therefore, research efforts have to be directed towards these aspects.
As a main applicational motivation, the simplified interference mitigation in coordinated/cooperative multi-user scenarios is in focus, where OFDM requires a tight synchronization and thus is insufficient. FBMC especially enables time-asynchronous multi-user communications and offers a reduced communication overhead and increased robustness at the same time.
The different types, applications and algorithms in doubly dispersive channels and asynchronous environments, especially in comparison to the broadly used OFDM standard, are differentiated and investigated. Channel estimation/MIMO equalization schemes or the synchronization issues in multi-user MISO/MIMO communications are possible extensions of these thesis topics. The theses are covering the recent developments for next-generation communication, which could be deployed in 5G/6G standards.
Guido Dartmann, Volker Lücken
This research work is also part of the European Union-funded METIS 2020 project, where future mobile communications perspectives and solutions are investigated.