Multiple access schemes for two-way relaying using multiple antennas in multi-user scenarios

Final Report Abstract

We have investigated different bidirectional multi-antenna non-regenerative relaying scenarios. To investigate relaying in future cellular networks, a cellular multi-user relaying scenario has been considered. To investigate relaying in future ad-hoc and sensor networks, a multi-pair relaying scenario and a multigroup multi-way relaying scenario have been considered. Additionally, to investigate transmission via the direct link in combination with two-way relaying, a single-pair two-way relaying scenario with direct link has been considered. Moreover, a scenario where a node with an own individual message is acting as relay has been investigated. Furthermore, we have introduced asymmetric data rate (ADR) requirements to consider that the required data rates are typically different for transmission and reception. To fulfill these ADR requirements while achieving high sum rates, we have introduced several low-complexity transmit strategies for the considered relaying scenarios. Via these transmit strategies, the transmit powers of the nodes, the transmit power distribution at the relay station and the numbers of simultaneously transmitted data streams have been jointly optimized. Moreover, we have exploited the capability of the nodes to perform self-interference cancellation for the relay transceive filter design. We have derived analytical solutions for self-interference aware relay transceive filters which require less antennas at the relay station than conventional filters. Additionally, we have proposed alternating approaches to jointly design the relay transceive filter and the filters at the nodes which further improve the performance. Furthermore, we have investigated two-way relaying with imperfect channel state information (CSI). We have proposed a pilot transmission scheme which requires less time slots than conventional schemes due to exploiting the spatial processing capabilities at the relay station. Additionally, we have proposed a robust relay transceive filter design which overcomes some of the performance degradation caused by imperfect CSI. Moreover, we have proposed transmit strategies for the multi-group multi-way relaying scenario which efficiently combine the spatial processing capabilities of the relay station with the temporal processing capabilities at the nodes. Due to these transmit strategies and the proposed relay transceive filter design, the required number of antennas at the relay station has been significantly reduced. In general, the proposed transmit strategies combined with the proposed filter designs significantly outperform conventional approaches in terms of the achievable data rates.

Publications

• „Non-regenerative multi-antenna two-hop relaying under an asymmetric rate constraint“, in Proceedings of the IEEE Wireless Communications and Networking Conference, Cancun, Mexico, March 2011
  H. Degenhardt, A. Klein
  
• „Self-interference aware MMSE filter design for a cellular multi-antenna two-way relaying scenario“, in Proceedings of the Eighth International Symposium on Wireless Communication Systems, Aachen, Germany, November 2011
  H. Degenhardt, T. Unger, A. Klein
  
• „Pilot Transmission Scheme and Robust Filter Design for Non-Regenerative Multi-Pair Two-Way Relaying“, in Proceedings of the IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, Sydney, Australia, September 2012
  H. Degenhardt, F. Hohmann, A. Klein
  
• „Self-interference aware MIMO filter design for non-regenerative multipair two-way relaying“, in Proceedings of the IEEE Wireless Communications and Networking Conference, Paris, France, April 2012
  H. Degenhardt, A. Klein
  
• „A Hybrid Approach Combining Non-Regenerative MIMO Two-Way Relaying and Direct Link Transmission“, in Proceedings of the International ITG Workshop on Smart Antennas, Stuttgart, Germany, March 2013
  H. Degenhardt, F. Hohmann, A. Klein
  
• „A Network Coding Approach to Non-Regenerative Multi-Antenna Multi-Group Multi-Way Relaying“, in Proceedings of the IEEE Vehicular Technology Conference, Dresden, Germany, June 2013
  H. Degenhardt, A. Klein
  
• „Known-Interference Aware Iterative MMSE Filter Design for Non-Regenerative Multi-Way Relaying“, in Proceedings of the IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing, Saint Martin, December 2013
  H. Degenhardt, A. Klein
  
• „Non-Regenerative Multi-Way Relaying: Combining the Gains of Network Coding and Joint Processing“, IEEE Transactions on Wireless Communications, vol. 12, no. 11, pp. 5692-5703, November 2013
  H. Degenhardt, Y. Rong, A. Klein