Partial Zero Forcing for Multi-Way Relay Networks

• Author / Creator

  Zhang, Wuhua

• The ever increasing demands for mobile network access have resulted a significant growth in bandwidth usage. By improving the system spectral efficiency, multi-way relay networks (MWRNs) provide promising approaches to address this challenge. In this thesis, we propose a novel linear beamforming design, namely partial zero-forcing (PZF), for MWRNs with a multiple-input-multiple-output (MIMO) relay. Compared to zero-forcing (ZF), PZF relaxes the constraints on the relay beamforming matrix such that only partial user-interference, instead of all, is canceled at the relay. The users eliminate the remaining interferences through self-interference and successive interference cancellation. A sum-rate maximization problem is formulated to exploits the extra degrees-of-freedom brought from PZF. In solving the optimization problem, a numerical method, called modified gradient-ascent method, is proposed. Simulation results show that the proposed PZF relay beamforming design achieves significantly higher network sum rates than existing linear beamforming designs.

• Subjects / Keywords

  • Zero-forcing
  • Interference cancellation
  • Sum-rate maximization
  • Beamforming
  • Multi-way relay networks

• Graduation date

  Fall 2015

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3N01023G

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.