DISTRIBUTED BEAMFORMING IN RELAY NETWORKS FOR ENERGY HARVESTING MULTI-GROUP MULTICAST SYSTEMS


DEMİR Ö. T., TUNCER T. E.

IEEE International Conference on Acoustics, Speech, and Signal Processing, Shanghai, China, 20 - 25 March 2016, pp.3296-3300 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Shanghai
  • Country: China
  • Page Numbers: pp.3296-3300
  • Keywords: Multi-group multicast beamforming, distributed beamforming, phase-only beamforming, SWIPT, SWIPT
  • Middle East Technical University Affiliated: Yes

Abstract

In this paper, simultaneous wireless information and power transfer (SWIPT) is considered for multi-group multicasting relay networks where there is no direct link between the source and destination nodes. Each source transmits its own multicast stream to a group of users with the help of single antenna relays which use amplify-and-forward relay protocol. Each user has energy harvesting capability. A part of the received signal is used for information decoding while the rest is used for energy harvesting. The design problem is to determine the complex relay weights and the power splitting ratios for the users. The resulting optimization problem is nonconvex and converted into a form suitable for quadratically constrained quadratic programming. In addition to the conventional relay beamforming, distributed phase-only beamformer design is also considered and both beamformer design problems are solved iteratively using feasible point pursuit-successive convex approximation algorithm. Several simulations are performed and the advantages of both approaches are outlined.