Relay-Assisted Beamforming for Multicast Systems with Energy Harvesting Capability

2016-05-19
Demir, Özlem Tuğfe
Tuncer, Temel Engin
In this paper, multi-group multicasting scenario is considered where single antenna sources transmit their own information to different groups of users with the help of single antenna relays. Users have energy harvesting capability, i.e., a part of the received signal is used for information decoding while the rest is used for energy harvesting. Beamforming is performed by the relays which use amplify-and-forward protocol. The design of complex relay coefficients and power splitting ratios for the users is studied and the resulting nonconvex optimization problem is converted into a form suitable for quadratically constrained quadratic programming. In this paper, phase-only beamforming is also considered and both problems are solved iteratively.

Suggestions

OPTIMUM DISCRETE DISTRIBUTED BEAMFORMING FOR SINGLE GROUP MULTICASTING RELAY NETWORKS WITH RELAY SELECTION
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2015-04-24)
In this paper, broadcast beamforming with relay selection is considered in wireless relay networks where there is no direct link between the source and the receivers. A source node transmits common information to many users employing multiple relays which use amplify-and-forward relay protocol. The channel state information is assumed to be available at a single relay to compute the relay weights and distribute them. Discrete relay weights are used due to several advantages including decreased overhead for ...
DISTRIBUTED BEAMFORMING IN RELAY NETWORKS FOR ENERGY HARVESTING MULTI-GROUP MULTICAST SYSTEMS
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2016-03-25)
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. T...
HYBRID BEAMFORMING WITH TWO BIT RF PHASE SHIFTERS IN SINGLE GROUP MULTICASTING
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2016-03-25)
In this paper, an efficient hybrid beamforming architecture combining analog and digital beamforming is proposed to reduce the number of radio frequency (RF) chains. It provides a good compromise between the higher degree of freedom of digital beamforming and hardware cost and complexity. In this hybrid system, two bit RF phase shifters are used as analog beamformers due to the fact that this enables the conversion of the combinatorial optimization problem to a continuous programming formulation. The overal...
Waveguide-based Monopulse Wideband Travelling-Wave Array
GULTEPE, Gokhan; DOGAN, Doganay; Aydın Çivi, Hatice Özlem (2017-07-14)
A novel, travelling-wave, waveguide antenna structure with monopulse capability in the two principal planes is proposed with increased frequency bandwidth. The array consists of two interleaved waveguide arrays which provide appropriate excitations to the antenna elements above the waveguide to generate proper sum and difference patterns. With the use of printed antennas and the elimination of the narrow frequency characteristics of the slots on the waveguides, the bandwidth of the array is greatly improved.
Discrete Relay Beamforming for Broadcasting with Relay Selection
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2015-05-19)
In this paper, broadcast beamforming problem is considered in relay-assisted wireless networks. Two-phase relay communication is adopted. In the first phase, a source transmits common information to multiple relays which use amplify-and-forward relay protocol. Each relay multiplies its received signal by a complex weight and transmits it to the receivers. The amplitudes and phases of complex relay weights are chosen from discrete sets in order to decrease overhead for the feedback channel. Relay selection i...
Citation Formats
Ö. T. Demir and T. E. Tuncer, “Relay-Assisted Beamforming for Multicast Systems with Energy Harvesting Capability,” 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53822.