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Exploiting known interference as green signal power for downlink beamforming optimization
journal contribution
posted on 2018-09-07, 10:24 authored by Christos Masouros, Gan Zheng© 1991-2012 IEEE. We propose a data-aided transmit beamforming scheme for the multi-user multiple-input-single-output (MISO) downlink channel. While conventional beamforming schemes aim at the minimization of the transmit power subject to suppressing interference to guarantee quality of service (QoS) constraints, here we use the knowledge of both data and channel state information (CSI) at the transmitter to exploit, rather than suppress, constructive interference. More specifically, we design a new precoding scheme for the MISO downlink that minimizes the transmit power for generic phase shift keying (PSK) modulated signals. The proposed precoder reduces the transmit power compared to conventional schemes, by adapting the QoS constraints to accommodate constructive interference as a source of useful signal power. By exploiting the power of constructively interfering symbols, the proposed scheme achieves the required QoS at lower transmit power. We extend this concept to the signal to interference plus noise ratio (SINR) balancing problem, where higher SINR values compared to the conventional SINR balancing optimization are achieved for given transmit power budgets. In addition, we derive equivalent virtual multicast formulations for both optimizations, both of which provide insights of the optimal solution and facilitate the design of a more efficient solver. Finally, we propose a robust beamforming technique to deal with imperfect CSI, that also reduces the transmit power over conventional techniques, while guaranteeing the required QoS. Our simulation and analysis show significant power savings for small scale MISO downlink channels with the proposed data-aided optimization compared to conventional beamforming optimization.
Funding
This work was supported by the Royal Academy of Engineering, U.K. and the Engineering and Physical Sciences Research Council (EPSRC) project EP/M014150/1.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Published in
IEEE Transactions on Signal ProcessingVolume
63Issue
14Pages
3628 - 3640Citation
MASOUROS, C. and ZHENG, G., 2015. Exploiting known interference as green signal power for downlink beamforming optimization. IEEE Transactions on Signal Processing, 63(14), pp. 3628-3640.Publisher
IEEEVersion
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/Acceptance date
2015-04-18Publication date
2015-05-07Notes
This is an Open Access Article. It is published by IEEE under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/ISSN
1053-587XeISSN
1941-0476Publisher version
Language
- en