Exploiting Known Interference as Green Signal Power for Downlink Beamforming Optimization

By Christos Masouros, Gan Zheng. IEEE Transactions on Signal Processing, 2015

355 citations recorded by the source corpus.

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.

Subfields: Aerospace Engineering, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/040ad40973fc9949bc2bcd1100db9bb9279955f4

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Citations in the corpus

Secure Transmission in Cognitive Satellite Terrestrial Networks (2016, background): “This is because interference will affect both legitimate and illegitimate receivers, if properly designed, and it could be used to achieve significant security enhancement for legitimate systems [25]–[27].”
Joint Radar and Communication Design: Applications, State-of-the-Art, and the Road Ahead (2019, background): “We refer readers to [69] for more details on the topic of interference exploitation.”
Simultaneous Wireless Information and Power Transfer (SWIPT): Recent Advances and Future Challenges (2018, background): “interference has been investigated in the work [81] with the knowledge of both DI and CSI at the transmitter.”