![]() ; Spano, Danilo ![]() ![]() in IEEE Communications Surveys and Tutorials (2020), 22(2), 796-839 Interference is traditionally viewed as a performance limiting factor in wireless communication systems, which is to be minimized or mitigated. Nevertheless, a recent line of work has shown that by ... [more ▼] Interference is traditionally viewed as a performance limiting factor in wireless communication systems, which is to be minimized or mitigated. Nevertheless, a recent line of work has shown that by manipulating the interfering signals such that they add up constructively at the receiver side, known interference can be made beneficial and further improve the system performance in a variety of wireless scenarios, achieved by symbol-level precoding (SLP). This paper aims to provide a tutorial on interference exploitation techniques from the perspective of precoding design in a multi-antenna wireless communication system, by beginning with the classification of constructive interference (CI) and destructive interference (DI). The definition for CI is presented and the corresponding mathematical characterization is formulated for popular modulation types, based on which optimization-based precoding techniques are discussed. In addition, the extension of CI precoding to other application scenarios as well as for hardware efficiency is also described. Proof-of-concept testbeds are demonstrated for the potential practical implementation of CI precoding, and finally a list of open problems and practical challenges are presented to inspire and motivate further research directions in this area. [less ▲] Detailed reference viewed: 128 (16 UL)![]() ; Zheng, Gan ![]() in Power Efficient Downlink Beamforming Optimization by Exploiting Interference (2015, December 06) We propose a new beamforming scheme for the multi-user multiple-input-single-output (MISO) downlink channel. While conventional beamforming aims at the minimization of the transmit power subject to ... [more ▼] We propose a new beamforming scheme for the multi-user multiple-input-single-output (MISO) downlink channel. While conventional beamforming aims at the minimization of the transmit power subject to suppressing interference to guarantee quality of service (QoS) constraints, here we exploit, rather than suppress, the constructive part of interference. By exploiting the power of constructively interfering symbols, the proposed scheme achieves the required QoS at lower transmit power. In addition, we derive an equivalent virtual multicast formulation for the proposed optimization to facilitate the design of a more efficient solver. Our simulation and analysis show significant power savings for small scale MISO downlink channels with the proposed optimization compared to conventional beamforming optimization. [less ▲] Detailed reference viewed: 125 (0 UL) |
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