In the recent years, the role of inherent interference in wireless communications has gone from that of a foe to a friend, as interference leverages different concepts that enhance the capacity of wireless networks. This talk will overview some of the techniques that depend on the existence of that interference, namely: physical layer network coding (PLNC), multiple-input multiple-output (MIMO) and massive MIMO, non-orthogonal multiple access (NOMA), as well as the ability to use full-duplex. All of these technologies are expected to play important roles in the capacity increase that is being planned for 5G, and contribute to a much higher energy efficiency, which is another very important objective in 5G. Multi-user massive MIMO is the technique contributing the most to the 5G user’s experience regarding data rate, mostly my applying straightforward special multiplexing techniques to the (possibly single-antenna) receivers, while thousands of antennas can be envisaged at the base-stations (up to thousands of antennas). The talk will present a technique that takes advantage of a property of matrix inversion that allows a more efficient computation of matrix inversions when considering that the number of users served by a base-station varies along time, and the fact that different users have the channel varying at different speeds. Given that 5G will include many device-to-device links, the heterogeneity of the connections will increase a lot and for that reason NOMA can accommodate further spectral increases by differentiating users in the power domain with power allocation coefficients depending on each user’s channel power. Additionally, PLNC further extends this idea by making use of the combination of data from several users obtained through the interfering channels. This talk will present the application of PLNC to the multi-way channel, leading to a very significant throughput gain. The emergence of in-band full-duplex (IBFD) capability almost doubles the capacity of a link. This talk will present recent advances in the signal processing domain of IBFD systems, namely recursive least squares for MIMO, which shows excellent results in reducing the loop-back interference. Moreover, the application of power optimisation techniques to maximise the sum data rate will also be presented. The talk will present recent results for the use of these techniques either when they are tested standalone and also when they are put together in order to exploit their cumulative benefits.

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Wireles,5G,Network Coding,Full-duplex,Massive MIMO