As larger bandwidths are used in multiple antenna wireless systems, the frequency selectivity of the antenna arrays starts to impact rate. Motivated by optimizing the achievable rate in compact antenna arrays, we present a system model that incorporates the effects of mutual coupling (MC) of wideband physically realizable single-input multiple-output (SIMO) and multiple-input single-output (MISO) antenna systems. For the SIMO system setup, we extract the noise correlation matrices for two different antenna array configurations (parallel and co-linear). We optimize the inter-element spacing in each alignment while maximizing the achievable rate and fixing the transmit power. Then, we compare the two compact antenna designs to a perfectly matched single omni-directional antenna while accounting for MC. Likewise, for the MISO antenna system, we derive the optimal beamformer that maximizes the achievable rate using the same antenna configurations as the SIMO system. Then, we study the impact of MC and develop a new single-port matching technique for wideband antenna arrays. Finally, we provide reciprocity plots to compare the performance of the SIMO-MISO systems using different channel models.

In this paper we present a novel capacity optimization methodology for a two-element multi-band single-input multiple-output (SIMO) antenna. We first introduce a system model that incorporates antenna mutual coupling in the wideband regime. Then, we extract the noise correlation matrices from two different antenna configurations (parallel and co-linear). We optimize the spacing in each scenario while maximizing the Shannon capacity under transmit power constraint. Consequently, we compare the two compact planar antenna designs to the AWGN capacity baseline at different inter- element spacing while accounting for mutual coupling. Finally, we introduce a matching network that maximizes the capacity of the wideband SIMO system.

In today's wireless networks, interference serves as a harmful factor that can notably degrade the overall performance. Nevertheless, interference can also be beneficial when utilized as an additional power source for radio frequency (RF) based energy harvesting in order to charge Internet of Things (IoT) devices. In this paper, we quantify the positive impact of interference for energy harvesting using tools from stochastic geometry; in particular, we derive an expression for a suitable success probability metric and validate its accuracy using Monte-Carlo simulations as a function of various system parameters. Moreover, we design, implement and evaluate an experimental test bed for RF-based energy harvesting using WiFi access points (APs) in order to demonstrate the practical performance gains resulting from interference as a function of the number of access points, their relative locations, and the receivers antenna configuration. The obtained experimental measurement results corroborate the insights extracted from the analytical derivations.