Understanding UAV-Based WPCN-Aided Capabilities for Offshore Monitoring Applications

Published in Wireless Communication Magazine, 2021

Despite the immense progress in the recent years, efficient solutions for monitoring remote areas are still missing today. This is especially notable in the context of versatile maritime and offshore use cases, owing to a broader span of operating regions and a lack of radio network infrastructures. In this article, we address the noted challenge by delivering a conceptual solution based on the convergence of three emerging technologies – unmanned aerial vehicles (UAVs), battery-less sensors, and wireless powered communication networks (WPCNs). Our contribution offers a systematic description of the ecosystem related to the proposed solution by identifying its key actors and design dimensions together with the relevant resources and performance metrics. A system-level modeling-based evaluation of an illustrative scenario delivers deeper insights into the considered operation and the associated trade-offs. Further, unresolved challenges and perspective directions are underpinned for a subsequent study.

Recommended citation: D. Carrillo, K. Mikhaylov, P. J. Nardelli, S. Andreev and D. B. da Costa, "Understanding UAV-Based WPCN-Aided Capabilities for Offshore Monitoring Applications," in IEEE Wireless Communications, doi: 10.1109/MWC.001.2000218.

Achievable Sum Rate and Outage Capacity of GFDM Systems with MMSE Receivers

Published in ICC 2020 - 2020 IEEE International Conference on Communications (ICC), 2020

This paper investigates the achievable sum rate and the outage capacity of generalized frequency division multiplexing systems (GFDMs) with minimum mean-square error (MMSE) receivers over frequency-selective Rayleigh fading channels. To this end, a Gamma-based approximation approach for the probability density function of the signal-to-interference-plus-noise ratio is presented, based on which accurate analytical formulations for the achievable sum rate and outage capacity are proposed. The accuracy of our analysis is corroborated through Monte Carlo simulation assuming different GFDM parameters. Illustrative numerical results are depicted in order to reveal the impact of the key system parameters, such as the number of subcarriers, number of subsymbols, and roll-off factors, on the overall system performance.

Recommended citation: D. Carrillo, S. Kumar, G. Fraidenraich, P. H. J. Nardelli and D. B. d. Costa, "Achievable Sum Rate and Outage Capacity of GFDM Systems with MMSE Receivers," ICC 2020 - 2020 IEEE International Conference on Communications (ICC), Dublin, Ireland, 2020, pp. 1-6, doi: 10.1109/ICC40277.2020.9149450.

Reconfigurable Intelligent Surface-Aided Grant-Free Access for Uplink URLLC

Published in 2020 2nd 6G Wireless Summit (6G SUMMIT), 2020

Reconfigurable intelligent surfaces (RISs) have been recently considered as one of the emerging technologies for future communication systems by leveraging the tuning capabilities of their reflecting elements. In this paper, we investigate the potential of an RIS-based architecture for uplink sensor data transmission in an ultra-reliable low-latency communication (URLLC) context. In particular, we propose an RIS-aided grant-free access scheme for an industrial control scenario, aiming to exploit diversity and achieve improved reliability performance. We consider two different resource allocation schemes for the uplink transmissions, i.e., dedicated and shared slot assignment, and three different receiver types, namely the zero-forcing, the minimum mean squared error (MMSE), and the MMSE-successive interference cancellation receivers. Our extensive numerical evaluation in terms of outage probability demonstrates the gains of our approach in terms of reliability, resource efficiency, and capacity and for different configurations of the RIS properties. An RIS-aided grant-free access scheme combined with advanced receivers is shown to be a well-suited option for uplink URLLC.

Recommended citation: D. Carrillo, C. Kalalas, A. S. de Sena, P. H. J. Nardelli and G. Fraidenraich, "Reconfigurable Intelligent Surface-Aided Grant-Free Access for Uplink URLLC," 2020 2nd 6G Wireless Summit (6G SUMMIT), Levi, Finland, 2020, pp. 1-5, doi: 10.1109/6GSUMMIT49458.2020.9083788.

Bit Error Probability for MMSE Receiver in GFDM Systems

Published in IEEE Communications Letters, 2018

In this letter, we consider the minimum mean-square error receiver for the generalized frequency division multiplexing system (GFDM) over frequency selective fading channels. We derive an approximate probability density function for the signal-to-interference-plus-noise ratio. This expression allows us to obtain a new approximate, but rather accurate formulation for the bit error probability for a M-quadrature amplitude modulation scheme. Our results resort on the pivotal properties exhibited by eigenvalues of a circulant matrix. Since the entries of the channel matrix H ch are complex Gaussian distributed, and the eigenvalues are given as a weighted sum of its entries, the joint eigenvalue distribution is also Gaussian. Comparisons of the simulated and analytical results validate our formulation and allow a quick and efficient tool to compute the bit error rate for the GFDM system.

Recommended citation: D. Carrillo, S. Kumar, G. Fraidenraich and L. L. Mendes, "Bit Error Probability for MMSE Receiver in GFDM Systems," in IEEE Communications Letters, vol. 22, no. 5, pp. 942-945, May 2018, doi: 10.1109/LCOMM.2018.2808475.

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