Alexandros-Apostolos A. Boulogeorgos

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—We study the outage performance of orthogonal frequency-division multiplexing dual-hop opportunistic amplify-and-forward relaying in the presence of I/Q imbalance (IQI) in all nodes. We derive a closed-form expression for the end-to-end outage probability for the general case where each node suffers from a different IQI level and assuming that the distance(More)
—We study the outage performance of orthogonal frequency-division multiplexing dual-hop opportunistic amplify-and-forward relaying in the presence of I/Q imbalance in all of the nodes' transceivers. We derive a closed-form expression for the end-to-end outage probability for the general case, where each node suffers from a different I/Q imbalance level and(More)
Direct-conversion radio (DCR) receivers can offer highly integrated low-cost hardware solutions for spectrum sensing in cognitive radio systems. However, DCR receivers are susceptible to radio frequency (RF) impairments, such as in-phase and quadrature-phase imbalance, low-noise amplifier nonlinearities and phase noise, which limit the spectrum sensing(More)
—Direct-conversion radio receivers can offer highly integrated low-cost hardware solutions for spectrum sensing in cognitive radio systems. However, these receivers are susceptible to radio frequency (RF) impairments, such as in-phase and quadrature-phase imbalance, low-noise amplifier nonlinearities and phase noise, which limit the spectrum sensing(More)
Internet of things (IoT) changes significantly the requirements for connectivity, mainly with regards to long battery life, low device cost, low deployment cost, extended coverage and support for a massive number of devices. Driven from these requirements, several different cellular and non-cellular low power wide area network (LPWAN) solutions are emerging(More)