Maria A. Lema

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We present a simple and realistic model of the circadian pacemaker that can be interpreted in molecular terms. The model, which consists of a single time-delay differential equation, simulates the expression of a generic clock protein that inhibits its own expression through a feedback mechanism. Despite its simplicity, this model fulfils most of the(More)
Maintaining multiple wireless connections is a promising solution to boost capacity in fifth-generation (5G) networks, where user equipment is able to consume radio resources of several serving cells simultaneously and potentially aggregate bandwidth across all of them. The emerging dual connectivity paradigm can be regarded as an attractive access(More)
Against previous Long Term Evolution (LTE) re-leases, LTE-Advanced (LTE-A) allows the use of non-contiguous resource allocation in the uplink (UL). This feature leads to an increase in spectral efficiency thanks to link performance gains obtained from frequency diversity. At the same time noncontiguous allocations bring higher peak to average power ratio(More)
The numerous advantages of single-frequency networks (SFNs) make them one of the preferred deployment options for digital video broadcasting terrestrial (DVB-T) operators. However, SFNs are exposed to self-interference that may reduce the effective coverage. This work deals with the optimal adjustment of internal delays at the transmitters to minimize areas(More)
The road to 5G is posing challenging requirements to the cellular network to introduce more applications from several industry verticals. Low delay, high scalability, ultrareliability and device-centric procedures are some of these requirements. Decoupled Uplink (UL) and Downlink (DL), DUDe, is a key enabler of the device-centric network, and provides a(More)
In the context of wireless communications, an accurate channel state information (CSI) is key for a correct radio resource management. In the uplink of Long Term Evolution Advanced (LTE-A), obtaining up-to-date CSI relies on user equipments (UEs), that send sounding signals throughout the available bandwidth. This procedure is quite challenging when(More)
Effective intercell interference (ICI) mitigation has been identified as a key challenge for emerging OFDMA cellular technologies such as Long Term Evolution (LTE). In order to address this issue, mobile operators have adopted static Intercell Interference Coordination (ICIC) strategies, including Fractional Frequency Reuse (FFR), given their low complexity(More)
Capitalizing on the latest developments in 5G and ultra-low delay networking as well as Artificial Intelligence (AI) and robotics, we advocate here for the emergence of an entirely novel Internet which will enable the delivery of skills in digital form. We outline the technical challenges which need to be overcome to enable such a vision, i.e., on the(More)