Database-assisted TV white space network is a promising paradigm of dynamic spectrum sharing, and can effectively improve spectrum utilization and alleviate spectrum scarcity via centralized control of TV white space databases residing in the cloud. In this article, we discuss business modeling for a database-assisted TV white space network, which is very important for wide commercialization of this…
Tags: 2015 OMNeT++ Projects
Dynamic Heterogeneous Learning Games for Opportunistic Access in LTE-Based Macro/Femtocell Deployments
Interference is one of the most limiting factors when trying to achieve high spectral efficiency in the deployment of heterogeneous networks (HNs). In this paper, the HN is modeled as a layer of closed-access LTE femtocells (FCs) overlaid upon an LTE radio access network. Within the context of dynamic learning games, this work proposes a novel heterogeneous multiobjective fully distributed…
Offshore low frequency AC transmission with back-to-back modular multilevel converter (MMC)
This paper evaluates the use of a back-to-back modular multilevel converter (B2B-MMC) in offshore low frequency (LF) AC transmission. The scheme is compared to two alternative transmission technologies: DC and 50Hz AC. The MMC topology is further compared to a cycloconverter. A high level design of a ±120kVdc, 250MW B2B-MMC system is described, with the…
100 GHz reflectometer for sensitivity analysis of MEMS sensors comprising an intermediate frequency Six-port receiver
Due to the growing market for Micro Electro Mechanical Systems (MEMS), especially for the application in mobile electronic devices like cameras, phones or tablet computers, cost and time efficient test and evaluation systems are required for the production process. This work presents a novel measurement setup for MEMS microphones, that allows an inline, contactless evaluation of…
A symbolic system synthesis approach for hard real-time systems based on coordinated SMT-solving
We propose an SMT-based system synthesis approach where the logic solver performs static binding and routing while the background theory solver computes global time-triggered schedules. In contrast to previous work, we assign additional time to the logic solver in order to refine the binding and routing such that the background theory solver is more likely…
Performance Analysis of Arbitrarily-Shaped Underlay Cognitive Networks: Effects of Secondary User Activity Protocols
This paper analyzes the performance of the primary users (PUs) and secondary users (SUs) in an arbitrarily-shaped underlay cognitive network. In order to meet the interference threshold requirement for a primary receiver at an arbitrary location, we consider different SU activity protocols that limit the number of active SUs. We propose a framework, based on the moment-generating…
Performance of Cognitive Hybrid Automatic Repeat reQuest: Stop-and-Wait
Detecting spectrum holes and efficiently accessing them are the two basic functions that enable acognitive radio (CR) to make use of the licensed spectrums of a primary radio (PR). In this paper, we consider a CR scheme, which opportunistically accesses a PR channel for communication between a pair of nodes based on the stop-and-wait hybrid automatic repeat request (SW-HARQ).…
Spectrum awareness and exploitation for Cognitive Radio Satellite Communications
The Digital Agenda for Europe (DAE) sets forth ambitious requirements for broadband communications, in which Satellite Communications (SatCom) play a major role. In this context, spectrum sharing techniques offer unprecedented opportunities to increase capacity and reduce costs in order to allow SatCom to meet the DAE objectives. The EU FP7 Project CoRaSat is assessing Cognitive…
Space–Time Coded Spatial Modulated Physical Layer Network Coding for Two-Way Relaying
Using the spatial modulation approach, where only one transmit antenna is active at a time, we propose two transmission schemes for two-way relay channel using physical layer network coding with space time coding using coordinate interleaved orthogonal designs (CIODs). It is shown that using two uncorrelated transmit antennas at the nodes, but using only one…
Optimal Configuration of Network Coding in Ad Hoc Networks
In this paper, we analyze the impact of network coding (NC) configuration on the performance of ad hoc networks with the consideration of two significant factors, namely, the throughput loss and the decoding loss, which are jointly treated as the overhead of NC. In particular, physical-layer NC and random linear NC are adopted in static…