In urban contexts, the increasing density of electronic devices equipped with Global Navigation Satellite System (GNSS) receivers and complementary positioning technologies is attracting research and development efforts devoted to an improvement of the quality of life towards the smart city paradigm. Vehicular and pedestrian positioning and navigation capabilities are among the major drivers for innovation in this process. Ultra-low-cost electronics such as smartphones and Internet of Things (IoT) sensors aim at providing accurate and reliable positioning solutions through a set of promising solutions. Among these, snapshot positioning allows to remotely perform the post-processing of GNSS signals in IoT sensor networks while Wi-Fi™ ranging and cooperative positioning provide auxiliary anchors of opportunity to enhance indoor/outdoor positioning capabilities. This paper presents an innovative platform to perform a centralised testing and assessment of such positioning and navigation technologies along with a set of results obtained in the context of the European project HANSEL, by relying on current network technologies and infrastructures (i.e., Wi-Fi™ and cellular connectivity).

Abstract-We consider a system where multiple users are connected to a small cell base station enhanced with computational capabilities. Instead of doing the computation locally at the handset, the users offload the computation of full applications or pieces of code to the small cell base station. In this scenario, this paper provides a strategy to allocate the uplink, downlink, and remote computational resources. The goal is to improve the quality of experience of the users, while achieving energy savings with respect to the case in which the applications run locally at the mobile terminals. More specifically, we focus on minimizing a cost function that depends on the latencies experienced by the users and provide an algorithm to minimize the latency experienced by the worst case user, under a target energy saving constraint per user.Index Terms-Multiuser systems, small cell networks, application offloading, scheduling, energy efficiency, adaptive rate.

Abstract-This paper addresses the trade-off between latency and energy consumption in wireless application offloading in a multiuser set-up. The advantages of carrying out offloading versus executing an application locally at the user terminal depend on multiple parameters. This paper evaluates the impact that the transmission rate and the load of the system have on the quality of service experienced by the users as well as on the energy saving that the users get from doing offloading. Based on this evaluation, the paper proposes a method to select the uplink data rate that minimizes the latency experienced by the user given a target energy saving with respect to the case of no offloading. The result depends on the channels conditions, the system load, the application parameters, and the energy consumption features of the terminal. The method is presented firstly for flat fading channels and secondly for non-flat fading channels.

Interference is a major obstacle in radio communications, especially when opportunistic frequency reuse is an inherent requirement for maximizing spectral efficiency in heterogeneous networks. A typical example is encountered in cellular communications where macro cell-edge users receive interference from small cell transmissions that use the same radio frequency band. Innovating interference management algorithms are employed towards this end, which due to their interdependencies with numerous parameters of the target operating scenario and various low-level implementation aspects, need to be prototyped in real-time signal processing platforms in order to be credibly verified. In this paper, we present the development and experimental validation of a macro/femto cell coexistence scenario in close to reallife conditions. The inclusion of an agile interference management scheme increased the signal processing complexity at the physical layer. This overhead was appropriately addressed by engaging advanced parallel processing techniques, optimizations of the arithmetic operations and intelligent reuse of logic and memory resources in the FPGA-based baseband processing architecture.

This paper introduce the Nonuniform Rational B-Spline (NURBS) surfaces to improve the geometric modeling of the Locally Corrected Nystro¨m (LCN) Method. Compared with the interpolation curvilinear quadrilaterals, the NURBS surfaces can approximate the model with higher accuracy and by much less elements. Thus, the size of the elements can be more flexibly chosen to fully exert the efficiency of the LCN method. Numerical results of the radar cross sections (RCS) show the validity of the proposed technique.