1,721,046 research outputs found
On the sensitivity of MIMO NC to channel estimation errors
No full textMIMO_NC is a recently proposed physical layer for wireless network coding. All previous work has analyzed this system under ideal channel state information (CSI). Instead, this paper studies the performance of MIMO_NC under imperfect CSI and as a function of the system parameters (rate, block size, MIMO_NC class) and compares it against classic network coding
A Low-Delay MAC Solution for MIMO Ad Hoc Networks
No full textBeamforming is regarded as a key element for multiantenna ad hoc networks. However, it cannot simultaneously provide the omnidirectional and long-range coverage required by broadcast transmissions, a problem known as the Asymmetry in Gain. We propose a scheme for control packet exchange over an extended radio coverage based on a Space Time Code technique. This solution is shown to solve the Asymmetry in Gain issue, and is proposed as part of a MAC protocol for MIMO ad hoc networks, whose performance benefits include increased throughput and reduced delay and energy consumption
Cooperative Cross Layer MAC Protocols for Directional Antenna Ad Hoc Networks
No full textThis paper deals with some of the main problems that affect directional antenna ad hoc networks, especially deafness and collisions. By means of a thorough study of the possibilities offered by an antenna array, we propose cooperation as a novel technique for deafness suppression, together with a low complexity multiuser detector and a collision avoidance algorithm tailored for this type of networks. Building on these ideas, a new family of protocols (called Cooperative MAC) is designed. A lower and an upper bound on its performance are compared with the Circular RTS/CTS protocol (CRCM), a known benchmark in this field. We are able to achieve interesting improvements
Phygital Play. HRI in a new gaming scenario.
No full textThis paper addresses the issue of screen time, a growing phenomenon triggered by the spread of digital devices, which may cause a health impact. The reduction of screen time emerges as a requirement, especially in games. For this reason, the paper offers an overview of the current Phygital game trend, through some related projects that highlight the potential of physical features in virtual games in terms of attraction and engagement. A new gaming framework is proposed as a step forward in the virtual-physical contamination. The proposed project consists of a
projected playground, on which people and robot(s) can physically interact. The role of the robot is enhanced entrusting it different roles, from a companion, to an adversary, to the avatar of a remote player. By abstracting the inherent complexities and providing common functionality, the proposed framework aims to simplify the development of games that wish to exploit both digital and physical elements
Analysis of dynamic performance of dispersed generation connected through inverter to distribution networks
No full textWith reference to the new technologies of distributed generation, the dynamic behaviour of inverter interfaced DGs embedded on a distribution system has been studied in order to assess their influence on the system under perturbed conditions, in particular their contribution to the fault currents.
The dynamic performance of inverter interfaces, with different types of controller depending upon the operation modes, has been simulated on both a grid connected radial network and an intentionally islanded portion of the network (microgrid), comparing the results with the behaviour of corresponding size traditional rotating generators connected directly to the grid. From the analysis the following considerations can be drawn
Design Considerations for Massively Parallel Channel Estimation Algorithms
No full textAccurate channel estimation may require complex algorithms for effective results, especially in the case of a multiuser detector. The introduction of Graphic Processing Units (GPUs) has opened up new possibilities for the implementation of numerically intensive channel estimation algorithms. This paper studies the implementation on GPUs of channel estimation algorithms for channels affected by strong phase noise. While classic Maximum Likelihood estimation is still the most competitive in terms of throughput and memory bandwidth, Steepest Ascent algorithms show the largest speed improvement due to their structure, which is the most suitable for implementation on a parallel processor like the GPU
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