Search results for "INTERFERENCE"
showing 10 items of 573 documents
Optimized design of high power density EMI filters for power electronic converters
2016
Nowadays, power density of power converters and related EMI filters is gaining more and more attention. This severely impacts on the design constraints in several application domains. A conventional design of the EMI filter does not guarantee the selection of components/configuration leading to the best power density. For this reason, an optimized design procedure of discrete EMI filters in terms of power density is proposed in this paper. It is based on a previously developed rule-based design procedure, introducing here additional features to obtain a more effective optimization of EMI filter's power density. The proposed approach has been validated in terms of EMI filter's performance an…
Enhanced LMMSE equalizer for high-speed single frequency network in HSDPA
2011
Currently, considerable interest has been shown in the research and standardization communities in multicell transmission schemes for HSPA, with a number of possible schemes under discussion that include Multiflow, Fast Cell Switching (FCS) and High-Speed Single Frequency Network (HS-SFN). In particular, HS-SFN is a promising technique that not only combines received energy from participating cells, but also reduces intercell interference with low UE complexity. In principle, HS-SFN can be implemented with a small modification to an LMMSE receiver at the UE. This paper introduces a more advanced LMMSE equalizer for High-Speed Single Frequency Network in HSDPA that achieves further performan…
Virtual Instruments: Uncertainty Evaluation in the Presence of Electromagnetic Interferences
2007
The electromagnetic interferences can influence the performances of a virtual instrument; consequently, in a generic measurement performed by using these instruments, the related uncertainty values can increase. In the paper, we report the results of various experimental tests performed with the aim to check if and how the radiated and/or conducted disturbances affect the instruments' characteristics and, in particular, the single uncertainty sources. Starting from these results and applying an already proposed method for the uncertainty estimation in the measurements performed by means of virtual instruments, it is possible to take into account and to evaluate the contribute of the electro…
Impact of industrial environments on the PC-based measurements
2007
In the paper we present a simple and fast procedure to evaluate the impact of the electromagnetic disturbances, which can be present in the industrial locations, on the measurements performed by a generic PC-based measurement instrument. The method is conceived starting from the data obtained by subjecting the instruments to the disturbances prescribed by the IEC-61326 standard. The results show that, even under heavy disturbances, the common good practices of shielding and grounding allow a correct employment of this kind of instrumentation.
Evaluation of radiated EMI in 42 V vehicle electrical systems by FDTD simulation
2007
In this paper a full 3D numerical scheme, based on the finite difference time domain method, is used to predict the electromagnetic radiated interference generated by 42 V vehicle power electronic driven electrical loads. An experimental set-up has been arranged on purpose in order to validate the proposed simulation tool. To this aim, the features of a semi-anechoic electromagnetic chamber have been exploited in order to operate in a shielded test site for the measurement of near field radiated emissions. Two different three-dimensional geometrical configurations of realistic vehicle installations of the loads, are studied. A comparative analysis among measured and computed results is perf…
AIOC2: A deep Q-learning approach to autonomic I/O congestion control in Lustre
2021
Abstract In high performance computing systems, I/O congestion is a common problem in large-scale distributed file systems. However, the current implementation mainly requires administrator to manually design low-level implementation and optimization, we proposes an adaptive I/O congestion control framework, named AIOC 2 , which can not only adaptively tune the I/O congestion control parameters, but also exploit the deep Q-learning method to start the training parameters and optimize the tuning for different types of workloads from the server and the client at the same time. AIOC 2 combines the feedback-based dynamic I/O congestion control and deep Q-learning parameter tuning technology to …
Capture Aware Sequential Waterfilling for LoraWAN Adaptive Data Rate
2020
LoRaWAN (Long Range Wide Area Network) is emerging as an attractive network infrastructure for ultra low power Internet of Things devices. Even if the technology itself is quite mature and specified, the currently deployed wireless resource allocation strategies are still coarse and based on rough heuristics. This paper proposes an innovative "sequential waterfilling" strategy for assigning Spreading Factors (SF) to End-Devices (ED). Our design relies on three complementary approaches: i) equalize the Time-on-Air of the packets transmitted by the system's EDs in each spreading factor's group; ii) balance the spreading factors across multiple access gateways, and iii) keep into account the c…
Impact of LTE’s Periodic Interference on Heterogeneous Wi-Fi Transmissions
2018
The problem of Wi-Fi and LTE coexistence has been significantly debated in the last years, with the emergence of LTE extensions enabling the utilization of unlicensed spectrum for carrier aggregation. Rather than focusing on the problem of resource sharing between the two technologies, in this paper, we study the effects of LTE's structured transmissions on the Wi-Fi random access protocol. We show how the scheduling of periodic LTE transmissions modifies the behavior of 802.11's distributed coordination function (DCF), leading to a degradation of Wi-Fi performance, both in terms of channel utilization efficiency and in terms of channel access fairness. We also discuss the applicability and…
Application of Thin ZnO ALD Layers in Fiber-Optic Fabry-Pérot Sensing Interferometers
2016
International audience; In this paper we investigated the response of a fiber-optic Fabry-Pérot sensing interferometer with thin ZnO layers deposited on the end faces of the optical fibers forming the cavity. Standard telecommunication single-mode optical fiber (SMF-28) segments were used with the thin ZnO layers deposited by Atomic Layer Deposition (ALD). Measurements were performed with the interferometer illuminated by two broadband sources operating at 1300 nm and 1550 nm. Reflected interference signal was acquired by an optical spectrum analyzer while the length of the air cavity was varied. Thickness of the ZnO layers used in the experiments was 50 nm, 100 nm, and 200 nm. Uncoated SMF…
Fiber-based device for the detection of low-intensity fluctuations of ultrashort pulses
2012
International audience; We describe a fiber-based device that can significantly enhance the low intensity fluctuations of an ultrashort pulse train to detect them more easily than with usual direct detection systems. Taking advantage of the Raman intrapulse effect that progressively shifts the central frequency of a femtosecond pulse propagating in an anomalous dispersion fiber, a subsequent spectral filtering can efficiently increase the level of fluctuations by more than one order of magnitude. We show that attention has to be paid to maintain the shape of the statistical distribution unaffected by the nonlinear process.