Nokia

About: Nokia is a company organization based out in Espoo, Finland. It is known for research contribution in the topics: Signal & Mobile station. The organization has 16625 authors who have published 28347 publications receiving 695725 citations. The organization is also known as: Nokia Oyj & Oy Nokia Ab.

Hand gesture recognition and virtual game control based on 3D accelerometer and EMG sensors

Abstract: This paper describes a novel hand gesture recognition system that utilizes both multi-channel surface electromyogram (EMG) sensors and 3D accelerometer (ACC) to realize user-friendly interaction between human and computers. Signal segments of meaningful gestures are determined from the continuous EMG signal inputs. Multi-stream Hidden Markov Models consisting of EMG and ACC streams are utilized as decision fusion method to recognize hand gestures. This paper also presents a virtual Rubik's Cube game that is controlled by the hand gestures and is used for evaluating the performance of our hand gesture recognition system. For a set of 18 kinds of gestures, each trained with 10 repetitions, the average recognition accuracy was about 91.7% in real application. The proposed method facilitates intelligent and natural control based on gesture interaction.

Influence of the electrolytes on electron transport in mesoporous TiO2-Electrolyte systems

Abstract: Diffusion coefficients of electrons in mesoporous TiO2−electrolyte systems are determined by laser pulse induced photocurrent measurements in the presence of a wide range of concentration of Li+, Na+, Mg2+, tetrabutylammonium cation (TBA+), or dimethylhexylimidazolium cation (DMHI+) in electrolytes. The total amount of photocharge generated by a laser pulse increases in the order of DMHI+< TBA+ < Na+ < Li+. The diffusion coefficients (DAmb) increase with increasing the cation density. In the case of TBA+, the increase of the diffusion coefficients is interpreted with ambipolar diffusion mechanism. In the case of Li+, Na+, Mg2+, and DMHI+, each diffusion coefficient increases to some extent with the cation density as in the case of TBA+, but does not fit well with ambipolar diffusion mechanism with the assumption of constant diffusion coefficient and electrons at the high density of the cations. Electron diffusion in the systems is discussed in terms of the surface cation density arising from the adsorptio...

Performance Evaluation of LTE and Wi-Fi Coexistence in Unlicensed Bands

Abstract: The deployment of modern mobile systems has faced severe challenges due to the current spectrum scarcity. The situation has been further worsened by the development of different wireless technologies and standards that can be used in the same frequency band. Furthermore, the usage of smaller cells (e.g. pico, femto and wireless LAN), coexistence among heterogeneous networks (including amongst different wireless technologies such as LTE and Wi-Fi deployed in the same frequency band) has been a big field of research in the academy and industry. In this paper, we provide a performance evaluation of coexistence between LTE and Wi-Fi systems and show some of the challenges faced by the different technologies. We focus on a simulator-based system- level analysis in order to assess the network performance in an office scenario. Simulation results show that LTE system performance is slightly affected by coexistence whereas Wi-Fi is significantly impacted by LTE transmissions. In coexistence, the Wi-Fi channel is most often blocked by LTE interference, making the Wi-Fi nodes to stay on the LISTEN mode more than 96% of the time. This reflects directly on the Wi-Fi user throughput, that decreases from 70% to ≈100% depending on the scenario. Finally, some of the main issues that limit the LTE/Wi-Fi coexistence and some pointers on the mutual interference management of both the systems are provided.

A system and method for accessing ubiquitous resources in an intelligent environment

Abstract: A system and method for enabling a wireless terminal to access and operate ubiquitous devices ('UDs'), such as televisions, DVD players, etc. The system (100) comprises a server (200) coupled to access points (300a-d) and UDs (500a j) via a LAN or a WLAN (105). Each access point is associated with both a map of an associated area and an overlay indicating the location of the UDs within that area. In response to wireless terminal (400) requests relayed by an access point (300), the server (200) retrieves the map and overlay associated with the access point (300), and transmits that data to the terminal (400) for display. Alternatively, a list of UDs may be transmitted. Selection of a UD (500) from the display (405) causes an image of the UD's control panel to be displayed, from which the device may be remotely controlled by the user. A mechanism is also provided to permit users to display maps of areas other than the one in which the user is currently located to permit remote control of UDs in such areas.

Analysis of DFT-Based Channel Estimators for OFDM

Abstract: In this paper we analyze the performance of three low-complexity channel estimators, based on the discrete Fourier transform (DFT), for orthogonal frequency-division multiplexing (OFDM) systems. Estimators of this type have been analyzed for discrete-time channels, and we extend this analysis to continuous-time channels. We present analytical expressions for their mean-squared error (MSE) and evaluate their complexity vs. symbol-error rate (SER) for 16-QAM. The analysis shows that this type of estimators may experience an irreducible error floor at high SNRs. However, in one of the three estimators the error floor can be eliminated while the complexity stays low and the performance is maximized.