Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
Cooperative communication has emerged as a promising technique to improve transmission reliability and spectral efficiency by utilizing virtual antenna arrays formed by multiple nodes in wireless networks. In this paper, we study distributed interference-aware random access strategies based on cooperative link selection scheduling for multi-hop wireless networks. In order to fully exploit the broadcast...
One of the outcomes in the last world radio communication conference 2007 (WRC-07) is assigning the 790-862 MHz band to the digital broadcasting (DB), and the new mobile system called International Mobile Telecommunication - Advanced (IMT-A) in co-primary basis in 2015. Until that year, the primary service (i.e., DB) should be protected from the new system (i.e., IMT-A). This paper investigates the...
The ubiquitous presence of powerful low-power wireless systems on chip (SoC) able to operate in the Industrial, Scientific and Medical (ISM) band has brought a new enhanced operational choice for real-time Radio Control (RC) applications such as aircrafts and cars in the hobby grade category. Frequency Hopping Spread Spectrum (FHSS) has become the dominant transmission technique for the previously...
Spurred by the increasing demand for mobile broadband services and the growing number of devices supporting multiple radio access technologies (e.g., cellular, WiMAX, Wi-Fi, Bluetooth), much research is being done to improve the user experience while addressing issues related to network efficiency, congestion, interference, and cost to operators, service providers, manufacturers, and consumers alike...
The characteristics of low transmission power and narrow bandwidth make the IEEE 802.15.4 system vulnerable to external interference. The interference varies in time, frequency and is not able to be recognized since the modulation technology is normally different. As applications in the field of electrostatic detection require large-scale deployment, the traditional method of switching channel to...
Noise frequency modulation signal (noise FM signal) is the main form of noise jamming. The research on it is focused on its signal characteristics. However, the material about best parameters selection of the jamming with which the best cover effect can be gotten is rare. The noise FM signal and its output of the radio receiver are derived theoretically in the paper, and the range of signal parameters...
A system for the real-time and fully automated detection, classification and localisation of acoustic sources in the marine environment has been developed at the Laboratory of Applied Bioacoustics (LAB) of the Technical University of Catalonia (UPC). The system features modules for the detection, the classification and localisation of short tonal sounds and impulsive sounds and the quantification...
A Mobile Ad hoc NETwork (MANET) is a network without any pre-existing communication infrastructure. Wireless mobile nodes can freely and dynamically self-organize into arbitrary and temporary network topologies. There have been many challenges on the dynamic structure of MANET. One of those is to find the path from a source node to a destination node in the network. In this paper, we propose a formula...
A novel design of an ultra wide band U-shaped monopole is presented and discussed. The antenna has a unique design consisting of a U shape with 2 additional arcs fed by a 50Ω microstrip feed. The antenna is low profile and has overall dimensions 30mm×30mm×1.5mm, which is compact in size for portable UWB applications. The simulated results show that the antenna has operating bandwidth (2.4-11.4GHz),...
Because the all factors of interference in R wave of normal ECG signals are few except for respiration, this algorithm uses R peak and position information to extract respiration signals (EDR) {ECG derived respiration signals }. The algorithm firstly get the correct R peak and position information from ECG, then interpolation should be done to keep the sample number the same as the original sample...
It is very weak that the reflected signal from the moving shell in gun tubes, due to the multi-mode interference noise. It is very important to eliminate the noise in order to improve the measurement accuracy. A method is presented which can eliminate effectively the noise by using the whitening method and K-L transformation. The mathematical derivation and the program which is designed with Labview8...
With the emergence of functional wireless terminals, increased network capacity is needed for wireless LANs. Considering the limited available frequency channels for wireless LAN, improving spatial channel reuse performance of MAC protocol is a key requirement for this purpose. In this paper, we present a novel RTS/CTS reservation scheme for CSMA/CA which improves spatial reuse by taking account for...
Hierarchical femtocell architectures have become popular recently because of their potential to provide increased coverage and capacity in cellular systems. However, introduction of femtocells might reduce the overlay macrocell system performance due to increased interference caused to macrocel-lular users. With MIMO precoding, the Least Interference (LI) technique can be employed at the femtocellular...
For wireless femtocells situated within a macrocell with a given transmitter power, we solve the problem of determining the femtocell transmitter power levels that maximize the SINR achieved in the femtocells, subject to a constraint on the minimum SINR realized in the macrocell.
Previous studies on Base Station Cooperation (BSC) have shown its significant capacity gains. These studies usually ignore the fact that a practical cellular network has a large number of Base Stations (BSs) and to coordinate these BSs will incur heavy signalling overhead, high transmission latency. In order to utilize BSC, a network has to be divided into separate groups, each of which cooperate...
Femtocell networks have great potential for mobile applications. However, interference due to the co-existence of macrocells and femtocells is a serious problem. In addition, dense femtocells introduce severe inter-system interference. In this paper, a graph theory based dynamic sub-band allocation technique is presented to avoid downlink interference. We model the cells and their mutual interference...
Base station coordination has received much attention as a means to reduce the inter-cell interference in cellular networks. However, this interference reducing ability comes at the expense of increased feedback, backhaul load and computational complexity. The degree of coordination is therefore limited in practice. In this paper we explore the trade-off between capacity and feedback load in a cellular...
It is demonstrated that the suitable relay selection or power control method is very important to network performance. However, there is little work concerning the combination of them in the multi-cell scenario. In this paper, we propose a cross-layer design to associate relay selection with power control scheme to increase the average network capacity, as well as to mitigate interference, where the...
Hybrid subcarrier exclusivity and sharing (HSEnS) scheme with optimized bit loading in uplink multicell OFDMA system is proposed in this paper. Optimizing bit loading under subcarrier exclusivity (SE) and subcarrier sharing (SS) schemes in two adjacent cells is analyzed. Bit loading criteria and boundary setting procedures for convex optimizing bit loading under SS scheme are proposed. And bit loading...
In this paper, we analyze the performance of an IEEE 802.15.4 radio link in the 2360-2400 MHz band to support the ongoing Medical Body Area Network (MBAN) standardization activities in IEEE 802.15. There has been a lot of interest recently in opening the 2360-2400 MHz band for secondary allocations to promote MBAN innovations by providing a spectrum with less interference. In this work, we characterize...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.