The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper focuses on the beneficial effects brought by the presence of multiple receivers to a slotted Aloha scheme. Starting from an analytical angle, we review and compare some recent results that characterize the throughput of such systems under different channel models, based on the assumption that incoming powers at receivers follow an i.i.d. distribution. While practical in some scenarios,...
In order to exploit millimeter wave (mmWave) bands for 5G communications, challenges mainly due to blockage and strong dependency on beamforming operation need to be overcome. In this work, we address some of the fundamental issues related to the use of mmWave bands for 5G communications, from propagation channel characteristics and modeling to the implications on system and network architecture design...
Recently there has been strong interest in extending the MIMO signal processing from the azimuth dimension to include the elevation plane. Therefore a 3D channel model is required for an accurate evaluation of MIMO performance. The MIMO system can also be deployed at the user terminal according to the LTE-Advanced system specifications. Therefore, this study exploits the elevation dimension at the...
We explore the rainfall effect on the capacity and achievable rates of millimeter-wave (mmW) multiple-input multiple-output (MIMO) systems. We first develop a tractable channel model for point-to-point millimeter-wave (mmW) MIMO systems to characterize the rainfall effect. The model development is based on the known stochastic properties of signal propagation in a random medium. Under this model,...
From the results of the ray-tracing simulation of 28 GHz frequency band over downtown of Ottawa and New York University campus, we propose 3D large-scale channel models for urban city which are applicable to a mmWave version of 3D spatial channel model. Due to the change of geographical topology dimension from 2D to 3D, the height information of the transmitter should be reflected to the parameters...
We consider Bayesian ranging methods for localization in wireless communication systems. Based on a channel model and given priors for the range and the line-of-sight (LOS) condition, we propose range estimators with and without LOS detection. Since the pdf of the received frequency-domain signals is unknown, we approximate the maximum-a-posteriori (MAP) and the minimum mean-squared error (MMSE) estimators...
Directional transmission and reception using multiple-input multiple-output (MIMO) technologies allows spatial multiplexing in a wireless network. However, multipath propagations in radio channels usually result in the angular spread of signal power, which causes interference among the sectors. Moreover, the random movement of the nodes leads to the variation of the interference. An accurate and mathematically...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.