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.
Traffic congestion is a serious problem in urban areas of many countries due to the increasing amount of vehicles on surface streets and accompanies fuel-wasting and air-pollution. This problem can be alleviated by adopting a ride-sharing service. The main idea of ride-sharing service is to collect travelers whose travel destinations are nearby into one vehicle. In doing so, we can reduce the amount...
Coordination of MIMO transmission across multiple cells can effectively reduce cell-edge interference. However, downlink multi-cell MIMO transmission requires additional channel state information at the cooperating base stations compared to the single-cell case. Therefore, reducing the feedback overhead is an important issue in multi-cell MIMO systems. This paper proposes an adaptive feedback interval...
This paper proposes a differential codebook-based method to reduce the feedback overhead for closed-loop MIMO-OFDM systems. With the assumed multimode transmit precoding, both the number of data streams (rank) and the index of precoding matrix are fed back to the transmitter at each sub-band. By exploiting the channel correlation in frequency domain, an enhanced differential codebook (a subset of...
Thanks to silence suppression, the VoIP capacity can be improved. When the voice users are listening or thinking, the VoIP system does not need to allocate resources to them, thereby being able to accommodate more users. The main issue is how to immediately allocate resources to the user, when the user transits from the silence state to the talkspurt state. The IEEE 802.16e/m system provides two typical...
This paper presents a self-optimizing algorithm that tunes the handover (HO) parameters of a LTE (Long-Term Evolution) base station in order to improve the overall network performance and diminish negative effects (call dropping , HO failures). The proposed algorithm picks the best hysteresis and time-to-trigger combination for the current network status. We examined the effects of this self-optimizing...
Since a large number of femtocells may coexist in one macrocell area, interference management becomes a major issue in the deployment of femtocells, and therefore has been researched actively. In the IEEE 802.16m, one way to mitigate interference is Low Duty Operation (LDO) Mode for femtocells. Femtocell in the LDO mode changes alternately between available interval and unavailable interval. During...
Connectivity is a fundamental requirement in the planning, design and evaluation of vehicular ad hoc networks (VANET). In this paper, we propose a new equivalent speed parameter and develop an analytical model to explain the effect of vehicle mobility on the connectivity of highway segments in a VANET. We prove that the equivalent speed is different from the average vehicle speed and it decreases...
Distributed and efficient relay selection and resource allocation are critical for large scale cooperative communication networks. To stimulate a potential relay station to cooperate with the source, a bargaining based relay selection and power allocation (BBRSPA) scheme is proposed. In this paper, Rubinstein-Stahl bargaining game is introduced to provide a possible solution to share the increased...
In a distributed antenna system, the optimal antenna deployment design scheme is proposed, in which both the location and the number of the distributed antennas (called access point, AP) are considered for energy efficiency. By minimizing the average distance between users and the APs, the optimal AP distribution is given. The optimal number of APs can be obtained considering both the circuit power...
The paper considers MIMO relay networks where a source node transmits the signals to a destination node through multiple relay nodes, each of which is equipped with multiple antennas. As shown by previous studies, using multiple relay nodes to forward the signals can improve the performance. The distributed array gain can be achieved at the destination node while maintaining the maximum spatial multiplexing...
A new cross layer path selection scheme with quality of service (QoS) support along urban areas is proposed. First, we introduce a cross-layer approach where the routing decision takes explicit consideration of the application layer objective function. Second, the queueing based mobility model, spatial traffic distribution and probability of connectivity for sparse and dense Vehicular Ad-Hoc Networks...
Through sensing and utilizing available network resources, cognitive network can obviously increase network performance. In this paper, a distributed on-demand routing protocol with traffic awareness (TACR) is proposed for cognitive wireless network. This routing protocol establishes the path based on the cognition and reasoning of traffic loads in a network and it also meet quality of service (QoS)...
We consider a wireless relay network with with hybrid-automatic retransmission request (HARQ) and Rayleigh fading channels. In this paper, we analyze the outage probability of the multi-relay delay-limited HARQ system with opportunistic relaying scheme in decode-and-forward mode. A simple and distributed relay selection strategy is proposed for multi-relay HARQ channels. Then, we analyze the performance...
Nonparametric belief propagation (NBP) is one of the best-known methods for cooperative localization in sensor networks. It is capable to provide information about location estimation with appropriate uncertainty and to accommodate non-Gaussian distance measurement errors. However, the accuracy of NBP is questionable in loopy networks. In this paper, we propose a novel approach, NBP based on spanning...
In this paper, a general framework, called probability-based solution (PBS), is proposed to balance the trade-off between the accessibility (in terms of the success probability to find a route reaching the destination) and the performance (in terms of spectral efficiency, outage probability or energy consumption) of distributed routing schemes in multi-hop wireless networks. In the PBS, the candidate...
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.