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.
Assume that a multi-user multiple-input multiple-output (MIMO) communication system must be designed to cover a given area with maximal energy efficiency (bits/Joule). What are the optimal values for the number of antennas, active users, and transmit power? By using a new model that describes how these three parameters affect the total energy efficiency of the system, this work provides closed-form...
The distance spectrum is used to estimate the maximum likelihood (ML) performance of block codes. A practical method which can run on a memory-constrained computer is proposed to calculate the distance spectrum of polar codes. Utilizing the distance spectrum, the frame error rate (FER) and bit error rate (BER) performances of non-systematic polar codes (NSPCs) and systematic polar codes (SPCs) are...
In this paper, we consider a K-cell multi-user interference network, where S single-antenna users are selected within each cell to carry out the uplink transmission with their M-antenna home base station, where 2 ≤ S ≤ M < KS. For the considered scenario, a novel intra-cell performance aware opportunistic interference alignment (OIA) scheme is proposed to mitigate the inter-cell interference while...
In cellular systems, the interference has been the most critical issue that practically limits the performance of overall networks. Furthermore, the distribution of the inter-cell interference (ICI) in conventional cellular networks employing orthogonal frequency-division multiple-access (OFDMA) with quadrature amplitude modulation (QAM) tends to approach a Gaussian distribution, which is known to...
In this paper we propose an energy efficient cognitive radio system. Our design considers an underlaying resource allocation combined with soft sensing information to achieve a sub-optimum energy efficient system. The sub-optimality is achieved by optimizing over a channel inversion power policy instead of considering a water-filling power policy. We consider an Energy per Goodbit (EPG) metric to...
The A∗ algorithm is an efficient method for decoding short linear block code based on tree search. However, it may suffer very long decoding latency in the worst-case channel condition. In this paper, we propose to apply some restrictions on the Hamming weights of search paths in the tree-search decoding. Simulation results show that with proper selection of path constraints in the A∗ algorithm, the...
IEEE 802.11ac is a next generation wireless local area network (WLAN) standard employing multi-user multiple-input multiple-output (MU-MIMO) scheme for the first time. Since precoding and user selection schemes influence the performance of MU-MIMO transmission, accurate channel state information (CSI) is required to select users and obtain precoding matrix. In this paper, we evaluate the performance...
Amplify-and-forward (AF) based two-way relaying (TWR) has shown its sum rate advantage over AF based one-way relaying (OWR) in the literature. However, this advantage can not be achieved in some cases. In this paper, we evaluate the sum rates of AF based OWR/TWR and provide the relationship with respect to the relative channel gains and the relative transmit power of the three nodes, i.e., the relay...
Nonlinear precoding multi-user multiple-input multiple-output using vector perturbation (VP MU-MIMO) can provide good frequency efficiency at the cost of computational complexity, which exponentially increases as the number of spatial multiplexed users increases. This is because the original VP precoding requires to exhaustively search the optimum transmit signal vector among all the combinations...
We study the resource allocation and management issues related to heterogeneous wireless systems made up of several Radio Access Technologies (RATs) that collectively provide a unified wireless network to a diverse set of users through co-ordination managed by a centralized Global Resource Controller (GRC). We assume that the user devices are multi-modal, which makes it possible for each device to...
A cognition scheme, whereby nodes are enabled with the full-duplex technology at the PHY layer in conjunction with packet fragmentation at the MAC layer, is proposed to increase the performance of cognitive radio networks. As full-duplex allows doubling the throughput by equipping secondary users (SUs) with the capability to sense and transmit simultaneously, it also enables them to inflict considerably...
Orthogonal frequency division multiplexing (OFDM) brings severe co-channel interference for cell-edge users (CEUs). To deal with this problem, traffic-pairing scheme based on particle swarm optimization (TP-PSO) is proposed as an efficient scheme in downlink Coordinated Multi-Point multi-user multi-input multi-output (CoMP-MU-MIMO) transmission/reception. This paper jointly considers CEUs' signal...
This paper proposes a novel routing protocol named Hierarchical Mesh Tree Protocol (HMTP) that achieves efficient routing at the MAC layer for multi-hop data collection in ad-hoc networks, wireless sensor networks, intelligent transportation system networks, etc. The proposed protocol enables the self-organization of a network into a hierarchical mesh tree topology. The mesh tree topology is used...
Hybrid Wireless Mesh Networks provide improved connectivity and reliability over traditional wireless networks. However due to rapidly changing traffic patterns, such networks are more likely to experience congestion which leads to data loss. Inability to differentiate between congested links and select best possible paths dynamically can be very expensive in a rapidly changing network topology. This...
Delay tolerant networking (DTN) is able to provide communication services in areas where there is no guarantee that a fully connected path between source and destination exists at any time, and seek to address the technical routing issues in wireless networks. Traditional routing protocols are unable to deliver messages between hosts in such conditions. PRoPHET protocol is among the most widely used...
In this paper, a routing strategy for Network Centric Warfare Applications is proposed. In Network Centric Warfare Applications, a Mobile Adhoc Wireless Network (MANET) is usually required to be setup on the fly between military nodes such as soldiers, armored vehicles, tanks and ships. Due to secrecy requirements, these applications mostly operate in data silence mode keeping the transmitted data...
We propose PCOR, a power control and routing scheme for rechargeable wireless sensor networks (WSNs) that are characterized by spatial and temporal variations of energy resources. The proposed scheme is applied to asynchronous WSNs where overhearing plays a dominant role in the energy consumption. PCOR performs quality aware route selection while reducing the energy consumption in sensor nodes that...
We propose user-aware deployment strategies for femto-cell access points (FAPs) in heterogeneous networks where users' spatial distribution and long-term signal-to-interference plus noise ratios (SINRs) are available to a control centre. Assuming basestations are already deployed, the information on user density and long-term rate coverage is utilized to generate spatial throughput metrics for determining...
Carrier Cloud is a promising concept towards the decentralization of mobile networks, to, in turn, alleviate mobile traffic load and reduce mobile operator cost. Carrier cloud is enabled by two main approaches, namely virtualization of the mobile network functions and networking over federated cloud. For intelligent carrier cloud dimensioning, the placement of mobile network functions over federated...
The broadcast nature of the wireless medium applied in Opportunistic Routing (OR) to improve the performance of wireless networks. OR protocols select a set of candidates as the next-hop forwarder. Each candidate can act as a potential forwarder if it receives the packet. Candidate selection is one of the main issues for OR protocols. In this paper, we implement and compare different ranges of OR...
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.