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.
In this paper, we introduce a full-duplex relay (FDR) based on block diagonalization (BD) and analyze the corresponding sum rate in a multiantenna multiuser relay system. The poposed precoding scheme can suppress the self-interference as well as to support multiple users at the same time slot. Simulation results show that the proposed FDR scheme enhances significantly the sum rate performance compared...
We investigate the problem of multi-user radio resource allocation for orthogonal frequency division multiple access (OFDMA) amplify-and-forward (AF) relays. In the single-user case, the problem reduces to the well know assignment problem, which maximizes the user rate. For the multi-user case we devise a resource allocation algorithm to achieve max-min fairness. We find max-min fairness since it...
This paper considers an OFDMA relay network and proposes an auction algorithm for the subchannel allocation to balancing efficiency and fairness with service differentiation. This algorithm allows users to fairly compete for the using of the subchannel through a new bidding strategy. We use the second-price sealed auction mechanism under which the dominant strategy of the bidder is bidding the true...
Recently, substantial attention has been paid to increase the achievable rates of wireless networks using different kinds of limited channel state information (CSI) feedback. This paper aims to investigate the effect of limited CSI feedback on the achievable rates of power-limited block fading channels constrained to have limited outage probability. Considering different power allocation strategies...
In this paper, a novel call admission control (CAC) scheme for multicast and unicast integrated services is proposed, which optimizes service provision capacity for both services. A resource sharing model is presented in which multiple classes services are dynamically admitted into the system. Several basic CAC rules for the above resource model are proposed first and improved mechanisms are investigated...
Channel allocation in cognitive radio networks completely determines the realizability and efficiency of cognitive radio since it is the final step before the cognitive subscribers can use the spectrum holes. In this paper, we consider channel allocation in cognitive radio networks as a resource allocation problem under the circumstance that the allocation of transmission rate, link and transmission...
The next generation of wireless networks (e.g., Long Term Evolution (LTE)and WiMAX) use multiple techniques to improve channel spectral efficiencies. In this paper we focus on one such technique, namely Coordinated Beam Switching (CBS). With CBS, each sector determines a sequence of beams (possibly with repetitions) over which it continuously cycles. Each sector independently determines its beam pattern...
In this paper, we study the optimal power allocation of wireless relay nodes which are used in the secondary user (SU) communication of a cognitive radio (CR) network. We consider the behavior of transmitting powers of SUs where those powers are limited to the tolerable interference as seen by the primary user (PU) communication. To improve the performance of the secondary communication based on minimizing...
The latest generation of wireless networks use OFDMA (Orthogonal Frequency Division Multiple Access) transmission technology in the downlink (e.g, WiMAX and LTE). The downlink is divided into bandwidth units and UEs (User Equipments) are each allocated a subset of these. Since at most one UE is assigned to each of these units, downlink transmissions within a sector are orthogonal. However, the transmission...
This paper presents an efficient technique for power allocation to the sensor nodes in a nonlinear sensor network (NSN). We minimize mean square error of the estimation of a random scalar parameter subject to a constraint on total amount of power consumed by the sensor nodes. This estimation is carried out at fusion center (FC) which receives the local observations from the sensors located at different...
In this paper, we consider the problem of joint adaptive beamforming from multiple Access Points (APs), equipped with array antennas, to multiple single-antenna User Equipments (UEs). We derive an iterative algorithm for Multi-Cell Beam-Forming (MCBF) under per-cell power constraints and the constraint that a UE may receive data transmission from a single AP. The scheme is suitable for coordinated...
Continuous growth of cellular subscribers as well as demands for high-speed and high-quality multimedia services have made it necessary to increase system capacity and data rate. On the other hand, the energy consumed goes up accordingly as the data rates increases. Therefore, designing an efficient resources allocation scheme and architecture to improve the output performance and reduce energy consumption...
This paper presents a link level analysis of the rate and energy efficiency performance of the LTE downlink considering the unitary codebook based precoding scheme. In a multi-user environment, appropriate radio resource management strategies can be applied to the system to improve the performance gain by exploiting multi-user diversity in the time, frequency and space domains and the gains can be...
This paper addresses the issues of coexistence for cognitive radio networks including both the coexistence between primary users (PUs) and secondary users (SUs), as well as the coexistence among SUs. The coexistence between SUs and PUs addresses the interference from SUs to PUs, whereas, the coexistence among SUs addresses sharing of identified spectrum opportunity among SUs to achieve efficient spectrum...
This paper addresses the power allocation and relay positioning problems in Amplify-and-forward cooperative networks over Weibull fading channels. We study adaptive power allocation (PA) with fixed relay location, optimal relay location with fixed power allocation, and joint optimization of the PA and relay location under total transmit power constraint, in order to minimize the outage probability...
The performance of multi-hop multiple-input, multiple-output (MIMO) communication scenarios is evaluated for space time block coded (STBC) and the proposed distributed cyclic delay diversity (CDD) technique. By increasing the frequency selectivity, multi-stage CDD with low complexity implementation yields significant performance improvement as relaying network. Both diversity techniques based on frequency-correlated...
Internet services will be pervasive in future intelligent transportation systems. To this end, vehicular Wi-Fi networks are introduced and widely deployed nowadays. However, quantitative performance in vehicular Wi-Fi networks has not been reported in the literature. In this paper, we conduct a measurement study in vehicular Wi-Fi networks to investigate the uplink and downlink throughput under diverse...
In the relay-enhanced cellular network, the target user will receive uncertain interference due to orthogonal transmission between BS and RS, which would make the traditional mechanisms of link adaptation and channel-aware scheduling invalid. In this paper, a novel resource scheduling scheme is proposed with a semi-static mode, in which dominant interferences for a target user are identified and inter-cell...
Distributed multiple-input multiple-output (DMIMO) system is a combination of distributed antenna systems (DAS) and co-located antenna systems (CAS). Power allocation between different antennas is a very important aspect in both DAS and CAS. In this paper, we investigate the downlink power allocation scheme in D-MIMO systems based on minimum symbol error rate (SER) criteria. We propose a power allocation...
Intra-frequency handover is an important RRM procedure in LTE and the (self-) optimization of its performance, in terms of handover reliability and handover frequency, has been studied extensively by 3GPP. We present a simulation analysis of the handover performance in an LTE macro deployment, considering the impact and interdependency of key handover settings (offset, TTT, filter coefficient K) for...
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.