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 analyze the performance of a downlink beamforming system with partitioned vector quantization (P-VQ). A multiuser multiple-input single-output (MU-MISO) downlink beamforming system with accurate channel state information (CSI) at user terminals is considered. The optimization of feedback bits allocation to different partitions and channel direction indicator (CDI), channel quality...
In 3GPP LTE Release-11 the Enhanced Physical Downlink Control Channel (EPDCCH) has been specified for downlink and uplink radio resource assignment notifications to User Equipments (UEs). EPDCCH has been designed to overcome several limitations of the Physical Downlink Control Channel (PDCCH) used in LTE Release 8–10. Some of the important design objectives of EPDCCH are: increased capacity for DL...
In this work, we present a low-complexity linear precoding scheme for downlink large-scale multiple-input multiple-output (MIMO) systems. The proposed scheme can achieve near minimum mean square error (MMSE) precoding performance in terms of the sum rate and is based on a matrix polynomial instead of matrix inversion. Simulation results show that matrix polynomials consisting of only a few terms are...
This paper investigates the impact of multiple BER requirements on resource allocation for orthogonal frequency division multiple access (OFDMA) downlink systems. Max-total capacity (MTC) and proportional fairness (PF) problems are considered. With the goal of maximizing either the instantaneous or long-term network capacity, we propose BER-driven resource allocation (BRA) schemes which exploit both...
In wireless resource allocation, improving system throughput and simultaneously enhancing user fairness are two fundamental but contradictory objectives. As for fairness, both short-term and long-term fairness are of significant importance. However, less effort has been dedicated to explore the optimal tradeoff between system throughput and the two mentioned fairness in terms of widely used Jain's...
This paper considers the problem of energy-efficient communication in the downlink of a cellular OFDMA network. User scheduling and power allocation are jointly optimized across a cluster of coordinated base stations so as to maximize the weighted sum of the energy efficiencies on the available resource slots under a per-subcarrier power constraint. The asymptotic noise-limited regime is also discussed...
The energy efficiency (EE) optimization in downlink carrier aggregated networks is addressed in this paper. To maximize EE by joint component carrier (CC) configuration and power control, we first model the problem as a mixed integer non-linear programming problem, which is NP-hard. Then the existence of optimal solution is proved. Based on the properties of optimal solution obtained by analysis,...
In this paper, sum rate optimization of multiuser multiple-input multiple-output broadcast (MU-MIMO) communication systems with perfect channel state information (CSI) at the base station is investigated. Since power allocation is a signomial optimization problem in the presence of multiuser interference (MUI), it is not a convex problem in general. Several optimal solutions proposed in the literature...
Fair bandwidth distribution among users remains a persistence issue in Wireless Mesh Networks (WMNs). Users which are more hops away from the gateway generally suffer from higher throughput degradation and hence higher delay. This is mainly due to the nature of IEEE 802.11 protocol, i.e. its operation in contention mode. In this paper, we propose a practical network-layer solution to address this...
This work studies dual-access-technology femtocells equipped with both cellular and non-cellular air interfaces with the goal of increasing per-user throughput as well as achieving user fairness. We target enterprise environments characterized by high data rates and/or dense user terminals such as corporate premises, shopping malls, or stadiums. To meet this high data demand, multiple femtocells are...
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.