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.
Power control is one of the key functions which are able to co-ordinate the system interference. In this paper, several power control schemes are investigated for a hybrid LTE system, which combines the direct device-to-device (D2D) mode communication and the normal cellular mode communication. In the system study, the power control for the D2D mode communication is emphasized. In general, the utilization...
Performance of next generation OFDM/OFDMA based Distributed Cellular Network (ODCN) where no cooperation based interference management schemes are used, is dependent on four major factors: 1) spectrum reuse factor, 2) number of sectors per site, 3) number of relay station per site and 4) modulation and coding efficiency achievable through link adaptation. The combined effect of these factors on the...
Careful management of inter-cell interference is important in OFDMA based systems such as LTE. In this paper, we study an uplink ICIC (Inter-cell Interference Coordination) mechanism, which fully utilizes the flexibility of frequency selective scheduling and rate adaptation, while dynamically limiting the interference experienced by the neighboring cells. This technique can be seen as an extension...
In cellular OFDMA networks, there exists a fundamental trade-off between the achievable cell capacity and the degree of fairness among the users in the cell. Several scheduling algorithms have been proposed which try to balance this tradeoff. The parameterization of these scheduling algorithms to achieve a certain desired fairness level is non-trivial. We show that the optimal fairness parameter settings...
In this paper, a new space-frequency combination technique is proposed for Alamouti coded Orthogonal Frequency Division Multiplexing (OFDM) in the context of cooperative communications. Since cooperative antennas are distributed, there may exist multiple carrier frequency offsets (MCFOs) which cause problems for conventional space-frequency decoding. The proposed algorithm, taking cues from existing...
In this paper we propose a novel hybrid multicarrier architecture for wireless LAN (WLAN) applications. We refer to this architecture as hybrid filtered multitone (HFMT). Depending on the experienced channel condition, H-FMT switches between short orthogonal FMT (SO-FMT) modulation, and adaptive orthogonal frequency division multiplexing (A-OFDM). Extensive numerical results show that H-FMT could...
Multi-carrier modulation and especially CP-OFDM is widely used nowadays in several radio communications. However, FBMC is a potential alternative to CP-OFDM since it does not require cyclic prefix, and thus, it has a higher spectral efficiency. One of the characteristics of FBMC is that the received data are accompanied by a two dimensional inter-symbol interference term (2D ISI), which complicates...
In this work, we analyze the performance of a multi-user sectored MIMO/OFDMA system under the limited feedback constraint. Dynamic radio resource management methods are used to a reuse-one sectorized cell in order to reduce the cross-sector interference. Simulation results show that the proposed strategy reduces the co-channel interference and maintain at the same time high spectral efficiency.
We study a cognitive channel reuse approach for autonomous femtocell deployment in an OFDMA-based cellular network. The objective is to manage the uplink interference from macrocell users to femtocell access points. Macrocell users are normally far away from the base station and may cause strong uplink interference to the close-by femtocells. By cognitive interference recognition, a femtocell access...
In the planning of cellular networks, link budget calculation is the first step to get the maximum allowable cell radius that guarantees a target signal to interference plus noise ratio (SINR) with a certain level of outage probability at the cell border. The interference margin as one of key inputs for link budget is used to compensate for co-channel interference. In this paper, a mathematical analysis...
Recent research on Frequency Reuse (FR) schemes for OFDM/OFDMA based cellular networks (OCN) suggest that a single fixed FR cannot be optimal to cope with spatiotemporal dynamics of traffic and cellular environments in a spectral and energy efficient way. To address this issue this paper introduces a novel Self Organizing framework for adaptive Frequency Reuse and Deployment (SO-FRD) for future OCN...
In the bistatic radar, it is important to suppress the undesired signals such as the direct propagated signal from transmitter and its multipath components. Conventionally, the suppression method by subtracting the replicas of the undesired signals is often used. However, it requires the precise delay times of the undesired signals. In this paper we propose a new method to detect the target without...
This paper considers blind and semiblind channel shortening methods based on carrier nulling criteria to mitigate the effect of inter-block interference in uplink OFDMA systems. We derive a sufficient condition that states that if the number of subcarriers unused by a desired user exceeds a given threshold then uplink channels can be shortened perfectly. Simulation results are shown to verify the...
Being sensitive to carrier frequency offset (CFO) is known to be one of the main drawbacks of multicarrier systems. In this paper, the effects of CFO on a filter bank based multicarrier system (FBMC) in a multipath fading channel are discussed, where an ideal root-raised cosine (RRC) filter with roll-off factor 1 is used as the prototype filter which enables analytical derivations of the interference...
In this paper we consider the Downlink Beamforming (DLBF) and resource allocation problem in MIMO-OFDMA systems. We consider the sum-power minimization or margin adaptive problem. This is a variable Signal to Interference and Noise Ratio (SINR), non-convex optimization problem and many aspects of this problem are not well understood. By using uplink downlink duality we first obtain the expression...
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.