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In this paper, the resource sharing problem of device-to-device (D2D) communications underlying evolved multimedia broadcast multicast service (EMBMS) system is investigated, and a novel round- robin resource sharing algorithm (RRSA) is proposed. To avoid the interference between D2D user equipments (DUEs) and cellular user equipments (CUEs) without consuming more frequency resources, in this study,...
Careful planning of wireless networks is essential to provide reliable communication, especially that microwave links are frequently chosen to interconnect access points within networks. The optimization of such networks belongs to the frequency assignment problems and focuses on setting polarization of the links or allocating the channels in a frequency duplex to reduce or eliminate the interference...
Fractional frequency reuse (FFR) and soft frequency reuse (SFR) are efficient interference avoidance techniques for emerging OFDMA cellular networks in improving system performance by regularly reusing the frequencies. In this paper, we evaluate the energy efficiency (EE) in bits/J and EE per channel per cell in bits/J/Hz/cell for both the static FFR and SFR systems, in Nakagami-m fading and path-loss...
In this paper, we consider joint user pairing and frequency allocation with beamforming (BF) assuming per user Quality of Service (QoS) requirements. A single-carrier frequency-division multiple-access (SC-FDMA) transmission employing a zero-forcing (ZF) detector at the receiver is assumed. The BF filter coefficients are jointly optimized with the user pairing and frequency allocation of the users...
A traffic distribution in a wireless network plays a major role in resource allocation. In this paper, we analyze throughput in Cognitive Radio Network (CRN) under two traffic distributions Pareto on-off and Poisson distribution. We consider a CRN where the cell is divided into different concrete circles and sectors. In each segment is analyzed and the channel is allocated accordingly while taking...
An interference coordination well suited to OFDMA based wireless network in which cells are divided into special region with various frequency reuse factors, is termed as Fractional Frequency Reuse (FFR). This research focuses on the concept as well working of FFR in Hexagonal geometrical structure for systematic frame work and evaluation. The scheme includes the extensive literature review of both...
Licensed but unutilized television (TV) band spectrum is called as TV white space in the literature. Ultra high frequency (UHF) TV band spectrum has very good wireless radio propagation characteristics. The amount of TV white space in the UHF TV band in India is of interest. Comprehensive quantitative assessment and estimates for the TV white space in the 470–590MHz band for four zones of India (all...
This paper proposes a new resource management algorithm that utilizes the self-organizing network functionality for optimising spectrum usage and minimising cross-tier interference between macrocell and femtocells and co-tier interference between femtocells. To achieve this, the proposed algorithm dynamically maximizes usage of all the available subcarriers by exploiting knowledge of the interference...
Specifying the transmission rate as the indicator of system throughput, the paper proposes an improved parallel algorithm of color sensitive graph coloring principle based on allocation adjustment factor for centralized cognitive radio communication network. By using the allocation adjustment factor, the spectrum allocation can better balance the total transmission rate of the system and the allocation...
Femto cell system is promising to provide cost effective strategy for high data traffic and high spectral efficient services in future wireless cellular system environment. However, the co-channel operation with current Macro networks occurs some severe interference between Macro and Femto cells. Hence, the interference cancellation or management schemes are imperative between Macro and Femto cells...
Recently, the femtocell concept has received considerable attention both in academic and industry as a promising solution for the deep indoor coverage problem as well as the increasing data demand of mobile devices. Large scale femtocell deployments are hindered mainly by the cross tier interference problem spawned by their inherent uncoordinated deployment and the shared use of the limited spectrum...
Heterogeneous networks are one of the solutions employed in next generation mobile networks to improve coverage and enhance spectral efficiency. This paper focuses on in-band heterogeneous deployments based on picocells, so interference coordination is necessary in order to increase system capacity. In addition, traditional association methods have to be revised. Several radio resource management...
Femtocell networks have gained momentum due to their important benefits, such as improved indoor coverage, higher areal spectral efficiency, enhanced signal quality, among others. Those benefits are only achievable if adequate deployment decisions and efficient resource allocation techniques are able to assure the seamless co-existence among Femtocell Access Points (FAPs) within the femtocell tier...
To increase cognitive radio operation efficiency, this paper proposes a new knowledge management functional architecture, based on the fittingness factor concept, for supporting spectrum management in non-stationary environments. It includes a reliability tester module that detects, based on hypothesis testing, relevant changes in suitability levels of spectrum resources to support a set of heterogeneous...
We propose the use of relay terminals at the cell edge of an LTE-based cellar system. Each relay terminal is equipped with a 120° directional antenna. We refer to this scheme as the Directional-Relay (DR) scheme. The DR scheme coordinates the inter-cell interference (ICI) stemming from adjacent cells and increases the desired signal level at cell-edge regions. To validate the performance of the DR...
LTE (Long Term Evolution) is standard developed by 3GPP (third generation partnership project) for providing 3G and 4G services. In LTE-Femtocell networks, macro cells and femtocells in innovative geometry, when coexist, and sharing overlapping frequency band, interference is bound to occur. To estimate effect of such interference and estimate overall capacity of such network is challenge addressed...
This paper deals with the problem of power allocation in a multi-user, multicarrier communication system. This problem arises, for example, in wireless OFDM or digital subscriber line networks. Users transmitting concurrently on the same sub-carriers cause interference to each other, and this interference is a serious limitation for system performance. We consider the problem of maximizing the weighted...
The recent development of regulatory policies that permit the use of TV bands spectrum on a secondary basis has motivated discussion about coexistence of primary (e.g. TV broadcasts) and secondary users (e.g. WiFi users in TV spectrum). However, much less attention has been given to coexistence of different secondary wireless technologies in the TV white spaces. Lack of coordination between secondary...
This paper proposes a new resource management (RRM) algorithm that utilizes the self-organizing network functionality for optimizing spectrum usage and minimizing co-layer interference between femtocells. To achieve this, the proposed algorithm dynamically maximizes usage of all the available subcarriers by exploiting knowledge of the users' location. Taking into account the associated overhead and...
We consider the problem of jointly allocating channel center frequencies and bandwidths for IEEE 802.11 wireless LANs (WLANs). The bandwidth used on a link affects significantly both the capacity experienced on this link and the interference produced on neighboring links. Therefore, when jointly assigning both center frequencies and channel widths, there is a trade-off between interference mitigation...
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