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The main goal of this work is to use the Cuckoo Search (CS) algorithm to optimize Fractional Frequency Reuse (FFR) of cellular network systems. FFR is an interference management technique well suited to OFDMA based cellular network systems, such as Long Term Evolution system (LTE). This paper proposes a mechanism that selects the optimal value of inner cell region radius in strict FFR that maximize...
For indoor coverage extension Long Term Evolution (LTE) has developed a Femtocell. However, in advance we should solve the interference problem between the femtocell and the macrocell. Here, we propose a scheme to interference mitigation in the LTE femtocell systems using Fractional Frequency Reuse (FFR). By the FFR under the macrocell allocating a frequency band, to avoid interference the femtocell...
This paper provides a joint implementation of Fractional Frequency Reuse (FFR) and relays in the downlink of multi-cellular networks like Long Term Evolution (LTE) networks. The forecasted benefits concern inter-cell interference (ICI) mitigation in each cell. Based on this network architecture and related improvements, individual user throughputs and signal to interference plus noise ratio (SINR)...
Inter-cell interference (ICI) is always a big issue in orthogonal frequency division multiple access (OFDMA) based communication networks. In this paper, we apply power control to an Improved Fractional Frequency Reuse (IFFR) scheme and investigate the system performance. IFFR scheme divides the whole available resources into two segments: the first segment and the second segment. The first segment...
Fractional Frequency Reuse (FFR) is an efficient method to mitigate Inter Cell Interference in multicellular Orthogonal Frequency Division Multiple Access (OFDMA) systems. In this paper, we analyze the downlink worst case Signal to Interference Ratio for FFR schemes. A closed form expression is derived analytically for the worst SIR, outage probability, and Spectral Efficiency (SE). The proposed analytical...
Interference coordination in optical wireless cellular networks using different frequency reuse techniques are discussed and compared in this paper. On the one hand, full frequency reuse maximises the system throughput at the cost of poor cell-edge user performance. On the other hand, cluster-based static resource partitioning offers good cell-edge user performance at the cost of low system throughput...
Long Term Evolution (LTE) technology is considered as the most possible candidate for next generation mobile communications. LTE networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. One limiting factor that influences LTE performance is the interference from neighbor cells, the so called Inter-Cell Interference (ICI)...
Maximizing system throughput and bandwidth utilization while guaranteeing fairness among users is a core technical challenge in the design of next generation cellular networks. In this context, fractional frequency reuse (FFR) is a helpful tool if it is flexible in terms of resource and power allocation as well as scheduling. Complementary to this tool, a well-chosen association of users to base station...
Current point-to-multipoint systems suffer significant performance losses due to greater attenuation along the signal propagation path at higher frequencies, transmit power constraints of mobile users and base stations, and interference from neighboring cells. Fractional Frequency Reuse (FFR) is a technique to counteract these effects. Typically, the proposed FFR technique partitions a cell into a...
In cellular systems, Fractional Frequency Reuse (FFR) partitions each cell into two regions; inner region and outer region and allocates different frequency band to each region. Since the users at the inner region are less exposed to inter-cell interference, the frequency resources in each inner region can be universally used. Based on this frequency band allocation, FFR may reduce channel interference...
A new fully decentralized dynamic fractional frequency reuse (FFR)-based scheme for cellular OFDMA networks is introduced. FFR is a technique to mitigate inter-cell interference to improve the throughput of interference-limited users on the cell edge, to the expense of the rest of the cell's users and the aggregate throughput. The proposed scheme aims to limit the FFR-incurred loss of the center users'...
To reduce frequency reuse scheme for orthogonal frequency division multiple access (OFDMA) systems, an algorithm based on Cantor Set Theory is introduced. Four fractional frequency reuse (FFR) schemes, improving cell-edge user's performance are derived. A low complexity scheduling algorithm is proposed based on these schemes. This FFR-based scheduling algorithm selects user for transmission according...
One of the most important challenges is how to manage inter-cell interference. Special care has to be taken regarding voice traffic which has more strict requirements on delay and packet loss. The goal of inter-cell interference coordination schemes is to decrease inter-cell interference and get higher cell throughput, so we evaluated the performance of inter-cell interference coordination schemes...
This paper focuses on coordinated scheduling to combat uplink inter-cell interference for LTE/LTE-Advanced. In OFDM system, inter-cell interference is the dominant interference which limits system capacity, especially the performance of cell edge users. Meanwhile inter-cell interference in OFDM system has an inherent characteristic of interference fluctuation, which reduces the efficiency of channel...
Femtocells are being deployed for coverage extension and higher data rates. However, interference problem between macrocell and femtocells should be solved before massive deployment. In this paper, we analyze the possible cases of frequency resource allocation in the OFDMA femtocell systems using Fractional Frequency Reuse (FFR) in order to minimize the interference between both cells. Under the assumed...
Femtocell is one of promising key technologies to increase the efficiency and coverage of next generation broadband wireless networks. However, there exists interference problem between femtocells and macrocell due to co-channel operation. In this paper, we propose an efficient frequency resource allocation scheme for newly deployed femtocells in the legacy OFDMA networks in order to maximize the...
Frequency reuse is a key concept for interference mitigation and thereby enhancing cell-edge performance in OFDMA networks. Two representative strategies are Fractional Frequency Reuse (FFR) and Soft Frequency Reuse (SFR). Both divide a cell into a center zone and an edge zone, and differentiate their levels of frequency reuse. Previous work on FFR and SFR has focused on networks of relatively small...
To mitigate inter-cell interference (ICI) and achieve higher spectrum efficiency, fractional frequency reuse (FFR) has been widely adopted by the next generation wireless systems, wherein different frequency reuse factors are applied to cell center and cell edge zones. In such conventional FFR, a contiguous radio spectrum is partitioned in a fixed fashion across all cells for edge and cell center...
Fractional Frequency Reuse (FFR) is one of the key concepts for enhancing cell-edge performance of OFDMA networks. Standard FFR allows one sub-band to be allocated for each cell. This limits the performance improvement of cell edge users, especially those bandwidth-sensitive users. With flexible sub-band allocation, cell edge can be allocated more than one sub-band, thereby performance can be improved...
Recently, Long Term Evolution (LTE) has developed a femtocell for indoor coverage extension. However, interference problem between the femtocell and the macrocell should be solved in advance. In this paper, we propose an interference management scheme in the LTE femtocell systems using Fractional Frequency Reuse (FFR). Under the macrocell allocating frequency band by the FFR, the femtocell chooses...
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