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In this paper we determine the optimal fractional frequency reuse (FFR) and resource allocation in OFDMA system. Since the users at the cell edge are more exposed to inter-cell interference therefore each cell is partitioned into two regions; inner region and outer region. We determine the optimal FFR factor for the outer region, bandwidth assigned to each region and subcarrier and power allocation...
This article addresses downlink resource allocation in multi-cell OFDMA mobile WiMAX systems using zone switching diversity method. We propose to use fractional frequency reuse for guaranteeing the quality of service for different service flows (SFs) in the system. Our approach includes an architecture which coordinates the allocation of resources in terms of slots (the basic allocation unit in time...
Recent mobile multimedia innovations evolved for the present society, is a mandatory requirement. To achieve this goal various forums have come forward with several design proposals to suit the group of applications in the Mobile multimedia networks (MMNs). In this regard, a new multi-protocol architecture for the medium access control is required to seamless mobile multimedia networking. Hence a...
This paper provides analysis of the inter cell interference coordination problem in multicell OFDMA systems. In order to reduce the interference without losing much frequency resources in each cell, cell users are partitioned into two classes, namely interior and exterior users. Frequency resources are universally used in all interior cells' areas whereas users of exterior zones have a frequency reuse...
The next generation of wireless networks (4G) will use OFDMA (Orthogonal Frequency Division Multiple Access) in the reverse link. In OFDMA, the reverse link resources assigned to a user are called tiles each of which consists of a subset of consecutive subcarriers. Since at most one user is assigned to each of these tiles then reverse link transmissions within a sector are orthogonal. However, the...
In this paper, we consider a new channel probing scheme for opportunistic scheduling in the uplink of orthogonal frequency division multiplexing (OFDM)-based wireless systems. To reduce signaling overhead for the probing, we consider a two-step channel probing process; called pre-probing and mainprobing. Good subchannels are first estimated through the pre-probing process using a probing signal transmitted...
Recently, several approaches for increasing spectral efficiency have been proposed to overcome the scarcity of spectral resources and to ensure that the ever-growing demand for high-data rate mobile communications can be met in the future. In this article, we focus on OFDM-based overlay systems that share a frequency band with already existing systems without degrading their performance. This is achieved...
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