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Existing feedback schemes of Channel State Information (CSI) in OFDMA systems can be mainly sorted into two categories as follows: 1) sounding channel feedback, and 2) precoder matrix indicator (PMI) feedback. However, both these two categories have some performance drawbacks and limitation of usage. In this paper, two Sounding-based Phase Feedback (SPF) schemes, namely, Type_1 SPF and Type_2 SPF,...
Orthogonal Frequency Division Multiplexing (OFDM) is very sensitive to carrier frequency offsets (CFO). The CFO results in intercarrier interference (ICI). This drawback of OFDM is inherited to Orthogonal Frequency Division Multiple Access (OFDMA). In this paper, we propose a new ICI model for an uplink OFDMA system that takes into account the presence of the cyclic prefix which is usually ignored...
This paper is concerned with dynamic resource allocation for heterogeneous downlink in orthogonal frequency division multiple access (OFDMA) systems. First, this paper formulates the resource allocation problem when one terminal may demand both non-real time (or best effort) transmission and real time transmission over the downlink simultaneously. We consider the constraint on the total transmission...
This paper proposes a transmit beamforming and subcarrier power allocation method for orthogonal frequency division multiple access (OFDMA) systems based on ??signal-to-leakage-plus-noise ratio?? (SLNR). As the transmit beamforming vector control criterion, we employ the maximization of the SLNR at each base station, while the subcarrier power allocation is performed by iterative water-filling algorithm...
Achieving the targeted data rates for next generation wireless communication systems requires using frequency reuse ratio 1 in these systems, but this in turn results in significant intercell interference observed especially by the users near cell edges. Cooperation between the base stations plays an important role in reducing the intercell interference. In this paper, we consider the problem of cooperative...
We study several channel quality reporting strategies for OFDMA systems that maximize the sum-rate while constrained by feedback and signaling overhead. These reporting schemes are based on the grouping idea, which essentially limits the number of users accessing a sub-channel or physical resource block. This in turn reduces the overhead needed to convey channel quality indication (CQI). On the other...
This paper proposes a novel Frequency Time scheduler, called Frequency Time Scheduler with Delay Constraints (FTSDC), in order to handle streaming traffic in OFDMA (Orthogonal Frequency Division Multiple Access) system. Streaming technique, widely developed and used in the internet to convey multimedia application (e.g., audio, video clip, etc.), is supposed to occupy a large share of bandwidth in...
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