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In this paper, we consider the problem of resource allocation in relay aided uplink multi-user transmission with a single destination node. We adopt the amplify-and-forward (AF) relaying scheme and the orthogonal frequency division multiple access (OFDMA) as the main transmission modulation. The optimization is formulated as maximizing the end-to-end system throughput subject to limited number of...
Opportunistic scheduling for wireless network coding (OWNC) combines the strategies of opportunistic scheduling and network coding. This paper applies two variants of OWNC on a two-user OFDMA system. Symbol-based OWNC decides a strategy from sum rate of the whole OFDM symbol. Subcarrier-based OWNC decides a strategy from the capacity on a subcarrier level. Novel algorithms are derived for power allocation...
In this paper, we consider a four-node relay-based OFDMA system. The expression of the upper bound for the achievable rate in Successive Relaying (SUR) protocol is derived by using the cut-set theorem for half-duplex systems. Based on this expression, the near-optimal solution of the achievable rate is obtained in the joint power and subcarrier allocation constraint, according to the dual problem...
We consider wireless telecommunications systems with orthogonal frequency bands, where each band is referred to as a channel, e.g., orthogonal frequency-division multiple access (OFDMA). For a given snap-shot in time, two joint channel assignment and power allocation optimization problems are presented, one in downlink and one in uplink. The objective is to maximize the minimum total Shannon capacity...
This paper investigates OFDMA downlink resource (spectrum and power) sharing algorithms for fixed relay stations. Iterative waterfilling is used in the power allocation process and shown to result in an optimal power allocation solution for multiple-relay networks. Iterative waterfilling is then developed with a power reallocation process to achieve more efficient spectrum utilization. Furthermore,...
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