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In order to minimize the total transmit power in the downlink orthogonal frequency division multiplexing (OFDM) system, an adaptive resource management approach is proposed in this paper by considering that an application, such as real-time video and high quality music stream, can have different quality of service (QoS) requirements for different layers. When multiple layers are addressed in resource...
In this paper, we propose a predictive resource allocation algorithm for multicast downlink OFDM systems with imperfect channel state information (CSI). We assume that the CSI is fed back to the base station (BS) through a delayed channel. To avoid the system degradation caused by the outdated CSI, we present a channel prediction scheme at the user side, which takes the delay time into account. Then,...
Power minimization problem under minimum rate constraint for each user is studied in this paper for multiuser OFDM systems. By thoroughly analyzing the necessary conditions for the optimum solution of the resource allocation problem, we deduce a heuristic Lagrange relaxation (LR) based resource allocation algorithm. Different from existing LR schemes which obtain Lagrange multipliers through exhaustive...
The development of intelligent resource management algorithms has been recently identified as a key technology for exploiting potential system diversity and improving power-spectral efficiency in wireless communication systems, as well as high-performance physical-layer techniques to provide high throughput, efficient resource use, and aggressive multiple access. In this paper, we propose an adaptive...
In this paper we study the traditional resource allocation model in IEEE802.16e (mobile WiMax) and propose two algorithms for scheduling and mapping higher layer data into the basic resource allocation units (slots) of OFDMA frames in IEEE802.16e. Both scheduling and mapping approaches are based on the quality of service requirements of each service flow in terms of data rate and bit error rate (BER)...
This paper investigates effects of pilot assisted channel estimation on dynamic resource allocation in a multiuser orthogonal frequency division multiplexing (OFDM) system. The channel estimation is done in each OFDM symbol through least-squared error (LSE) or minimum mean-squared error (MMSE) algorithm. The performance of each of these algorithms is evaluated through computer simulations. The maximal...
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