Browsing by Author "Yang, Zi-Yang"

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A Downlink Mapping Algorithm for Two-Level Requests in IEEE 802.16e Systems under AMC Mode
(2013)
Yang, Zi-Yang
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Kuo, Yaw-Wen
;
Lee, Tsern-Huei
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傳播研究所
;
Institute of Communication Studies
This paper proposes a downlink mapping algorithm for two-level requests in Orthogonal Frequency Division Multiple Access based IEEE 802.16e systems under the Adaptive Modulation and Coding (AMC) mode by which the modulation and coding scheme (MCS) of a user may be different for available subchannels. Given a set of requests each with two priorities, the proposed algorithm efficiently allocates a two-dimensional (time and frequency) burst with a suitable MCS to each user to maximize the system throughput with service differentiation. Simulation results show that the proposed algorithm outperforms the Efficient Downlink Mapping Allocation (EDMA) algorithm [5] in terms of the throughput of high priority data, but slightly sacrifice in overall throughput. The proposed algorithm can improve up to 98.8% more the average allocated ratio of urgent data than the EDMA.
An Efficient Downlink Mapping Algorithm for AMC Mode in WiMAX Systems
(2012)
Lee, Tsern-Huei
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Yang, Zi-Yang
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Huang, Qi-Quan
;
Kuo, Yaw-Wen
;
傳播研究所
This paper proposes an efficient downlink resource allocation scheme for Orthogonal Frequency Division Multiple Access based WiMAX systems using the Adaptive Modulation and Coding mode operation. Given a set of user requests, the proposed algorithm determines the modulation scheme and allocates a two-dimensional (time and frequency) burst to each user. It is known that finding the optimal solution for such a resource allocation problem is NP-complete. To reduce the computation complexity, this paper proposes a heuristic solution. Compared with the Efficient Downlink Bandwidth Allocation (EDBA) algorithm [6], the proposed scheme achieves higher channel utilization and system throughput with similar execution time. Simulation results show that the average channel utilization of the proposed scheme is about 75 similar to 85% and that of EDBA is about 60 similar to 70%.
Efficient resource allocation algorithm for overlay D2D communication
(2017-09-04)
Yang, Zi-Yang
;
Kuo, Yaw-Wen
;
電信工程研究所
;
Institute of Communications Engineering
Device-to-device (D2D) communication in cellular systems offers an economically viable means of improving the system capacity by allocating multiple D2D links within the same resource block (RB), under appropriate interference-control techniques. In this paper, we propose an efficient resource allocation algorithm that enables maximum spatial reuse in orthogonal frequency division multiple access (OFDMA) systems. Given a set of D2D requests, the proposed algorithm greedily determines the number of RBs required, following the reliability criteria. Simulation results show that, compared to the greedy algorithm (Lee, Choi, and Jeon, 2013), the proposed algorithm could save up to 18.6% RBs, improve the throughput per RB by up to 23.4%, and reduce the computation time by up to 67.9%. (C) 2017 Elsevier B.V. All rights reserved.