Browsing by Author "Tang, Chih-Hsuan"

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Green Transmission Technologies for Balancing the Energy Efficiency and Spectrum Efficiency Trade-off
(2014-11-01)
Wu, Yiqun
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Chen, Yan
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Tang, Jie
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So, Daniel K. C.
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Xu, Zhikun
As 4G wireless networks are vastly and rapidly deployed worldwide, 5G with its advanced vision of all connected world and zero distance communications is already at the corner. Along with the super quality of user experience brought by these new networks, the shockingly increasing energy consumption of wireless networks has become a worrying economic issue for operators and a big challenge for sustainable development. Green Transmission Technologies (GTT) is a project focusing on the energy-efficient design of physical-layer transmission technologies and MAC-layer radio resource management in wireless networks. In particular, fundamental trade-offs between spectrum efficiency and energy efficiency have been identified and explored for energy-efficiency-oriented design and optimization. In this article, four selected GTT solutions are introduced, focusing on how they utilize the degrees of freedom in different resource domains, as well as how they balance the trade-off between energy and spectrum efficiency. On top of the elaboration of separated solutions, the GTT toolbox is introduced as a systematic tool and unified simulation platform to integrate the proposed GTT solutions together.
Pilot-channel-aided successive interference cancellation for uplink WCDMA systems
(2007-07-01)
Tang, Chih-Hsuan
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Wei, Che-Ho
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this paper, a pilot-channel-aided successive-interference-cancellation (SIC) scheme for uplink wideband code-division multiple-access system is presented. In order to alleviate the interferences from other users' pilot-channel signals, this scheme performs pilot-channel-signal removal (PCSR) for all users before data detection. Three ordering methods for successive-cancellation process are discussed and compared in the aspect of architecture, latency, computational complexity, and error performance. In addition, channel estimation performed independently with the pilot-channel of each user is taken into consideration in the analyses. The pilot-channel-aided SIC performs variously with different ordering methods, pilot-to-traffic amplitude. ratios, grouping intervals, power-distribution ratios, and propagation conditions. From our analyses and simulations, the SIC with ordering based on RAKE outputs at the first stage in properly chosen grouping interval is suggested over multipath fading channels when error performance and practicability are jointly concerned.
Self-Optimized Cloud RAN Based Smart Zone
(2014)
Tang, Chih-Hsuan
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Chen, Yen-Keui Chen
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Wang, Li-Chun
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交大名義發表
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National Chiao Tung University
Due to the exploded demand for mobile traffic and diverse service type, flexible mobile networks with high capacity is drawing lots of research efforts. Distributed large scale (DLS) MIMO has superiority over centralized large scale MIMO and separated small cells due to lower signal loss to users and central control. In this paper, we present a self-optimization method for Cloud RAN based DLS MIMO. The method includes network dimensioning and antenna clustering with adaptability to the migration of hardware/virtualization technology and user over time. Other advantages are easing the process for dimensioning and optimization, requiring fewer antennas, and less demand for controller & baseband computing power due to the characteristic of low complexity.