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Energy Efficient Spectrum Allocation for Green Radio in Two-tier Cellular Networks. Wenchi Cheng, Hailin Zhang, Liqiang Zhao and Yongzhao Li Global Telecommunications Conference, 2009. GLOBECOM 2010. IEEE Reporter : 李後愷. Outline. Introduction System model - PowerPoint PPT Presentation
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Energy Efficient Spectrum Allocation for Green Radio in Two-tier Cellular Networks
Wenchi Cheng, Hailin Zhang, Liqiang Zhao and Yongzhao Li
Global Telecommunications Conference, 2009. GLOBECOM 2010. IEEE
Reporter : 李後愷
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Outline
Introduction System model Model for energy consumption in downlink Spectrum allocation for green radio Simulation and results Conclusion
Introduction
Green Radio, which aims to reduce energy consumption of information and communication technologies (ICTs).
Over 80% of the power in mobile communications is consumed in the radio access network, especially cost in base stations.
Actually, there are already a lot of energy efficient strategies in cellular access networks. However, these strategies mainly focus on smart ends with uplink energy constrains.
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System model
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System model
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System model
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The mean number of femtocells per cell site is readily obtained as
Users are assumed to be uniformly distributed inside each cell site
System model
Two main different strategies for femtocell access have been proposed so far:
Public Access where all the users can access all the femtocells of a given operator.
Private Access where only the subscriber of the femtocell and a list of invited users can access a given femtocell.
U = Um+NfUf denote the average number of users per cell with Um and Uf referring to the number of outdoor users of per macrocell and indoor users of per femtocell respectively
Green factor: the b/J power efficiency per subchannel.
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Channel Model and Scheduling Strategy
Three factors have bad effects on signal quality: path loss, shadowing (slow fading), multipath fading (fast fading)
Each BS assigns rate adaptively based on the received SIR per user
We assign:
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Channel Model and Scheduling Strategy
BS & FAP Power Consumption
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Spectrum allocation for green radio
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According to recent surveys, over 50 percent of calls and 70 percent of data services will take place indoors in the future.
Spectrum allocation for green radio
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Simulation
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Simulation
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Conclusion
Maximizing the green factor under spatial spectral efficiency is an effective way to improve energy efficiency
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每週一句
Have + pp.
Had + pp.
Past tense
now
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