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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/65521

    Title: 單載波頻分多重存取環境之無妒忌子通道分配;Envy-Free Subchannel Allocation Mechanism in SC-FDMA Environments
    Authors: 湯智淵;Tang,Chih-Yuan
    Contributors: 通訊工程學系
    Keywords: 單載波頻分多重存取;子通道分配;無妒忌;公平性;SC-FDMA;subchannel allocation;envy-free;fairness
    Date: 2014-07-28
    Issue Date: 2014-10-15 17:02:37 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 近年來,隨著行動通訊技術的發展,手持裝置使用者的人數愈來愈多,所需的頻寬也愈來愈大,在有限的頻寬下,利用這些資源達到最大的傳輸量,是通訊研究的重點。但比較少研究探討使用者間的公平性問題,在日漸增多的行動通訊使用者趨勢下,這會是一個重要的課題。
    3GPP LTE系統使用單載波頻分多重存取為上行技術,理由是單載波頻分多重存取為在正交頻分多重存取前加上離散傅立葉轉換預編碼,可以降低功率峰均值比,有效增加傳送功率。然而,在LTE上行規格裡,單載波頻分多重存取在子通道分配部分比正交頻分多重存取的自由度低很多,有著子通道分配方式的限制。所以在滿足這些限制下,如何有效的分配子通道而最小化使用者間頻譜效率,維持使用者間的公平性,是研究的核心。
    ;Nowadays, thanks to the evolution of mobile communication, number of mobile equipment is increasing and bandwidth is also growing. Communication research want to find how to achieve maximum throughput in the limited bandwidth. But, fairness between users was talk about rarely in studies. It’s an important issue under the trend of increasing mobile communication users.
    3GPP LTE uses single-carrier frequency division multiple access(SC-FDMA)architecture for the uplink. Unlike Orthogonal frequency division multiple access(OFDMA), SC-FDMA add a pre-coder FFT. This method can reduce the peak to average power ratio, and effectively increase the transmission power efficiency. But, there are some restrictions of subchannel allocation in SC-FDMA. How to allocate the subchannels efficiently under the restrictions to maintain the fairness between users, is the kernel target in study.
    In this thesis, we proposed a subchannel allocation algorithm called ‟ envy-free suchannel allocation’’ which can reduce the envy behavior among users due to unequal allocated subchannel in SC-FDMA environments. The proposed scheme minimizes the total system spectral efficiency difference between each users. And then we proposed how to find the best tradeoff between fairness and total system spectral efficiency. It can improve fairness between users, subject to maintaining some total system spectral efficiency.
    Simulation results show that, by maintaining at least 80% and 75% total system spectral efficiency of ITU-R Ped.A channel and Veh.A channel, envy-free method can improve the spectral efficiency difference between users 40 times than general maximum total system spectral efficiency method in same SER performance. This envy-free subchannel allocation method significantly reduce the envy behavior among users.
    Appears in Collections:[通訊工程研究所] 博碩士論文

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