近年來，智慧行動裝置的普及使得幾乎每個人都擁有它，使得移動通信服務隨著趨勢而發展，並且由於移動通信網絡的成熟，預計將有更多物聯網（IoT）應用。設備到設備（D2D）通信技術是改進現有網絡的方法之一。它可以實現大量的品質提升，為用戶提供復用有限的頻譜資源，減少基地台的負載，中繼輔助的D2D通信可以更好地解決基地台通道品質差的用戶問題。
　　本文考慮在用戶擁有的用戶設備(UE)被激勵使用令牌來形成D2D對的情況下，啟用D2D蜂窩網絡。他們以交易方式為D2D服務交換Token。同時，這些設備能夠選擇傳輸模式，即通過蜂窩傳輸或D2D傳輸接收數據。具有一定激勵機制的用戶願意加入交易系統，例如使用token來增加優先級。並利用一種特殊的調度算法使系統公平高效。同時使用比例式公平排程演算法，令通訊品質好的用戶在大部分的時候有較高優先權傳輸，提高系統吞吐量與確保合作用戶有高優先權。
　　模擬結果表明，本文可以幫助通道傳輸能力較差的用戶提高頻譜資源的利用率。在相同的頻譜資源下，合作用戶比起自私用戶具有更高的吞吐量和更低的丟包率。當系統為高負載時，它比所有直接轉到eNB的用戶都要高效，令所有用戶有誘因加入這個Token系統。

In recent years, the popularity of smart mobile devices has led almost everyone to have smart mobile devices, making mobile communication services evolve with the trend, and because of the maturity of mobile communication networks, more Internet of Thing (IoT) applications are expected to be shipped. Device-to-Device (D2D) communication technology is one of the ways to improve the existing networks. It can achieve much quality improvement, provide users to reuse the limited spectrum resources, reduce the load on the base station, and the relay-assisted D2D communication can better solve the problem of user of poor channel quality in base stations.
This thesis considers enabling D2D cellular networks where user-owned user devices (UE) are motivated to use tokens to form D2D pairs. They exchange tokens electronically for D2D services. At the same time, these devices have the ability to select a transmission mode, ie receive data over a cellular link or a D2D link. And users with certain incentives are willing to join the trading system, for example using token to increase priority. And use a special scheduling algorithm to make the system fair and efficient.
Simulation results show that this thesis can help users with poor channel transmission and improve the utilization of spectrum resources. With the same spectrum resources, the cooperative users have more throughput and lower drop ratio. And when the system is fully loaded, it is more efficient than all users transferring directly to eNB.

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