在本論文中，我們想要去最佳化上行雲端無線電接取網路的總傳輸率。在傳統的無線電接取網路中，基地台會去解碼使用者的訊息。相較於傳統上的基地台，在上行雲端無線電接取網路中的遠端無線射頻單元(RRU)會將收到的訊號直接往後送到雲端內的傳送基頻單元(BBU)去做聯合解碼。由於前端(Fronthaul)的頻寬是有限的，所以遠端無線射頻單元必須要將收到的訊號做壓縮。而我們想要解的總傳輸率的最佳化問題，總傳輸率並不是凸函數，因此我們透過一階近似法(first order approximation)去延伸差分凸規劃演算法來解決問題。最後的模擬結果顯示我們的做法改進了先前的做法。

In this thesis, we want to optimize the sum rate of the uplink cloud radio
access network (C-RAN). In traditional RAN, base stations will decode users’
messages. Corresponding to traditional base stations, the radio remote units
(RRUs) in C-RAN will forward their received signals and let the baseband
unit (BBU) in the cloud to be the joint decoding. Due to finite bandwidth
of the fronthaul, the RRUs need to compress their received signals. Our sum
rate optimization over fronthaul compression is not convex. Thus we apply
the first-order approximation to invoke the difference of convex algorithms for solving it. Simulation results show that our work improve the performance of previous works.

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