無線技術已廣泛應用在生活中,並且講求高傳輸率、高頻寬使用效率、低功率,因此正交分頻多工系統成為目前最有能力達到需求的技術。在多細胞的系統下,共頻帶干擾是影響傳輸品質的重要因素,因此需要隨時做功率控制,讓通訊不中斷。 在這篇論文中討論如何在多細胞多使用者的環境中增加傳輸系統的效能,並著重在功率的效益上,因為如果能夠有效控制功率,相對地,傳輸率和頻寬使用效率自然能夠提升。我們設計一種資源配置演算法,決定載波、位元和功率的配置,解決同頻帶干擾的問題,並將傳輸功率最小化。我們利用Lagrange和Greedy方法,並加以設計,從模擬中可以看出,我們的演算法勝過現有的演算法。 This paper develops a sub-carrier, bit and power allocation algorithm for downlink multi-cell OFDMA systems. The model of the co-channel interference (CCI) channel is considered, where the transmit signal from each base station (BS) causes interference to the other users in other co-channel cells. This algorithm aims to minimize the total transmit power while satisfying the required data rate of each user, symbol error rate and the power constraint on each BS and each link. We propose a scheme to sort all users such that we can do the resource allocation on all users in sequence. Moreover, we use the Lagrange and Greedy algorithm to do sub-carrier allocation and bit-loading. This methodology is applicable to low mobility multi-cell OFDMA wireless communication systems. The simulation results shows that the proposed algorithm greatly outperform the existing algorithm.