在本文中，我們討論兩個主題。第一個部份，我們提出了一個在使用波束形成技術的多細胞正交分頻多工系統上使用疊代方式的分散式位元和功率分配演算法。考慮由用戶端傳送訊號到基地台的情況且多細胞系統的通道考慮頻率重複使用。每一個用戶端傳送的訊號造成其他基地台接收的干擾。這個演算法是在達成每個用戶端傳輸速率和訊號錯誤率要求下，不超過傳輸最大功率上限，達成使所有用戶使用的功率和最小的目的。這個提出的演算法比固定傳送位元量的方式可以達到更好的效能並且和多使用者的貪婪演算法達到相近的效能同時降低了運算所需的複雜度，在模擬結果可以得到證明。第二個部份，我們提出了一個修改的位元和功率配置的演算法使用在多輸入多輸出的單細胞正交分頻多工系統，同樣考慮訊號由用戶端傳送訊號到基地台的情況。每個子載波都可以被一個以上的使用者來傳送訊號。這個修改的演算法同樣是在達成每個用戶端傳輸速率和訊號錯誤率要求下，不超過傳輸最大功率上限，達成使所有用戶使用的功率和最小的目的。從模擬結果可以發現這個修正的演算法比多使用者的貪婪演算法有更好的頻譜效益。 This thesis discusses two topics. First, we develop a distributed bit and power allocation algorithm with beamforming in an iterative fashion for multi-cell orthogonal frequency-division multiplexing (OFDM) systems on uplink. The model of the multi-cell channel with frequency reuse is considered. The transmit signal from each mobile causes interference to the received signals of other base stations. The scheme aims to minimize the total mobile transmit power which satisfying the required data rate, maximum transmit power constraint and bit error rate (BER) of each mobile. The proposed scheme offers better performance than the fixed bit allocation and tremendously reduces computational complexity compared to the multi-user greedy method with insignificant performance degradation as demonstrated in the simulation results. Second, we develop a modified bit and power allocation algorithm with multiple-input multiple-output (MIMO) for single cell multi-user OFDM systems on uplink. The model of the multi-user channel with sub-channel reuse is considered. The modified scheme aims to minimize the total user transmit power which satisfying the required data rate, maximum transmit power constraint and bit error rate of each user. The proposed modified algorithm offers better spectrum efficiency than the multi-user greedy algorithm as illustrated in the simulation results.
