該文在分析OFDMA系統(tǒng)容量的基礎上，提出了適用于自適應OFDMA系統(tǒng)的隨機服務模型，即M| M| m| n馬爾可夫排隊模型，根據這個模型，我們提出了基于系統(tǒng)吞吐量和用戶QoS要求的呼叫接納控制策略。理論分析和仿真結果表明，當系統(tǒng)中只有FTP業(yè)務時，M| M| m| n模型與自適應OFDMA系統(tǒng)的隨機服務特征非常相似，應用這個模型對系統(tǒng)的阻塞概率和文件的服務時間進行定量分析，其結果與實際系統(tǒng)的性能基本吻合。
關鍵詞：OFDMA；隨機服務模型；呼叫接納控制；QoS

Abstract: Based on the analysis of OFDMA system capacity, a stochastic model, M| M| m| n Markov queue model, is proposed. According to the model, the call admission control strategy is presented, where the number of call connections into the network is limited by the system throughput and user’s QoS requirements. The results demonstrate that the M| M| m| n model is suitable to adaptive OFDMA system supporting for FTP service, and the curves of blocking probability verse arrival rate and average service time verse arrival rate achieved by it coincide with that provided by the simulating results.
Key words: OFDMA; Stochastic model; Call admission control; QoS