該文在分析OFDMA系統(tǒng)容量的基礎(chǔ)上，提出了適用于自適應(yīng)OFDMA系統(tǒng)的隨機(jī)服務(wù)模型，即M| M| m| n馬爾可夫排隊(duì)模型，根據(jù)這個(gè)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(jié)果表明，當(dāng)系統(tǒng)中只有FTP業(yè)務(wù)時(shí)，M| M| m| n模型與自適應(yīng)OFDMA系統(tǒng)的隨機(jī)服務(wù)特征非常相似，應(yīng)用這個(gè)模型對(duì)系統(tǒng)的阻塞概率和文件的服務(wù)時(shí)間進(jìn)行定量分析，其結(jié)果與實(shí)際系統(tǒng)的性能基本吻合。
關(guān)鍵詞：OFDMA；隨機(jī)服務(wù)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