【摘要】：作為下一代無線通信中的關鍵技術垂直貝爾實驗室分層空時正交頻分復用(Vertical Bell Laboratories Layered Space Time-Orthogonal Frequency Division Multiplexing,VBLAST-OFDM)能夠極大地提高頻譜利用率。通過與自適應技術的融合處理,可根據(jù)不同用戶的服務質量(Quality of Service,Qo S)要求和子載波的信道狀態(tài)信息(Channel State Information,CSI),動態(tài)地分配子載波和數(shù)據(jù)比特,能達到進一步提高頻譜利用率的目的。本文從實際通信環(huán)境出發(fā),對多用戶VBLAST-OFDM資源分配算法進行理論上和技術上的研究。單獨針對物理層的傳輸策略,以系統(tǒng)吞吐量最大化為優(yōu)化目標,在相關瑞利衰落信道下給出了一種基于部分CSI的自適應子載波分配算法。算法通過Kronecker內積描述信道相關的特性,引用均值反饋模型模擬CSI的反饋機制,從而獲得了相應的數(shù)學物理模型,并得出了對應的自適應子載波分配方法。實驗結果表明,該算法不僅能有效地反映天線相關矩陣中相關系數(shù)以及延時反饋參數(shù)對系統(tǒng)吞吐量的影響,且與未利用均值反饋模型的子載波分配相比具有明顯的優(yōu)越性�；诳鐚拥膫鬏敳呗�,以系統(tǒng)最大吞吐量為目標,通過充分考慮應用層不同業(yè)務的服務質量要求和數(shù)據(jù)鏈路層的動態(tài)特性,在相關信道下給出基于部分CSI的跨層資源分配算法。該算法的目標函數(shù)包括子載波占用情況,功率限制,傳輸速率,不同業(yè)務的服務質量需求及數(shù)據(jù)鏈路層的隊列狀態(tài)信息等約束參數(shù),在基站端數(shù)據(jù)鏈路層存在有限緩存條件下,根據(jù)Kronecker內積表示相關信道模型,通過均值反饋模型描述物理層信息的傳遞過程,并利用服務質量性能指標表示不同業(yè)務的需求,進而推導出相應的跨層資源分配原則。實驗結果表明:該算法不僅考慮了反饋延時對系統(tǒng)吞吐量的影響,同時在考慮數(shù)據(jù)鏈路層的動態(tài)特性和不同業(yè)務需求情況下,與現(xiàn)有算法比較,不僅可滿足不同業(yè)務用戶的Qo S需求,而且可獲得高的吞吐量和較低的丟包率。
[Abstract]:As a key technology in the next generation wireless communication, vertical Bell Labs layered Space-Time orthogonal Frequency Division Multiplexing (Vertical Bell Laboratories Layered Space Time-Orthogonal Frequency Division) Multiplexing VBLAST-OFDM (orthogonal Frequency Division Multiplexing) can greatly improve the spectral efficiency. By combining with adaptive technology, the subcarriers and data bits can be dynamically allocated according to the quality of service (Quality of Service QoS) requirements of different users and the channel state information (Channel State) of the subcarriers, which can further improve the spectral efficiency. In this paper, the multi-user VBLAST-OFDM resource allocation algorithm is studied theoretically and technically based on the actual communication environment. An adaptive subcarrier allocation algorithm based on partial CSI in correlated Rayleigh fading channel is proposed for the physical layer transmission strategy and the optimal target is to maximize the system throughput. The algorithm uses Kronecker inner product to describe the characteristics of channel correlation and uses the mean feedback model to simulate the feedback mechanism of CSI. Thus the corresponding mathematical and physical model is obtained and the corresponding adaptive subcarrier allocation method is obtained. Experimental results show that the proposed algorithm can not only effectively reflect the influence of correlation coefficient and delay feedback parameters in antenna correlation matrix on system throughput, but also has obvious advantages over subcarrier allocation without mean feedback model. Based on the cross-layer transmission strategy, aiming at the maximum throughput of the system, a cross-layer resource allocation algorithm based on partial CSI is proposed under the correlation channel by fully considering the QoS requirements of different services in the application layer and the dynamic characteristics of the data link layer. The objective functions of the algorithm include subcarrier occupancy, power limitation, transmission rate, QoS requirements of different services and queue state information of the data link layer. According to the Kronecker inner product representation correlation channel model, the mean feedback model is used to describe the transfer process of physical layer information, and the quality of service performance index is used to represent the requirements of different services, and the corresponding cross-layer resource allocation principle is deduced. Experimental results show that the proposed algorithm not only considers the effect of feedback delay on system throughput, but also takes into account the dynamic characteristics of data link layer and different traffic requirements. It can not only satisfy the QoS requirements of different service users, but also achieve high throughput and low packet loss rate.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN929.53

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