本文關(guān)鍵詞： 緩存輔助中繼 雙向多中繼網(wǎng)絡(luò) 平均和速率 功率分配 KKT條件　出處：《西南交通大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：中繼技術(shù),即信源節(jié)點(diǎn)不直接發(fā)送數(shù)據(jù)給目的節(jié)點(diǎn),而是通過(guò)引入的中繼節(jié)點(diǎn)進(jìn)行數(shù)據(jù)的轉(zhuǎn)發(fā),從而完成信源節(jié)點(diǎn)和目的節(jié)點(diǎn)之間的數(shù)據(jù)交換。中繼技術(shù)的引入可有效對(duì)抗衰落,提升系統(tǒng)的傳輸可靠性。緩存輔助的中繼技術(shù),即給中繼節(jié)點(diǎn)配備緩存,使得中繼能夠儲(chǔ)存接收的數(shù)據(jù),而不用立即轉(zhuǎn)發(fā)出去,從而打破傳統(tǒng)的一收一發(fā)的固定傳輸模式,系統(tǒng)可以根據(jù)當(dāng)前時(shí)隙不同的鏈路信道質(zhì)量好壞以及緩存中的數(shù)據(jù)狀態(tài),自適應(yīng)地選擇鏈路進(jìn)行信息的傳輸。同時(shí),緩存技術(shù)也為多中繼網(wǎng)絡(luò)選擇最佳中繼提供更多機(jī)會(huì)。緩存的引入對(duì)提升中繼系統(tǒng)吞吐量、分集增益以及信噪比等方面都有重要貢獻(xiàn)。本文主要研究緩存技術(shù)在雙向多中繼網(wǎng)絡(luò)中的應(yīng)用,即基于系統(tǒng)平均和速率最大化的緩存輔助雙向多中繼網(wǎng)絡(luò)優(yōu)化問(wèn)題。論文首先簡(jiǎn)單介紹幾種基本的中繼網(wǎng)絡(luò)傳輸模型,給出不同的中繼轉(zhuǎn)發(fā)策略以及基于不同通信指標(biāo)的中繼選擇策略。其次,研究現(xiàn)有的緩存輔助的中繼技術(shù),即針對(duì)單中繼網(wǎng)絡(luò)的緩存輔助鏈路選擇策略,針對(duì)多中繼網(wǎng)絡(luò)的緩存輔助中繼選擇策略以及緩存輔助技術(shù)在雙向單中繼網(wǎng)絡(luò)中的應(yīng)用。接著,研究緩存輔助技術(shù)在雙向多中繼網(wǎng)絡(luò)中的應(yīng)用,即針對(duì)緩存輔助的雙向多中繼系統(tǒng),以緩存空間無(wú)限大為前提,在緩存收發(fā)信息平衡的情況下,以系統(tǒng)平均和速率最大化為目標(biāo),提出聯(lián)合優(yōu)化中繼選擇、傳輸模式選擇和傳輸速率選擇的網(wǎng)絡(luò)調(diào)度方案]。具體地,運(yùn)用KKT條件求解的優(yōu)化方法,在每個(gè)時(shí)隙根據(jù)信道狀態(tài)信息,自適應(yīng)地選擇最合適的中繼、傳輸模式及傳輸速率。本文對(duì)所提方案Ⅰ的性能進(jìn)行了仿真分析,并和傳統(tǒng)的中繼處沒(méi)有配備緩存的TDBC協(xié)議、MABC協(xié)議以及點(diǎn)到點(diǎn)的雙向中繼協(xié)議進(jìn)行了比較,證明由于緩存的引入導(dǎo)致了雙向中繼網(wǎng)絡(luò)系統(tǒng)性能的極大提升。最后,針對(duì)所提出的緩存輔助的雙向多中繼網(wǎng)絡(luò)調(diào)度方案Ⅰ中所有節(jié)點(diǎn)都采用固定相等的傳輸功率,并未考慮功率限制問(wèn)題,提出根據(jù)不同鏈路狀態(tài),自適應(yīng)地給各個(gè)節(jié)點(diǎn)分配功率進(jìn)行信息傳輸,考慮在各個(gè)節(jié)點(diǎn)平均功率受限制的情況下,對(duì)所提出的調(diào)度方案Ⅰ進(jìn)行優(yōu)化,即緩存輔助的雙向多中繼網(wǎng)絡(luò)調(diào)度方案Ⅱ。本文對(duì)優(yōu)化方案Ⅱ的性能進(jìn)行了仿真研究,并和以固定功率進(jìn)行傳輸?shù)姆桨涪竦男阅苓M(jìn)行了比較,證明功率分配可以更大地提升系統(tǒng)的整體性能,實(shí)現(xiàn)系統(tǒng)的平均和速率最大化的優(yōu)化目標(biāo)。
[Abstract]:Relay technology, that is, the source node does not send data directly to the destination node, but transmits the data through the introduced relay node. Thus the data exchange between the source node and the destination node is completed. The introduction of relay technology can effectively resist fading and enhance the transmission reliability of the system. It enables the relay to store the received data without forwarding it immediately, thus breaking the traditional fixed transmission mode of one receive and one transmission, and the system can vary the link channel quality and the data state in the cache according to the current time slot. At the same time, cache technology also provides more opportunities for multi-relay network to choose the best relay. The introduction of cache can improve the throughput of relay system. Diversity gain and signal-to-noise ratio (SNR) play an important role. In this paper, the application of cache technology in bidirectional multi-relay networks is studied. That is to say, the buffer-assisted bi-directional multi-relay network optimization problem based on system average and rate maximization. Firstly, several basic relay network transmission models are introduced briefly in this paper. Different relay forwarding strategies and relay selection strategies based on different communication indexes are given. Secondly, the existing cache assisted relay technology is studied, that is, cache assisted link selection strategy for single relay network. The cache assisted relay selection strategy for multi-relay network and the application of cache auxiliary technology in bidirectional single-relay network are discussed. Then, the application of cache auxiliary technology in bidirectional multi-relay network is studied. That is to say, in the case of buffer receiving and sending information balance and system average and rate maximization, a joint optimization of relay selection is proposed for buffer-assisted bi-directional multi-relay systems with infinite buffer space as the premise. The network scheduling scheme of transmission mode selection and transmission rate selection]. Specifically, using the optimization method of KKT condition solving, adaptively selecting the most suitable relay in each time slot according to the channel state information, In this paper, the performance of the proposed scheme I is simulated and analyzed, and compared with the traditional TDBC protocol without buffer and the point to point two-way relay protocol. It is proved that the performance of bidirectional relay network system is greatly improved due to the introduction of cache. Finally, all nodes in the proposed buffer-assisted bi-directional multi-relay network scheduling scheme I adopt fixed and equal transmission power. Without considering the power limitation problem, this paper proposes an adaptive allocation of power to each node for information transmission according to different link states, and optimizes the proposed scheduling scheme I under the condition that the average power of each node is limited. In this paper, the performance of optimization scheme 鈪，

本文編號(hào)：1508249