基于D2D中繼的TD-LTE集群系統(tǒng)切換機(jī)制研究
發(fā)布時(shí)間：2019-05-22 10:59
【摘要】：隨著公網(wǎng)集群系統(tǒng)的進(jìn)一步發(fā)展,集群用戶所需的傳輸速率和服務(wù)質(zhì)量將越來越高。傳統(tǒng)的LTE切換技術(shù)采用硬切換技術(shù),存在切換時(shí)延長(zhǎng)、掉話率高和業(yè)務(wù)不穩(wěn)定的問題,已無法滿足集群系統(tǒng)的需求。在集群通信系統(tǒng)中,使用用戶間通信(D2D)技術(shù)進(jìn)行輔助切換可以提高切換過程中的傳輸速率、信干噪比,但建立大量的D2D連接會(huì)帶來較大的時(shí)延、信令以及能量開銷。此外,D2D用戶復(fù)用小區(qū)頻譜資源不可避免地帶來干擾,如何對(duì)網(wǎng)絡(luò)資源進(jìn)行分配盡可能地減少干擾顯得至關(guān)重要。在這種背景下,本文展開了對(duì)LTE集群系統(tǒng)切換優(yōu)化機(jī)制的研究,主要包括:首先,從LTE系統(tǒng)切換流程和判決準(zhǔn)則方面研究分析了其缺陷和不足,指出硬切換技術(shù)存在切換時(shí)延長(zhǎng)和掉話率高的問題。接著,本文對(duì)學(xué)術(shù)界在集群系統(tǒng)切換方面的研究成果進(jìn)行了總結(jié)分析,同時(shí)也分析了基于D2D中繼的切換機(jī)制的優(yōu)點(diǎn)及存在的問題。其次,參考現(xiàn)有文獻(xiàn)中基于D2D的輔助切換方法,本文提出了一種基于分簇多播的公網(wǎng)集群系統(tǒng)切換方法。該方法采用基于層次分析法的簇頭選擇和分簇算法,將集群用戶的移動(dòng)性和剩余電量納入決策因素,選擇綜合評(píng)價(jià)指標(biāo)最高的終端作為簇頭,可減少簇頭的數(shù)量,并延長(zhǎng)D2D通信的時(shí)間,實(shí)現(xiàn)穩(wěn)定的網(wǎng)絡(luò)分簇結(jié)構(gòu),保障集群用戶在切換過程中業(yè)務(wù)的連續(xù)性和高傳輸速率。仿真結(jié)果表明,該優(yōu)化方法能提高集群用戶在切換過程中的傳輸速率和信干噪比,降低集群用戶的能量消耗。最后,針對(duì)D2D多播復(fù)用小區(qū)頻譜資源帶來的干擾問題建模,本文提出了一種基于D2D多播的集群系統(tǒng)資源分配優(yōu)化算法。此算法的優(yōu)化目標(biāo)是系統(tǒng)吞吐量最大化,將資源分配拆分為資源塊分配和功率分配兩步進(jìn)行求解。第一步以最小化干擾為目標(biāo)為多播簇尋找共享頻譜的蜂窩用戶,并進(jìn)行資源塊分配;第二步,采用遺傳算法的思想搜索最優(yōu)功率分配方案。之后,編寫C++程序?qū)Υ怂惴ㄟM(jìn)行了仿真驗(yàn)證,仿真結(jié)果驗(yàn)證了此算法在抑制干擾、提升系統(tǒng)吞吐量方面的有效性。
[Abstract]:With the further development of public network cluster system, the transmission rate and quality of service required by cluster users will be higher and higher. The traditional LTE switching technology adopts hard switching technology, which has the problems of prolonged switching, high drop rate and unstable service, which can not meet the needs of cluster system. In cluster communication system, the use of inter-user communication (D2D) technology for auxiliary switching can improve the transmission rate and signal-to-noise ratio (SNR) in the switching process, but the establishment of a large number of D2D connections will bring large delay, signaling and energy overhead. In addition, D2D user reuse cell spectrum resources inevitably bring interference, how to allocate network resources to reduce interference as much as possible is very important. In this context, this paper studies the switching optimization mechanism of LTE cluster system, including: first, its defects and shortcomings are studied and analyzed from the aspects of LTE system switching process and decision criteria. It is pointed out that the hard switching technology has the problems of prolonging switching and high drop rate. Then, this paper summarizes and analyzes the research results of cluster system switching in academic circles, and also analyzes the advantages and existing problems of switching mechanism based on D2D relay. Secondly, referring to the auxiliary switching method based on D2D in the existing literature, this paper proposes a switching method of public network cluster system based on cluster multicasting. In this method, the cluster head selection and clustering algorithm based on analytic hierarchy process (AHP) is adopted, the mobility and residual electricity of cluster users are brought into the decision factors, and the terminal with the highest comprehensive evaluation index is selected as the cluster head, which can reduce the number of cluster heads. The time of D2D communication is extended, the stable network clustering structure is realized, and the service continuity and high transmission rate of cluster users in the process of switching are guaranteed. The simulation results show that the optimization method can improve the transmission rate and SNR of cluster users in the switching process, and reduce the energy consumption of cluster users. Finally, aiming at the interference problem caused by spectrum resources in D2D multicasting cells, a resource allocation optimization algorithm for cluster systems based on D2D multicasting is proposed in this paper. The optimization goal of this algorithm is to maximize the throughput of the system, and the resource allocation is divided into two steps: resource block allocation and power allocation. The first step is to find the cellular users of shared spectrum for the target of minimizing interference, and the resource block allocation is carried out. in the second step, the idea of genetic algorithm is used to search for the optimal power allocation scheme. After that, C program is written to verify the algorithm, and the simulation results verify the effectiveness of the algorithm in suppressing interference and improving the throughput of the system.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN929.5
本文編號(hào)：2482894
[Abstract]:With the further development of public network cluster system, the transmission rate and quality of service required by cluster users will be higher and higher. The traditional LTE switching technology adopts hard switching technology, which has the problems of prolonged switching, high drop rate and unstable service, which can not meet the needs of cluster system. In cluster communication system, the use of inter-user communication (D2D) technology for auxiliary switching can improve the transmission rate and signal-to-noise ratio (SNR) in the switching process, but the establishment of a large number of D2D connections will bring large delay, signaling and energy overhead. In addition, D2D user reuse cell spectrum resources inevitably bring interference, how to allocate network resources to reduce interference as much as possible is very important. In this context, this paper studies the switching optimization mechanism of LTE cluster system, including: first, its defects and shortcomings are studied and analyzed from the aspects of LTE system switching process and decision criteria. It is pointed out that the hard switching technology has the problems of prolonging switching and high drop rate. Then, this paper summarizes and analyzes the research results of cluster system switching in academic circles, and also analyzes the advantages and existing problems of switching mechanism based on D2D relay. Secondly, referring to the auxiliary switching method based on D2D in the existing literature, this paper proposes a switching method of public network cluster system based on cluster multicasting. In this method, the cluster head selection and clustering algorithm based on analytic hierarchy process (AHP) is adopted, the mobility and residual electricity of cluster users are brought into the decision factors, and the terminal with the highest comprehensive evaluation index is selected as the cluster head, which can reduce the number of cluster heads. The time of D2D communication is extended, the stable network clustering structure is realized, and the service continuity and high transmission rate of cluster users in the process of switching are guaranteed. The simulation results show that the optimization method can improve the transmission rate and SNR of cluster users in the switching process, and reduce the energy consumption of cluster users. Finally, aiming at the interference problem caused by spectrum resources in D2D multicasting cells, a resource allocation optimization algorithm for cluster systems based on D2D multicasting is proposed in this paper. The optimization goal of this algorithm is to maximize the throughput of the system, and the resource allocation is divided into two steps: resource block allocation and power allocation. The first step is to find the cellular users of shared spectrum for the target of minimizing interference, and the resource block allocation is carried out. in the second step, the idea of genetic algorithm is used to search for the optimal power allocation scheme. After that, C program is written to verify the algorithm, and the simulation results verify the effectiveness of the algorithm in suppressing interference and improving the throughput of the system.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN929.5
【參考文獻(xiàn)】
相關(guān)期刊論文 前3條
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2 蔣青;蔣毅;張浩;;一種適合于第四代公網(wǎng)集群系統(tǒng)的切換算法[J];無線電通信技術(shù);2013年06期
3 陳浩;蔣青;施意;;TD-LTE集群通信系統(tǒng)中基于小區(qū)篩選和AHP的切換算法研究[J];信息通信技術(shù);2013年02期
，本文編號(hào)：2482894
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