高移动场景下超奈奎斯特与时域重叠复用传输性能分析

发布时间：2018-04-15 06:17

本文选题：FTN + OVTDM　；参考：《西南交通大学》2015年硕士论文

【摘要】：超奈奎斯特(FTN)传输和时域重叠复用(OVTDM)技术是突破传统Nyquist传输准则的两种思想,其特点就是能够在提升数据速率的同时,获得高效的频谱利用率。FTN侧重于加快符号速率,通过人为缩短符号间隔让其小于Nyquist的传输间隔,以达到提升频谱效率的效果,同时通过尽量保持最小欧氏距离来保障差错概率。OVTDM技术则通过采用移位叠加传输,人为引入可控的符号间干扰,以改善信号输出电平分布。OVTDM强调采用波形分割的思想来区分不同信号,以获得尽可能大的编码增益和较高的频谱利用率。由于OVTDM采用的不是电平而是波形分割,因而也属于一种波形编码。已有研究表明,虽然FTN和OVTDM系统都对不同系统的译码性能进行了分析,不过都是基于AWGN信道或者低速时变信道场景的分析,有关高速场景下FTN或者OVTDM系统的性能表现,尚未有文献进行研究。为此,有必要进行接收机设计的改进,以更好地估计由高移动性产生的快时变信道状态和有效地消除符号间干扰(ISI,Inter Symbol Interference)和载波间干扰(ICI,Inter carrier Interference),等等。考虑到高移动场景下的快时变信道干扰的影响,本论文对已有FTN和OVTDM接收机的结构进行了改进,增加了基于迭代算法的快时变干扰估计和预消除模块,对由信道快时变特性和非正交传输引入的干扰预先进行粗略估计和消除。仿真分析表明,FTN系统中的加速因子对于系统性能的影响较大。论文对于在数据传输速率提升和保证系统误码性能的折衷方案进行了分析,重点研究了FTN系统和OVTDM系统的误码性能,并基于实际应用采用噪声白化机制来消除有色噪声的强相关性的影响,以改进高移动场景下接收机系统性能。
[Abstract]:Ultra-Nyquist FTNN transmission and time-domain overlapping multiplexing (TDM) technology are two ideas that break through the traditional Nyquist transmission criterion. Its characteristic is that it can increase the data rate and achieve efficient spectral efficiency. FTN focuses on accelerating the symbol rate.By artificially shortening the symbol interval so that it is smaller than the transmission interval of Nyquist, the spectral efficiency can be improved, and the error probability can be guaranteed by keeping the minimum Euclidean distance. OVTDM technology adopts shift superposition transmission.In order to improve the signal output level distribution. OVTDM emphasizes the idea of waveform segmentation to distinguish different signals in order to obtain as much coding gain as possible and high spectral efficiency.OVTDM is also a waveform coding because it uses waveform segmentation instead of level.Previous studies have shown that, although both FTN and OVTDM systems have analyzed the decoding performance of different systems, they are based on the analysis of AWGN channel or low-speed time-varying channel scenarios, and the performance of FTN or OVTDM systems in high-speed scenarios.No literature has been studied.Therefore, it is necessary to improve the receiver design in order to better estimate the fast time-varying channel state generated by high mobility and effectively eliminate the ISI I / I Symbol interference and ICI / Inter carrier interference, and so on.Considering the influence of fast time-varying channel interference in high mobile scene, the structure of existing FTN and OVTDM receivers is improved in this paper, and the modules of fast time-varying interference estimation and pre-cancellation based on iterative algorithm are added.The interference introduced by fast time-varying channel and non-orthogonal transmission is estimated and eliminated in advance.The simulation results show that the acceleration factor in FTN system has a great influence on the performance of the system.In this paper, the tradeoff between improving the data transmission rate and ensuring the error performance of the system is analyzed, and the error performance of the FTN system and the OVTDM system is mainly studied.Based on the practical application, noise whitening mechanism is adopted to eliminate the influence of strong correlation of colored noise in order to improve the performance of receiver in high mobile scene.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.5

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