宽带与宽带虚拟MIMO无线信道传输特性研究

发布时间：2018-03-10 04:06

本文选题：信道模型和参数　切入点：信道测量　出处：《华北电力大学》2015年博士论文　论文类型：学位论文

【摘要】：无线系统在室内室外的广泛应用使得科学家和工程师们在不断发展新的技术来提高传输速率和信道容量。由于分配给无线系统的可用的频谱有限,因而多输入多输出以及虚拟多输入多输出被应用到新的无线系统中来提高频谱效率和系统容量。基于室内到室外的测量数据,本文研究了动态和固定范围两种去噪方法。研究发现,当从测量的信道响应中可以清晰地观察到信号的噪底和动态范围时,利用动态去噪的方法较合适。固定范围去噪时对时延功率谱没有大的影响,使用动态去噪会使得到延功率谱会有较为明晰的变化。K因子的统计值和去除噪音后的值进行了比较,通过比较可以看出莱斯K因子对去噪的方法是不敏感的,即使不去噪声对K因子也没有大的影响。本文在2.25 GHz和5.25 GHz载频以及100MHz带宽下,通过实际测量研究了城市微蜂窝中宽带信道模型和信道特性,比较研究了两个频段在信道模型、信道参数以及参数相关性方面的异同。研究结果表明,在同一路径两个频段绝大多数信道参数是独立的,但它们的相干带宽却有很好的相关性。本文通过对现代化办公室环境多用户MIMO信道的实际测试,研究了虚拟多输入和多输出(V-MIMO)的特性,并将这些研究结果与传统多输入多输出(MIMO)在理论和实验上进行了比较。结果表明,V-MIMO技术在许多场景中可以有效提高信道容量。在无线通信中,信道容量是一个相关性参数。信道容量受许多参数的影响,如信道的K因子、rms时延扩展、空间相关性等。本文研究了信道参数如K因子、rms时延扩展和空间相关性对V-MIMO信道容量的影响,对静止多用户系统,开展了对多用户信道的信道容量、K因子、rms时延扩展和空间相关性的评估。在本文中,通过在基站或接入点使用线性预编码方案,研究了V-MIMO无线系统的性能。其基本思想是通过基站采用预编码来验证虚拟MIMO在性能上优于单用户MIMO。用在本文接收机中的线性预编码方案有迫零(ZF),最小均方误差(MMSE)和连续干扰消除(SIC)方法。最后研究了发射和接收联合波束成形方法。使用线性预编码方案,连续干扰消除(SIC)与最小均方误差(MMSE)、迫零算法(ZF)相比可以得到更高的信道容量。在分析连续干扰消除(SIC)线性预编码时,相比单用户MIMO, V-MIMO系统可获得信道最大传输速率。利用发射和接收联合波束成形,本文研究了两种传输模式,一种是最大本征模式(单波束)和本征模式(多波束)传输,本文分析了注水法和等功率分配的两种本征模传输方法。与其它本征模传输相比,使用注水法可得到更大的信道容量。和传统MIMO系统比较,V-MIMO系统可获得信道最大传输速率。
[Abstract]:The widespread use of wireless systems indoors and outdoors has led scientists and engineers to develop new technologies to improve transmission rates and channel capacity. Thus, multiple input multiple output and virtual multiple input multiple output are applied to new wireless systems to improve spectrum efficiency and system capacity. In this paper, dynamic and fixed range denoising methods are studied. It is found that when the noise bottom and dynamic range of the signal can be clearly observed from the measured channel response, The method of dynamic denoising is more suitable. When denoising in fixed range, there is no great influence on the delay power spectrum. It can be seen by comparison that Rice K factor is insensitive to denoising methods, and even without noise removal has no great effect on K factor. In this paper, the carrier frequencies of 2.25 GHz and 5.25 GHz and 100MHz bandwidth are obtained. The broadband channel model and channel characteristics in urban microcellular are studied by actual measurement. The similarities and differences between the two frequency bands in channel model, channel parameters and their correlation are compared. The results show that, In the same path, most of the channel parameters in two frequency bands are independent, but their coherent bandwidth has good correlation. In this paper, a practical test of multiuser MIMO channel in modern office environment is carried out. The characteristics of virtual multi-input and multi-output V-MIMOs are studied. The theoretical and experimental results are compared with those of the traditional MIMO. The results show that the V-MIMO technology can effectively improve the channel capacity in many scenarios. The channel capacity is a dependent parameter. The channel capacity is affected by many parameters, such as the K factor of the channel and the delay spread of RMS. The influence of channel parameters such as K factor rms delay spread and spatial correlation on the capacity of V-MIMO channel is studied in this paper. The channel capacity factor RMS delay spread and spatial correlation of multiuser channels are evaluated. In this paper, linear precoding schemes are used at base stations or access points. In this paper, the performance of V-MIMO wireless system is studied. The basic idea is to use precoding to verify the performance of virtual MIMO is superior to that of single-user MIMO.The linear precoding scheme used in the receiver in this paper is Zero-forcing and minimum mean Square error (MMSE). And continuous interference cancellation (CCI) method. Finally, the combined beamforming method of transmitting and receiving is studied. Linear precoding scheme is used. Compared with the minimum mean square error (MMSE) and zero forcing algorithm (ZFF), the channel capacity of continuous interference cancellation (CICI) is higher than that of MMSE (minimum mean Square error). Compared with single user MIMO-MIMO system, the channel maximum transmission rate can be obtained in V-MIMO system. Using transmit and receive joint beamforming, this paper studies two transmission modes, one is maximum intrinsic mode (single beam) and the other is intrinsic mode (multi-beam) transmission. In this paper, two intrinsic mode transmission methods of water injection and equal power distribution are analyzed. Compared with other intrinsic mode transmission, the channel capacity can be obtained by using the water injection method. Compared with the traditional MIMO system, the V-MIMO system can obtain the maximum channel transmission rate.
【学位授予单位】：华北电力大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN919.3

【参考文献】