互耦和相干信号条件下MIMO信道参数估计方法研究

发布时间：2018-06-13 22:05

本文选题：阵列信号处理 + 参数估计　；参考：《天津大学》2014年硕士论文

【摘要】：MIMO通信系统具有高速率和高可靠性的特点,近年来引起了广泛关注。对方位角、时延等信道特性参数快速而准确的估计是充分了解MIMO无线信道特征、保障无线信号可靠传输的前提。然而,传统参数估计算法受互耦、相干信源和高斯色噪声等因素影响性能急剧下降,研究可抑制阵列互耦、相干和高斯色噪声的参数估计方法具有重要意义。在高斯色噪声背景下,针对信源相干和阵列互耦问题,本文提出了一种能够准确估计信源到达角的算法。首先,采用辅助阵元校正互耦误差。然后结合空间平滑技术和四阶累积量构建平滑矩阵,实现对高斯噪声的抑制和对信号的解相干。最后使用ESPRIT算法获得信源的来波方向。仿真实验表明在任意高斯噪声环境下算法能够精确估计到达角,并且算法性能接近没有互耦误差的理想情况。空间平滑技术需要构建各个子阵列的协方差矩阵,计算量较大。进而本文基于四阶累积量构建一个独立于信号相干性的Toeplitz矩阵以代替空间平滑。复杂度分析证实该算法具有更小计算量,同时仿真结果表明本算法可有效估计到达角且准确度接近没有互耦的理想情况。相比采用空间平滑的算法,本算法具有更好的估计性能。综上所述,本文主要研究了互耦和相干信源条件下适用于任意高斯噪声环境的MIMO信道参数估计方法。除理论分析之外,还进行了仿真论证,进一步验证了文中提出的算法的有效性。
[Abstract]:MIMO communication system has attracted much attention in recent years because of its high speed and high reliability. The fast and accurate estimation of the channel characteristic parameters such as azimuth and delay is the premise to fully understand the MIMO wireless channel characteristics and ensure the reliable transmission of wireless signal. However, the traditional parameter estimation algorithm is affected by mutual coupling, coherent source and Gao Si color noise, etc. It is of great significance to study the parameter estimation method which can suppress array mutual coupling, coherence and Gao Si color noise. Under the background of Gao Si color noise, an algorithm for estimating the source arrival angle is proposed to solve the problem of source coherence and array mutual coupling. First of all, auxiliary array elements are used to correct the mutual coupling error. Then the smoothing matrix is constructed with spatial smoothing technique and fourth-order cumulant to suppress the Gao Si noise and decorrelate the signal. Finally, the Esprit algorithm is used to obtain the direction of the source. Simulation results show that the algorithm can estimate the angle of arrival accurately under arbitrary Gao Si noise, and the performance of the algorithm is close to the ideal condition without mutual coupling error. Spatial smoothing technique needs to construct covariance matrix of each subarray, which requires a large amount of computation. Furthermore, a Toeplitz matrix independent of signal coherence is constructed based on fourth-order cumulants to replace spatial smoothing. The complexity analysis shows that the algorithm has less computational complexity and the simulation results show that the algorithm can effectively estimate the arrival angle and the accuracy is close to the ideal situation without mutual coupling. Compared with the spatial smoothing algorithm, this algorithm has better estimation performance. To sum up, this paper mainly studies the Gao Si channel parameter estimation method suitable for arbitrary Gao Si noise environment under the condition of mutual coupling and coherent source. In addition to theoretical analysis, simulation is also carried out to further verify the effectiveness of the proposed algorithm.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.3

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