下行多小区多用户MIMO系统的鲁棒性传输优化
发布时间：2019-01-05 22:06
【摘要】：随着无线通信的发展,要求无线网络中能够容纳更多用户,系统容量更大,用户服务质量更好,未来无线通信系统的目标是以最低的频谱、功耗和硬件复杂度要求提供各种高品质的高速率服务。在多小区MIMO系统下行链路中,干扰问题已经成为无线通信中多天线技术提升系统性能的一个主要障碍,一个基站同时服务多个用户,会存在小区内干扰,同时用户还会受到来自相邻小区的干扰,除此之外,还有噪声干扰。如何对系统作收发机作优化,设计发射端预编码矩阵和接收机已经成为通信系统的难题之一。传统方法通常假设CSI没有误差,然而在实际情况中,完美的信道估计是不可实现的,有误差的CSI会显著降低系统的性能,所以不能直接套用传统算法。本文讨论的正是在多小区MIMO系统下行链路中,当信道估计误差在一定有界区域内,针对一系列优化问题,以系统MSE和发射功率为性能指标,提出相应迭代算法,利用凸优化工具包求解,得到最优收发机设计方案。第一部分介绍了课题的背景与研究意义,对本论文所做的研究工作作了概述,指明了研究方向,描述了鲁棒性优化及凸优化问题,为后面的工作提供了理论基础。第二部分针对下行多小区MIMO系统,在有信道误差及发射功率有约束的情况下,以减小用户接收信号MSE为目标,提出了一种基于凸优化理论的鲁棒性传输设计方案。信道误差是有界的,所以系统的MSE也将在一个不确定区域内,最小化此范围内的最差MSE值,可以得到最优预编码矩阵和接收机,从而解决一系列MSE优化问题,包括用户总MSE最小化、用户最大MSE最小化。对于CB场景的优化可以直接利用单小区MIMO场景的方法进行扩展得到；而在JP传输方式中,由于每基站功率单独约束,直接优化困难,本文以最小化用户接收信号MSE的上界为目标进行优化设计。仿真结果表明,当CSI有误差时,对比传统的优化设计方法,基于凸优化的收发机设计方案能够有效地提高系统性能,降低MSE。在第三部分中,本文换一个角度,在有信道误差及系统MSE有约束的情况下,研究以系统传输功率为目标的鲁棒性传输优化,并提出了基于凸优化理论的传输方案。同样,针对CB场景,可以直接利用单小区MIMO场景算法扩展得到,而针对JP场景,先对MSE函数作缩放,再进行优化设计,得到最优收发器设计方案。仿真结果表明,对比其它相应算法,本算法性能有显著提高。
[Abstract]:With the development of wireless communication, the wireless network is required to accommodate more users, the system capacity is larger, the user quality of service is better, the goal of the future wireless communication system is to use the lowest spectrum. Power consumption and hardware complexity require a variety of high-quality high-rate services. In the downlink of multi-cell MIMO system, interference problem has become a major obstacle for multi-antenna technology in wireless communication to improve system performance. If a base station serves multiple users at the same time, there will be intra-cell interference. At the same time, users will also be affected by the interference from adjacent cells, in addition to noise interference. How to optimize the transceiver and design the transmitter precoding matrix and receiver has become one of the difficult problems in communication system. Traditional methods usually assume that CSI has no error, but in practice, perfect channel estimation is impossible, and CSI with errors can significantly reduce the performance of the system, so the traditional algorithm can not be directly applied. In this paper, in the downlink of multi-cell MIMO system, when the channel estimation error is in a bounded region, for a series of optimization problems, taking the system MSE and transmit power as the performance index, the corresponding iterative algorithm is proposed. The optimal transceiver design scheme is obtained by using convex optimization toolbox. The first part introduces the background and significance of the research, summarizes the research work done in this paper, points out the research direction, describes the robust optimization and convex optimization problems, and provides a theoretical basis for the later work. In the second part, a robust transmission design scheme based on convex optimization theory is proposed for downlink multi-cell MIMO systems with channel errors and transmission power constraints, aiming at reducing user received signal MSE. The channel error is bounded, so the MSE of the system will be minimized in an uncertain region, and the optimal precoding matrix and receiver can be obtained, and a series of MSE optimization problems can be solved. This includes the minimization of the total MSE of the user and the minimization of the maximum MSE of the user. The optimization of CB scene can be directly extended by using the method of single cell MIMO scene. In JP transmission mode, because of the power constraints of each base station, it is difficult to optimize directly. The aim of this paper is to minimize the upper bound of the received signal MSE. The simulation results show that when CSI has errors, compared with the traditional optimization design method, the design scheme based on convex optimization can effectively improve the system performance and reduce the MSE.. In the third part, under the condition of channel error and system MSE constraint, the robust transmission optimization with transmission power as the target is studied, and a transmission scheme based on convex optimization theory is proposed. In the same way, for the CB scene, we can directly use the single-cell MIMO scene algorithm to extend it, while for the JP scene, the MSE function is scaled first, and then the optimal transceiver design scheme is obtained by optimizing the design. Simulation results show that the performance of this algorithm is significantly improved compared with other corresponding algorithms.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.3
本文编号：2402362
[Abstract]:With the development of wireless communication, the wireless network is required to accommodate more users, the system capacity is larger, the user quality of service is better, the goal of the future wireless communication system is to use the lowest spectrum. Power consumption and hardware complexity require a variety of high-quality high-rate services. In the downlink of multi-cell MIMO system, interference problem has become a major obstacle for multi-antenna technology in wireless communication to improve system performance. If a base station serves multiple users at the same time, there will be intra-cell interference. At the same time, users will also be affected by the interference from adjacent cells, in addition to noise interference. How to optimize the transceiver and design the transmitter precoding matrix and receiver has become one of the difficult problems in communication system. Traditional methods usually assume that CSI has no error, but in practice, perfect channel estimation is impossible, and CSI with errors can significantly reduce the performance of the system, so the traditional algorithm can not be directly applied. In this paper, in the downlink of multi-cell MIMO system, when the channel estimation error is in a bounded region, for a series of optimization problems, taking the system MSE and transmit power as the performance index, the corresponding iterative algorithm is proposed. The optimal transceiver design scheme is obtained by using convex optimization toolbox. The first part introduces the background and significance of the research, summarizes the research work done in this paper, points out the research direction, describes the robust optimization and convex optimization problems, and provides a theoretical basis for the later work. In the second part, a robust transmission design scheme based on convex optimization theory is proposed for downlink multi-cell MIMO systems with channel errors and transmission power constraints, aiming at reducing user received signal MSE. The channel error is bounded, so the MSE of the system will be minimized in an uncertain region, and the optimal precoding matrix and receiver can be obtained, and a series of MSE optimization problems can be solved. This includes the minimization of the total MSE of the user and the minimization of the maximum MSE of the user. The optimization of CB scene can be directly extended by using the method of single cell MIMO scene. In JP transmission mode, because of the power constraints of each base station, it is difficult to optimize directly. The aim of this paper is to minimize the upper bound of the received signal MSE. The simulation results show that when CSI has errors, compared with the traditional optimization design method, the design scheme based on convex optimization can effectively improve the system performance and reduce the MSE.. In the third part, under the condition of channel error and system MSE constraint, the robust transmission optimization with transmission power as the target is studied, and a transmission scheme based on convex optimization theory is proposed. In the same way, for the CB scene, we can directly use the single-cell MIMO scene algorithm to extend it, while for the JP scene, the MSE function is scaled first, and then the optimal transceiver design scheme is obtained by optimizing the design. Simulation results show that the performance of this algorithm is significantly improved compared with other corresponding algorithms.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.3
【参考文献】
相关硕士学位论文 前1条
1 刘石坚;基于协同波束成形的小区间干扰管理技术[D];电子科技大学;2012年
，本文编号：2402362
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