多用户广义空间调制系统下行链路线性预编码研究

发布时间：2018-06-27 14:59

本文选题：多用户 + GSM　；参考：《郑州大学》2017年硕士论文

【摘要】：广义空间调制(GSM)因其高吞吐量、高能效等优点而成为未来超高速无线通信系统的关键技术之一。将GSM应用于多用户多输入多输出(MU-MIMO)系统能够提高时间和频率资源利用率,但用户间干扰(MUI)的引入将降低多用户广义空间调制(MU-GSM)系统的性能,目前已有许多能够提高系统性能的预编码方案,但大部分预编码方案致力于将干扰信号消除,本文从利用干扰的角度对MU-GSM系统预编码技术进行了深入研究,主要工作如下:1.通过对点对点GSM系统的可达速率进行仿真分析,发现相比垂直分层空时(V-BLAST)系统,点对点GSM系统可以使用较少的RF链路数达到更高的可达速率。同时基于次序统计对点对点GSM系统的误符号率(SER)性能进行了理论分析,仿真结果表明所推导的点对点GSM系统误符号率解析式能够比较准确地估计点对点GSM系统的SER。2.通过对发射端天线分组,构建了可以极大提高GSM系统频谱效率的单小区下行链路MU-GSM系统模型。直接使用传统线性预编码方法消除干扰信号时,GSM系统信道增益矩阵和发送信号矩阵特有的稀疏性将导致发送信息的丢失。本文通过建立能够提取活跃天线信息的虚拟转换矩阵构建出等效虚拟MU-MIMO系统解决了上述问题,并在此基础上提出了可以消除单小区MU-GSM系统下行链路干扰的线性预编码方法。进一步的,基于干扰分类思想,通过建立干扰判断矩阵,提出了能够利用单小区MU-GSM系统中有用干扰的多用户广义空间调制部分线性预编码(MU-GSM-PLP)方法和基于MMSE准则的多用户广义空间调制部分线性预编码(MU-GSM-MMSE-PLP)方法。仿真结果表明利用干扰的线性预编码方法可以为系统提供更高的和速率和较低的误比特率(BER)。3.为了进一步利用干扰,相位旋转预编码方法被应用于单小区下行链路MU-GSM系统,进而提出了广义空间调制相位旋转线性预编码(MU-GSM-PALP)方法和基于MMSE准则的广义空间调制相位旋转线性预编码(MU-GSM-MMSE-PALP)方法。MU-GSM-PALP和MU-GSM-MMSE-PALP线性预编码方法利用相位修正矩阵使所有干扰成为了可以为目标符号提供有用能量增益的有用干扰,因此这两种线性预编码方法可以进一步提高单小区MU-GSM系统的和速率,并降低单小区MU-GSM系统的BER,本文通过蒙特卡洛仿真验证了其优越性。
[Abstract]:Generalized Spatial Modulation (GSM) has become one of the key technologies in future ultra-high speed wireless communication systems because of its high throughput and high energy efficiency. The application of GSM to MU-MIMO systems can improve the utilization of time and frequency resources, but the introduction of interuser interference (MUI) will reduce the performance of MU-GSM systems. At present, there are many precoding schemes which can improve the performance of the system, but most of the precoding schemes are devoted to eliminating interference signals. In this paper, the pre-coding technology of MU-GSM system is deeply studied from the point of view of interference. The main work is as follows: 1. Through the simulation and analysis of the reachable rate of point GSM system, it is found that the point to point GSM system can use less RF links to achieve higher reachable rate than V-BLAST system. At the same time, the performance of symbol error rate (SER) of point GSM system is theoretically analyzed based on order statistics. The simulation results show that the derived analytic formula of symbol error rate of point to point GSM system can estimate SER.2 of point to point GSM system more accurately. By grouping the transmitter antennas, a single cell downlink MU-GSM system model is constructed, which can greatly improve the spectrum efficiency of GSM system. When the interference signal is eliminated directly by the traditional linear precoding method, the unique sparseness of channel gain matrix and transmission signal matrix in GSM system will lead to the loss of transmission information. In this paper, an equivalent virtual MU-MIMO system is constructed by building a virtual conversion matrix that can extract active antenna information. Based on this, a linear precoding method is proposed to eliminate downlink interference in a single cell MU-GSM system. Furthermore, based on the idea of interference classification, the interference judgment matrix is established. The multiuser generalized spatial modulation partial linear precoding (MU-GSM-PLP) method and the MU-GSM-MMSE-PLP method based on MMSE criterion are proposed to utilize the useful interference in single-cell MU-GSM system. The simulation results show that the interference linear precoding method can provide higher sum rate and lower bit error rate (BER). 3 for the system. In order to further utilize interference, phase rotation precoding is applied to single cell downlink MU-GSM system. Furthermore, the generalized spatial modulation phase rotation linear precoding (MU-GSM-PALP) method and the generalized spatial modulation phase rotation linear precoding (MU-GSM-MMSE-PALP) method based on MMSE criterion are proposed. MU-GSM-PALP and MU-GSM-MMSE-PALP linear precoding methods use phase correction matrix to make all dry. Disturbance becomes a useful interference that can provide useful energy gain for the target symbol, Therefore, these two linear precoding methods can further improve the sum rate of single-cell MU-GSM system and reduce the Bert of single-cell MU-GSM system.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN919.3

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