四维无线调制解调器的理论研究
发布时间：2018-08-05 13:19
【摘要】：本文提出了一个同时使用电磁波幅度、相位、辅助极化角和极化相位差异角来携带信息的四维无线调制解调器。借助于空间电磁源入射矢量天线的电磁场信号表达式,我们描述了利用矢量天线调制、解调空间电磁波四维参数的基本原理。在系统的发送端(即调制端),我们根据空间中线形与环形天线通电后的电磁场分布,推导了利用矢量天线中电、磁偶极子来产生含四维调制参数信号的方法。并分别讨论了单用户和多用户情况下发送端的具体实现方式。对于接收端(即解调端),我们给出了以矢量天线(或其阵列)为载体、几何代数为数学工具进行参数解调的方法。四维调制信号的解调过程需要首先对接收到的电磁场信号进行波达方向(DOA)估计。由于几何代数模型下的DOA参数估计方法在复杂度、性能以及数据存储空间方面较其它算法具有优势,故本文将分别使用几何代数模型下的最优加权内积算法与多重信号分离算法来估计单用户和多用户场景下接收信号的DOA参数。在获得了四维调制信号的DOA参数后,接收端将通过最小二乘算法来估计各个调制参数以实现四维解调过程。本文从理论上推导了单用户和多用户场景下四维无线调制解调器的误符号率,并用仿真加以了验证。理论分析与仿真结果均表明：本文提出的四维无线调制解调器较传统调制解调器具有更高的传输速率和更低的误符号率。为了提升四维无线调制解调器的完善性,本文还提出了一种基于格理论来构造高维星座图的方法。星座图的增益指数是格理论中的一个术语,它可以分解成格的编码增益和星座图边界的成形增益。本文将最大化星座图增益指数的过程构造为一系列优化问题,并将星座图的几何特性作为优化问题的约束条件。由于可通过求解优化问题来得到所需的星座图,因此本文的方法可以作为一种构造高维星座图的通用方法。相比现有算法均只适用于星座点个数较少的情况,本文方法可以简便地构造星座点数目较大的高维星座图。仿真结果显示出：在星座点数目较少时,由本文方法所构造的星座图的误符号率性能与最优值十分接近；而当星座点数目较多时,本文构造的星座图较传统基于整数格的星座图具有更低的误符号率。
[Abstract]:This paper presents a four-dimensional wireless modem which uses the amplitude, phase, auxiliary polarization angle and polarization phase difference angle of the electromagnetic wave simultaneously to carry information. By means of the expression of electromagnetic field signal of space electromagnetic source incident vector antenna, we describe the basic principle of modulating and demodulating four dimensional parameters of space electromagnetic wave by vector antenna. Based on the electromagnetic field distribution of linear and annular antennas in space, a method of generating four-dimensional modulated parameter signals by using electric and magnetic dipoles in vector antennas is derived. The implementation of single-user and multi-user senders is discussed respectively. For the receiver (demodulator), we present a method of parameter demodulation using vector antenna (or its array) as carrier and geometric algebra as mathematical tool. The demodulation process of four dimensional modulation signal requires the (DOA) estimation of the received electromagnetic field signal. The DOA parameter estimation method based on geometric algebraic model has advantages over other algorithms in terms of complexity, performance and data storage space. Therefore, in this paper, the optimal weighted inner product algorithm and the multiple signal separation algorithm are used to estimate the DOA parameters of the received signals in single-user and multi-user scenarios, respectively. After obtaining the DOA parameters of the four-dimensional modulation signal, the receiver will estimate the modulation parameters by using the least square algorithm to realize the four-dimensional demodulation process. In this paper, the symbol error rate of four-dimensional wireless modem in single-user and multi-user scenarios is derived theoretically and verified by simulation. The theoretical analysis and simulation results show that the proposed four-dimensional wireless modem has higher transmission rate and lower symbol error rate than the traditional modem. In order to improve the perfection of four-dimensional wireless modem, a method of constructing high-dimensional constellation diagram based on lattice theory is proposed. The gain exponent of constellation graph is a term in lattice theory. It can be decomposed into the coding gain of lattice and the shaping gain of constellation graph boundary. In this paper, the process of maximizing the gain exponent of constellation graph is constructed as a series of optimization problems, and the geometric properties of the constellation graph are taken as the constraints of the optimization problem. Because the required constellation graph can be obtained by solving the optimization problem, the method in this paper can be used as a general method to construct the high-dimensional constellation graph. Compared with the existing algorithms, this method can easily construct the high-dimensional constellation graph with a large number of constellation points. The simulation results show that when the number of constellation points is small, the symbol error rate performance of the constellation diagram constructed by this method is very close to the optimal value, but when the number of constellation points is large, The constellation graph constructed in this paper has lower symbol error rate than the traditional constellation diagram based on integer lattice.
【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN915.05
本文编号：2165916
[Abstract]:This paper presents a four-dimensional wireless modem which uses the amplitude, phase, auxiliary polarization angle and polarization phase difference angle of the electromagnetic wave simultaneously to carry information. By means of the expression of electromagnetic field signal of space electromagnetic source incident vector antenna, we describe the basic principle of modulating and demodulating four dimensional parameters of space electromagnetic wave by vector antenna. Based on the electromagnetic field distribution of linear and annular antennas in space, a method of generating four-dimensional modulated parameter signals by using electric and magnetic dipoles in vector antennas is derived. The implementation of single-user and multi-user senders is discussed respectively. For the receiver (demodulator), we present a method of parameter demodulation using vector antenna (or its array) as carrier and geometric algebra as mathematical tool. The demodulation process of four dimensional modulation signal requires the (DOA) estimation of the received electromagnetic field signal. The DOA parameter estimation method based on geometric algebraic model has advantages over other algorithms in terms of complexity, performance and data storage space. Therefore, in this paper, the optimal weighted inner product algorithm and the multiple signal separation algorithm are used to estimate the DOA parameters of the received signals in single-user and multi-user scenarios, respectively. After obtaining the DOA parameters of the four-dimensional modulation signal, the receiver will estimate the modulation parameters by using the least square algorithm to realize the four-dimensional demodulation process. In this paper, the symbol error rate of four-dimensional wireless modem in single-user and multi-user scenarios is derived theoretically and verified by simulation. The theoretical analysis and simulation results show that the proposed four-dimensional wireless modem has higher transmission rate and lower symbol error rate than the traditional modem. In order to improve the perfection of four-dimensional wireless modem, a method of constructing high-dimensional constellation diagram based on lattice theory is proposed. The gain exponent of constellation graph is a term in lattice theory. It can be decomposed into the coding gain of lattice and the shaping gain of constellation graph boundary. In this paper, the process of maximizing the gain exponent of constellation graph is constructed as a series of optimization problems, and the geometric properties of the constellation graph are taken as the constraints of the optimization problem. Because the required constellation graph can be obtained by solving the optimization problem, the method in this paper can be used as a general method to construct the high-dimensional constellation graph. Compared with the existing algorithms, this method can easily construct the high-dimensional constellation graph with a large number of constellation points. The simulation results show that when the number of constellation points is small, the symbol error rate performance of the constellation diagram constructed by this method is very close to the optimal value, but when the number of constellation points is large, The constellation graph constructed in this paper has lower symbol error rate than the traditional constellation diagram based on integer lattice.
【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN915.05
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1 蒋景飞;几何代数模型矢量天线阵列信号的方法及应用[D];复旦大学;2011年
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