单通道高阶MPSK信号分离方法

发布时间：2018-01-18 01:33

本文关键词：单通道高阶MPSK信号分离方法　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：单通道混合信号的分离在信号处理领域是重要的研究内容之一。相对于多天线接收系统,单个天线系统成本低廉、能耗低以及系统设计简单。另一方面,随着异构通信网络的广泛应用,由于频谱的重复利用,单个通道内出现两个或多个信号的现象也越来越常见。由于单通道混合信号在时域和频域上是部分或完全重叠的,无法使用传统的时域或频域滤波的方法对混合信号分离。因此对单通道接收的多分量信号的分离方法展开研究,具有重要的意义。本文对单通道接收多个高阶MPSK时频混叠信号的分离算法进行研究。在构造出单通道混合信号的虚拟多通道模型的基础之上,研究了基于半定松弛和低秩半定松弛的信号分离方法。本文的主要工作如下:1)提出了基于半定松弛单通道时频混合信号分离方法。首先,利用过采样技术,构建虚拟多入多出模型,并将原问题中输入信号变量的离散值约束松弛为半定约束,从而得到一个半定规划问题。其次,利用内点法和随机化方法,设计了求解该半定规划问题以及符号序列的方法。最后,根据虚拟多通道信号模型的特殊结构,引入判决反馈均衡机制,提高了信号分离的性能。2)提出了基于低秩半定松弛单通道时频混合信号分离方法。首先,增加秩1约束到半定规划问题,得到一个低秩的半定规划问题,并利用交替变量法,将多变量优化问题转变为单变量优化问题。其次,分析了起始点的选择、局部最优解的扰动以及信号判决等策略和方法,以得到原问题的较好近似解。最后,通过引入反馈均衡机制,进一步改善了信号分离的性能。
[Abstract]:The separation of single channel mixed signals is one of the important research contents in the field of signal processing. Compared with multi-antenna receiving system, single antenna system has low cost, low energy consumption and simple system design. With the wide application of heterogeneous communication networks, the reuse of spectrum. The occurrence of two or more signals in a single channel is also becoming more and more common, because the mixed signals of single channel are partially or completely overlapped in time domain and frequency domain. Traditional time-domain or frequency-domain filtering methods can not be used to separate mixed signals, so the separation method of multi-component signals received by single channel is studied. In this paper, the separation algorithm of multiple high-order MPSK time-frequency aliasing signals is studied. Based on the construction of a virtual multi-channel model of single-channel mixed signals. The methods of signal separation based on semidefinite relaxation and low-rank semidefinite relaxation are studied. The main work of this paper is as follows: (1) A method of time-frequency mixed signal separation based on semidefinite relaxation is proposed. Firstly, oversampling technique is used. The virtual multi-input multi-output model is constructed, and the discrete value constraints of input signal variables in the original problem are relaxed to semi-definite constraints. Secondly, the interior point method and randomization method are used to solve the semi-definite programming problem. The method of solving the semidefinite programming problem and symbol sequence is designed. Finally, according to the special structure of the virtual multi-channel signal model, the decision feedback equalization mechanism is introduced. The performance of signal separation is improved. (2) A method of time-frequency mixed signal separation based on low-rank semidefinite relaxation single channel is proposed. Firstly, a low-rank semidefinite programming problem is obtained by adding rank 1 constraint to semidefinite programming problem. The alternative variable method is used to transform the multivariable optimization problem into the univariate optimization problem. Secondly, the strategies and methods of selecting the starting point, the disturbance of the local optimal solution and the signal decision are analyzed. Finally, by introducing feedback equalization mechanism, the performance of signal separation is further improved.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN911.7

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