基于压缩感知的脉冲超宽带系统的检测器设计

发布时间：2018-05-14 11:26

本文选题：压缩感知 + 脉冲超宽带系统　；参考：《电子科技大学》2014年硕士论文

【摘要】：近年来,人们对所有类型的无线服务的需求急剧上升,未来无线通信市场还将会得到大幅度扩张。频带等资源的稀缺性制约着无线通信的发展,而UWB系统可以与其他系统分享频带并且能够在低功率下运行,因此具有很高的应用前景。本文将主要关注脉冲超宽带系统(IR-UWB)系统的检测器设计领域。高速率采样是IR-UWB检测器面临的一个主要挑战。近年来,压缩感知技术在超宽带领域的应用越来越受到瞩目。压缩感知是一种新兴的信号处理技术,利用信号的稀疏性以及相关的重构算法极大的降低了采样速率。而基于压缩感知的检测器所要求的采样速率远低于传统的奈奎斯特速率,使其在功能实现上更加简洁,并且具有非常高的性能表现。但是,这种检测器不是专门为IR-UWB信号所设计。另外,这种检测器要求大量的相关器去捕捉信号能量,具体实现上有一定难度。本文首先把基于压缩感知的检测器和能量检测器进行比较,结果证明如果基于压缩感知的检测器在具备足够相关器的条件下,其性能超越能量检测器。然后,本文提出一种广义压缩感知检测器,通过在模拟数字转化器(ADC)能够支持的范围内提高采样率,可以减少所要求相关器的数量。同样,本文研究了伪随机相关器的码率对压缩感知检测器性能的影响,给出了当码率低于奈奎斯特速率时的检测概率边界。最后,本文设计了一种更适合于IR-UWB信号的基于压缩感知的结构化相关器,并且推导出该相关器的性能极其边界。相关仿真结果显示使用这类相关器的压缩感知检测器在IR-UWB系统中比使用传统的基于相关器的检测器更具优势。
[Abstract]:In recent years, the demand for all types of wireless services has risen sharply, and the wireless communication market will expand greatly in the future. The scarcity of resources such as frequency band restricts the development of wireless communication, and UWB system can share the frequency band with other systems and can operate under low power, so it has a high application prospect. This paper will focus on the design of IR-UWB system detector. High rate sampling is a major challenge for IR-UWB detectors. In recent years, the application of compressed sensing technology in UWB has attracted more and more attention. Compression sensing is a new signal processing technology, which greatly reduces the sampling rate by using the sparse signal and related reconstruction algorithms. The compression sensing detector requires a much lower sampling rate than the traditional Nyquist rate, which makes it more concise in the functional implementation and has a very high performance. However, this detector is not specifically designed for IR-UWB signals. In addition, the detector requires a large number of correlators to capture signal energy, which is difficult to implement. In this paper, the compression sensing based detector and the energy detector are compared. The results show that if the compression sensing based detector has enough correlators, its performance surpasses the energy detector. Then a generalized compression sensing detector is proposed which can reduce the number of required correlators by increasing the sampling rate within the range supported by the analog digital converter (ADC). The influence of the bit rate of pseudorandom correlator on the performance of compression sensing detector is also studied in this paper. The detection probability boundary is given when the bit rate is lower than Nyquist rate. Finally, a compressing aware structured correlator is designed for IR-UWB signals, and the performance of the correlator is derived. Correlation simulation results show that the compression sensing detector using this kind of correlator is superior to the traditional correlating-based detector in IR-UWB system.
【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】：TN925

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