MRI: Acquisition of High Speed Mixed Signal Test Equipment

EIA 02- 15753 Collins，OliverUniversity of Notre Dame MRI：高速混合信号测试设备的获取本提案研究正交和Σ-Δ调制/解调，支持通信/信号处理研究，以使用模拟器进行实验验证。实验验证的新想法，在Σ-Δ数模和模数转换将进行探讨。Σ-Δ调制允许一个本质上线性的两电平量化器通过将量化噪声从信号频带移走以便通过滤波去除来再现高分辨率信号。 Σ-Δ调制器试图找到+1和-1的最佳序列，使得在滤波之后，该+1和-1的序列与给定的、相同滤波的、离散时间的、单位幅度限制的序列滤波之间的平方欧几里德距离被最小化。这项研究的目的是表明，Σ-Δ调制构成了一个粗糙的优化算法，切实可行的技术解决了这个优化问题，足以提高动态范围超出目前的最先进的PI声称，实质性的改善几乎肯定会暴露出固有的非理想性，甚至单比特量化器。由于其输出端阻抗匹配不完美的反射会产生位与位之间的相互作用，因此即使是单个位D到A也会产生噪声和杂散信号。所要求的设备，三件高速，混合信号测试：数据发生器，网络分析仪和信号分析仪，将允许调查这些影响，并允许更好的单比特和多比特量化器的设计。 数据发生器将被用作波分复用项目中的激励源;网络分析仪的上级范围将有助于微波遥感项目。预计模数和数模带宽和动态范围将有所改善。当数字计算必须连接到物理世界时，设备是重要的（例如，获得天线辐射的模拟信号）。由于数字革命依赖于这些转换，因此接口对于发送和存储信息至关重要。提高依赖于这些转换的制造系统的性能和降低复杂性，如个人CD播放机、蜂窝电话、高清晰度电视、计算机调制解调器、深度通信系统，将使我们所有人受益。此外，除了支持研究外，这些设备还将支持三门本科课程中的增强项目，并有助于使学生对行业具有吸引力，以便雇用和指导所需的设计项目。

EIA 02-15753Collins, OliverUniversity of Notre DameMRI: Acquisition of High Speed Mixed Signal Test Equipment This proposal, studying quadrature and Sigma Delta modulation/demodulation, supports communications/signal processing research for experimental validation using simulators. Experimental verification of new ideas in Sigma Delta digital-to-analog and analog-to-digital conversion will be explored. Sigma Delta modulation allows an intrinsically linear two level quantizer to reproduce a high resolution signal by shifting the quantization noise away from the signal band for removal by filtering. The Sigma Delta modulator tries to find the optimal sequence of +1's and -1's such that, after filtering, the squared Euclidean distance between this sequence of +1's and -1's and a given, identically filtered, discrete-time, unity-amplitude-limited sequence filtering is minimized. The research aims to show that Sigma Delta modulation constitutes a crude optimization algorithm and that practicable techniques solve this optimization problem well enough to improve dynamic range beyond the current state-of-the-art. The PI claims that the substantial improvement will almost certainly expose the inherent nonidealities of even single bit quantizers. Because of the bit-to-bit interactions produced by reflections from imperfect impedance matches at its output, even single bit D to A generates noise and spurious signals. The equipment requested, three pieces of high speed, mixed signal test: a data generator, a network analyzer, and a signal analyzer, will allow investigation of these effects and permit the design of better single- and multiple-bit quantizers. The data generator will be used as a stimulus source in a wavelength division multiplexing project; the superior range of the network analyzer will contribute to a microwave remote sensing project. Improvement in analog-to-digital and digital-to-analog bandwidth and dynamic range is expected. The devices are important whenever digital computation must be interfaced to physical world (e.g., getting the analog signal radiated by an antenna). Since the digital revolution depends on these conversions, the interface is critical to send and store information. Improved performance and reduced complexity in manufacturing systems that depend on these conversions, such as personal CD players, cellular telephones, high definition TV, computer modems, deep communication systems would benefit us all. Moreover, in addition to supporting research, the equipment will support enhanced projects in three undergraduate courses and contribute to make the students attractive to industry for both hiring and mentoring the required design projects.