基于时间交替的高速采集技术研究与实现

发布时间：2018-03-27 23:39

本文选题：时间交替采样　切入点：高速数据采集　出处：《中北大学》2017年硕士论文

【摘要】：数据采集系统广泛运用于电子通信设备、测试测量技术及仪器与雷达等电子系统中。随着电子技术、通信技术和计算机技术的高速发展,所测物理量对实时信号处理的速度和精度的要求不断提高,同时也对数据采集设备的速度和精度提出更高的要求。模数转换器ADC(Analog-to-Digital Converter)的采样率和分辨率直接决定了数据采集系统的采样速度和精度。然而,由于集成电路工艺的限制,模数转换器芯片无法保持较高的采样精度的前提下提高采样速度。时间交替TI(Time-interleaved)采样技术的提出成为了解决这一问题最有效可行的方案之一,能够有效突破单片ADC无法同时提高采样率和分辨率的瓶颈。虽然TIADC系统在保持采样精度不变的同时提高了采样速度,由于多片ADC之间的性能差异、采样间隔非均匀等因素带来了包括时间误差、增益误差和偏置误差的通道失配误差。这些误差将会导致对采集到的信号进行重建时产生诸如时域波形失真、引入频谱混叠、降低系统信噪比等问题,从而影响采样信号的精确重构和分析。本文通过分析TIADC系统的原理和数学模型,运用Matlab软件分析通道失配误差的频谱特性,根据分析结果提出误差校正算法。通过设计模拟信号输入模块、时钟产生模块、时间交替采样的模数转换模块、逻辑控制及数据缓存模块实现了12bit、400Msps高速数据采集系统。该系统将采集到的数据上传到上位机进行分析,并通过误差校正算法对采集到的数据进行误差校正。仿真与测试结果表明系统数据采集功能正常,误差校正算法滤除了由通道失配误差引起的时域波形中的毛刺噪声和频谱中的谐波失真,同时提高了系统动态参数,验证了设计的可行性和算法的有效性。
[Abstract]:Data acquisition systems are widely used in electronic communication equipment, test and measurement technology, and electronic systems such as instruments and radar. With the rapid development of electronic technology, communication technology and computer technology, The requirements for the speed and accuracy of the real time signal processing are constantly improved. The sampling rate and resolution of the analog-to-digital converter (ADC(Analog-to-Digital) directly determine the sampling speed and precision of the data acquisition system. However, due to the limitation of the integrated circuit technology, the speed and accuracy of the data acquisition system are also required. The ADC chip can not keep high sampling precision and improve the sampling speed. The time alternating time interleaved sampling technology has become one of the most effective and feasible solutions to this problem. It can effectively break through the bottleneck that monolithic ADC can not increase the sampling rate and resolution simultaneously. Although the TIADC system not only keeps the sampling accuracy unchanged, but also improves the sampling speed, because of the performance difference between multi-chip ADC, The non-uniform sampling interval brings channel mismatch errors including time error, gain error and bias error. These errors will lead to the distortion of the acquired signal such as time domain waveform distortion and the introduction of spectrum aliasing. In this paper, the principle and mathematical model of TIADC system are analyzed, and the spectrum characteristics of channel mismatch error are analyzed by Matlab software. According to the analysis results, an error correction algorithm is proposed. The analog signal input module, the clock generation module, the time alternating sampling A / D conversion module are designed. The logical control and data cache module implements a 12bit-400 Msps high-speed data acquisition system, which uploads the collected data to the upper computer for analysis. The data collected is corrected by error correction algorithm. The simulation and test results show that the data acquisition function of the system is normal. The error correction algorithm filters the burr noise in the time-domain waveform and the harmonic distortion in the spectrum caused by the channel mismatch error. At the same time, it improves the dynamic parameters of the system and verifies the feasibility of the design and the validity of the algorithm.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN792

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