Signal Processing

Efficient real-time signal processing algorithms and hardware are crucial for modern instrumentation, imaging, and communication systems. The NDSU signal processing group develops software and hardware approaches necessary to realize power- and cost-effective solutions for various applications such as structural health monitoring, biomedical imaging, and others.

Current research themes:

  1. Development of improved algorithms for electrochemical impedance spectroscopy (EIS), particularly as applied to portable health monitoring of corrosion. Activities include development of (a) real-time performance monitors and parameter adjustment for DSP-based EIS systems, (b) low peak-factor pseudo-logarithmically spaced multi-frequency test signals for DSP-based EIS systems, and (c) optimization of multisine excitations for receiver undersampling. Elements of the multisine EIS techniques developed at NDSU now appear in commercial EIS instrumentation from Gamry Instruments as part of their OptiEIS application.
  2. Collaborative development of signal processing algorithms for an asynchronous cell array chip with Dr. Mark Pavicic at the NDSU Center for Nanoscale Science and Engineering (CNSE). The cell array chip (US Patent 7,956,639) is asynchronous and spatially programmed, both of which are unusual features of signal processing hardware.  The architecture is well suited to bit-serial processing as well as multi-rate signal processing applications, which form the focus of current research efforts. Previously, the NDSU signal processing group successfully collaborated with Dr. Pavicic on the characterization and calibration of a parallel clockless transient waveform digitizer.
  3. Development of efficient algorithms for biomedical signal processing, including the development of (a) a modified Goertzel structure for efficient real-time blood velocity profile estimation and (b) DSP-based pulse-doppler blood flow measurement using software gating. Both projects achieved significant improvements in processing efficiency.
  4. Development of calibration and other mechanisms for communication systems, including development of (a) internal calibration techniques for quadrature receiver mismatch errors and (b) a vector calibration system (US Patent 7,088,765).  Additional efforts include optimal basestation configuration for dual-coverage and other cellular/wireless  applications.

Group members: Roger Green

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