Spectrum Monitoring Using SpectrumAnalysis LabVIEW Software, Nanoceptors, and Various Digitizing Solutions

: High-speed spectrum sensing is a key component in numerous radar applications and can be accomplished by using modern digitizers paired with radios. This effort uses a gallium-germanium (GaGe) 16-bit, 200-MS/s Peripheral Component Interconnect Express (PCIe) digitizer for spectrum sensing. The digitizer rapidly captures 40-MHz-wide snapshots of the spectrum, which are first filtered and down-converted by a SI-8614 Nanoceptor(trademark) receiver and then processed using LabVIEW virtual instruments (VIs), optimized to achieve near-continuous capture rates and less hardware intensive real-time monitoring. For optimal capture rates, I use a LabVIEW producer-consumer loop; the producer loop quickly adds data to a queue (captured from the digitizer) and the consumer loop pulls data off the queue to process it at an often slower pace (using CUDA to perform multi-channel fast Fourier transform [FFT] computations). Apart from wideband spectrum sensing, this hardware configuration is also useful for detecting nonlinear targets. A higher resolution digitizer, the NI PXI-5922, is integrated and used to measure harmonics as low as 130 dBm while maintaining the ability to capture higher power fundamental signals. The use of 24-bit high fidelity audio cards is investigated for viability as a low-cost, high resolution digitizing solution for similar narrowband applications.