Hardware Implementation and RF High-Fidelity Modeling and Simulation of Compressive Sensing Based 2D Angle-of-Arrival Measurement System for 2–18 GHz Radar Electronic Support Measures

Abstract

This article presents the hardware implementation and a behavioral model-based RF system modeling and simulation (M&S) study of compressive sensing (CS) based 2D angle-of-arrival (AoA) measurement system for 2–18 GHz radar electronic support measures (RESM). A 6-channel ultra-wideband RF digital receiver was first developed using a PXIe-based multi-channel digital receiver paired with a 6-element random-spaced 2D cavity-backed-spiral-antenna array. Then the system was tested in an open lab environment. The measurement results showed that the system can measure AoA of impinging signals from 2–18 (GHz) with overall RMSE of estimation at 3.60, 2.74, 1.16, 0.67 and 0.56 (deg) in L, S, C, X and Ku bands, respectively. After that, using the RF high-fidelity M&S (RF HF-M&S) approach, a 6-channel AoA measurement system behavioral model was also developed and studied using a radar electronic warfare (REW) engagement scenario. The simulation result showed that the airborne AoA measurement system could successfully measure an S-band ground-based target acquisition radar signal in the dynamic REW environment. Using the RF HF-M&S model, the applicability of the system in other frequencies within 2–18 (GHz) was also studied. The simulation results demonstrated that the airborne AoA measurement system can be used for 2–18 GHz RESM applications.

Accumulatively Increasing Sensitivity of Ultrawide Instantaneous Bandwidth Digital Receiver with Fine Time and Frequency Resolution for Weak Signal Detection

“…The parameters used in the study were (1) ADC sampling frequency was at 2.56 GHz, (2) since the real samples were used in the FFT, the single-tone CW signal frequency was randomly picked within 100 and 1180 MHz in each calculation, hence the DRX IBW was about 1080 MHz, and (3) the data lengths used in FFT were from 2 5 to 2 20 . The signal detection in this study was defined as not only the peak signal in a frequency-bin being higher than the threshold, but also the frequency-bin location should be within ±3 bins of the input signal frequency.…”

“…The details of the threshold calculation can be found in the Chapter 6 of [9], which will also be briefly discussed in Section 5, when we develop the time-slot-based thresholds for AIRS. Figure 1 shows the calculated thresholds for P f as of 10 −7 versus the length of FFT from 2 5 to 2 20 . Using the parameters given above, Figure 2 shows the POD with P f as of 10 −7 , when the Input-SNR before FFT is against different lengths of FFT.…”

“…In parallel to the ADC development, very large or long-length FFT on FPGA have been studied for non-real-time applications. Kanders and Mellqvist [15] introduced onemillion-point (2 20 ) FFT that was implemented on a single FPGA with a throughput of 233 MSamples/Sec and 95.6 dB signal to quantization noise ratio. FPGA-based 4-channel with about 2 17 -point FFT was introduced in [16] for space-based synthetic aperture radar application.…”

“…FPGA-based 4-channel with about 2 17 -point FFT was introduced in [16] for space-based synthetic aperture radar application. For biology, astronomy, and medical imaging applications, an FPGA-based high-throughput 2 20 -point sparse Fourier transform was presented in [17], which can be applied on frequency-sparse data to generate the latest 500 frequency locations and values every 1.16 millisecond. Its FPGA implantation can process streamed input at 0.86 GSamples/Sec.…”

“…The signal detection can be progressive, or the DRX sensitivity can be cumulatively increased, while the new time-slot data is becoming available from the ADC and being processed by the BFFT-based TTFT. As soon as the signal amplitudes/powers in certain frequency-bins are higher than a certain threshold, the signal detections can be asserted [19,20]. Since large frequency-bins are used in the given IBW and time-slot-based signal detection is used, the AIRS-based DRX can achieve both fine TMR and FMR.…”