#
HDDM Hardware Evaluation for Robust Interference Mitigation^{ †}

^{*}

^{†}

## Abstract

**:**

## 1. Introduction

## 2. Background

#### 2.1. Interference Signals Analysis

#### 2.2. Pulse Blanking (PB) Methods

#### 2.3. Notch Filter (NF)

#### 2.4. Frequency Domain Adaptive Filtering (FDAF)

#### 2.5. Advanced Mitigation Methods

#### 2.6. High-Rate DFT-Based Data Manipulator (HDDM)

## 3. Implementation

## 4. Experimental Setup

- Interference #1: Slow moving wide-band linear chirp with 35 MHz bandwidth and a chirp repetition rate of 100 μs (Figure 11a,b).
- Interference #2: Fast moving wide-band linear chirp with 35 MHz bandwidth and a chirp repetition rate of 16 μs (Figure 11c,d).
- Interference #3: Combined #1 and #2 interference signals (Figure 11e,f).
- Interference #4: Medium moving out-of-band linear chirp with 10 MHz bandwidth and a chirp repetition rate of 100 μs, this chirp does not overlap with the GNSS signals being tested; however, it still limits the receivers dynamic range.
- Interference #5: Slow frequency hopper with a dwell time of 10 μs and a frequency range of 35 MHz (Figure 12a,b).
- Interference #6: Fast frequency hopper with a dwell time of 1 μs and a frequency range of 35 MHz (Figure 12c,d).
- Interference #7: Slow matched spectrum chirp for a BOC(1,1) signal, with 35 MHz bandwidth and a chirp repetition rate of 100 μs (Figure 12e,f).
- Interference #8: Slow pulsed noise signal, with 35 MHz bandwidth, 500 μs pulse width, and 50% duty cycle (Figure 13a,b).
- Interference #9: Fast pulsed noise signal, with 35 MHz bandwidth, 1 ms pulse width, and 50% duty cycle (Figure 13c,d).
- Interference #10: Single-tone CW at 1 575.42 MHz, i.e., in the center of the GPS L1 frequency band.
- Interference #11: Single-tone CW at 1 576.42 MHz, i.e., 1 MHz above the the center of the GPS L1 frequency band.

## 5. Results

## 6. Discussion

## 7. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## Abbreviations

ADC | analog-to-digital converter |

AltBOC | alternative binary offset carrier |

ANF | adaptive notch filtering |

ARM | Acorn RISC Machine |

ASIC | application-specific integrated circuit |

BOC | binary offset carrier |

BPSK | binary phase-shift keying |

$C/{N}_{0}$ | carrier-to-noise density ratio |

CORDIC | coordinate rotation digital computer |

COTS | commercial-off-the-shelf |

CW | continuous-wave |

DFT | discrete Fourier transform |

DME | distance measurement equipment |

DSP | digital signal processor |

Dual-FDAF | dual-channel frequency-domain adaptive filtering |

FBPB | filter-bank pulse blanking |

FDAF | frequency-domain adaptive filtering |

FFT | fast Fourier transform |

FLL | frequency-locked loop |

FM | frequency-modulation |

FMCW | frequency-modulated continuous-wave |

FPGA | field-programmable gate array |

GNSS | global navigation satellite system |

HDDM | high-rate DFT-based data manipulator |

HW | hardware |

IDFT | inverse discrete Fourier transform |

IF | intermediate-frequency |

IFFT | inverse fast Fourier transform |

IIR | infinite impulse response |

IP | intellectual property |

ISR | interference-to-signal ratio |

JSR | jamming-to-signal ratio |

KLT | Karhunen-Loève transform |

LMS | least mean squares |

LO | local oscillator |

LPF | low pass filter |

LUT | look-up table |

ML | machine learning |

NB | narrow-band |

NF | notch filter |

PB | pulse blanking |

PC | personal computer |

PL | programming logic |

PNT | positioning, navigation, and timing |

PPD | privacy protection device |

PRN | pseudo-random noise |

PS | processing system |

PSD | power spectral density |

PVT | position, velocity, and time |

RF | radio-frequency |

RFCS | radio-frequency constellation simulator |

RFFE | radio-frequency front-end |

RTL | register-transfer level |

SDR | software-defined radio |

SoC | system-on-chip |

SSC | spectral separation coefficient |

STFT | short-time Fourier transform |

SW | software |

SWAP-C | size, weight, power, and cost |

VHDL | very-high-speed integrated circuit hardware description language |

WANF | wavelet-based adaptive notch filter |

WB | wide-band |

## References

- Eliardsson, P.; Alexandersson, M.; Pattinson, M.; Hill, S.; Waern, A.; Ying, Y.; Fryganiotis, D. Results from measuring campaign of electromagnetic interference in GPS L1-band. In Proceedings of the 2017 International Symposium on Electromagnetic Compatibility—EMC EUROPE, Angers, France, 4–7 September 2017; pp. 1–6. [Google Scholar] [CrossRef]
- Van der Merwe, J.R.; Meister, D.; Otto, C.; Stahl, M.; Rügamer, A.; Etxezarreta Martinez, J.; Felber, W. GNSS interference monitoring and characterisation station. In Proceedings of the 2017 European Navigation Conference (ENC), Lausanne, Switzerland, 9–12 May 2017; pp. 170–178. [Google Scholar] [CrossRef]
- Bartl, S.; Berglez, P.; Hofmann-Wellenhof, B. GNSS interference detection, classification and localization using Software-Defined Radio. In Proceedings of the 2017 European Navigation Conference (ENC), Lausanne, Switzerland, 9–12 May 2017; pp. 159–169. [Google Scholar] [CrossRef]
- Marcos, E.P.; Caizzone, S.; Konovaltsev, A.; Cuntz, M.; Elmarissi, W.; Yinusa, K.; Meurer, M. Interference awareness and characterization for GNSS maritime applications. In Proceedings of the 2018 IEEE/ION Position, Location and Navigation Symposium (PLANS), Monterey, CA, USA, 23–26 April 2018; pp. 908–919. [Google Scholar] [CrossRef]
- Hashemi, A.; Thombre, S.; Giorgia Ferrara, N.; Zahidul, M.; Bhuiyan, H.; Pattinson, M. STRIKE3-case study for standardized testing of timing-grade GNSS receivers against real-world interference threats. In Proceedings of the 2019 International Conference on Localization and GNSS (ICL-GNSS), Nuremberg, Germany, 4–6 June 2019; pp. 1–8. [Google Scholar] [CrossRef] [Green Version]
- Hegarty, C.; Van Dierendonck, A.; Bobyn, D.; Tran, M.; Grabowski, J. Suppression of pulsed interference through blanking. In Proceedings of the IAIN World Congress and the 56th Annual Meeting of The Institute of Navigation, San Diego, CA, USA, 26–28 June 2000; pp. 399–408. [Google Scholar]
- Mitch, R.H.; Dougherty, R.C.; Psiaki, M.L.; Powell, S.P.; O’Hanlon, B.W.; Bhatti, J.A.; Humphreys, T.E. Signal characteristics of civil GPS jammers. In Proceedings of the 24th International Technical Meeting of the Satellite Division of the Institute of Navigation, Portland, OR, USA, 19–23 September 2011. [Google Scholar]
- Van der Merwe, J.R.; Garzia, F.; Rügamer, A.; Felber, W. High-rate DFT-based data manipulator (HDDM) algorithm for effective interference mitigation. In Proceedings of the IEEE/ION PLANS, Portland, OR, USA, 20–23 April 2020. [Google Scholar]
- Garzia, F.; Van der Merwe, J.R.; Rügamer, A.; Felber, W. Hardware implementation and evaluation of the HDDM. In Proceedings of the 2020 International Conference on Localization and GNSS (ICL-GNSS), Tampere, Finland, 2–4 June 2020. [Google Scholar]
- Van der Merwe, J.R.; Garzia, F.; Saad, M.; Kreh, B.; Rügamer, A.; Monroy Gonzalez Plata, R.; Felber, W. Receiver bandwidth compression for multi-GNSS signal processing. In Proceedings of the 33rd International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2020), St. Louis, MO, USA, 21–25 September 2020. [Google Scholar]
- Betz, J.W.; Goldstein, D.B. Candidate designs for an additional civil signal in GPS spectral Bands. In Proceedings of the Institute of Navigation Technical Meeting, Portland, OR, USA, 24–27 September 2002. [Google Scholar]
- Kaplan, E.D.; Hegarty, C.J. Understanding GPS: Principles and Applications, 2nd ed.; Artech House Mobile Communications Series; Artech House: London, UK, 2006. [Google Scholar]
- Van der Merwe, J.R.; Rügamer, A.; Felber, W. Simultaneous jamming and navigation pseudolite system. In Proceedings of the 2020 International Conference on Localization and GNSS (ICL-GNSS), Tampere, Finland, 2–4 June 2020; pp. 1–7. [Google Scholar]
- Musumeci, L.; Dovis, F. A comparison of transformed-domain techniques for pulsed interference removal on GNSS signals. In Proceedings of the 2012 International Conference on Localization and GNSS, Starnberg, Germany, 25–27 June 2012; pp. 1–6. [Google Scholar] [CrossRef]
- Borio, D. Swept GNSS jamming mitigation through pulse blanking. In Proceedings of the 2016 European Navigation Conference (ENC), Helsinki, Finland, 30 May–2 June 2016. [Google Scholar]
- Rügamer, A.; Joshi, S.; van der Merwe, J.R.; Garzia, F.; Felber, W.; Wendel, J.; Schubert, F.M. Chirp mitigation for wideband GNSS signals with filter bank pulse blanking. In Proceedings of the 30th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2017), Portland, OR, USA, 25–29 September 2017; pp. 3924–3940. [Google Scholar]
- Borio, D.; Camoriano, L.; Lo Presti, L. Two-pole and multi-pole notch filters: A computationally effective solution for GNSS interference detection and mitigation. IEEE Syst. J.
**2008**, 2, 38–47. [Google Scholar] [CrossRef] - Borio, D.; O’Driscoll, C.; Fortuny, J. Tracking and mitigating a jamming signal with an adaptive notch filter. Inside GNSS
**2014**, 9, 67–73. [Google Scholar] - Wendel, J.; Schubert, F.M.; Rügamer, A.; Taschke, S. Limits of narrowband interference mitigation using adaptive notch filters. In Proceedings of the 29th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2016), Portland, OR, USA, 12–16 September 2016. [Google Scholar]
- Gamba, M.T.; Falletti, E. Performance comparison of FLL adaptive notch filters to counter GNSS jamming. In Proceedings of the 2019 International Conference on Localization and GNSS (ICL-GNSS), Nuremberg, Germany, 4–6 June 2019; pp. 1–6. [Google Scholar] [CrossRef]
- Tsang, C. Operation principle and loss of blanking pulse of the navigation system on Space Shuttle. In Proceedings of the IEEE Conference on Aerospace Applications, Vail, CO, USA, 4–9 February 1990; pp. 93–102. [Google Scholar]
- Powe, M.; Owen, J.I.R. The European GNSS L5/E5 Interference Environment and the Performance of Pulsed Interference Mitigation Techniques. In Proceedings of the 17th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2004), Long Beach, CA, USA, 21–24 September 2004; pp. 122–131. [Google Scholar]
- Gao, G.X. DME/TACAN interference and its mitigation in L5/E5 bands. In Proceedings of the 20th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS 2007), Fort Worth, TX, USA, 25–28 September 2007; pp. 1191–1200. [Google Scholar]
- Van der Merwe, J.R.; Rügamer, A.; Garzia, F.; Felber, W.; Wendel, J. Evaluation of mitigation methods against COTS PPDs. In Proceedings of the 2018 IEEE/ION Position, Location and Navigation Symposium (PLANS), Monterey, CA, USA, 23–26 April 2018; pp. 920–930. [Google Scholar] [CrossRef]
- Borio, D. Sub-band robust GNSS signal processing for jamming mitigation. In Proceedings of the 2018 European Navigation Conference (ENC), Gothenburg, Sweden, 14–17 May 2018; pp. 72–83. [Google Scholar] [CrossRef]
- Borio, D.; Li, H.; Closas, P. Huber’s non-linearity for GNSS interference mitigation. Sensors
**2018**, 18, 2217. [Google Scholar] [CrossRef] [PubMed] [Green Version] - Borio, D.; Closas, P. Robust transform domain signal processing for GNSS. NAVIGATION J. Inst. Navig.
**2019**, 66, 305–323. [Google Scholar] [CrossRef] [Green Version] - Gamba, M.T.; Falletti, E.; Rovelli, D.; Tuozzi, A. FPGA implementation issues of a two-pole adaptive notch filter for GPS/Galileo receivers. In Proceedings of the 25th International Technical Meeting of the Satellite Division of the Institute of Navigation, Nashville, TN, USA, 17–21 September 2012; pp. 3549–3557. [Google Scholar]
- Borio, D. Loop analysis of adaptive notch filters. IET Signal Process.
**2016**, 10, 659–669. [Google Scholar] [CrossRef] - Gamba, M.T.; Falletti, E. Performance analysis of FLL schemes to track swept jammers in an adaptive notch filter. In Proceedings of the 2018 9th ESA Workshop on Satellite Navigation Technologies and European Workshop on GNSS Signals and Signal Processing (NAVITEC), Noordwijk, The Netherlands, 5–7 December 2018; pp. 1–8. [Google Scholar] [CrossRef]
- Van der Merwe, J.R.; Rügamer, A.; Garzia, F.; Felber, W. Wavelet based adaptive notch filtering to mitigate COTS PPDs. In Proceedings of the 32nd International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2019), Miami, FL, USA, 16–20 September 2019. [Google Scholar]
- Raimondi, M.; Julien, O.; Macabiau, C.; Bastide, F. Mitigating pulsed interference using frequency domain adaptive filtering. In Proceedings of the 19th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2006), Fort Worth, TX, USA, 26–29 September 2006. [Google Scholar]
- Ojeda, O.A.Y.; Grajal, J.; Lopez-Risueno, G. Analytical performance of GNSS receivers using interference mitigation techniques. IEEE Trans. Aerosp. Electron. Syst.
**2013**, 49, 885–906. [Google Scholar] [CrossRef] - Zhang, Y.; Wu, H.; Gao, Y. Transform domain interference suppression in GPS/BD-2 receiver based on fractional Fourier transform. In Proceedings of the 26th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2013), Nashville, TN, USA, 16–20 September 2013. [Google Scholar]
- Liu, A.; An, J.; Wang, A. Effect of transform domain interference suppression on PN code tracking loops. In Proceedings of the 2010 IEEE 12th International Conference on Communication Technology, Nanjing, China, 11–14 November 2010; pp. 1064–1067. [Google Scholar] [CrossRef]
- Gabelli, G.; Casile, R.; Guidotti, A.; Corazza, G.E. GNSS Jamming Interference: Characterization and Cancellation. In Proceedings of the 2013 International Technical Meeting of the Institute of Navigation, San Diego, CA, USA, 27–29 January 2013; pp. 828–834. [Google Scholar]
- Wang, W.; Guo, M.; Chen, J.B. A New Narrowband Interference Mitigation Algorithm Based on Adaptive Wavelet Packet Decomposition. In Proceedings of the 2014 Fourth International Conference on Instrumentation and Measurement, Computer, Communication and Control, Harbin, China, 18–20 September 2014; pp. 6–11. [Google Scholar] [CrossRef]
- Dovis, F. GNSS Interference Threats and Countermeasures; Artech House GNSS Technology and Applications Series; Artech House: London, UK, 2015. [Google Scholar]
- Chien, Y.; Chen, P. Wavelet-packet-transform-based adaptive predictor to mitigate GNSS jammers. In Proceedings of the 2015 International Conference on Wavelet Analysis and Pattern Recognition (ICWAPR), Guangzhou, China, 12–15 July 2015; pp. 14–19. [Google Scholar] [CrossRef]
- Amin, M.G.; Borio, D.; Zhang, Y.D.; Galleani, L. Time-Frequency Analysis for GNSSs: From interference mitigation to system monitoring. IEEE Signal Process. Mag.
**2017**, 34, 85–95. [Google Scholar] [CrossRef] - Abdoush, Y.; Pojani, G.; Bartolucci, M.; Corazza, G.E. Time-frequency interference rejection based on the S-transform for GNSS applications. In Proceedings of the 2017 IEEE International Conference on Communications (ICC), Paris, France, 21–25 May 2017; pp. 1–6. [Google Scholar] [CrossRef]
- Querol, J.; Onrubia, R.; Alonso-Arroyo, A.; Pascual, D.; Park, H.; Camps, A. Performance Assessment of Time-Frequency RFI Mitigation Techniques in Microwave Radiometry. IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens.
**2017**, 10, 3096–3106. [Google Scholar] [CrossRef] - Querol, J.; Camps, A. Real-time Pre-correlation Anti-jamming System for Civilian GNSS Receivers. In Proceedings of the 30th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2017), Portland, ON, USA, 25–29 September 2017; pp. 1267–1288. [Google Scholar] [CrossRef]
- Chien, Y.R.; Chen, P.Y.; Fang, S.H. Novel Anti-Jamming Algorithm for GNSS Receivers Using Wavelet-Packet-Transform-Based Adaptive Predictors. IEICE Trans. Fundam. Electron. Commun. Comput. Sci.
**2017**, E100.A, 602–610. [Google Scholar] [CrossRef] - Li, D.; Zhang, P.; Zhao, J.; Cheng, J.; Zhao, H. MP mitigation in GNSS positioning by GRU NNs and adaptive wavelet filtering. IET Commun.
**2019**, 13, 2756–2766. [Google Scholar] [CrossRef] - Vos, E.E.; Francois Luus, P.S.; Finlay, C.J.; Bassett, B.A. A Generative Machine Learning Approach to RFI Mitigation for Radio Astronomy. In Proceedings of the 2019 IEEE 29th International Workshop on Machine Learning for Signal Processing (MLSP), Pittsburgh, PA, USA, 13–16 October 2019; pp. 1–6. [Google Scholar] [CrossRef]
- Van der Merwe, J.R.; Rügamer, A.; Garzia, F. High-Rate DFT-Based Data Manipulator And Data Manipulation Method for High Performance and Robust Signal Processing. European Patent 19163779, 19 March 2019. [Google Scholar]
- Welch, P. The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms. IEEE Trans. Audio Electroacoust.
**1967**, 15, 70–73. [Google Scholar] [CrossRef] [Green Version] - Kootsookos, P.J.; Lovell, B.C.; Boashash, B. A unified approach to the STFT, TFDs, and instantaneous frequency. IEEE Trans. Signal Process.
**1992**, 40, 1971–1982. [Google Scholar] [CrossRef] [Green Version] - Storn, R. Radix-2 FFT-pipeline architecture with reduced noise-to-signal ratio. IEE Proc. Vis. Image Signal Process.
**1994**, 141, 81–86. [Google Scholar] [CrossRef] - Urquijo, S.; Rügamer, A.; Milosiu, H.; Felber, W. Dual-channel Configurable GNSS Receiver Front-end for Wideband Reception. In Proceedings of the 32nd International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS+ 2019), Miami, FL, USA, 16–20 September 2019; pp. 246–255. [Google Scholar]

**Figure 1.**Block diagram for FBPB. ©IEEE. Reprinted, with permission, from [9].

**Figure 2.**Block diagram for FDAF. ©IEEE. Reprinted, with permission, from [8].

**Figure 3.**Block diagram for Dual-FDAF. ©IEEE. Reprinted, with permission, from [8].

**Figure 4.**FFT block selection comparison between different algorithms. ©IEEE. Reprinted, with permission, from [9].

**Figure 5.**HDDM block diagram. ©IEEE. Reprinted, with permission, from [9].

**Figure 6.**Conceptual comparison of mitigation algorithms, with the line thickness representing the computational complexity of different algorithms. Single points are relatively simple algorithms where the complexity is not indicated. This symbolic plot serves to provide an intuitive understanding of the different algorithms.

**Figure 7.**Comparison of triangular register methods. ©IEEE. Reprinted, with permission, from [9].

**Figure 10.**Experimental setup. ©IEEE. Adapted, with permission, from [9].

Receiver Number | # 1 | # 2 | # 3 | |
---|---|---|---|---|

Device Description | 14 bit | 8 bit | 4 bit | |

Xilinx SoC device | Zynq7045 | ZynqUS+ 9EG | ZynqUS+ 9EG | |

Input word-length [bits] | 14 | 8 | 4 | |

PB word-length [bits] | 12 | 12 | 12 | |

Output word-length [bits] | 8 | 4 | 4 | |

Baseband sampling frequency ${f}_{s}$ [MHz] | 108 | 62.5 | 62.5 | |

Max. PL dynamic power [W] | 4.3 | 2.5 | 2 | |

Max. PL static power [W] | 0.3 | 0.7 | 0.7 | |

Module size | N/A | 80 × 60 × 15 mm | 80 × 60 × 15 mm | |

Component | Resource | # 1 | # 2 | # 3 |

Signal Conditioning | Slice LUTs | ~24,000 | ~16,600 | ~23,000 |

DSP | 317 | 219 | 153 | |

HDDM | Slice LUTs | ~17,000 | ~14,000 | ~14,000 |

DSP | 157 | 159 | 129 | |

Mixer | Slice LUTs | 19 | ~700 | ~700 |

DSP | 0 | 0 | 0 | |

LPF | Slice LUTs | ~6000 | ~2000 | ~6000 |

DSP | 152 | 36 | 0 | |

NF | Slice LUTs | 239 | 196 | 210 |

DSP | 8 | 8 | 8 |

Mass-Market Receiver | High-End Receiver | |
---|---|---|

Price | 54 | 895 (eval. kit) |

Power consumption (typ.) | 150 mW | 600 mW |

Module size | 17.0 × 22.4 × 3.5 mm | 31 × 31 × 4 mm |

Interference mitigation capabilities | Unknown | Wideband and CW interferer mitigation |

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Garzia, F.; van der Merwe, J.R.; Rügamer, A.; Urquijo, S.; Felber, W.
HDDM Hardware Evaluation for Robust Interference Mitigation. *Sensors* **2020**, *20*, 6492.
https://doi.org/10.3390/s20226492

**AMA Style**

Garzia F, van der Merwe JR, Rügamer A, Urquijo S, Felber W.
HDDM Hardware Evaluation for Robust Interference Mitigation. *Sensors*. 2020; 20(22):6492.
https://doi.org/10.3390/s20226492

**Chicago/Turabian Style**

Garzia, Fabio, Johannes Rossouw van der Merwe, Alexander Rügamer, Santiago Urquijo, and Wolfgang Felber.
2020. "HDDM Hardware Evaluation for Robust Interference Mitigation" *Sensors* 20, no. 22: 6492.
https://doi.org/10.3390/s20226492