scholarly journals Cascaded Multitype Interferences Suppression Method Using Sparse Representation and Array Processing for GNSS Receiver

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Qiang Guo ◽  
Liangang Qi
Keyword(s):  
Sparse Representation ◽  
Array Processing ◽  
Matching Pursuit ◽  
Interference Suppression ◽  
Satellite System ◽  
Signal Interference ◽  
Wideband Interference ◽  
Interference Signals ◽  
Suppression Method ◽  
Global Navigation Satellite

Interference suppression techniques have been intensively studied in nearly two decades due to their importance for maintaining the integrity and functionality of global navigation satellite system (GNSS). However, the interference suppression method applicable for the complex receiving environment in which there are multitype interfering signals has not been considered in most of the researches. To deal with this problem better, a cascaded multitype interferences suppression method using sparse representation and array processing is proposed. In the first stage, according to the sparsity of the narrowband and modulated wideband interference signals, a novel parallel multichannel signal interference suppression method based on matching pursuit (MP) algorithm and a design strategy for the overcomplete dictionary are proposed to mitigate the interferences with sparse features. Then, the minimum power distortionless response (MPDR) beamformer is employed in the second stage to suppress the residuary interferences (such as Gaussian noise interferences). Compared with existing algorithms, the proposed method can not only effectively suppress the interference arriving from the same direction with the desired signal and increase the Degree of Freedom (DoF) of the array antenna, but also introduce no distortion into the navigation signal. The effectiveness of the proposed method is illustrated by theoretical analysis and several simulation results.

The Application of a Linear FM Interference Suppression in DSSS Technology Systems

2014 ◽  
Vol 644-650 ◽  
pp. 4599-4602
Author(s):  
Gang Fu ◽  
Jian Hua Lin ◽  
Qian He
Keyword(s):  
Spread Spectrum ◽  
Communication System ◽  
Interference Suppression ◽  
Direct Sequence Spread Spectrum ◽  
Signal Interference ◽  
Interference Signal ◽  
Direct Sequence ◽  
Research Focus ◽  
Wideband Interference ◽  
Suppression Technique

Spread spectrum communication system wideband interference suppression technique has drawn increasing attention. In this paper, the typical broadband interference signal interference LFM (Linear Frequency-Modulated, LFM), for example, the results of research focus and reviews the current direct sequence spread spectrum (Direct Sequence Spread Spectrum, DSSS) system wideband interference suppression.

scholarly journals Space-Time-Frequency Adaptive Processor for Multiple Interference Suppression in GNSS Applications

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Qiang Guo ◽  
Lian-gang Qi ◽  
Jianhong Xiang
Keyword(s):  
Interference Suppression ◽  
Satellite System ◽  
Space Time ◽  
Similar Frequency ◽  
Time Frequency ◽  
Weight Calculation ◽  
Global Navigation Satellite ◽  
Short Time ◽  
Multiple Interference ◽  
Adaptive Processor

To enhance the multiple interference suppression performance of global navigation satellite system (GNSS) receivers without extra antenna elements, a space-time-frequency adaptive processor (STFAP) is investigated. Firstly, based on the analysis of the autocorrelation function of the multicomponent signal, we propose a common period estimation and data block technique to segment the received signal data into blocks. Secondly, the signal data in each block are short-time Fourier transformed into time-frequency (TF) domain, and the corresponding TF points with similar frequency characteristics are regrouped to structure space-time-frequency (STF) data matrixes. Finally, a space-time-frequency minimum output power- (STF-MOP) based weight calculation method is introduced to suppress multiple interfering signals according to their sparse characteristics in TF and space domains. Simulation results show that the proposed STFAP can effectively combat more wideband periodic frequency-modulated (WBPFM) interferences even some of them arriving from the same direction as GNSS signals without increasing the number of antenna elements.

scholarly journals Experimental Evaluation of the Impact of Different Types of Jamming Signals on Commercial GNSS Receivers

2020 ◽  
Vol 10 (12) ◽  
pp. 4240 ◽  
Author(s):  
Haidy Elghamrawy ◽  
Malek Karaim ◽  
Mohamed Tamazin ◽  
Aboelmaged Noureldin
Keyword(s):  
Satellite System ◽  
Signal Interference ◽  
Interference Signal ◽  
Long Distance ◽  
Wideband Signals ◽  
Global Positioning ◽  
Gnss Receivers ◽  
Propagation Medium ◽  
Global Navigation Satellite ◽  
The Impact

The received global navigation satellite system (GNSS) signal has a very low power due to traveling a very long distance and to the nature of the signal’s propagation medium. Thus, GNSS signals are easily susceptible to signal interference. Signal interference can cause severe degradation or interruption in GNSS position, navigation, and timing (PNT) services which could be very critical, especially in safety-critical applications. The objective of this paper is to evaluate the impact of the presence of jamming signals on a high-end GNSS receiver and investigate the benefits of using a multi-constellation system under such circumstances. Several jamming signals are considered in this research, including narrowband and wideband signals that are located on GPS L1 or GLONASS L1 frequency bands. Quasi-real dynamic trajectories are generated using the Spirent™ GSS6700 GNSS signal simulator combined with an interference signal generator through a Spirent™ GSS8366 unit. The performance evaluation was carried out using several evaluation metrics, including signal power degradation, navigation solution availability, dilution of precision (DOP), and positioning accuracy. The multi-constellation system presented better performance over the global positioning system (GPS)-only constellation in most cases. Moreover, jamming the GPS band caused more critical effects than jamming the GLONASS band.

scholarly journals Low-Complexity Spatial-Temporal Filtering Method via Compressive Sensing for Interference Mitigation in a GNSS Receiver

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Chung-Liang Chang ◽  
Guo-Shing Huang
Keyword(s):  
Compressive Sensing ◽  
Interference Mitigation ◽  
Low Complexity ◽  
Satellite System ◽  
Minimum Variance ◽  
Graphic User Interface ◽  
Gnss Receiver ◽  
Minimum Variance Distortionless Response ◽  
Wideband Interference ◽  
Global Navigation Satellite

A compressive sensing based array processing method is proposed to lower the complexity, and computation load of array system and to maintain the robust antijam performance in global navigation satellite system (GNSS) receiver. Firstly, the spatial and temporal compressed matrices are multiplied with array signal, which results in a small size array system. Secondly, the 2-dimensional (2D) minimum variance distortionless response (MVDR) beamformer is employed in proposed system to mitigate the narrowband and wideband interference simultaneously. The iterative process is performed to find optimal spatial and temporal gain vector by MVDR approach, which enhances the steering gain of direction of arrival (DOA) of interest. Meanwhile, the null gain is set at DOA of interference. Finally, the simulated navigation signal is generated offline by the graphic user interface tool and employed in the proposed algorithm. The theoretical analysis results using the proposed algorithm are verified based on simulated results.

scholarly journals The Unbiased Characteristic of Doppler Frequency in GNSS Antenna Array Processing

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Yuchen Xie ◽  
Zhengrong Li ◽  
Feiqiang Chen ◽  
Huaming Chen ◽  
Feixue Wang
Keyword(s):  
Antenna Array ◽  
Carrier Phase ◽  
Array Processing ◽  
Doppler Frequency ◽  
Low Complexity ◽  
Satellite System ◽  
Accurate Estimation ◽  
Array Technology ◽  
Gnss Receivers ◽  
Global Navigation Satellite

The antenna array technology, especially the spaced-time array processing (STAP), is one of the effective methods used in Global Navigation Satellite System (GNSS) receivers to refrain the power of jamming and enhance the performance of receivers in the circumstance of interference. However, biases induced to the receiver because of many reasons, including characteristic of antennas, front-end channel electronics, and space-time filtering, are extremely harmful to the high precise positioning of receivers. Although plenty of works have been done to calibrate the antenna and to mitigate these biases, achieving a good performance of antijamming, high accuracy, and low complexity at the same time still remains challenging. Different from existing works, this paper leverages the characteristic of GNSS signal’s Doppler frequency in STAP, which is proven to remain unbiased to solve the problem, even when the nonideal antennas are used and the interference circumstance changes. Since the integration of frequency is carrier phase, the unbiased Doppler frequency leads to an accurate estimation of carrier phase which can be used to calibrate the antenna array without extra apparatus or complicating algorithms. Therefore, a simple Doppler-aid strategy may be developed in the future to solve the difficulty of STAP bias mitigation.

scholarly journals A Nonlinear Transfer Function Based Receiver for Wideband Interference Suppression

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Kuangyuan Ying ◽  
Hao Gao ◽  
Dusan Milosevic ◽  
Peter Baltus
Keyword(s):  
Transfer Function ◽  
Interference Suppression ◽  
Interference Signal ◽  
Nonlinear Method ◽  
Receiver System ◽  
Nonlinear Transfer ◽  
Wideband Interference ◽  
Frequency Independent ◽  
Interference Signals ◽  
Multimode Operation

Wideband receivers for multistandards operation can simplify the system and lower the cost. In a wideband receiver, the tolerance of large interference signal within the operating band is important. Traditional frequency-domain filtering suffers from lacking in filtering capability for in-band interference signals. This paper describes a receiver system exploiting nonlinear transfer function. Based on the fundamental nonlinear theory, the receiver with nonlinear method can provide frequency-independent filtering for large blockers and linear amplification for weak desired signals simultaneously. The interference suppression performance depends on the amplitude discrimination between the envelope of the large and small signal. The operation of the nonlinear receiver is based on the amplitude of the interferer envelope. A feedforward path is designed to extract the envelope information of the interferer and a feedback path is added to keep track of the environment. With frequency-independent filtering, the nonlinear receiver system enhances both in-band and out-of-band linearity, thus enabling wideband multimode operation.

Compact antenna array receiver for robust satellite navigation systems

2014 ◽  
Vol 7 (6) ◽  
pp. 735-745 ◽  
Author(s):  
S. Irteza ◽  
E. Schäfer ◽  
R. Stephan ◽  
A. Hornbostel ◽  
M. A. Hein
Keyword(s):  
Antenna Array ◽  
Degrees Of Freedom ◽  
Satellite System ◽  
Navigation Systems ◽  
Matching Network ◽  
Compact Antenna ◽  
Interference Signals ◽  
Satellite Navigation Systems ◽  
Global Navigation Satellite ◽  
The Impact

A compact navigation receiver comprising a decoupled and matched four-element L1-band antenna array with an inter-element separation of a quarter of the free-space wavelength is presented in this paper. We investigate the impact of the decoupling and matching network on the robustness of the navigation receiver. It is observed that in order to achieve high robustness with a compact antenna array, it is necessary to employ a decoupling and matching network, particularly in case of three spatially separated interferers. Furthermore, we study the influence of the polarization impurity of the compact planar antenna array on the equivalent carrier-to-interference-plus-noise ratio (CINR) of the receiver when impinged with different numbers of diametrically polarized interference signals. It is shown that the higher-order modes possess strong polarization impurity, which may halve the available degrees-of-freedom for nulling in the presence of linear-polarized interferers, using a conventional null-steering algorithm. We verify the robustness of the designed compact receiver by means of a complete global-navigation-satellite-system demonstrator. It is shown that the maximum jammer power that is allowed us to maintain the CINR above 38 dBHz with three interferers can be improved by more than 10 dB if a decoupling and matching network is employed.

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