Abstract
Adaptive antenna array processing is widely known to provide significant anti-interference capabilities within a Global Navigation Satellite Systems (GNSS) receiver. A main challenge in the quest for such receiver architecture has always been the computational/processing requirements. Even more demanding would be to try and incorporate the flexibility of the Software-Defined Radio (SDR) design philosophy in such an implementation. This paper documents a feasible approach to a real-time SDR implementation of a beam-steered GNSS receiver and validates its performance. This research implements a real-time software receiver on a widely-available x86-based multi-core microprocessor to process four-element antenna array data streams sampled with 16-bit resolution. The software receiver is capable of 12 channels all-in-view Controlled Reception Pattern Antenna (CRPA) array processing capable of rejecting multiple interferers. Single Instruction Multiple Data (SIMD) instructions assembly coding and multithreaded programming, the key to such an implementation to reduce computational complexity, are fully documented within the paper. In conventional antenna array systems, receivers use the geometry of antennas and cable lengths known in advance. The documented CRPA implementation is architected to operate without extensive set-up and pre-calibration and leverages Space-Time Adaptive Processing (STAP) to provide adaptation in both the frequency and space domains. The validation component of the paper demonstrates that the developed software receiver operates in real time with live Global Positioning System (GPS) and Wide Area Augmentation System (WAAS) L1 C/A code signal. Further, interference rejection capabilities of the implementation are also demonstrated using multiple synthetic interferers which are added to the live data stream.
Highlights
Global Navigation Satellite Systems (GNSS) signals are relatively weak and vulnerable to deliberate or unintentional interference [1]
Once the N channels assigned to a given satellite are simultaneously tracked, the Integrated Carrier Phase (ICP) are initialized by filtered phases of the in-phase (I) and quadrature (Q) components of correlator outputs
This paper describes the implementation of a software receiver for GPS/Wide Area Augmentation System (WAAS) L1 C/A code signals to demonstrate the feasibility of Controlled Reception Pattern Antenna (CRPA) technology for civil applications
Summary
Global Navigation Satellite Systems (GNSS) signals are relatively weak and vulnerable to deliberate or unintentional interference [1]. Developed a four-element antenna array and front-ends for dual-band L1/L5 signals They implemented a MATLAB-based software receiver for field test of adaptive beamforming algorithms with directions of satellites calculated from DoA estimation. The key contributions of this paper are summarized as follows: (a) this is the first published work which demonstrates a real-time all-in-view CRPA software receiver running on a CPU but describes the implementation in significant detail with actual code examples critical to the architecture;. This information is not necessary for beamforming in our approach but it can be useful to illustrate the functionality of the receiver Based on this bias information, which is used to generate a simplified antenna model, angle-frequency responses are calculated accurately to show the functionality of the implemented STAP in the spatial and temporal domains in the presence of multiple interferers with different bandwidths. The results demonstrate the performance of the software receiver under multiple interferers in the spatial and temporal domains
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
