  This paper presents the new generation of LabVIEW-based GPS receiver testbed
that is based on National Instruments' (NI) LabVIEW (LV) platform in
conjunction to C/C++ dynamic link libraries (DLL) used inside the platform for
performance execution. This GPS receiver has been optimized for real-time
operation and has been developed for fast prototyping and easiness on future
additions and implementations to the system. The receiver DLLs are divided into
three baseband modules: acquisition, tracking, and navigation. The openness of
received baseband modules allows for extensive research topics such as signal
quality improvement on GPS-denied areas, signal spoofing, and signal
interferences. The hardware used in the system was chosen with an effort to
achieve portability and mobility in the SDR receiver. Several acceleration
factors that accomplish real-time operation and that are inherent to LabVIEW
mechanisms, such as multithreading, parallelization and dedicated
loop-structures, are discussed. The proposed SDR also exploits C/C++
optimization techniques for single-instruction multiple-data (SIMD) capable
processors in software correlators for real-time operation of GNSS tracking
loops. It is demonstrated that LabVIEW-based solutions provide competitive
real-time solutions for fast prototyping of receiver algorithms.
