Performance Analysis of Algorithms for NavIC Signal Acquisition

Indian Space Research Organization (ISRO) developed and designed the Indian Regional Navigation Satellite System (IRNSS), an indigenous navigation system.It is named as NavIC, Navigation with Indian Constellation by Indian Prime Minister. NavIC is a seven-satellite constellation that will offer India with accurate positioning, navigation, and timing services. The focal modules of NavIC receiver are acquisition, tracking and navigation unit. The data processing unit for recognising satellite signals and their related code phase and carrier frequency is called acquisition. Various acquisition strategies, such as Serial search and Parallel Code Phase search algorithms, are explored and contrasted with Cooley-Tukey FFT and sub-sampled Fast Fourier transform techniques in this chapter (ssFFT). The acquisition computation time for a ssFFT based NavIC receiver is faster than parallel FFT acquisition, and the Cooley-Tukey FFT IRNSS acquisition algorithm is faster and offers better code phase and carrier frequency values than the serial search acquisition approach, according to the results obtained in MATLAB. Reduction in the acquisition time and computation complexity is observed by the exploitation of properties of sparse FFT, Fourier transform and decimator and by the use of sub sampled FFT.