Effect of pulse blanking on navigation data demodulation performance in GNSS system

Abstract

The paper addresses the impact of the most common pulsed interference countermeasure, the pulse blanking, on the data demodulation stages of the GNSS receiver. Few works in the literature deal with this aspect, taking into account not only the / 0 drop but the impact of the coding strategy and the structure of the navigation message. In several works the structure of the navigation message is provided as a fact. The following paper investigates how some of the parameters (e.g. data rate) in Direct Sequence Spread Spectrum (DS-SS) systems could be optimized together with the pulse blanking parameters in order to improve the robustness to the interference in future evolutions of GNSS systems. After a brief general review of the DS-SS modulation, this paper will provide a description of the impact of the pulse blanking mitigation algorithm on the data demodulation performance for both un-coded and coded DS/BPSK systems. In particular, theoretical derivation of the expected Bit Error Rate (BER) will be provided. Theoretical derivation is supported by a set of fully software simulations, thanks to the use of a fully and flexible DS-BPSK system simulator developed during research activity.

An Assessment of Impact of Adaptive Notch Filters for Interference Removal on the Signal Processing Stages of a GNSS Receiver

“…Many precorrelation approaches have been proposed so far in the literature based on the techniques in the time domain [6], [7], the frequency domain [8], the time-frequency domain [9], and the transformed domain [10], [11]. The adaptive filter techniques can be implemented for interference suppression [12], among which the infinite impulse response (IIR)-based adaptive notch filter (ANF) is particularly appealing due to its low complexity and low computational load [13], [14].…”