Indoor Adaptive GNSS Signal Acquisition. Part 1: Theory and Simulations

Abstract

Indoors, GNSS signal encounters severe multipath power loss and fading which leads to significant signal degradation of the amplitude and phase to perform GPS (or GNSS) signal acquisition. To overcome these effects, piling up received GPS (or GNSS) data is a traditional (or conventional) method; however, it exhibits two shortcomings (drawbacks or limitations): instable detection performance, such as the probability of false alarm (PFA) fluctuates due to changes of the signal-to-noise ratio (SNR); and elongated acquisition time caused by extended accumulation duration and over repetitive FA occurrence (or "penalty"). To overcome the first shortcoming, an adaptive structure is employed in GNSS signal acquisition that enables constant FA rate (CFAR) criteria to guarantee a stable detection performance on the GNSS signal acquisition. To overcome the second shortcoming, an adaptive determination on accumulation length is employed to minimize the accumulation duration; therefore, a double-dwell structure (DDS) is used to reduce the processing time "penalty" caused by FA. Simulation results illustrate that an adaptive, stable detection implementation and DDS reduce the average acquisition time by almost fifty percent (or by half or a factor of two).

Advanced Anti-Jam Indoor Adaptive GNSS Signal Acquisition: Part 1, Normal Distribution--Theory and Simulations

“…The main purpose of this paper is to provide insights as to whether a Bayesian parameter estimation algorithm combined with Markov Chain, Monte Carlo global search [3]- [6] is a suitable algorithm to improve the performance of a double-dwell structure (DDS) [7] against interference and/or jamming.…”

“…In this section, a brief introduction of DDS in GPS signal acquisition is discussed because of the obvious advantage of DDS lies in reducing the average acquisition time by lowering "penalty" time caused by false alarm (FA) and tracking loss (TL) [7]. [7].…”

“…By comparing and contrasting the two combination methods (or subsystems), the hardware resource in module is not utilized. Therefore, parallel method (or subsystem) is preferred in this paper [7]. interference and/or jamming [7].…”

“…Therefore, parallel method (or subsystem) is preferred in this paper [7]. interference and/or jamming [7].…”

“…The unfitness of conventional structure lies in two aspects: considering the discussions on GPS signal pseudorandom code carrier phase domain search in Fig. 1, the carrier frequency domain search was not considered; the cascade form is studied in the existed DDS [7] with coherent accumulation (CAC) structure taken as the first tier and non-coherent accumulation (NCAC) as the second one. What is the man issue with the conventional DDS?…”