Search results for "Phase lock loop"

showing 3 items of 3 documents

A software receiver phase lock loop analysis and design to implement adaptive phase tracking using a finite impulse response loop filter

2009

In this paper we analyze the design of a digital Phase Lock Loop (PLL) for a Global Navigation Satellite System (GNSS) software receiver. Even if the topic of phase tracking has been widely studied, we found it useful to provide a short walkthrough for the design of a PLL in a real software receiver, avoiding to introduce the common theoretical phase-based model and aiming to the practical implementation of a system that deals with frequencies. Nonetheless, our analysis and design will grow away from the canonical approach, in the way that we will not resort to analog filter theory. The result is a PLL which is more reactive than the ones usually found in literature and that implements a si…

Phase lock loop software receiver trackingSettore ING-INF/03 - TelecomunicazioniGNSS PLL
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Phase lock loop false lock avoidance in presence of global navigation satellite system signal

2009

In this paper we analyse the operation of a fully digital Phase Lock Loop (PLL) in a false lock regime, using real data. The issue has been noticed while we were testing performance of our software receiver in a moving user scenario. While the phenomenon of false lock has been described in other papers about PLLs, our intent is to describe a practical, and in our opinion interesting, issue we encountered and how we got over it.

GNSSPLLSettore ING-INF/03 - TelecomunicazioniGNSS; PLLPhase lock loop false lock GNSS
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A software receiver adaptive phase lock loop method

2009

The aim of this paper is to introduce a new and relatively simple algorithm which is capable to tune the parameters of the loop filter in a phase lock loop, like the one that can be found in a global navigation satellite system receiver. The parameters are chosen while the system is running, in order to make the bandwidth of the filter adaptive with respect to the signal dynamic and strength. A wider bandwidth is obtained to make the filter more reactive when searching the carrier, while the bandwidth gets narrower when the system is in the tracking state, in order to cut off as much noise as possible. The algorithm is based on the observation of the estimated variance of the phase lock loo…

phase lock looploop filterSettore ING-INF/03 - Telecomunicazionisoftware receiversoftware receiver phase lock loop adaptive filter loop filterGNSS PLL; software receiver; phase lock loop; adaptive filter; loop filterGNSS PLLadaptive filter
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