Systems and methods for signal acquisition using predicted environmental context

摘要

This disclosure involves methods and systems for a GNSS receiver to ascertain its environmental context and subsequently adjust the signal processing and search algorithms to provide improved acquisition. A rapid pre-scan is performed to determine the presence of relatively strong signals. If no satellites are found in the initial pre-scan, successively more sensitive searches are conducted until at least one satellite is acquired. The information from these pre-scans is used to predict the environmental context of the receiver and correspondingly tailor the parameters for the remaining search operations.

主权项

1. A method for acquiring signals with a mobile receiver based on predicted environmental context, the method comprising, with the receiver:
providing a plurality of search steps wherein each search step comprises a correlation operation having a total integration time and is configured to correspond to a distinct signal level ranging from relatively stronger to relatively weaker such that the total integration time of each search step is greater than the total integration time of a preceding search step, wherein the plurality of search steps includes a first search step having less sensitivity than a second search step having less sensitivity than a third search step; performing a pre-scan search at successive search steps from a first pre-scan search step to a last pre-scan search step within the plurality of search steps until at least one satellite is acquired; performing a context awareness decision based, at least in part, on how many satellites were acquired and the configuration of the last pre-scan search step; setting an initial scan search step from the plurality of search steps based, at least in part, on the context awareness decision, wherein setting the initial scan search step comprises setting the initial scan search step to a search step within the plurality of search steps having a sensitivity greater than the last pre-scan search step; and performing a scan search to identify unacquired satellites using the initial scan search step wherein the initial scan search step has a greater sensitivity than the last pre-scan search step and wherein performing a scan search includes performing the search at successive search steps starting at the initial scan search step.