Receiver Design

Consumer GPS/GLONASS: Accuracy and Availability Trials of a One-Chip Receiver in Obstructed Environments

December 1, 2011By
figure5-opener

A one-chip multiconstellation GNSS receiver, now in volume production, has been tested in severe urban environments to demonstrate the benefits of multiconstellation operation in a consumer receiver. Bringing combined GPS/GLONASS from a few tens of thousands of surveying receivers to many millions of consumer units, starting with satnav personal navigation devices in 2011, followed by OEM car systems and mobile phones, significant shifts the marketplace. The confidence of millions of units in use and on offer should encourage manufacturers of frequency-specific components, such as antennas and SAW filters, to enter volume mode in terms of size and price. read more

This article is tagged with , and posted in GNSS, Receiver Design, Uncategorized

Space-Time Equalization Techniques for New GNSS Signals

October 1, 2011By
Figure_3

Spatial and temporal information of signals received from multiple antennas can be applied to mitigate the impact of new GPS and Galileo signals’ binary-offset sub-carrier, reducing multipath and interference effects. read more

This article is tagged with and posted in GNSS, Receiver Design

Future Wave: L1C Signal Performance and Receiver Design

April 1, 2011By
L1C-3

The new GPS L1C signal will be broadcast by the Block III satellites, with first launches as early as 2014. L1C innovations significantly enhance PNT performance as well as interoperability with other GNSS signals. The authors describe the benefits of its new features and how best to make use of each one. read more

This article is tagged with , , and posted in Receiver Design, Signal Processing

Dynamic Duo: Combined GPS/GLONASS Receivers in Urban Environments

January 1, 2011By
Aerial view of downtown Calgary from the southwest, with test trajectory shown in red.

The impact of adding GLONASS to HS-GPS is assessed using a software receiver operating in an actual urban canyon environment. Results are compared with standard and high sensitivity GNSS receivers and show a significant improvement in the availability of position solutions when GLONASS is added. An assisted high sensitivity receiver architecture is introduced which enables high fidelity signal measurements even in degraded environments. read more

This article is tagged with and posted in Receiver Design, Road

Spoofing Detection and Mitigation with a Moving Handheld Receiver

September 1, 2010By
Nielsen-Opener

A single spoofing source has a different spatial signal distribution from the authentic GPS signal. An antenna array can estimate the spatial distribution of the received signal and thus discriminate the spoofing signal from the authentic one. Moving a handheld receiver with a single antenna during signal capture snapshots produces a form of a synthetic array, highly effective in discriminating spoofing signals sourced from a point-source jammer. read more

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Part 2: The Origins of GPS, Fighting to Survive

June 1, 2010By
At the JPO. Frank Butterfield of Aerospace, Col. Parkinson, and Cdr. Bill Huston, deputy JPO director from the U.S. Navy,
in the early 1970s. A model of a Phase I GPS satellite stands on the table between the latter two.

GPS Phase I program approval meant that the real work could begin. The conclusion of a two-part history, told by the people who made it. read more

Part 1: The Origins of GPS, and the Pioneers Who Launched the System

May 1, 2010By
Mathematician Bill Guier (l) and physicist George Weiffenbach (r), told APL Research Center director Frank T. McClure (c), about their success using Doppler tracking for satellites. “McClure’s brain started going into fast forward,” remembered John Dassoulas. “Knowing the navigational challenges the U.S. Navy faced, McClure said, ‘Well, if you can find out where the satellite is, you ought to be able to turn that problem upside down and find out where you are.’ “

The original system study, the key innovations, and the forgotten heroes of the world’s first — and still greatest — global navigation satellite system. True history, told by the people who made it. Part One of a Two-Part Special Feature. read more

Real-Time Software Receivers: Challenges, Status, Perspectives

September 1, 2009By
FIGURE 2. Single-instruction single-data versus single-instruction multiple-data.

By Marcel Baracchi-Frei, Grégoire Waelchli, Cyril Botteron, and Pierre-André Farine The idea of a software receiver is to replace the data processing implemented in hardware with software and to sample the analog input signal as close as possible to the antenna. Thus, the hardware is reduced to the minimum — antenna and analog-to-digital converters (ADCs) — while all the signal processing... read more

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