Read the article about oneNav’s L5 GNSS technology in the September/October 2020 issue of GPS World
L5-Only Receiver Designed for Mobile Phones
by Greg Turetzky
The Fifth Generation of GNSS—Single Frequency L5
GNSS has evolved. Generation 1 GNSS was based on L1 C/A code and deployed in mobile phones starting in the late 1990s. GNSS Generations 2 and 3 evolved to include new navigation satellite constellations (Glonass, Galileo, Beidou), and the multiple frequencies and coding schemes deployed across those constellations. GNSS Generation 4 brought modernized L5 signaling.
Why Consumer Devices Need L5
Mobile positioning performance has lots of room for improvement. Every GNSS user in every segment will benefit from using the new, modernized signals in the L5 band. L5 signals are more accurate and more reliable than L1, and L5 signals are available in sufficient numbers to support positioning anywhere in the world.
Why Not Use Hybrid L1/L5?
The benefits of L5 are clear. That’s why many GNSS suppliers have started building hybrid L1/L5 solutions for mobile devices. Simply adding an L5 receiver on top of a legacy L1 solution may seem like a natural progression. But continuing to use the legacy L1 solution could negatively impact performance, and adds unnecessary RF complexity.
oneNav’s pureL5TM Wideband GNSS Receiver
oneNav’s pureL5TM solution provides all of the benefits of L5, without the downsides of L1. Less is more. Our innovative array processor directly acquires L5 without L1 aiding, while delivering fast TTFF. oneNav uses the full wideband L5 signal, including both a and b sidebands, to deliver better sensitivity and accuracy. Using L5’s full 50MHz bandwidth, oneNav’s receiver measures channel characteristics (in addition to pseudoranges), and utilizes AI/machine learning to further enhance performance, particularly in urban canyons. pureL5TM is a simpler design than L1/L5, due to its single L5 receive chain but delivers better performance.