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How software applied to antennas is redefining GNSS performance

The software (SW) defined vehicle represents a significant shift in the automotive industry, allowing for greater flexibility, upgradability, and personal customisation. It refers to a car that relies heavily on software to control and manage different aspects of its operation from driving functions, user interfaces to connectivity.

Software defined vehicles, according to the Boston Consulting Group, are set to create more than $650 billion for the industry by 2030 and call for leaders to partner effectively ahead of this transformation.

In this blog, GNSS expert, Manuel Del Castillo, discusses how this trend has also arrived to GNSS antennas, which have always been the weakest link in mass market GNSS receivers. SW-defined antennas improve positioning accuracy and extend the operating domain of ADAS - while also adding cybersecurity protection.

The ‘problem’ of the GNSS antenna

GNSS receivers traditionally used large antennas, because satellites orbit the earth in medium earth orbits (MEO’s), 20,000 km from the surface of the Earth. A high quality antenna and RF front end is therefore essential to the performance of a GNSS receiver.

As GNSS receivers started to become a commodity in cars, smartphones and wearables, the antenna has constantly been downsized as much as possible, so they don’t spoil the aesthetics of the device. 20 years ago, smartphones with GPS used to have a bulky helicoidal antenna, and early fitness watches had an equally bulky patch antenna in the wristband. As GPS devices became more popular, the OEMs started to differentiate through the mechanical design, and the one thing that stood in the designers way was the antenna. As the digital processing part of the receivers continued to improve, the antennas were allowed to shrink while maintaining similar overall receiver performance. Nowadays, GNSS antennas in smartphones are generally PIFAs (planar inverted F antennas) with relatively poor efficiency and performance, but easy to add to a smartphone PCB (printed circuit board).

The receiver mechanical design has won the battle over the antenna performance, and we rely on receivers’ performance compensating for the loss of antenna performance.

Can you imagine how we could boost the performance of mass market GNSS receivers if we could go back to high quality bulky antennas?

High performance receivers do a good job compensating for low performance PIFA antennas… but can you imagine if we could connect a high performance antenna to a state of the art GNSS receiver? It would immediately boost the performance through the roof! This is just a fantasy, because as discussed above, the receiver’s mechanical design rules.

However, recent developments on SW applied to the RF signals makes it possible to synthesize a high performance antenna with a small PIFA, taking advantage of the end user motion. This innovation breaks the trend of having to deal with ever worsening antennas and can provide a sudden boost in GNSS performance: a 6dB-10dB improvement in sensitivity, a 2x-12x improvement in measurement accuracy and a 3x-10x improvement in integrity.

Supercorrelation SW technology applied to mass market GNSS receivers

Our overarching Supercorrelation technology is a software based solution, which synthesizes an aperture antenna by performing long-coherent integration on the motion-compensated RF samples over time, as the receiver moves. Our motion compensation technique applies to smartphones, wearables and automotive segments alike.

Benefits for the automotive industry

When you apply this SW antenna innovation to GNSS receivers in vehicles, you get a much better quality GNSS sensor that enables ADAS system designers to re-think the weight they can place on the GNSS functionality. The accuracy and integrity boosts obtained in urban environments allow for extension of the operational domain of current hands-free driving systems that use GNSS as a cross-check mechanism.

But benefits don’t stop there: Supercorrelation technology rejects GNSS spoofer signals, because the synthesized antenna behaves as a highly directional one, in the direction of the predicted Line-of-Sight (LoS) of each signal, therefore rejecting non-legitimate signals coming from non-LoS angles.

Can you imagine the value of minimizing the threat of GNSS spoofing to ADAS and future autonomous driving systems?

SW innovation applied to RF signals has been able to revert the trend of GNSS antenna performance degradation and increase the value of the GNSS sensor in the automotive industry. And, by achieving this with a software solution, FocalPoint helps minimise the manufacturing complexity, the overall system cost, reduce the environmental impact of the antenna component all whilst having the flexibility to upgrade features with minimal effort.

For further insight into this innovative technology solution with applications in the automotive industry, smartphone and wearables sectors, where an enhanced level of safety and user experience is crucial, please contact us for an introductory conversation.