Spectrum co-existence challenges in the fully connected car

ALI BAWANGAONWALA | QORVO, INC.

Continuing advances in technologyare making the autonomous vehicle apractical reality, and there is frequentdiscussion among technologists about Wi-Fiand 5G as enablers of the connected car.

Equally important, but less talked about, are the complexities of bringing these technologies together and making them work hand-in-hand without creating interference issues that impact safety and operation.

The players in the autonomous vehicle industry must solve these challenges before the world can realize the potential of truly autonomous vehicles.

An autonomous vehicle is one capable of navigating itself from point A to point B without human intervention. This will take place through the sharing data, such as position and speed, with surrounding vehicles and infrastructures.

As depicted by this figure from Qualcomm, the 5G spectrum is divided into a sub-6-GHz region and a millimeter wave region.

The data sharing will happen via Vehicleto-Everything (V2X) communication systems that enhance driver awareness of potential hazards, improving collision avoidance and significantly reducing fatalities.

V2X is a wireless technology aimed at enabling data exchanges between a vehicle and its surroundings. It includes capabilities for Vehicle-to-Vehicle (V2V), Vehicle-to- Infrastructure (V2I), Vehicle-to-Network (V2N) and Vehicle-to-Pedestrians (V2P) communications.

V2X is based on 5.9-GHz dedicated short-range communications, specifically defined for fast-moving objects and enabling establishment of a reliable radio link, even in non-line-of-sight conditions.

In addition to boosting safety, V2X will also enhance traffic efficiency by providing warnings for upcoming traffic congestion and proposing alternative routes. This supports eco-friendly driving with reduced CO2 emissions, greater transport efficiency and less need for vehicle maintenance.

DSRC VS. C-V2X

V2X can either be DSRC (Dedicated Short- Range Communications) or C-V2X (Cellular- Vehicle-to-Everything). Until a few years ago, DSRC, based on the IEEE 802.11p standard, was the only V2X technology available, with production in the U.S. and Japan beginning in 2017. C-V2X, which utilizes cellular technology, was introduced more recently to create a direct communications link between vehicles.

Complicating the market situation as a whole is the fact that different countries and automakers are supporting one or the other approach. But while C-V2X and DSRC are different standards, they address the same problem using the same spectrum, and can co-exist.

A wide range of technologies play a role in providing full vehicular connectivity. Each technology has its own niche and must work with all the others in the autonomous car without degrading the performance of other technologies.

V2X (DSRC, C-V2X) for automotive safety: The automotive ecosystem will use V2X to communicate among vehicles, with roadside infrastructure, and with the overall environment to improve safety-consciousness and pave the way to autonomous driving.

• 4G/5G cloud connectivity for vehicle OEM services: 4G/5G connectivity could be used to remotely diagnose and monitor car operations, make over-the-air software updates, perform teleoperation, and redefine car ownership by operating a fleet of shared, autonomous vehicles.

• 4G/5G cloud connectivity for in-vehicle experiences: Drivers and passengers could use this type of connectivity to enjoy new in-vehicle experiences, from augmented reality-based navigation, to rear-seat entertainment and music streaming services.

• Wi-Fi for premium in-vehicle experiences and automotive dealer services: Drivers and passengers could enjoy many enhanced in-car Wi-Fi based experiences. For example, efficient Wi-Fi connectivity throughout the vehicle could support ultra-high definition (ultra- HD) video streaming to multiple displays and enable screen mirroring from compatible devices and wireless backup cameras. Wi-Fi could also support automotive dealer services, enabling automatic check-in, diagnostic data transfer and software updates.

• Bluetooth: Drivers and passengers could stream high-fidelity music via Bluetooth, as well as benefit from practical services such as using a smartphone as a key fob.

• SDARS (Satellite Digital Audio Radio Services): With connectivity to satellitebased radio services, vehicle occupants are connected to their favorite radio broadcasts no matter where they are.

Filter products are the key to enabling this kind of coexistence. Two of the parameters that characterize high-performance filter products are the resonator qualities, i.e. quality-factor (Q) and coupling-factor (k2). High Q is necessary to minimize insertion loss, while high k2 enables wider bandwidth.

Technology advances at the resonator level have brought low insertion loss and high selectivity performance with wider bandwidth filter products at frequencies up to 6 GHz. As an example of what’s possible in RF filtering today, consider that Qorvo’s filter products are designed using patented, Bulk-Acoustic-Wave (BAW) technology that is optimized to address complex selectivity requirements, from 1.5 GHz up to 6 GHz in standard footprints.

The Qorvo QPQ2200Q filter is the world’s first filter product designed to address coexistence of V2X with 5.6 GHz Wi-Fi for autonomous vehicles. Another example is the 2.4 GHz Wi-Fi coexist filter, QPQ2254Q, designed to enable coexistence with LTE B40 and B41.

Qorvo automotive V2X, Wi-Fi frontend modules, along with filter products and SDARS offerings, have been developed in close alignment with chipset and module suppliers – as well as carmakers. Through design and packaging, these solutions are delivering the accuracy, reliability and ruggedness essential to intelligent communication systems in the autonomous vehicle. Seamless co-existence of all the technologies on the connected car spectrum will ensure that our ever-mobile world is safer, more reliable and more enjoyable for all of us.

REFERENCES: Qorvo RF filters, https://www.qorvo.com/ products/filters-duplexers/rf-filters