Accelerating Design and Test of 802.11p Devices for the Connected Car Using A Range of Flexible, High-Performance Solutions
One of the critical issues facing society today is automotive safety. According to figures released by the World Health Organization (WHO), approximately 2,500 people are killed on roads every day, which equates to nearly 1 million people each year. Automotive companies have recognized their role in this challenge and are now proactively working to adapt to new technologies designed to improve road safety and reduce the incidence of accidents that cause death and injury on the road. Using advanced wireless communications, these companies will improve car safety for drivers, passengers, pedestrians and others. At the same time, they will provide a slew of other benefits, ranging from better traffic management, improved energy efficiency and updated in-car entertainment/information systems. All of these benefits will be delivered though connected car technologies.
The connected car’s vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) access point communications (Figure 1) are enabled using a scheme known as Dedicated Short Range Communication (DSRC). Though other wireless technologies such as LTE-V, part of 3GPP Rel-14, and 5G are being considered, DSRC is currently implemented using a variation of the IEEE 802.11 Wireless LAN (WLAN) format. Specifically modified to work in an automotive environment, this WLAN format is known as the 802.11p standard.
A connected car is typically equipped with wireless access and WLAN. This allows the car communicate via the internet with other devices, both inside and outside the vehicle, and with other vehicles and nearby infrastructure nodes. Connected cars, for example, share information on road and traffic situations to provide an early warning of potential hazards or information regarding commerce transactions and toll collection. By doing so, nearby cars would have the ability to take appropriate action. This application note looks in detail at the 802.11p standard and at how 802.11p devices can be designed, tested and analyzed.
Applying advanced technologies like 802.11p offers enormous benefits for the automotive industry, but it also presents new design and test challenges for developers and manufacturers. Vehicles with 802.11p will communicate with other vehicles and roadside infrastructure, sharing information regarding location, speed, acceleration, and even anti-lock braking system activation. They’ll also share more mission-critical road and traffic condition information; regardless of whether or not they are visible to one other or around a blind curve.
To ensure a robust 802.11p system, accurate physical layer tests are essential. One of the specific challenges associated with testing 802.11p-based devices is being able to properly generate the waveforms needed for receiver measurement, with fading as necessary. When measuring the transmitter, dealing with the much stricter spectrum emission mask, transmitter power and more, can also be problematic.
What’s required to overcome these challenges is an effective test and measurement strategy for 802.11p devices; one that enables appropriate signal generation and analysis to properly test and measure communication links (e.g., the transmitter and receiver). The signal generation and analysis solutions utilized should offer fast measurement times and switching speeds, scalability to allow the tools to be tailored to the users changing test needs, and flexibility…